OpAccess Insecticide-treatedξdurableξwallξliningξ (ITWL ... · MessengerξandξRowlandξMalar J Pageξ2ξofξ18 maintainandconsolidategainsandtotransitiontowards malariaeliminationanderadication[20],thereisagrow

Messenger and Rowland Malar J (2017) 16:213 DOI 10.1186/s12936-017-1867-z

REVIEW

Insecticide-treated durable wall lining (ITWL): future prospects for control of malaria and other vector-borne diseasesLouisa A. Messenger* and Mark Rowland

Abstract

While long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the cornerstones of malaria vector control throughout sub-Saharan Africa, there is an urgent need for the development of novel insecticide delivery mechanisms to sustain and consolidate gains in disease reduction and to transition towards malaria elimination and eradication. Insecticide-treated durable wall lining (ITWL) may represent a new paradigm for malaria control as a potential complementary or alternate longer-lasting intervention to IRS. ITWL can be attached to inner house walls, remain efficacious over multiple years and overcome some of the operational constraints of first-line control strate-gies, specifically nightly behavioural compliance required of LLINs and re-current costs and user fatigue associated with IRS campaigns. Initial experimental hut trials of insecticide-treated plastic sheeting reported promising results, achieving high levels of vector mortality, deterrence and blood-feeding inhibition, particularly when combined with LLINs. Two generations of commercial ITWL have been manufactured to date containing either pyrethroid or non-pyrethroid formulations. While some Phase III trials of these products have demonstrated reductions in malaria incidence, further large-scale evidence is still required before operational implementation of ITWL can be considered either in a programmatic or more targeted community context. Qualitative studies of ITWL have identified aesthetic value and observable entomological efficacy as key determinants of household acceptability. However, concerns have been raised regarding installation feasibility and anticipated cost-effectiveness. This paper critically reviews ITWL as both a putative mechanism of house improvement or more conventional intervention and discusses its future prospects as a method for controlling malaria and other vector-borne diseases.

Keywords: Insecticide-treated durable wall lining, Malaria, Leishmaniasis, Chagas disease, Vector control, Insecticide resistance

© The Author(s) 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

BackgroundIn recent years considerable reductions in global malaria burden have been achieved by scaling-up key diagnostic, treatment and preventative measures [1]. Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) remain the cornerstones of malaria vector control, both targeting indoor feeding and resting mosquito vec-tor populations [2–5]. Long-term effectiveness of these strategies is currently under threat from widespread emergence of insecticide resistance to pyrethroid LLINs

[6, 7], as well as to other chemical classes used for IRS [8, 9]. Furthermore, maintaining high coverage at the community-level of either intervention can be opera-tionally challenging. Universal coverage (UC) campaigns of LLINs have been adopted as the standard of care by most National Malaria Control Programmes (NMCPs) [1]; however, net usage is known to decline during hot seasons [10–12], and LLIN efficacy and durability under field conditions [13, 14] and rates of household attrition are also of increasing concern [15, 16]. In some epidemi-ological settings, IRS can be highly effective [1, 17] but the short residual activities of most insecticide formula-tions [18] render it logistically demanding and economi-cally unsustainable for many endemic countries [19]. To

Open Access

Malaria Journal

*Correspondence: [email protected] Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK

http://creativecommons.org/licenses/by/4.0/

http://creativecommons.org/publicdomain/zero/1.0/

http://creativecommons.org/publicdomain/zero/1.0/

http://crossmark.crossref.org/dialog/?doi=10.1186/s12936-017-1867-z&domain=pdf

Page 2 of 18Messenger and Rowland Malar J (2017) 16:213

maintain and consolidate gains and to transition towards malaria elimination and eradication [20], there is a grow-ing impetus to develop alternate or complementary interventions [4, 5, 21], novel insecticide classes [22, 23], combinations [24, 25], formulations [26, 27] and cost-effective, scalable mechanisms of delivery [28–30], as well as to evaluate a potential role for concurrent housing improvement in disease control [31–33].

Initial experimental development and evaluation of insecticide‑treated housing materialsInsecticide treatment of house or shelter materials was first pioneered as a method to control malaria during humanitarian emergencies in countries affected by war [34–37]. Impregnation of utilitarian tents or tarpaulins with deltamethrin was intended to circumvent the logis-tical difficulties of achieving high coverage with IRS or insecticide-treated nets (ITNs), producing high rates of mosquito mortality in experimental platform studies and pilot malaria control projects in Pakistan [35–37]. Early experimental hut evaluations of pyrethroid (deltamethrin or permethrin) and non-pyrethroid (pirimiphos-methyl, organophosphate or bendiocarb, carbamate) treated plastic sheeting (ITPS) as an interior wall liner, indicated that this intervention functions in a similar manner to IRS against host-seeking vectors entering indoors and alighting on walls either before or after blood-feeding, or if blocked from feeding by a mosquito net (Table 1). Only limited personal protection from biting was observed when ITPS was evaluated alone, suggesting disease con-trol would instead be achieved through a ‘mass effect’ on vector density and longevity at the community-level [38, 41, 42, 46–48]. Depending upon the excito-repellant properties of different insecticides used to treat ITPS, some studies also reported increased deterrence rates and exophily among susceptible mosquito populations, demonstrating the potential to directly interrupt human-vector contact, further contributing to a reduction in malaria transmission [38, 41, 42, 46]. For the majority of entomological parameters, ITPS efficacy was correlated with intervention surface area, with increasing coverage affording higher rates of mortality, deterrence and blood-feeding inhibition [38, 39, 46].

Initial community‑level trials of insecticide‑treated housing materialsFollowing preliminary trials of experimentally-treated plastic materials (Table 1), commercial ITPS (ZeroFly®) was originally produced by Vestergaard Frandsen (Swit-zerland) as high density laminated polyethylene sheets containing deltamethrin (55 mg/m2). Based on LLIN technology, the insecticide is incorporated into the pol-ymer during manufacture and diffuses to the surface

slowly, in a controlled fashion, acting as a long-lasting insecticide reservoir. Initial community-level evaluations of ZeroFly® ITPS in temporary labour shelters and vil-lages in India [40, 43] and among displaced populations in Sierra Leone [44] and Angola [45] supported the ento-mological outcomes reported by experimental hut tri-als, achieving significant reductions in malaria incidence (Table 2). Similar observations of the impact of coverage on intervention effectiveness were observed in Sierra Leone, where protective efficacy from malaria improved from 15 to 60% when ITPS coverage increased from ceiling only to include all four tent walls [44]. However, when carbamate-treated ITPS was evaluated in combina-tion with UC or targeted LLIN distribution among rural houses in Benin, no additional malaria protection was reported, potentially attributable to limited wall coverage (only the upper thirds of walls were covered due to insec-ticide safety concerns), and the short residual activity of a single treatment of bendiocarb [21].

Commercial development of insecticide‑treated housing materialsThe promising results demonstrated by ITPS stimulated an interest in developing a long-lasting, sustainable, community-level version for permanent use in malaria endemic settings. Such a material would offer the pros-pect of a novel system of insecticide delivery, which could be more residual than IRS, provide a more uniform cov-ering of the wall with insecticide and potentially improve the interior appearance of traditional dwellings, particu-larly in rural areas. To identify an acceptable wall lining material, among urban and rural houses in Angola and Nigeria, three deltamethrin-treated prototypes (polyeth-ylene woven shade cloth, laminated polyethylene plastic sheeting (ZeroFly®) and polyester netting (PermaNet® 2.0) were assessed for their levels of household accept-ability, installation feasibility and willingness to pay (Fig. 1) [52]. Rural participants highly favoured the con-cept of a wall lining for malaria control because of its observable impact on mosquitoes and other nuisance insects and perceived decorative value, given an exist-ing predilection for house decorations. Of the prototype materials, polyethylene shade cloth was the most popu-lar because of its ease of installation and resemblance to local materials. Based on these pilot field trials, the origi-nal iteration of insecticide-treated durable wall lining (henceforth ITWL; referred in previous publications as ‘durable lining’ or ‘DL’) was produced in the form of high density polyethylene woven sheets containing deltame-thrin (ZeroVector®; 175 mg/m2) (Fig. 1). Initial small-scale studies across multiple African and Asian countries demonstrated consistently high levels of user accept-ability, entomological efficacy and no significant loss of


Tabl

e 1

Sum

mar

y of

exp

erim

enta

l hut

tria

ls d

emon

stra

ting

the

impa

ct o

f ins

ecti

cide

‑tre

ated

hou

sing

mat

eria

ls o

n m

alar

ia v

ecto

r con

trol

Fiel

d si

te,

coun

try,

tr

ial t

ype

Inte

rven

tion(

s)In

sect

icid

e (d

osag

e)In

terv

entio

n co

vera

geCo

ntro

l(s)

(dos

age)

Maj

or m

alar

ia

vect

or

spec

iesre

sist

ance

stat

us

Ento

mol

ogic

al p

aram

eter

sbRe

fer-

ence

sM

orta

lity

Det

erre

nce

Exiti

ng ra

tes

Bloo

d fe

edin

g in

hibi

tion

Pers

onal

pr

otec

tion

Impa

ct

on in

sect

icid

e re

sist

ance

Afg

han

refu

gee

cam

p,

Paki

-st

an,

expe

ri-m

enta

l pl

at-

form

s

Impr

egna

ted

poly

then

e ta

rpau

lins

Del

tam

e-th

rinFu

ll co

vera

gea

Unt

reat

ed

poly

then

e ta

rpau

lin

An. s

ubpi

c-tu

sND

, An.

st

ephe

nsiN

D

Hig

h m

osqu

ito

mor

talit

y (8

6–10

0%);

no s

igni

fican

t dif-

fere

nces

bet

wee

n in

terv

entio

ns

ND

ND

No

impa

ct o

n bl

ood

feed

ing

(~20

% fo

r al

l int

erve

ntio

ns)

ND

ND

[36]

(45

mg/

m2 )

Spra

yed

poly

then

e ta

rpau

lins

(30

mg/

m2 )

Impr

egna

ted

poly

then

e te

nts

(45

mg/

m2 )

Afg

han

refu

gee

cam

p,

Paki

-st

an,

expe

ri-m

enta

l pl

at-

form

s

Poly

ethy

lene

ca

nvas

Del

tam

e-th

rin

(ND

)

Full

cove

rage

Unt

reat

ed

canv

as te

ntAn

ophe

lines

(s

pp.

grou

ped)

ND

Incr

ease

d m

osqu

ito

mor

talit

y re

lativ

e to

co

ntro

l (51

vs.

26%

, re

spec

tivel

y)

No

sign

ifica

nt

redu

ctio

n in

m

ean

no. o

f m

osqu

itoes

re

lativ

e to

co

ntro

l (7

vs.

19, r

espe

c-tiv

ely)

ND

Redu

ced

bloo

d fe

edin

g re

lativ

e to

co

ntro

l (9

vs. 4

6%,

resp

ectiv

ely)

ND

ND

[37]

Bobo

D

iou-

lass

o,

Burk

ina

Faso

, ex

peri-

men

tal

Wes

t A

frica

n hu

ts

[50]

Poly

ethy

lene

sh

eetin

gPe

rmet

hrin

(2

% w

/w)

Ceili

ng o

nly

Unt

reat

ed

poly

eth-

ylen

e sh

eet-

ing

An. g

ambi

aer

Mor

talit

y co

rrel

ated

w

ith c

over

age

(20%

fo

r tw

o w

alls

; 45%

fo

r fou

r wal

ls; 4

6%

for f

our w

alls

+ c

eil-

ing

cove

red)

Det

erre

nce

corr

elat

ed

with

cov

erag

e (2

8% fo

r tw

o w

alls

; 43%

fo

r fou

r wal

ls;

46%

for f

our

wal

ls +

cei

ling

cove

red)

All

trea

tmen

ts

high

ly re

pelle

nt

(indu

ced-

exop

h-ily

68–

78%

)

No

sign

ifica

nt im

pact

on

blo

od fe

edin

g;

leve

l of i

nhib

ition

co

rrel

ated

with

sur

-fa

ce a

rea

cove

red

(10%

for t

wo

wal

ls

vs. 2

7% fo

r fou

r w

alls

+ c

eilin

g)

ND

Mor

talit

y an

d bl

ood

feed

ing

inhi

bitio

n kd

rr /kdr

r < k

drr /k

drs +

kdr

s

/kdr

s (19

vs.

64%

and

12

vs. 6

2% fo

r fo

ur w

alls

+

cei

ling,

re

spec

tivel

y)

[38]

Two

wal

ls

Four

wal

lsU

ntre

ated

co

ntro

lFo

ur

wal

ls +

cei

l-in

g

Coto

nou,

Be

nin,

ex

peri-

men

tal

Wes

t A

frica

n hu

ts

Poly

prop

ylen

e m

esh

Bend

ioca

rb

(200

mg/

m2 )

Top

third

s of

w

alls

Del

tam

ethr

in-

trea

ted

mos

quito

ne

t (IT

N;

45 m

g/m

2 )

An. g

ambi

aer

Mor

talit

y pr

opor

tiona

l to

wal

l sur

face

are

a co

vere

d (8

0% v

s. 10

0% fo

r upp

er th

ird

of w

all o

r ful

l cov

er-

age,

resp

ectiv

ely)

No

sign

ifica

nt

redu

ctio

n in

m

ean

no. o

f m

osqu

itoes

in

full

cove

rage

hu

t rel

ativ

e to

con

trol

(2

02 v

s. 20

6,

resp

ectiv

ely)

ND

Hig

h le

vels

of b

lood

fe

eing

inhi

bitio

n; n

o si

gnifi

cant

incr

ease

w

hen

com

bini

ng

wal

l tre

atm

ents

w

ith IT

Ns

com

pare

d to

ITN

s al

one

(100

%

vs. 9

4%, r

espe

c-tiv

ely)

ND

ND

[39]

Full

cove

rage

Unt

reat

ed

mos

quito

ne

t


Tabl

e 1

cont

inue

d

Fiel

d si

te,

coun

try,

tr

ial t

ype

Inte

rven

tion(

s)In

sect

icid

e (d

osag

e)In

terv

entio

n co

vera

geCo

ntro

l(s)

(dos

age)

Maj

or m

alar

ia

vect

or

spec

iesre

sist

ance

stat

us

Ento

mol

ogic

al p

aram

eter

sbRe

fer-

ence

sM

orta

lity

Det

erre

nce

Exiti

ng ra

tes

Bloo

d fe

edin

g in

hibi

tion

Pers

onal

pr

otec

tion

Impa

ct

on in

sect

icid

e re

sist

ance

Bobo

D

iou-

lass

o,

Burk

ina

Faso

, ex

peri-

men

tal

Wes

t A

frica

n hu

ts

Poly

prop

ylen

e sh

eetin

g (IT

PS)

Bend

ioca

rb

(400

mg/

m2 )

Upp

er th

irds

of w

alls

Del

tam

e-th

rin L

LIN

(P

erm

aNet

®

2.0;

55

mg/

m2 )

An. g

ambi

aer

Sign

ifica

ntly

hig

her

mos

quito

mor

talit

y w

hen

inte

rven

tions

us

ed in

com

bina

tion

(ITPS

+ L

LIN

: 73%

vs.

ITPS

alo

ne: 5

3%)

ND

Sign

ifica

ntly

hi

gher

vec

tor

exop

hily

whe

n in

terv

entio

ns

com

bine

d (L

LIN

+ IR

S: 6

1%;

ITPS

+ L

LIN

s: 50

%)

Sign

ifica

nt b

lood

fe

edin

g in

hibi

tion

only

whe

n IT

PS

com

bine

d w

ith

LLIN

(58%

) rel

a-tiv

e to

unt

reat

ed

cont

rol

ND

Freq

uenc

y of

ac

e-1R a

llele

si

gnifi

cant

ly

high

er

amon

g he

t-er

ozyg

ote

surv

ivor

s fro

m

indi

vidu

al

IRS

and

ITPS

trea

t-m

ents

but

no

t whe

n co

mbi

ned

with

LLI

N

[41]

IRS

(ben

-di

ocar

b;

400

mg/

m2 )

Mor

talit

y si

mila

r for

pa

rtia

l cov

erag

e of

IT

PS v

s. fu

ll co

vera

ge

with

IRS

(53%

vs.

42%

, res

pect

ivel

y)U

ntre

ated

m

osqu

ito

net

Bobo

D

iou-

lass

o,

Burk

ina

Faso

, ex

peri-

men

tal

Wes

t A

frica

n hu

ts

Poly

ethy

lene

sh

eetin

g (IT

PS)

Perm

ethr

in

(2%

w/w

)Fu

ll co

vera

geH

oled

per

me-

thrin

LLI

N

(Oly

set®

; 2%

w/w

)

An. g

ambi

aer

Sign

ifica

ntly

hig

her

mos

quito

mor

talit

y w

hen

ITPS

use

d in

com

bina

tion

with

LLI

N (6

0%)

com

pare

d to

alo

ne

(34%

)

No

sign

ifica

nt

redu

ctio

ns in

m

ean

no. o

f m

osqu

itoes

in

ITPS

hut

s w

ithou

t (4

43) o

r with

un

trea

ted

nets

(309

-315

), re

lativ

e to

co

ntro

l (42

2)

Sign

ifica

nt

incr

ease

in

exop

hily

for

sing

le (I

TPS

alon

e: 8

0%; L

LIN

al

one:

77%

) an

d co

mbi

ned

inte

rven

tions

(IT

PS +

LLI

N:

79%

)

Com

bine

d us

e of

IT

PS +

LLI

N d

id

not s

igni

fican

tly

incr

ease

blo

od

feed

ing

inhi

bitio

n ov

er L

LIN

alo

ne

(75%

vs.

82%

, re

spec

tivel

y)

Com

bine

d us

e of

IT

PS +

LLI

N

sign

ifica

ntly

in

crea

sed

pers

onal

pr

otec

tion

over

LLI

N

alon

e (8

8%

vs. 1

6%,

resp

ectiv

ely

Sign

ifica

ntly

m

ore

kdrr /k

drr

dead

w

ith L

LIN

(5

5%) a

nd

ITPS

+ L

LIN

(6

7%) t

han

ITPS

alo

ne

(17%

)

[42]

Inta

ct o

r ho

led

untr

eate

d m

osqu

ito

net

Unt

reat

ed

cont

rol

Muh

eza,

Ta

n-za

nia,

ex

peri-

men

tal

East

A

frica

n hu

ts

[51]

Poly

este

r wal

l ha

ngin

gs

(NW

H)

Pirim

ipho

s m

ethy

l (1

g/m

2 )

Ceili

ng o

nly

Unt

reat

ed

cont

rol

An. g

ambi

ae

s.l.s/

r(c) , A

n.

fune

stus

An. g

ambi

ae a

nd A

n.

fune

stus

mor

talit

y si

gnifi

cant

ly h

ighe

r fo

r p-m

ethy

l NW

H

than

del

tam

ethr

in

NW

Hs

(92%

vs.

11%

an

d 78

% v

s. 6%

, re

spec

tivel

y fo

r tw

o w

alls

)

Sign

ifica

nt

redu

ctio

ns

in m

osqu

ito

entr

y fo

r p-

met

hyl

(65–

95%

) and

de

ltam

ethr

in

(50–

56%

) tr

eate

d N

WH

Sign

ifica

ntly

in

crea

sed

exit-

ing

rate

s in

NW

H

huts

com

pare

d to

unt

reat

ed

cont

rol

Lim

ited

effec

t on

bloo

d fe

edin

g ra

tes

(52–

77%

) rel

ativ

e to

un

trea

ted

cont

rol

(64–

67%

)

ND

ND

[46]

Two

wal

ls

Four

wal

lsAn

. gam

biae

and

An.

fu

nest

us m

orta

lity

sign

ifica

ntly

hig

her

for t

wo

wal

ls th

an

ceili

ngs

only

(59

and

39%

, res

pect

ivel

y)

Det

erre

nce

incr

ease

d w

ith

incr

easi

ng

cove

rage

(6

5–77

% v

s. 92

–95%

for

two

wal

ls

vs. f

our

wal

ls +

cei

l-in

g)

Four

w

alls

+ c

eil-

ing

No

impr

ovem

ent i

n m

osqu

ito m

orta

lity

whe

n co

vera

ge

incr

ease

d be

yond

tw

o w

alls

Del

tam

e-th

rin

(55

mg/

m2 )

Two

wal

ls


Tabl

e 1

cont

inue

d

Fiel

d si

te,

coun

try,

tr

ial t

ype

Inte

rven

tion(

s)In

sect

icid

e (d

osag

e)In

terv

entio

n co

vera

geCo

ntro

l(s)

(dos

age)

Maj

or m

alar

ia

vect

or

spec

iesre

sist

ance

stat

us

Ento

mol

ogic

al p

aram

eter

sbRe

fer-

ence

sM

orta

lity

Det

erre

nce

Exiti

ng ra

tes

Bloo

d fe

edin

g in

hibi

tion

Pers

onal

pr

otec

tion

Impa

ct

on in

sect

icid

e re

sist

ance

Tias

salé

, Cô

te

d’Iv

oire

, ex

peri-

men

tal

Wes

t A

frica

n hu

ts

Poly

ethy

lene

w

all l

inin

g (W

L)

Pirim

ipho

s m

ethy

l (1

g/m

2 )

Four

wal

lsH

oled

de

ltam

e-th

rin L

LIN

(P

erm

aNet

®

2.0;

55

mg/

m2 )

An. g

ambi

ae s

.s.r

Sign

ifica

ntly

hig

her

mor

talit

y w

ith

p-m

ethy

l WL

than

py

reth

roid

WL

(66%

vs

. 32%

, res

pect

ivel

y)

Sign

ifica

nt

redu

ctio

ns

in m

osqu

ito

entr

y fo

r p-

met

hyl

WL/

NH

W

only

whe

n co

mbi

ned

with

LLI

N

(59%

/65%

vs

. 28%

/3%

, re

spec

tivel

y)

Sign

ifica

ntly

in

crea

sed

exiti

ng ra

tes

for p

-met

hyl

WL

(53%

) an

d p-

met

hyl

NW

H +

LLI

N

(59%

), re

lativ

e to

unt

reat

ed

cont

rol (

29%

)

Lim

ited

effec

t on

bloo

d fe

edin

g ra

tes

(82–

94%

) rel

ativ

e to

un

trea

ted

cont

rol

(95%

), un

less

com

-bi

ned

with

LLI

N

(9–1

3%)

Lim

ited

pers

onal

pr

otec

tion

for p

-met

hyl

WL/

NW

H

rela

tive

to

untr

eate

d co

ntro

l (4

%/0

%),

unle

ss

com

bine

d w

ith L

LIN

(9

3%/9

2%)

Sign

ifica

ntly

hi

gher

nu

mbe

rs

of a

ce-1

R he

tero

zy-

gote

(RS)

and

ho

moz

ygot

e (R

R) s

urvi

vors

co

mpa

red

to

susc

eptib

le

hom

ozy-

gote

s (S

S)

follo

win

g ex

posu

re

to p

-met

hyl

WLs

/NH

Ws

[47]

Four

w

alls

+ c

eil-

ing

Hol

ed

untr

eate

d m

osqu

ito

net

No

impr

ovem

ent i

n m

osqu

ito m

orta

lity

whe

n p-

met

hyl

WL/

NW

H c

over

age

incr

ease

d fro

m w

alls

on

ly (6

6%/4

9%)

to w

alls

+ c

eilin

gs

(56%

/69%

)

Com

bine

d W

L an

d LL

IN d

id

not l

imit

the

sele

ctio

n of

ace

-1R

com

pare

d to

W

L al

one

Nyl

on N

HW

Pirim

ipho

s m

ethy

l (1

g/m

2 )

Four

wal

ls

Four

w

alls

+ c

eil-

ing

Unt

reat

ed

plas

tic

shee

ting

No

incr

ease

in

mos

quito

mor

talit

y w

hen

WL/

NH

W

com

bine

d w

ith

LLIN

s (7

2%/6

1% v

s. 61

%/5

3%, r

espe

c-tiv

ely)

Poly

ethy

lene

WL

(Zer

oVec

tor®

)D

elta

me-

thrin

(1

75 m

g/m

2 )

Four

wal

ls


Tabl

e 1

cont

inue

d

Fiel

d si

te,

coun

try,

tr

ial t

ype

Inte

rven

tion(

s)In

sect

icid

e (d

osag

e)In

terv

entio

n co

vera

geCo

ntro

l(s)

(dos

age)

Maj

or m

alar

ia

vect

or

spec

iesre

sist

ance

stat

us

Ento

mol

ogic

al p

aram

eter

sbRe

fer-

ence

sM

orta

lity

Det

erre

nce

Exiti

ng ra

tes

Bloo

d fe

edin

g in

hibi

tion

Pers

onal

pr

otec

tion

Impa

ct

on in

sect

icid

e re

sist

ance

Bobo

D

iou-

lass

o,

Burk

ina

Faso

, ex

peri-

men

tal

Wes

t A

frica

n hu

ts

Poly

ethy

lene

WL

Pirim

ipho

s m

ethy

l (1

g/m

2 )

Four

wal

lsH

oled

de

ltam

e-th

rin L

LIN

(P

erm

aNet

®

2.0;

55

mg/

m2 )

An. g

ambi

ae

s.s.s/

r(c)

Sign

ifica

ntly

hig

her

mor

talit

y w

ith

p-m

ethy

l WL

than

py

reth

roid

WL

(>95

% v

s. 40

%,

resp

ectiv

ely)

Larg

est r

educ

-tio

ns in

m

osqu

ito

entr

y fo

r pyr

e-th

roid

WL

and

p-m

ethy

l WL

whe

n us

ed in

co

mbi

natio

n w

ith L

LIN

(7

4 an

d 62

%,

resp

ectiv

ely)

Sign

ifica

ntly

in

crea

sed

exiti

ng ra

tes

for

p-m

ethy

l WL

(53%

), re

lativ

e to

unt

reat

ed

cont

rol (

33%

)

Bloo

d fe

edin

g si

g-ni

fican

tly re

duce

d w

hen

p-m

ethy

l WL/

NW

Hs

com

bine

d w

ith L

LIN

(91%

/90%

vs

. 50/

50%

, res

pec-

tivel

y)

Per

sona

l pr

otec

tion

for p

-met

hyl

WL/

NW

H

rela

tive

to

untr

eate

d co

ntro

l (5

6%/7

2%),

incr

ease

d w

hen

com

bine

d w

ith L

LIN

(9

5%/9

4%)

Sign

ifica

ntly

hi

gher

nu

mbe

rs o

f ac

e-1R s

urvi

-vo

rs (1

00%

) fo

llow

ing

expo

sure

to

p-m

ethy

l W

L al

one,

co

mpa

red

to

susc

eptib

le

vect

ors

(32%

)

[48]

Four

w

alls

+ c

eil-

ing

Hol

ed

untr

eate

d m

osqu

ito

net

Sign

ifica

ntly

hig

her

mor

talit

y w

ith

p-m

ethy

l WL/

NH

W

eith

er a

lone

or i

n co

mbi

natio

n w

ith

LLIN

(100

% fo

r all)

Com

bine

d W

L an

d LL

IN

limite

d th

e se

lect

ion

of

ace-

1R com

-pa

red

to W

L al

one

Nyl

on N

HW

Pirim

ipho

s m

ethy

l (1

g/m

2 )

Four

wal

ls

Four

w

alls

+ c

eil-

ing

Unt

reat

ed

plas

tic

shee

ting

No

sign

ifica

nt in

crea

se

in m

orta

lity

whe

n py

reth

roid

WL

com

bine

d w

ith

LLIN

s (4

8% v

s. 40

%,

resp

ectiv

ely)

Poly

ethy

lene

WL

(Zer

oVec

tor®

)D

elta

me-

thrin

(1

75 m

g/m

2 )

Four

wal

ls

Four

w

alls

+ c

eil-

ing

IRS

indo

or re

sidu

al s

pray

ing,

ITN

inse

ctic

ide-

trea

ted

net,

ITPS

inse

ctic

ide-

trea

ted

plas

tic s

heet

ing,

LLI

N lo

ng-la

stin

g in

sect

icid

al n

et, N

D n

ot d

escr

ibed

, NW

H n

et w

all h

angi

ngs,

r res

ista

nt to

one

or m

ore

inse

ctic

ides

und

er

inve

stig

atio

n, s

susc

eptib

le to

one

or m

ore

inse

ctic

ides

und

er in

vest

igat

ion,

WL

wal

l lin

ing

a Ful

l cov

erag

e de

fined

as

four

inne

r wal

ls in

exp

erim

enta

l hut

s or

all

inte

rior s

urfa

ces

in a

λ-s

hape

d te

nt, a

s ap

plic

able

b Ent

omol

ogic

al p

aram

eter

s re

port

ed re

lativ

e to

unt

reat

ed c

ontr

ol, u

nles

s ot

herw

ise

spec

ified

c Res

ista

nt to

pyr

ethr

oids

but

sus

cept

ible

to o

rgan

opho

spha

tes


Tabl

e 2

Sum

mar

y of

com

mun

ity‑

leve

l tri

als

dem

onst

rati

ng th

e im

pact

of i

nsec

tici

de‑t

reat

ed h

ousi

ng m

ater

ials

on

mal

aria

con

trol

Fiel

d si

te, c

ount

ry,

tria

l typ

eIn

terv

entio

n(s)

Inse

ctic

ide

(dos

-ag

e)In

terv

entio

n co

vera

geCo

ntro

l(s) (

dosa

ge)

Maj

or m

alar

ia v

ecto

r sp

ecie

sresi

stan

ce s

tatu

sIm

pact

on

vect

or p

opul

atio

nsc

Impa

ct o

n di

seas

e in

cide

ncec

Refe

renc

es

Oris

sa, I

ndia

, com

mu-

nity

-leve

laPo

lyet

hyle

ne

shee

ting

(ITPS

) D

elta

met

hrin

(5

5 m

g/m

2 )Fu

ll co

vera

geb

Unt

reat

ed p

last

ic

shee

ting

An. c

ulic

ifaci

ess , A

n.

fluvi

atili

ssSi

gnifi

cant

redu

ctio

ns in

mos

quito

ho

use

entr

y (8

0–89

%),

vect

or in

door

po

pula

tion

dens

ity (9

5–10

0%),

bloo

d fe

edin

g (7

5%) a

nd p

arity

rate

s (7

4–77

%)

Sign

ifica

nt re

duct

ion

in m

alar

ia in

cide

nce

(65–

70%

)

[40]

Unt

reat

ed c

ontr

olIn

crea

sed

imm

edia

te (5

6%) a

nd d

elay

ed

(100

%) m

osqu

ito m

orta

lity

and

indu

ced

exop

hily

(41%

)

Hum

an b

lood

inde

x de

crea

sed

to 0

Utt

ar P

rade

sh, I

ndia

, co

mm

unity

-leve

l (t

empo

rary

labo

ur

shel

ters

)

Poly

ethy

lene

sh

eetin

g (IT

PS)

Del

tam

ethr

in

(265

mg/

m2 )

Full

cove

rage

Unt

reat

ed p

last

ic

shee

ting

An. c

ulic

ifaci

ess , A

n.

fluvi

atili

ssSi

gnifi

cant

redu

ctio

ns in

indo

or v

ecto

r po

pula

tion

dens

ity a

nd b

lood

feed

ing,

bo

th to

0%

Sign

ifica

nt re

duct

ion

in

mal

aria

inci

denc

e to

0%

[43]

Libe

rian

refu

gee

cam

ps, S

ierr

a Le

one,

com

mun

ity-

leve

l (te

mpo

rary

sh

elte

rs)

Poly

ethy

lene

sh

eetin

g (IT

PS)

Del

tam

ethr

in

(55

mg/

m2 )

Ceili

ng +

roof

Unt

reat

ed p

last

ic

shee

ting

An. g

ambi

ae s

.l.s , An.

fu

nest

us s

.l.sN

DPr

otec

tive

effica

cy fr

om

mal

aria

infe

ctio

n of

60

% a

nd 1

5% fo

r ful

l or

part

ial I

TPS

cove

rage

, re

spec

tivel

y

[44]

Four

tent

w

alls

+ c

eilin

gSi

gnifi

cant

incr

ease

in ti

me

to fi

rst m

alar

ia in

fect

ion

amon

g fu

ll IT

PS c

over

age

grou

p

Sign

ifica

nt in

crea

ses

in

mea

n H

b co

ncen

trat

ion

in b

oth

inte

rven

tion

grou

ps


Tabl

e 2

cont

inue

d

Fiel

d si

te, c

ount

ry,

tria

l typ

eIn

terv

entio

n(s)

Inse

ctic

ide

(dos

-ag

e)In

terv

entio

n co

vera

geCo

ntro

l(s) (

dosa

ge)

Maj

or m

alar

ia v

ecto

r sp

ecie

sresi

stan

ce s

tatu

sIm

pact

on

vect

or p

opul

atio

nsc

Impa

ct o

n di

seas

e in

cide

ncec

Refe

renc

es

Oui

dah-

Kpom

assè

-To

ri Bo

ssito

, Ben

in,

com

mun

ity-le

vel

Poly

prop

ylen

e sh

eetin

g (IT

PS)

Bend

ioca

rb

(200

mg/

m2 )

Upp

er th

irds

of

wal

lsD

elta

met

hrin

LLI

N

(Per

maN

et®

2.0

; 55

mg/

m2 ) (

targ

eted

co

vera

ge to

pre

g-na

nt w

omen

and

<

6 ye

ars)

An. g

ambi

ae s

.l.s/r , A

n.

fune

stus

s.l.N

DN

o si

gnifi

cant

redu

ctio

ns in

hum

an

bitin

g ra

te, s

poro

zoite

rate

or E

IR fo

r all

inte

rven

tions

No

sign

ifica

nt re

duct

ions

in

mal

aria

inci

denc

e, p

reva

-le

nce

or p

aras

ite d

ensi

ty

for I

TPS +

LLI

N, U

C o

f LLI

N

or L

LIN

+ IR

S co

mpa

red

to ta

rget

ed L

LIN

[21]

Sign

ifica

ntly

gre

ater

pro

port

ions

of

paro

us m

osqu

itoes

and

indo

or re

stin

g ve

ctor

s in

ITPS

+ L

LIN

vill

ages

IRS

Bend

ioca

rb

(400

mg/

m2 )

All

hous

e w

alls

kdr a

llele

freq

uenc

y in

crea

sed

in a

ll in

terv

entio

n gr

oups

Perm

aNet

® 2

.0

LLIN

Del

tam

ethr

in

(55

mg/

m2 )

Uni

vers

al c

over

-ag

e

Balo

mbo

, Ang

ola,

co

mm

unity

-leve

lPo

lyet

hyle

ne

shee

ting

(ITPS

) (Z

eroF

ly®

)

Del

tam

ethr

in

(360

mg/

m2 )

Full

cove

rage

Del

tam

ethr

in L

LIN

(P

erm

aNet

® 2

.0;

55 m

g/m

2 )

An. f

unes

tusN

D a

nd o

ther

m

inor

ano

phel

ine

spp.

Sign

ifica

nt re

duct

ions

in in

door

ve

ctor

pop

ulat

ion

dens

ity (8

2% fo

r IT

PS +

LLI

Ns;

78%

for I

RS; 7

3% fo

r WL)

an

d in

tens

ity o

f mos

quito

bite

s in

m

ost i

nter

vent

ion

villa

ges,

mea

sure

d us

ing

anti-

Anop

hele

s sal

iva

IgG

ant

i-bo

dies

leve

ls

Sign

ifica

nt re

duct

ions

in

mal

aria

inci

denc

e (5

8%

for I

TPS +

LLI

Ns;

54%

for

IRS;

51%

for W

L)

[45]

IRS

(lam

bdac

yhal

o-th

rin; 2

5 m

g/m

2 )Po

lyet

hyle

ne W

L (Z

eroV

ecto

r®)

Del

tam

ethr

in

(175

mg/

m2 )

EIR

ento

mol

ogic

al in

ocul

atio

n ra

te, H

b ha

emog

lobi

n, IR

S in

door

resi

dual

spr

ayin

g, IT

PS In

sect

icid

e-tr

eate

d pl

astic

she

etin

g, L

LIN

long

-last

ing

inse

ctic

idal

net

, ND

not

des

crib

ed, r

resi

stan

t to

one

or m

ore

inse

ctic

ides

und

er

inve

stig

atio

n, s

susc

eptib

le to

one

or m

ore

inse

ctic

ides

und

er in

vest

igat

ion,

UC

univ

ersa

l cov

erag

e, W

L w

all l

inin

ga I

ndic

ates

trad

ition

al, p

erm

anen

t rur

al h

ouse

hold

s or

vill

ages

, unl

ess

othe

rwis

e sp

ecifi

edb F

ull c

over

age

defin

ed a

s fo

ur in

ner h

ouse

wal

ls, a

ll in

terio

r sur

face

s in

tem

pora

ry s

truc

ture

s or

all

inte

rior s

urfa

ces

in a

λ-s

hape

d te

nt, a

s ap

plic

able

c Out

com

es re

port

ed re

lativ

e to

unt

reat

ed c

ontr

ol, u

nles

s ot

herw

ise

spec

ified


insecticidal activity over 1 year of household use [53, 54]. However, no phase III evaluation of this product was ever conducted due to the emergence of widespread pyre-throid resistance among vector populations across sub-Saharan Africa [6, 7]. In response, the latest generation of commercial ITWL (PermaNet® Lining; Vestergaard Frandsen) was designed as a non-woven, high density polypropylene fabric containing a proprietary mixture of two non-pyrethroid insecticides (abamectin 0.25% and fenpyroximate 1%), to potentially mitigate insecticide resistance (Fig. 1). This product is currently the subject of an ongoing cluster-randomized controlled trial in an area of pyrethroid-resistance in rural North-East Tanza-nia, in comparison with UC of LLINs, assessing whether this version of ITWL can provide additional protection from malaria [55].

A potential role for insecticide‑treated housing materials in resistance managementNow that pyrethroid resistance is pervasive across Africa, there has been a policy shift away from pyrethroid IRS towards the restriction of this insecticide class to LLINs

for which there are currently no approved alternatives [49]. Because the ‘mode of action’ of ITWL is analo-gous to a long-lasting IRS and Africa has become a LLIN using continent, the combined use of ITWL and LLINs may have resistance management potential. In areas with pyrethroid-resistant vector populations, the role of ITPS/ITWL plus LLINs or IRS to mitigate selection of resist-ant genotypes was investigated in experimental settings. Theoretically, combining interventions with different active ingredients can improve vector control because mosquitoes which are resistant to the insecticide in one intervention may be susceptible to the chemical class contained in the other. Several studies demonstrated that the combination of ITPS and LLINs can increase mor-tality, blood feeding inhibition and personal protection, the latter largely provided by LLINs, [41, 48], but that ITPS, when used alone, may select for resistant vectors, as evidenced by higher proportions of mosquitoes carry-ing resistance genes surviving in ITPS-treated huts [41, 42, 47, 48]. The difference in selection pressures likely reflects the different stages of the gonotrophic cycle, which ITPS and LLINs disrupt. Host-seeking mosquitoes

Fig. 1 Commercial ITWL products. a Polyethylene plastic sheeting (ZeroFly®). b Polyester netting (PermaNet® 2.0). c Polyethylene woven shade cloth (ZeroVector®). d Polypropylene non-woven fabric (PermaNet® Lining)


upon encountering a LLIN may persist in their attempt to feed, by either making more flights between treated walls and the netted sleeper, increasing the chances of exposure to a lethal dose of the non-pyrethroid insecti-cide in the ITPS, or from the pyrethroid LLIN by probing for longer on the net surface, particularly if they have a degree of pyrethroid resistance and are less irritated. In this scenario, a proportion of females resistant to either insecticide would be killed. However, in the absence of a LLIN, once successfully fed, females become relatively quiescent and alight on the walls where differential selec-tion, between susceptible and resistant genotypes, to the ITPS insecticide occurs. This explanation is plausible in Burkina Faso where resistance to the ITPS insecticide was rare and was selected by the ITPS when applied alone but not when ITPS was combined with LLINs [48]. However, in Côte d’Ivoire, where the baseline frequency of resistance to the organophosphate-containing ITPS was higher and where multiple resistance mechanisms to this chemical class were present [56], the same combina-tion of interventions, as applied in Burkina Faso, did not significantly increase mosquito mortality rate over ITPS or LLIN alone, and did not limit the selection of resistant genotypes [47]. Hence the resistance management poten-tial of combining ITWL and LLIN is not a foregone con-clusion but appears to depend on the mechanisms and frequency of resistance already present in a locality or country as a result of previous selective pressures. These studies caution the application of ITWL in areas with resistant vectors in the absence of high community-level net coverage to safeguard continuing personal protection afforded by LLINs.

Key determinants of community‑level ITWL acceptabilityThe principal rationales of ITWL, which render it an attractive alternative to IRS, are its longevity, provision of protection to LLIN non-compliers and potential to over-come the user and donor fatigue associated with repeated rounds of spraying. Consequently, the majority of latterly ITWL studies have focused on identifying key determi-nants of acceptability and operational feasibility of imple-menting this intervention in endemic areas (Table 3). In general, themes of decorative value, ownership prestige, few noticeable adverse events and immediate and sus-tained entomological efficacy have all been reported to positively affect participant receptivity and compliance [52, 53, 57]. The relative influence of these factors on levels of community acceptability varies between study sites. In Angola, despite householders initially com-mending ITWL for improving their house aesthetics, once the material was considered ineffectual, the major-ity of participants removed theirs [52]. By contrast, in a

multi-centre trial, respondents unanimously reported wanting to keep their ITWL even if it had no impact at all on mosquito populations or other nuisance insects [53]. Other attractive features of ITWL described in these studies include, the concept of a single intervention that would alleviate the daily inconvenience of multiple con-trol measures, its role as an additional building material to block holes in walls, reduce draughts, noise and dust, and how easily it can be removed and re-installed when certain communities participate in annual house reno-vations, particularly re-smearing walls with mud dur-ing festive periods [57, 59]. Common aspects of ITWL which were causes for concern amongst householders were its impact on house ventilation, possible flammabil-ity, fragility, especially in the context of damage caused by children, and how long-term exposure to smoke from internal, unventilated fires may affect its aesthetics, dura-bility and insecticidal efficacy. Finally, one more unex-pected, negative outcome reported in several sites was the collateral cessation of LLIN use and other methods of disease control, as ITWL was perceived to be either a suf-ficient or superior malaria prevention strategy [57–59]. These observations clearly demonstrate that application of this intervention must be accompanied by re-iterative community sensitization to sustain the use of all available control measures.

Future prospects of ITWL for malaria control: control intervention or method of house improvement?In the absence of unequivocal evidence to support ITWL as an alternate control measure to IRS, the questions remain, how will this intervention function to reduce malaria, in what epidemiological situation will it war-rant implementation and how will it be executed to scale? There is increasing evidence to support a crucial role for housing improvement in malaria control [31–33, 60, 61]. It can be envisaged that ITWL could act as an effective and insecticidal method of house, and in particular, eave screening, if affixed to the base of the roof or ceiling and proven to have long-term durability. However, with con-comitant housing, social and economic development, will potential communities still accept ITWL as readily based on its perceived aesthetics? Reports from more affluent urban residents in Nigeria suggest this might not be the case [50]. Alternatively, even if ITWL were to be proven effective and applied in a similar manner to IRS, there are considerable implications for installation logistics. Previ-ously, ITWL has been primarily installed using locally-sourced nails, often covered with plastic caps to improve wall grip [62]. Installation time, which accounts for time taken to attach the material to house walls, as well as preparation (removal of all household and wall items)


Tabl

e 3

Sum

mar

y of

key

det

erm

inan

ts o

f ins

ecti

cide

‑tre

ated

wal

l lin

ing

acce

ptab

ility

, ide

ntifi

ed th

roug

h qu

alit

ativ

e co

mm

unit

y su

rvey

s

Fiel

d si

te(s

), co

untr

y (s

ampl

e si

ze)

Inte

rven

tion

(in

sect

icid

e)St

udy

dura

tion

Key

dete

rmin

ants

of

inte

rven

tion

acce

ptab

ility

Supp

ortin

g qu

otat

ions

Add

ition

al o

bser

vatio

nsRe

fere

nces

Hua

mbo

pro

vinc

e,

Ang

ola

(60)

; Enu

gu

(60)

, Kan

o (5

7) a

nd

Lago

s (6

1), N

iger

ia

Blue

pol

yeth

ylen

e w

oven

sha

de c

loth

(Z

eroV

ecto

r®) (

Del

-ta

met

hrin

)

12 m

onth

sIm

med

iate

ent

omol

ogic

al

effica

cy‘T

he th

ing

is pi

ckin

g in

sect

s the

way

I c

an’t

expl

ain.

It’s

pick

ing

them

lik

e a

mag

net.

It w

as v

ery

very

eff

ectiv

e.’ (F

emal

e 18

–29

year

s, ru

ral E

nugu

)

ITW

L w

as c

omm

ende

d fo

r bei

ng a

sin

gle

prev

en-

tativ

e m

easu

re w

hich

cou

ld a

llevi

ate

the

use

of m

ultip

le s

trat

egie

s in

corp

orat

ed in

to d

aily

ro

utin

e

[52]

Aes

thet

ic v

alue

‘Sin

ce w

e ha

ve p

ut th

at th

ing,

it h

as

beau

tified

my

hous

e.’ (F

emal

e 18

–29

year

s, ru

ral E

nugu

)

Hig

her l

evel

s of

acc

epta

bilit

y in

Nig

eria

may

be

attr

ibut

able

to o

vera

ll gr

eate

r aw

aren

ess

of

mal

aria

and

pre

vent

ativ

e m

easu

res

Blue

lam

inat

ed

poly

ethy

lene

pla

stic

sh

eetin

g (Z

eroF

ly®

) (D

elta

met

hrin

)

Ang

olan

par

ticip

ants

, des

pite

repo

rtin

g po

sitiv

e fe

edba

ck, u

ltim

atel

y re

mov

ed th

eir I

TPS

once

it

was

per

ceiv

ed a

s in

effec

tual

A d

icho

tom

y em

erge

d be

twee

n ru

ral a

nd u

rban

ho

useh

olde

rs; t

he la

tter

reje

cted

the

use

of w

all

linin

gs b

ased

on

obje

ctio

ns to

thei

r aes

thet

ics

and

inst

alla

tion

feas

ibili

ty

Blue

pol

yest

er n

ettin

g (D

elta

met

hrin

)O

f the

thre

e pr

otot

ype

mat

eria

ls, Z

eroV

ecto

r®

was

the

mos

t pop

ular

bec

ause

of i

ts e

ase

of

inst

alla

tion

and

rese

mbl

ance

to lo

cal m

ater

ials

Río

Mun

i, Eq

uato

rial

Gui

nea

(40)

, Obu

asi

mun

icip

ality

, Gha

na

(60)

, Kou

likor

o, M

ali

(24)

, Mpu

mal

anga

So

uth

Afri

ca (1

2)

and

Hoa

Bin

h pr

ov-

ince

, Vie

tnam

(12)

Blue

pol

yeth

ylen

e w

oven

sha

de c

loth

(Z

eroV

ecto

r®) (

Del

-ta

met

hrin

)

12–1

5 m

onth

sIm

med

iate

and

sus

tain

ed

ento

mol

ogic

al e

ffica

cy‘T

his f

abric

was

ver

y he

lpfu

l be

caus

e th

e m

osqu

itoes

hav

e fle

d. T

he fl

ies a

lso le

ave

us a

lone

.’ (M

ali,

fem

ale)

Maj

ority

of p

artic

ipan

ts e

xpre

ssed

inte

rest

in

keep

ing

the

ITW

L fo

r dec

orat

ion

even

if it

did

no

t kill

mos

quito

es o

r oth

er n

uisa

nce

inse

cts

[53]

Aes

thet

ic v

alue

‘The

text

ile is

ver

y go

od b

ecau

se in

ad

ditio

n to

its i

nsec

ticid

al a

ctiv

ity,

it m

akes

the

room

mor

e be

auti-

ful.’

(Mal

i, fe

mal

e)

Whe

n off

ered

the

choi

ce o

f oth

er v

ecto

r con

trol

in

terv

entio

ns (I

RS o

r ins

ectic

ide-

trea

ted

cur-

tain

s), I

TWL

was

the

mos

t pop

ular

, irr

espe

ctiv

e of

ear

lier h

ouse

hold

allo

catio

n

Pote

ntia

l pro

tect

ion

from

m

alar

ia‘S

ince

the

text

ile a

rriv

ed I

have

not

se

en a

cas

e of

mal

aria

.’ (M

ali,

fem

ale)


Tabl

e 3

cont

inue

d

Fiel

d si

te(s

), co

untr

y (s

ampl

e si

ze)

Inte

rven

tion

(in

sect

icid

e)St

udy

dura

tion

Key

dete

rmin

ants

of

inte

rven

tion

acce

ptab

ility

Supp

ortin

g qu

otat

ions

Add

ition

al o

bser

vatio

nsRe

fere

nces

Hig

hlan

d an

d lo

w-

land

, Pap

ua N

ew

Gui

nea

(40)

Blue

pol

yeth

ylen

e w

oven

sha

de c

loth

(Z

eroV

ecto

r®) (

Del

-ta

met

hrin

)

1 m

onth

Imm

edia

te a

nd s

usta

ined

en

tom

olog

ical

effi

cacy

‘The

firs

t day

afte

r [IT

PS]a in

stal

la-

tion

I saw

mos

quito

es fl

ying

into

th

e ho

use,

con

tact

the

mat

eria

l an

d th

en ju

st fa

ll off

and

die

. The

co

ckro

ache

s clim

bed

up th

e [IT

PS

cove

red]

wal

l and

die

d in

stan

tly.’

(Low

land

s vi

llage

, mal

e)

Part

icip

ants

app

reci

ated

the

ITPS

act

ing

as a

ddi-

tiona

l bui

ldin

g m

ater

ial,

bloc

king

hol

es in

wal

ls,

redu

cing

dra

ught

s, no

ise

and

dust

ent

erin

g th

e ho

use

[57]

Pote

ntia

l pro

tect

ion

from

m

alar

ia‘W

e do

not

wan

t to

be si

ck w

ith

mal

aria

. If t

he k

ids a

re si

ck, w

e w

ill st

rugg

le to

wal

k a

long

way

to

go

to th

e ho

spita

l. We

do n

ot

wan

t thi

s to

happ

en. T

his p

last

ic

shee

ting

will

hel

p pr

otec

t us a

nd

our c

hild

ren

from

get

ting

sick

with

mal

aria

.’ (Lo

wla

nds

villa

ge,

mal

e)

Man

y re

cipi

ents

cea

sed

LLIN

use

, per

ceiv

ing

the

ITPS

to b

e su

ffici

ent a

nd/o

r sup

erio

r for

pr

otec

tion

Aes

thet

ic v

alue

‘Whe

n I o

pene

d th

e do

or a

nd w

ent

into

the

hous

e it

look

ed a

lot

diffe

rent

[fol

low

ing

ITPS

inst

alla

-tio

n]. M

y ho

use

look

ed b

eaut

iful

and

was

glo

win

g.’ (

Hig

hlan

ds

urba

n, m

ale)

It w

as d

ifficu

lt to

est

ablis

h ‘ro

utin

e’ in

stal

latio

n du

e to

het

erog

eneo

us h

ouse

siz

e, s

hape

and

co

nstr

uctio

n

Ow

ners

hip

pres

tige

‘One

of m

y sis

ters

cam

e an

d sa

w

the

dura

ble

linin

g sh

eets

and

lik

ed it

and

said

she

wish

ed sh

e co

uld

have

got

one

like

this

too.

’ (Is

land

s vi

llage

, fem

ale)

Hou

seho

lder

s ra

ised

con

cern

s ab

out t

he p

rod-

ucts

flam

mab

ility

, fra

gilit

y an

d po

ssib

ility

of

thef

t by

the

inst

alla

tion

team

Few

obs

erva

ble

side

effe

cts

‘I hav

e a

smal

l chi

ld a

nd I

was

wor

-rie

d th

at th

e in

sect

icid

e on

the

dura

ble

linin

g sh

eet m

ight

hav

e a

bad

effec

t on

my

child

.’ (Is

land

s vi

llage

, fem

ale)

ITPS

was

exp

osed

to s

mok

e fro

m in

tern

al, u

nven

-til

ated

fire

s w

hich

may

resu

lt in

mor

e ra

pid

degr

adat

ion,

redu

ctio

n in

aes

thet

ic a

ppea

l and

im

pact

inse

ctic

idal

long

evity

and

pot

ency

Hig

hlan

d an

d lo

w-

land

, Pap

ua N

ew

Gui

nea

(38)

Blue

pol

yeth

ylen

e w

oven

sha

de c

loth

(Z

eroV

ecto

r®)

36 m

onth

sIm

med

iate

and

sus

tain

ed

aest

hetic

val

ue‘Y

es, i

nitia

lly it

[the

DL]

look

ed v

ery

nice

. It m

ade

the

hous

e lo

ok

nice

, but

now

that

it is

losin

g its

co

lour

s or m

aybe

the

dust

cov

-er

ed it

so it

s col

ours

are

fadi

ng.

But i

t’s st

ill lo

okin

g ni

ce o

n th

e w

all a

s it i

s.’ (H

ighl

ands

urb

an,

36 m

onth

s)

Des

pite

redu

ctio

ns in

per

ceiv

ed e

ffect

iven

ess

over

tim

e, h

ouse

hold

ers

did

not r

emov

e th

e m

ater

ial a

nd m

ost e

xpre

ssed

inte

rest

in o

btai

n-in

g a

new

one

Des

pite

redu

ctio

ns in

per

ceiv

ed a

esth

etic

val

ue

over

tim

e, h

ouse

hold

ers

still

felt

thei

r hom

e in

terio

r was

enh

ance

d. H

owev

er, n

o pa

rtic

i-pa

nts

expr

esse

d in

tere

st in

inst

allin

g a

DL

for

appe

aran

ce s

ake

alon

e, s

ugge

stin

g pe

rcei

ved

ento

mol

ogic

al e

ffect

iven

ess

was

impo

rtan

t for

in

itial

and

con

tinue

d ac

cept

abili

ty


Tabl

e 3

cont

inue

d

Fiel

d si

te(s

), co

untr

y (s

ampl

e si

ze)

Inte

rven

tion

(in

sect

icid

e)St

udy

dura

tion

Key

dete

rmin

ants

of

inte

rven

tion

acce

ptab

ility

Supp

ortin

g qu

otat

ions

Add

ition

al o

bser

vatio

nsRe

fere

nces

(Del

tam

ethr

in)

Pote

ntia

l pro

tect

ion

from

m

alar

ia‘F

or m

ysel

f, w

hen

this

thin

g [D

L]

was

ther

e I s

ee th

at m

e or

my

fam

ily m

embe

rs h

ad n

ever

bee

n sic

k w

ith m

alar

ia si

nce

this

thin

g w

as in

stal

led.

Not

one

of u

s was

in

fect

ed w

ith m

alar

ia. T

his i

s why

I l

ike

that

thin

g.’ (

Isla

nds

villa

ge,

36 m

onth

s)

Hou

seho

lder

s fro

m th

e co

oler

hig

hlan

d re

gion

su

gges

ted

that

the

mat

eria

l war

med

the

hous

e, w

hich

was

con

side

red

a de

sira

ble

func

-tio

n. T

his ‘

war

min

g’ b

enefi

t was

not

repo

rted

by

thos

e in

the

low

land

s

[58]

Ease

of u

se a

nd p

erce

ived

eff

ectiv

enes

s co

mpa

red

to o

ther

mal

aria

con

trol

m

etho

ds

‘Pre

viou

sly w

e us

ed to

do

the

wor

k of

tyin

g up

net

s and

slee

p an

d ev

en in

the

nigh

t to

wak

e up

and

tie

up

nets

and

now

this

gree

n ne

t is

here

, sor

ry b

lue

net [

DL]

, tha

t w

e do

not

hav

e th

e ha

rd w

ork

of

tyin

g th

e ne

ts. I

t’s [D

L] o

n th

e w

all

help

ing

us to

kill

mos

quito

es so

w

e ju

st sl

eep

rela

xing

’(H

ighl

ands

vill

age,

36

mon

ths)

Man

y re

cipi

ents

repo

rted

cea

sing

LLI

N u

se, p

er-

ceiv

ing

the

ITPS

to b

e su

ffici

ent a

nd/o

r sup

erio

r fo

r pro

tect

ion.

Hou

seho

lder

s m

ade

no in

dica

-tio

n to

sug

gest

aw

aren

ess

that

this

redu

ctio

n in

net

use

mig

ht in

crea

se ri

sk o

f mal

aria

‘[DL]

is b

ette

r tha

n th

e m

osqu

ito

net a

nd th

e ot

her t

hing

is th

at I

can

brea

the

prop

erly

whe

n I’m

sle

epin

g, b

ut in

the

mos

quito

net

I f

eel t

hat I

am

bre

athi

ng in

all

the

med

icin

e/tr

eatm

ent f

rom

the

net.

Now

that

we

are

usin

g th

is [t

he D

L], w

e do

n’t w

ant t

o us

e th

e m

osqu

ito n

et, o

ur n

ets a

re p

iling

up

ther

e. I

am re

ady

to se

ll m

ine.

W

e do

n’t r

eally

like

mos

quito

ne

ts. T

hese

net

s [D

L] a

re b

ette

r th

an m

osqu

ito n

ets.

For m

e an

d m

y fa

mili

es g

ood

I’m sa

ying

this.

’ (Is

land

s vi

llage

, 12

mon

ths)

Few

obs

erva

ble

side

effe

cts

com

pare

d to

oth

er m

alar

ia

cont

rol m

etho

ds

‘I don

’t lik

e us

ing

the

mos

quito

ne

t. So

met

imes

I ha

ve sh

ort-

ness

of b

reat

h.’ (

Isla

nds

villa

ge,

12 m

onth

s)

Due

to th

e ty

pe o

f hou

sing

mat

eria

l use

d in

PN

G, D

L du

rabi

lity

may

be

long

er th

an a

ver-

age

hous

e lif

espa

n, s

ugge

stin

g th

at e

ffect

ive

dura

tion

wou

ld b

e la

rgel

y de

term

ined

by

the

age

and

cond

ition

of t

he h

ouse

at t

he ti

me

of

inst

alla

tion,

rath

er th

an th

e pr

oduc

t its

elf

Bioe

ffica

cy te

stin

g de

mon

stra

ted

no lo

ss in

in

sect

icid

al a

ctiv

ity a

fter

36

mon

ths

indi

catin

g th

at p

artic

ipan

t per

cept

ions

of r

educ

ed p

rod-

uct e

ffect

iven

ess

are

not n

eces

saril

y sy

nony

-m

ous

with

act

ual i

neffe

ctiv

enes

s


Tabl

e 3

cont

inue

d

Fiel

d si

te(s

), co

untr

y (s

ampl

e si

ze)

Inte

rven

tion

(in

sect

icid

e)St

udy

dura

tion

Key

dete

rmin

ants

of

inte

rven

tion

acce

ptab

ility

Supp

ortin

g qu

otat

ions

Add

ition

al o

bser

vatio

nsRe

fere

nces

Lim

popo

pro

vinc

e,

Sout

h A

frica

(40)

Gre

en, o

rang

e, b

row

n,

or p

urpl

e po

lyet

hyl-

ene

mon

ofila

men

t (d

elta

met

hrin

or

alph

a-cy

perm

e-th

rin)

6 m

onth

sIm

med

iate

and

sus

tain

ed

ento

mol

ogic

al e

ffica

cy‘N

etb h

elps

a lo

t bec

ause

ther

e ar

e no

t as m

any

mos

quito

es li

ke

befo

re. L

ike

nets

for b

oth

room

s.’

(Fem

ale,

age

28,

hou

se w

ith

gree

n lin

ing)

Maj

ority

of p

artic

ipan

ts c

ease

d us

ing

othe

r m

etho

ds to

pre

vent

mal

aria

, inc

ludi

ng s

pray

ing

inse

ctic

ides

and

bur

ning

mos

quito

coi

ls a

nd

othe

r mat

eria

ls

[59]

‘The

net

is h

elpi

ng u

s bec

ause

mos

-qu

itoes

are

not

as m

any

as b

efor

e w

hen

ther

e is

no li

ning

.’ (Fe

mal

e,

age

73, h

ut w

ith b

row

n lin

ing)

Hou

seho

lder

s di

sagr

eed

over

whe

ther

ITW

L sh

ould

cov

er th

e en

tire

wal

l or o

nly

the

top

port

ion,

out

of r

each

of c

hild

ren

and

pote

ntia

l da

mag

e

Smok

e da

mag

e an

d so

ot a

ccum

ulat

ion

from

co

okin

g ov

er o

pen,

unv

entil

ated

fire

s w

as

rais

ed a

s an

issu

e w

hich

mig

ht im

pact

ITW

L lo

ng-t

erm

aes

thet

ic a

ppea

l and

inse

ctic

idal

effi

cacy

Aes

thet

ic v

alue

‘The

net

is to

o m

uch

good

. It

deco

rate

my

room

and

it k

ill

mos

quito

es a

nd c

ockr

oach

es.’

(Fem

ale,

age

48,

hou

se w

ith

oran

ge li

ning

)

The

abili

ty to

rem

ove

and

re-in

stal

l ITW

L w

ould

ov

erco

me

logi

stic

al p

robl

ems

asso

ciat

ed w

ith

IRS

in th

e ar

ea, n

amel

y th

e an

nual

or b

i-ann

ual

mud

re-s

mea

ring,

re-p

aint

ing

or w

ashi

ng o

f w

alls

that

occ

urs

durin

g th

e fe

stiv

e se

ason

DL

dura

ble

linin

g, IR

S in

door

resi

dual

spr

ayin

g, IT

PS In

sect

icid

e-tr

eate

d pl

astic

she

etin

g, IT

WL

inse

ctic

ide-

trea

ted

dura

ble

wal

l lin

ing,

LLI

N lo

ng-la

stin

g in

sect

icid

al n

eta I

n th

e st

udy

by P

ulfo

rd e

t al.

ITPS

is u

sed

to re

fer t

o Ze

roVe

ctor

® IT

WL,

not

to Z

eroF

ly®

ITPS

b In

the

stud

y by

Kru

ger e

t al.

net i

s us

ed to

refe

r to

the

mes

h IT

WL,

not

to L

LIN

s or

oth

er m

osqu

ito n

ets


and clean-up, is largely correlated with overall house size, construction and number of rooms to be covered. From an economic perspective, lengthy or highly variable installation times, among communities containing het-erogeneous house constructions, will have repercussions on intervention cost-effectiveness, potentially requiring financing mechanisms that many African countries lack [63]. By comparison to IRS, which is estimated at as lit-tle as $5 for pyrethroid (ICON™ lambdacyhalothrin cap-sule suspensions) to $23.50 for organophosphate sachets (Actellic CS 3000) [64], ITWL installation also requires the purchase, temporary storage and transportation of large ITWL rolls (measuring 2.4 × 210 m and weighing 40 kg each), supporting fixings and resources (e.g. nails, hammers, tape measures, step ladders etc.), often to remote and inaccessible locations. In this scenario, unlike IRS, the cost of contracting and deploying specialist installation teams by NMCPs would likely be financially prohibitive.

Other, as yet unanswered issues, include just how much of a wall or house must be covered with ITWL to impact disease transmission, could ITWL coverage be restricted to sleeping rooms with only limited loss of effectiveness and how can high quality intervention installation and community maintenance be ensured and monitored, as ITWL is expected to function for multiple years, without external upkeep or interference. Moreover, should ITWL durability be assessed in terms of overall household-level coverage, given it will likely impact malaria trans-mission like IRS, through a reduction in overall vector population density, or because of its long-lasting LLIN-like properties, will the formation of holes from daily household wear and tear also impact efficacy? Given its higher cost, ITWL is unlikely to be considered for wide-spread programmatic implementation but instead may be more appropriate as a method to control malaria in areas where pyrethroid-resistant vectors predominate, or to reduce epidemic hot spots of transmission [20, 65]. Unlike vertical IRS programmes and mass LLIN distribu-tions, potential delivery systems for ITWL could utilize a combination of social mobilization and microfinanc-ing or subsidization, designating direct responsibility of installation and maintenance to community members.

Future prospects of ITWL for control of other vector‑borne diseasesTo date, ITWL has primarily been evaluated for its effec-tiveness as a malaria control strategy. However, there are fundamental features underlying the biology of other vector-borne diseases where ITWL could also play a critical role in interrupting disease transmission. Leish-maniasis remains an important neglected tropical dis-ease with an estimated 350 million individuals at risk

worldwide [66]. Vector management is one of the prin-cipal disease control strategies, targeting putative resting sites of phlebotomine sand flies, usually with IRS [67]. In addition to all of the aforementioned limitations of IRS, because some vector species display crepuscular feeding activities, LLINs can also be ineffective in these endemic countries [68]. Recently, the efficacy of ZeroVector® ITWL was investigated in a multi-centre study in Bangla-desh, India and Nepal, demonstrating high levels of sand fly mortality and household acceptability and decreases in vector density over 12 months of household use [69, 70]. However, no epidemiological endpoints to assess the impact of ITWL on incidences of visceral leishma-niasis were measured, indicating further evaluations of this intervention are still needed. ITWL also war-rants consideration as a supplementary intervention to control Chagas disease, which is transmitted by highly domiciliated triatomine bug vectors, inhabiting cracks in the walls of rural adobe houses across Latin America [71]. Despite achieving substantial reductions in disease incidence through historic large-scale trans-national IRS campaigns, active transmission persists, particularly in the Gran Chaco, where rapid domestic re-infestation abounds and insecticide resistance is increasing; both of which are exacerbated by decentralized regional control efforts in areas of recurrent political, social and economic instability [72]. While ITWL has yet to be directly evalu-ated against Chagas disease, organophosphate and juve-nile growth hormone containing insecticidal vinyl paints (Inesfly 5A IGR®), based on similar principles to ITWL, have thus far reported encouraging experimental results [73, 74] and long-term reductions in levels of household triatomine infestation [75, 76].

ConclusionsInsecticide-treated durable wall lining (ITWL) is a novel method of vector control, which when attached to inner house walls remains efficacious over multiple years and can circumvent some of the logistical constraints asso-ciated with first-line control strategies. To date, there is substantial phase II data indicating ITWL can impact malaria vector populations, with complete wall coverage affording the highest rates of mosquito mortality, deter-rence and blood-feeding inhibition in experimental hut trials. However, there is currently limited Phase III evi-dence to support operational implementation of ITWL either as a control intervention in a programmatic con-text or as an insecticidal method of house improvement or eave screening. While aesthetic value and observable entomological efficacy are key determinants of accept-ability, additional studies are still required to determine feasible and cost-effective financing mechanisms of installation to sustain ITWL durability during long-term


field use. Further large-scale community-level trials are warranted to support the development and evaluation of ITWL as a potential alternate control strategy for malaria and other vector-borne diseases.

AbbreviationsCRT: cluster-randomized controlled trial; CS: capsule suspension; DL: durable lining; IGR: insect growth regulator; ITN: insecticide-treated net; IRS: indoor residual spraying; ITPS: insecticide-treated plastic sheeting; ITWL: insecticide-treated durable wall lining; LLIN: long-lasting insecticidal net; NMCP: National Malaria Control Programme; UC: universal coverage.

Authors’ contributionsLAM and MR co-drafted the manuscript. Both authors read and approved the final manuscript.

AcknowledgementsLAM and MR are supported by the Malaria Centre of the London School of Hygiene and Tropical Medicine (http://malaria.lshtm.ac.uk).

Competing interestsThe authors declare that they have no competing interests.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims in pub-lished maps and institutional affiliations.

Received: 21 February 2017 Accepted: 15 May 2017

References 1. WHO. World malaria report 2014. Geneva: World Health Organization;

2014. 2. Lengeler C. Insecticide-treated bed nets and curtains for preventing

malaria. Cochrane Database Syst Rev. 2004;2:CD000363. 3. Pluess B, Tanser FC, Lengeler C, Sharp BL. Indoor residual spraying for

preventing malaria. Cochrane Database Syst Rev. 2010;4:CD006657. 4. West PA, Protopopoff N, Wright A, Kivaju Z, Tigererwa R, Mosha FW,

et al. Indoor residual spraying in combination with insecticide-treated nets compared to insecticide-treated nets alone for protection against malaria: a cluster randomised trial in Tanzania. PLoS Med. 2014;11:e1001630.

5. Pinder M, Jawara M, Jarju LB, Salami K, Jeffries D, Adiamoh M, et al. Efficacy of indoor residual spraying with dichlorodiphenyltrichloroethane against malaria in Gambian communities with high usage of long-lasting insecticidal mosquito nets: a cluster-randomised controlled trial. Lancet. 2015;385:1436–46.

6. Ranson H, N’Guessan R, Lines J, Moiroux N, Nkuni Z, Corbel V. Pyrethroid resistance in African anopheline mosquitoes: what are the implications for malaria control? Trends Parasitol. 2011;27:91–8.

7. Strode C, Donegan S, Garner P, Enayati AA, Hemingway J. The impact of pyrethroid resistance on the efficacy of insecticide-treated bed nets against African anopheline mosquitoes: systematic review and meta-analysis. PLoS Med. 2014;11:e1001619.

8. Protopopoff N, Matowo J, Malima R, Kavishe R, Kaaya R, Wright A, et al. High level of resistance in the mosquito Anopheles gambiae to pyrethroid insecticides and reduced susceptibility to bendiocarb in north-western Tanzania. Malar J. 2013;12:149.

9. Riveron JM, Chiumia M, Menze BD, Barnes KG, Irving H, Ibrahim SS, et al. Rise of multiple insecticide resistance in Anopheles funestus in Malawi: a major concern for malaria vector control. Malar J. 2015;14:344.

10. Koenker HM, Loll D, Rweyemamu D, Ali AS. A good night’s sleep and the habit of net use: perceptions of risk and reasons for bed net use in Bukoba and Zanzibar. Malar J. 2013;12:203.

11. Frey C, Traore C, De Allegri M, Kouyate B, Muller O. Compliance of young children with ITN protection in rural Burkina Faso. Malar J. 2006;5:70.

12. Toé LP, Skovmand O, Dabire KR, Diabate A, Diallo Y, Guiguemde TR, et al. Decreased motivation in the use of insecticide-treated nets in a malaria endemic area in Burkina Faso. Malar J. 2009;8:175.

13. Gnanguenon V, Azondekon R, Oke-Agbo F, Beach R, Akogbeto M. Durability assessment results suggest a serviceable life of two, rather than three, years for the current long-lasting insecticidal (mosquito) net (LLIN) intervention in Benin. BMC Infect Dis. 2014;14:69.

14. Hakizimana E, Cyubahiro B, Rukundo A, Kabayiza A, Mutabazi A, Beach R, et al. Monitoring long-lasting insecticidal net (LLIN) durability to validate net serviceable life assumptions, in Rwanda. Malar J. 2014;13:344.

15. Koenker H, Kilian A, de Beyl CZ, Onyefunafoa EO, Selby RA, Abeku T, et al. What happens to lost nets: a multi-country analysis of reasons for LLIN attrition using 14 household surveys in four countries. Malar J. 2014;13:464.

16. Kilian A, Koenker H, Obi E, Selby RA, Fotheringham M, Lynch M. Field durability of the same type of long-lasting insecticidal net varies between regions in Nigeria due to differences in household behaviour and living conditions. Malar J. 2015;14:123.

17. Mabaso ML, Sharp B, Lengeler C. Historical review of malarial control in southern African with emphasis on the use of indoor residual house-spraying. Trop Med Int Health. 2004;9:846–56.

18. WHO. Indoor residual spraying: an operational manual for IRS for malaria transmission, control and elimination. Geneva: World Health Organiza-tion; 2013.

19. White MT, Conteh L, Cibulskis R, Ghani AC. Costs and cost-effectiveness of malaria control interventions—a systematic review. Malar J. 2011;10:337.

20. Killeen GF. Characterizing, controlling and eliminating residual malaria transmission. Malar J. 2014;13:330.

21. Corbel V, Akogbeto M, Damien GB, Djenontin A, Chandre F, Rogier C, et al. Combination of malaria vector control interventions in pyrethroid resist-ance area in Benin: a cluster randomised controlled trial. Lancet Infect Dis. 2012;12:617–26.

22. Oxborough RM, N’Guessan R, Kitau J, Tungu PK, Malone D, Mosha FW, et al. A new class of insecticide for malaria vector control: evaluation of mosquito nets treated singly with indoxacarb (oxadiazine) or with a pyrethroid mixture against Anopheles gambiae and Culex quinquefascia-tus. Malar J. 2015;14:353.

23. Oxborough RM, N’Guessan R, Jones R, Kitau J, Ngufor C, Malone D, et al. The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecti-cides for malaria vector control. Malar J. 2015;14:124.

24. Ngufor C, N’Guessan R, Fagbohoun J, Odjo A, Malone D, Akogbeto M, et al. Olyset Duo® (a pyriproxyfen and permethrin mixture net): an experi-mental hut trial against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus in Southern Benin. PLoS ONE. 2014;9:e93603.

25. N’Guessan R, Ngufor C, Kudom AA, Boko P, Odjo A, Malone D, et al. Mos-quito nets treated with a mixture of chlorfenapyr and alphacypermethrin control pyrethroid resistant Anopheles gambiae and Culex quinquefascia-tus mosquitoes in West Africa. PLoS ONE. 2014;9:e87710.

26. Oxborough RM, Kitau J, Jones R, Mosha FW, Rowland MW. Experimen-tal hut and bioassay evaluation of the residual activity of a polymer-enhanced suspension concentrate (SC-PE) formulation of deltamethrin for IRS use in the control of Anopheles arabiensis. Parasites Vectors. 2014;7:454.

27. Oxborough RM, Kitau J, Jones R, Feston E, Matowo J, Mosha FW, et al. Long-lasting control of Anopheles arabiensis by a single spray application of micro-encapsulated pirimiphos-methyl (Actellic® 300 CS). Malar J. 2014;13:37.

28. Stewart ZP, Oxborough RM, Tungu PK, Kirby MJ, Rowland MW, Irish SR. Indoor application of attractive toxic sugar bait (ATSB) in combination with mosquito nets for control of pyrethroid-resistant mosquitoes. PLoS ONE. 2013;8:e84168.

29. Qualls WA, Muller GC, Traore SF, Traore MM, Arheart KL, Doumbia S, et al. Indoor use of attractive toxic sugar bait (ATSB) to effectively control malaria vectors in Mali, West Africa. Malar J. 2015;14:301.

30. Kitau J, Oxborough R, Kaye A, Chen-Hussey V, Isaacs E, Matowo J, et al. Laboratory and experimental hut evaluation of a long-lasting insecticide treated blanket for protection against mosquitoes. Parasites Vectors. 2014;7:129.

http://malaria.lshtm.ac.uk


31. Kirby MJ, Ameh D, Bottomley C, Green C, Jawara M, Milligan PJ, et al. Effect of two different house screening interventions on exposure to malaria vectors and on anaemia in children in The Gambia: a randomised controlled trial. Lancet. 2009;374:998–1009.

32. Tusting LS, Ippolito MM, Willey BA, Kleinschmidt I, Dorsey G, Gosling RD, et al. The evidence for improving housing to reduce malaria: a systematic review and meta-analysis. Malar J. 2015;14:209.

33. Roll Back Malaria. Consensus statement on housing and malaria. Geneva: Roll Back Malaria Housing and Malaria Work Stream; 2015.

34. Hewitt S, Rowland M, Muhammad N, Kamal M, Kemp E. Pyrethroid-sprayed tents for malaria control: an entomological evaluation in Pakistan. Med Vet Entomol. 1995;9:344–52.

35. Bouma MJ, Parvez SD, Nesbit R, Winkler AM. Malaria control using perme-thrin applied to tents of nomadic Afghan refugees in northern Pakistan. Bull World Health Organ. 1996;74:413–21.

36. Graham K, Mohammad N, Rehman H, Nazari A, Ahmad M, Kamal M, et al. Insecticide-treated plastic tarpaulins for control of malaria vectors in refugee camps. Med Vet Entomol. 2002;16:404–8.

37. Graham K, Rehman H, Ahmad M, Kamal M, Khan I, Rowland M. Tents pre-treated with insecticide for malaria control in refugee camps: an entomological evaluation. Malar J. 2004;3:25.

38. Diabate A, Chandre F, Rowland M, N’Guessan R, Duchon S, Dabire KR, et al. The indoor use of plastic sheeting pre-impregnated with insecticide for control of malaria vectors. Trop Med Int Health. 2006;11:597–603.

39. Djènontin A, Chabi J, Baldet T, Irish S, Pennetier C, Hougard JM, et al. Man-aging insecticide resistance in malaria vectors by combining carbamate-treated plastic wall sheeting and pyrethroid-treated bed nets. Malar J. 2009;8:233.

40. Sharma SK, Upadhyay AK, Hague MA, Tyagi PK, Mohanty SS, Mittal PK, et al. Field evaluation of ZeroFly—an insecticide incorporated plastic sheeting against malaria vectors & its impact on malaria transmission in tribal area of northern Orissa. Indian J Med Res. 2009;130:458–66.

41. Djènontin A, Chandre F, Dabire KR, Chabi J, N’guessan R, Baldet T, et al. Indoor use of plastic sheeting impregnated with carbamate combined with long-lasting insecticidal mosquito nets for the control of pyrethroid-resistant malaria vectors. Am J Trop Med Hyg. 2010;83:266–70.

42. Chandre F, Dabire RK, Hougard JM, Djogbenou LS, Irish SR, Rowland M, et al. Field efficacy of pyrethroid treated plastic sheeting (durable lining) in combination with long lasting insecticidal nets against malaria vectors. Parasites Vectors. 2010;3:65.

43. Mittal PK, Sreehari U, Razdan RK, Dash AP. Evaluation of the impact of ZeroFly®, an insecticide incorporated plastic sheeting on malaria incidence in two temporary labour shelters in India. J Vector Borne Dis. 2011;48:138–43.

44. Burns M, Rowland M, N’guessan R, Carneiro I, Beeche A, Ruiz SS, et al. Insecticide-treated plastic sheeting for emergency malaria prevention and shelter among displaced populations: an observational cohort study in a refugee setting in Sierra Leone. Am J Trop Med Hyg. 2012;87:242–50.

45. Brosseau L, Drame PM, Besnard P, Toto JC, Foumane V, Le Mire J, et al. Human antibody response to Anopheles saliva for comparing the efficacy of three malaria vector control methods in Balombo, Angola. PLoS ONE. 2012;7:e44189.

46. Ngufor C, Tungu P, Malima R, Kirby M, Kisinza W, Rowland M. Insecticide-treated net wall hangings for malaria vector control: an experimental hut study in north-eastern Tanzania. Malar J. 2014;13:336.

47. Ngufor C, Chouaibou M, Tchicaya E, Loukou B, Kesse N, N’Guessan R, et al. Combining organophosphate-treated wall linings and long-lasting insecticidal nets fails to provide additional control over long-lasting insecticidal nets alone against multiple insecticide-resistant Anopheles gambiae in Côte d’Ivoire: an experimental hut trial. Malar J. 2014;13:396.

48. Ngufor C, Tchicaya E, Koudou B, N’Fale S, Dabire R, Johnson P, et al. Com-bining organophosphate treated wall linings and long-lasting insecticidal nets for improved control of pyrethroid resistant Anopheles gambiae. PLoS ONE. 2014;9:e83897.

49. WHO. Global plan for insecticide resistance management in malaria vec-tors. Geneva: World Health Organization; 2012.

50. Darriet F, N’Guessan R, Hougard JM, Traore-Lamizana M, Carnevale P. An experimental tool essential for the evaluation of insecticides: the testing huts. Bull Soc Pathol Exot. 2002;95:299–303 (in French).

51. Smith A. A verandah-trap hut for studying the house-frequenting habits of mosquitoes and for assessing insecticides. I. A description of the

verandah-trap hut and of studies on the egress of Anopheles gambiae Giles and Mansonia uniformis (Theo.) from an untreated hut. Bull Entomol Res. 1965;56:161–9.

52. Messenger LA, Miller NP, Adeogun AO, Awolola TS, Rowland M. The devel-opment of insecticide-treated durable wall lining for malaria control: insights from rural and urban populations in Angola and Nigeria. Malar J. 2012;11:332.

53. Messenger LA, Matias A, Manana AN, Stiles-Ocran JB, Knowles S, Boakye DA, et al. Multicentre studies of insecticide-treated durable wall lining in Africa and South-East Asia: entomological efficacy and household acceptability during one year of field use. Malar J. 2012;11:358.

54. Kweka EJ, Lee MC, Mwang’onde BJ, Tenu F, Munga S, Kimaro EE, et al. Bio-efficacy of deltamethrin based durable wall lining against wild populations of Anopheles gambiae s.l. in Northern Tanzania. BMC Res Notes. 2017;10:92.

55. Mtove G, Mugasa JP, Messenger LA, Malima RC, Mangesho P, Magogo F, et al. The effectiveness of non-pyrethroid insecticide-treated durable wall lining to control malaria in rural Tanzania: study protocol for a two-armed cluster randomized trial. BMC Public Health. 2016;16:633.

56. Edi CV, Djogbenou L, Jenkins AM, Regna K, Muskavitch MA, Poupardin R, et al. CYP6 P450 enzymes and ACE-1 duplication produce extreme and multiple insecticide resistance in the malaria mosquito Anopheles gambiae. PLoS Genet. 2014;10:e1004236.

57. Pulford J, Tandrapah A, Atikinson JA, Kaupa B, Russell T, Hetzel MW. Fea-sibility and acceptability of insecticide-treated plastic sheeting (ITPS) for vector control in Papua New Guinea. Malar J. 2012;11:342.

58. Kuadima JJ, Timinao L, Naidi L, Tandrapah A, Hetzel MW, Czeher C, et al. Long-term acceptability, durability and bio-efficacy of ZeroVector® dura-ble lining for vector control in Papua New Guinea. Malar J. 2017;16:93.

59. Kruger T, Sibanda MM, Focke WW, Bornman MS, de Jager C. Acceptability and effectiveness of a monofilament, polyethylene insecticide-treated wall lining for malaria control after six months in dwellings in Vhembe District, Limpopo Province, South Africa. Malar J. 2015;14:485.

60. Liu JX, Bousema T, Zelman B, Gesase S, Hashim R, Maxwell C, et al. Is hous-ing quality associated with malaria incidence among young children and mosquito vector numbers? Evidence from Korogwe, Tanzania. PLoS ONE. 2014;9:e87358.

61. Wanzirah H, Tusting LS, Arinaitwe E, Katureebe A, Maxwell K, Rek J, et al. Mind the gap: house construction and the risk of malaria in Ugandan children. PLoS ONE. 2015;10:e0117396.

62. Messenger LA, Larsen ML, Thomas JH, Rowland M. Installation of insecti-cide-treated durable wall lining: evaluation of attachment materials and product durability under field conditions. Parasites Vectors. 2014;7:508.

63. Kolaczinski K, Kolaczinski J, Kilian A, Meek S. Extension of indoor residual spraying for malaria control into high transmission settings in Africa. Trans R Soc Trop Med Hyg. 2007;101:852–3.

64. Oxborough RM. Trends in US President’s Malaria Initiative-funded indoor residual spray coverage and insecticide choice in sub-Saharan Africa (2008–2015): urgent need for affordable, long-lasting insecticides. Malar J. 2016;15:146.

65. Bousema T, Stresman G, Baidjoe AY, Bradley J, Knight P, Stone W, et al. The impact of hotspot-targeted interventions on malaria transmission in Rachuonyo South District in the Western Kenyan highlands: a cluster-randomized controlled trial. PLoS Med. 2016;13:e1001993.

66. WHO Expert Committee. Control of the leishmaniasis: report of a meeting of the WHO expert committee on the control of leishmaniases, Geneva, 22–26 March 2010. WHO Tech Rep Ser. 2010;949:1–186.

67. Picado A, Dash AP, Bhattacharya S, Boelaert M. Vector control inter-ventions for visceral leishmaniasis elimination initiative in South Asia, 2005–2010. Indian J Med Res. 2012;136:22–31.

68. Picado A, Singh SP, Rijal S, Sundar S, Ostyn B, Chappuis F, et al. Long-lasting insecticidal nets for prevention of Leishmania donovani infection in India and Nepal: paired cluster randomised trial. BMJ. 2010;341:c6760.

69. Mondal D, Das ML, Kumar V, Huda MM, Das P, Ghosh D, et al. Efficacy, safety and cost of insecticide treated wall lining, insecticide treated bed nets and indoor wall wash with lime for visceral leishmaniasis vector control in the Indian sub-continent: a multi-country cluster randomized controlled trial. PLoS Negl Trop Dis. 2016;10:e0004932.

70. Huda MM, Kumar V, Das ML, Ghosh D, Priyanka J, Das P, et al. Entomologi-cal efficacy of durable wall lining with reduced wall surface coverage for strengthening visceral leishmaniasis vector control in Bangladesh, India and Nepal. BMC Infect Dis. 2016;16:539.


• We accept pre-submission inquiries

• Our selector tool helps you to find the most relevant journal

• We provide round the clock customer support

• Convenient online submission

• Thorough peer review

• Inclusion in PubMed and all major indexing services

• Maximum visibility for your research

Submit your manuscript atwww.biomedcentral.com/submit

Submit your next manuscript to BioMed Central and we will help you at every step:

71. Bern C. Chagas’ disease. N Engl J Med. 2015;373:456–66. 72. Gürtler R. Sustainability of vector control strategies in the Gran Chaco

Region: current challenges and possible approaches. Mem Inst Oswaldo Cruz. 2009;104(Suppl1):52–9.

73. Maloney KM, Ancca-Juarez J, Salazar R, Borrini-Mayori K, Niemierko M, Yukich JO, et al. Comparison of insecticidal paint and deltamethrin against Triatoma infestans (Hemiptera: Reduviidae) feeding and mortality in simulated natural conditions. J Vector Ecol. 2013;38:6–11.

74. Amelotti I, Catala SS, Gorla DE. Experimental evaluation of insecticidal paints against Triatoma infestans (Hemiptera: Reduviidae), under natural climatic conditions. Parasites Vectors. 2009;2:30.

75. Gorla DE, Ortiz RV, Catala SS. Control of rural house infestation by Triatoma infestans in the Bolivian Chaco using a microencapsulated insecticide formulation. Parasites Vectors. 2015;8:255.

76. Alarico AG, Romero N, Hernandez L, Catala S, Gorla D. Residual effect of a microencapsulated formulation of organophosphates and piriproxifen on the mortality of deltamethrin resistant Triatoma infestans populations in rural houses of the Bolivian Chaco region. Mem Inst Oswaldo Cruz. 2010;105:752–6.

Documents

OpAccess Insecticide-treatedξdurableξwallξliningξ (ITWL ... · MessengerξandξRowlandξMalar J Pageξ2ξofξ18 maintainandconsolidategainsandtotransitiontowards malariaeliminationanderadication[20],thereisagrow