Update 176 final - WHO · The geo France, (Scotlan countrie Sentinel confirme human infe s with varia ion about .htm er of specim Data sourc activity in t. Growing n nza viruses,

Influenza update | 07 January 2013 1

Influenza Update N° 176 04 January 2013

Summary

Reporting of influenza activity has been irregular in the past two weeks due to the holiday season in many countries. As a result, overall virus detections reported have dropped off although in most countries in the northern temperate regions, influenza activity appears to have continued rising.

Many countries of North America, Europe, north Africa, eastern Mediterranean and temperate Asia have reported increasing influenza activity over the past weeks. North China has started its influenza season.

In tropical Asia, influenza activity was similar to previous weeks, with persistent low-level circulation.

Influenza activity in sub-Saharan Africa has declined in most countries, with the exception of the Democratic Republic of Congo and Ghana.

In the Caribbean, central America and tropical south America, influenza activity decreased to low levels, except for Bolivia, where there is increasing circulation of influenza A(H3N2).

Influenza activity in countries of the southern hemisphere is currently at inter-seasonal levels.

Several unconfirmed media stories have reported a number of deaths related to infection with influenza A(H1N1)pdm09 in different parts of the world. As with other seasonal influenza viruses, it is expected that some deaths would occur with infection, in particular now when influenza season starts in Northern Hemisphere. These reports at times refer to this A(H1N1)pdm09 virus as “swine flu”, causing some confusion with other viruses that recently reported in the United States. A(H1N1)pdm09 virus has been circulating in humans for more than 3 years and now is a seasonal human influenza virus.

Note: Global epidemiology and surveillance updates are periodically collected from data reported by National authorities or organizations responsible for reporting this data. For further information on specific influenza virus activity in the world and scientific literature for practitioners and other professionals in the field, please visit the links provided at the end of this document.

Virological Update

http://www.who.int/influenza/gisrs_laboratory/updates/en/


Reporting of influenza activity was irregular in the past week, due to the holiday season in many parts of the

world, and only limited new information was available for this report.

Countries in the temperate zone of the northern hemisphere

North America

Influenza activity in North America has increased sharply since the last report with Canada and the United States both reporting widespread transmission of influenza.

Influenza activity in Canada continued to rise with increases in all indicators in the last two weeks. The influenza-like illness (ILI) consultation rate increased from 4% at the time of the previous report to 6.6%, with the highest rate observed in children <5 years old, followed by 5-19 year olds. The percentage of samples that tested positive for influenza also increased from 17.8% to 31.1%. In the last two weeks, 127 new influenza outbreaks were reported: 87 in long-term-care facilities, nine in hospitals, one in a school, and 30 in other facilities or communities. This represents a marked increase from the previous report of 22 outbreaks. 241 laboratory confirmed influenza associated hospitalizations were reported in five provinces; 97% (236/241) were influenza A, of which, half (117/236) were sub-typed. Of those with subtype information, 97.5% (114/117) were influenza A(H3N2) and 1.5% (3/117) were A(H1N1)pdm09. Just over half of these cases (51%, 123/241) were aged 65 years or older. Sixteen influenza associated deaths were reported in the last two weeks of 2012; all with influenza A.

Influenza A continued to predominate in Canada, with very few detections of influenza B. Of the respiratory specimens that were positive for influenza in the previous reporting week, 97.7% (4525/4632) were positive for influenza A, and 2.3% (107/4632) for influenza B. Of the influenza A viruses that were sub-typed, 97.4% (1164/1195) were A(H3N2) and 2.6% (31/1195) were A(H1N1)pdm09. Since the start of the season, the National Microbiology Laboratory has antigenically characterized 177 influenza viruses (136 A(H3N2), 17 A(H1N1)pdm09 , and 24 influenza B). The 136 influenza A(H3N2) viruses were antigenically similar to the vaccine virus A/Victoria/361/2011. The 17 A(H1N1)pdm09 viruses were antigenically similar to the vaccine virus A/California/07/09. Among the influenza B viruses, 20 were antigenically similar to the vaccine virus B/Wisconsin/01/2010 (Yamagata lineage) and four were similar to B/Brisbane/60/2008 (Victoria lineage; component of the previous 2011-2012 seasonal influenza vaccine). None of the viral samples tested were resistant to the neuraminidase inhibitors oseltamivir (n=128) or zanamivir (n=127).

In the United States of America (USA), influenza activity has also been increasing and the Centers for Disease Control and Prevention reports that this is the earliest season in nearly a decade. ILI consultation rates increased from 4.2% to 5.6% in the previous week, while the percent of clinical specimens testing positive for influenza increased from 29.6% to 31.6%. Earlier in the season, the most active areas of influenza activity in terms of geographic spread was in the eastern half of the country; this has now increased to include almost all states, with the exception of the Pacific coast. Widespread influenza activity was reported by 41 states (compared to 31 previously). The proportion of deaths attributed to pneumonia and influenza has been under the epidemic threshold for most of the season. Two influenza-associated pediatric deaths were reported (compared to eight in the previous report); both were associated with influenza B viruses.

In the USA, the majority of influenza viruses detected were A(H3N2), however influenza B accounted for a larger proportion than in Canada. Of the 2961 influenza positive specimens in the last week of 2012, 79% were influenza A and 21% were influenza B. Of the influenza A viruses with sub-type information, 98% were A(H3N2). Since 1 October 2012, the CDC has antigenically characterized 413 influenza viruses. All 17 A(H1N1)pdm09 viruses tested were characterized as A/California/7/2009-like and 99.3% of the 279 A(H3N2) influenza viruses tested were A/Victoria/361/2011-like. Of the 115 influenza B viruses characterized 69% were B/Wisconsin/1/2010-like of the Yamagata lineage, the B virus component of this seasons trivalent influenza vaccine, and 31% were of the Victoria lineage. Since 1 October, none of the 526 A(H3N2), 39 A(H1N1)pdm09, or 226 B viruses have been resistant to neuraminidase inhibitors.

No new infectioninformatoutbreak

Numb

Europe

Influenzacontinenof influeCentre fthe last w(EU/EEA

In EU/Efrom thedifferentinfluenzacontrastA(H3N2A(H1N1viruses f

In the lareportedreportedThe geoFrance, (Scotlancountrie

Sentinelconfirme

human infens with variation about k.htm

ber of specim

Data sourc

a activity innt. Growing nnza viruses,for Disease Pweek of NovA).

EA countriese previous wt from that oba A accountet to North A) and 49% )pdm09 increfrom sentine

ast week ofd medium ind medium acographic sprNorway and

nd), and spos had report

SARI hospied cases in f

ections of noant influenza

H3N2v inf

mens positive

ce: FluNet (www

n the Europenumbers of c though ovePrevention avember for th

s, 25.3% of week. The dbserved in Ned for about

America, of t(638/1293)

eased in prol sources wit

f December tensity trans

ctivity two weread of influd the UK (Eradic by Ested widespre

italization ratour countries

ovel influenza viruses havfections can

e for influenza

.who.int/flunet). GData g

e has increcountries in derall reportingand Control (he countries

clinical samdistribution orth America60% of influ

the influenzawere A(H1

oportion, relath subtype in

2012, four smission. Preeeks ago, anuenza activitngland), regtonia, Greecad activity.

tes that weres (Belgium, F

In

a A virus weve been repn be found

a by subtype

Global Influenza enerated on 05/0

ased, mainldifferent partsg was reduceECDC) annoof the Europ

mples were pof viruses ta. Throughouuenza virusesa A viruses 1N1)pdm09.tive to A(H3

nformation in

countries (Feviously this

nd no countrity was repo

gional by Italce, Lithuania

e positive forFrance, Irela

nfluenza upd

ere reported orted from 1d at http://

in the Northe

Surveillance and01/2013

y in the nos of the regioed due to thounced the spean Union a

positive for inypes and sut Europe, ss detected athat were sIn the last

N2), making that week.

France, Italys season, onies had repo

orted as widly, the Nethe

a and Spain.

r influenza and and the U

date | 07 Jan

in the last 11 states sin/www.cdc.go

ern America

d Response Syste

orthern and on reported ie holiday se

start of the inand the Euro

nfluenza viruubtypes in ince the beg

and influenzasubtyped, 51t week of Dup 72% (13

y, the Nethenly France aorted mediumdespread by erlands and Prior to the

also increaseUnited Kingd

nuary 2013

week. A totance July 201ov/flu/swinefl

transmission

em (GISRS)

western paincreasing de

eason. The Enfluenza seapean Econo

us, a slight rEurope wasinning of the

a B, 40%. Ho1% (655/129December,

39/194) of inf

erlands and and Luxembom activity bef

Belgium, Dthe United

e last two w

ed with 42 laom).

3

al of 312 12. More u/h3n2v-

n zone

rt of the etections

European son from mic Area

reduction s notably e season, owever in 93) were influenza fluenza A

Norway) ourg had fore that.

Denmark, Kingdom

weeks, no

boratory-

Since thRomaniaA(H1N1B/WiscoNone ofthe neur

Numb

Norther

Increasireportedinfluenzainfluenza

he end of a and Swi)pdm09 A

onsin/1/2010-f the 28 A(Hraminidase in

ber of specim

Data sourc

rn Africa and

ng influenzad increasing a A(H1N1)pa B, while all

September, tzerland) ha

A/California/7-like (Yamag1N1)pdm09,nhibitors, ose

ens positive

ce: FluNet (www

d the easter

activity has circulation of

pdm09 and l three virus

seven counave antigen

7/2009 (H1gata lineage 37 A(H3N2eltamivir and

for influenza


rn Mediterra

been noted f influenza Ainfluenza Bsub-types we

In

ntries (Denmnically chara1N1)-like, e, and eight) and 16 B v

d zanamavir.

a by subtype


anean region

in North AfrA(H1N1)pdm0. Pakistan dere in circula

nfluenza upd

mark, Englaacterized 852 A(H3Nt B/Brisbaneviruses teste

in the northe


n

rica and the 09, and Irandetected incation in Alger

date | 07 Jan

and, German1 influenza

N2) A/Victe/60/2008-liked in that per

ern European

d Response Syste

Middle East., Oman and

creasing leveria.

nuary 2013

ny, Latvia, viruses; s

oria/361/201ke (Victoria riod were res

transmissio

em (GISRS)

. Bahrain anQatar have els of A(H3

4

Portugal, six were 1-like,15 lineage). sistant to

n zone

d Jordan detected

3N2) and

Num

Temper

Influenzahas incrsentinel report. Coutbreakdeaths aviruses A(H3N2Chineserelated B/Brisbalike. Nonand zan

In Mongon the reportingviruses influenza

InfluenzaevidenceA(H1N1

mber of speci

Data sourc

rate Asia

a activity remreased for thsurveillance

China has oks were repoattributed to detected; 2%) and 19% w

e National Into A/Victoria

ane/60/2008-ne of the inflamivir.

golia, influenzwhole, thereg the highessuch as resa positive sa

a activity ree of increas)pdm09 in th

mens positiv

ce: FluNet (www

mained at lowhe fifth consee sites that wofficially annorted in the acute respira% (4/192) wwere A(H1N1fluenza Cena/361/2011(H-like; 6 (100%luenza samp

za activity ine were markst rates. Whspiratory syn

amples in the

mained low sing activity, he Republic o

ve for influenz


w levels throecutive weekwere due to nounced the

previous weatory infectio

were influenza1)pdm09. Am

nter since OcH3N2)-like; %) influenza ples tested w

ncreased, duked inter-reg

hile most ILIncytial virus

e last week a

in both Japwith detect

of Korea.

In

za by subtyp


ughout the tk in northernILI increasedstart of the

eek, in Shanons. Influenzaa B. Of the mong influenctober, 201269 (95.8%) B/Yamagata

were resistan

ue to influengional differe

in recent w, rhinovirusccounted for

pan and the ions of influ

nfluenza upd

pe in the north


emperate ren China. Thed to 3.9% coe influenza snxi and Hubea A accounteinfluenza A

nza viruses a2, 198 (100%

influenza Ba viruses arent to the neu

nza A(H3N2)ences, with

weeks was aand human

r approximat

Republic ofuenza A(H3N

date | 07 Jan

hern Africa tr

d Response Syste

gion of Asiae proportion oompared to season in nei Provincesed for 98% (that were s

antigenically %) influenza B/Victoria vire related to Braminidase i

). Although ISelnghe an

associated wn coronavirusely half of th

f Korea, howN2) in Japan

nuary 2013

ransmission z

em (GISRS)

, however, ILof outpatient3.2% in the

northern Chis, and there 188/192) of

sub-typed, 8characterizeA(H3N2) virruses are reB/Wisconsin/inhibitors, os

LI activity innd Dornod pwith other reses, the ince ILI sample

wever, there n, and A(H3

5

zone

LI activity t visits at previous na. Four were no

influenza 1% were ed by the ruses are elated to /01/2010-seltamivir

ncreased provinces espiratory crease in es tested.

is some 3N2) and

Number

Countr

Tropica

In both peaks inwith the

Influenzaof virus reportedmost wid

Sub-Sah

Most coGhana DemocraA(H1N1

of specimen

Data sourc

ries in the t

al countries

central Amen late summeexception of

a activity throdetections

d increasing dely reported

haran Africa

untries in Sucontinued tatic Republ)pdm09. Zam

s positive for

ce: FluNet (www

tropical zon

of the Amer

erica and theer. Influenzaf Cuba, whic

oughout the being reportcirculation o

d sub-types t

a

ub-Saharan Ato report ciric of Cong

mbia and Ma

r influenza by


ne

ricas

e Caribbean,a A(H3N2) anch reported A

tropical zoneted in all coof influenza throughout th

Africa experirculation of go, there isadagascar ar

In

y subtype in t


detections nd influenza

A(H1N1)pdm0

e of south Amountries, exc

A(H3N2). Inhe region.

enced decrepredominan

s increasingre also report

nfluenza upd

the eastern A


of influenza B were the

09.

merica contincept the Plurnfluenza A(H

easing detectntly influenzg influenza ting low-leve

date | 07 Jan

Asia transmis

d Response Syste

declined to most widely

nued to declrinational StaH3N2) and i

tions of influeza A(H1N1)p

activity froel detections

nuary 2013

ssion zone

em (GISRS)

low levels fry detected su

ine with low ate of Bolivinfluenza B w

enza virus. Hpdm09 whilem mainly of influenza

6

rom their ub-types,

numbers ia, which were the

However, e in the influenza B virus.

Number

Tropica

Influenzacontinuin

India comainly Aof all thrand Thareported

Influenzaseasonawere A(H4% influ

of specimen

Data sourc

al Asia

a activity in ng low-level

ontinued to rA(H1N1)pdmree influenzaailand. Simid in Viet Nam

a activity inal thresholdsH3N2), and enza B. In so

s positive for

ce: FluNet (www

most countrcirculation in

report declinm09, and is na sub-types, lar to previo

m.

Singapore s. In Singapoin Hong Konouthern Chin

r influenza by


ries of south n Cambodia,

ning influenznow at inter-s

while A(H3Nous weeks,

and southeore and soutng SAR, 62%na, influenza

In

y subtype in t


east Asia h Lao PDR, S

za positive sseasonal levN2) and influ

transmissio

ern China, inthern China,

% (28/45) werB detections

nfluenza upd

the middle A


has remainedSri Lanka, Th

samples fromvels. Sri Lanuenza B viruon of predo

ncluding Ho, half of the re attributed s increased.

date | 07 Jan

frica transmi

d Response Syste

d similar to phailand and V

m its peak ika reported uses were deminantly inf

ng Kong SAinfluenza vito influenza

nuary 2013

ssion zone

em (GISRS)

previous weeViet Nam.

in mid-Septepersistent cetected in Cfluenza B v

AR, remainerus positive A(H1N1)pdm

7

eks, with

ember of irculation

Cambodia irus was

ed below samples

m09, and

Number

Countr

Influenza

Source o

of specimen

Data sourc

ries in the t

a activity in a

Number

Data sourc

of data

s positive for

ce: FluNet (www

temperate z

all temperate

of specimens

ce: FluNet (www

r influenza by


zone of the

e countries o

s positive for i


In

y subtype in t


e southern

of the southe

influenza by s


nfluenza upd

the south eas


hemisphe

rn hemisphe

subtype in the


date | 07 Jan

st Asia transm

d Response Syste

ere

ere is now at

e southern he

d Response Syste

nuary 2013

mission zone

em (GISRS)

inter-season

misphere

em (GISRS)

8

e

nal levels.


The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.

The updates are based on available epidemiological and virological data sources, including FluNet (reported by the Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.

Link to web pages Epidemiological Influenza updates: http://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance Epidemiological Influenza updates archives 2012: http://www.who.int/influenza/surveillance_monitoring/updates/GIP_surveillance_2012_archives Virological surveillance updates : http://www.who.int/influenza/gisrs_laboratory/updates/summaryreport Virological surveillance updates archives :

http://www.who.int/influenza/gisrs_laboratory/updates/en/index.html

Contact [email protected]

Documents

Update 176 final - WHO · The geo France, (Scotlan countrie Sentinel confirme human infe s with varia ion about .htm er of specim Data sourc activity in t. Growing n nza viruses,