Ubt *I 4'$t ORGANISATION MONDIALE

&%I ~3 *t DE IA SANTE W O R L D HEALTH O R G A N I Z A T I O N

BUREAU R~GIONAL DE LA REGIONAL OFFICE FOR THE EASTERN MEDITERRANEAN

REGIONAL COMMITTEE FOR THE EASTERN m1-

Ninth Session ORIGINAL : ENGLISH

Agenda item 17

TECHNICAL DISCUSSIONS - SUB-COMTTW A

ANCYLOSTOUSIS

Pages

( a) Ancylostomime (b) Necatorinae

BIOLOGY OF LARVAE

MODE OF INFECTION

(a) The gas t r~ in tes t ina l symptoms ( b) Diarrhoeic and dysenteric aynptoms ( c) Spptoms of general weakness (d) The cardio-vascular symptoms

THE AETIOLW OF OEDEMA IN C A S E OF ANCYLOSTOMIASIS

TJdE QUESTION OF VITAMIN DEFICIENCY

HAFMTOLOGICAL XNVSTIGATIONS

COMMJ3NTS ON THE INTENSITY OF INFECTION

Till?, R U T I O N OF NUTRITION TO PAMSITISM

EFFECT' OF ANGYLOSTONIASE ON THE: OUTPUT OF JABOUi3

THE ~ B C T S OF SANITA~E Z~@~~OVEWTS ON THE 'PREVALENCE OF ANCYL~TOIEASIS

P B E V U N C E OF ANCYLOSTOMIASIS IN THE COUNT1ZIES OF THE EWTERN ~ f T E & T A ~ REGION

T h i s hklminth is widely spread in the world, Its distribution in the

t rop ics and sub-tropics has been,up t o the present,of appreciable dimensions,

and it has also occurred i n Europe, It has been we31 known among t h e driers

of Germany and of Cornwall 'in England. 1% also occurred among the labourers

engaged in t he construction of the S t , Gothard tunnel,

Its d is t r ibu t ion is not uniform. ~t is f m i d v e v frequently in Algeria

and Tunis. Jn the Province of E m t , United Arab Republic, it is a population

disease, It is also present in Central Africa, East AfYica and especially in

Portuguese East Africa. In certain other countries of Africa iC mainly occurs

i n mines, such as the Cape Colony, Orange River Colony, Basutoland and Bechuana-

land andl the greater part of the Transvaal (in that country it occurs almost

exclusiveLy among gold miners), In Natal, however, it occurs generally,

In Asia, there are heavily infested centresv, such as the East Indies.

I n -the gold f ie lds of Madras, every labourer is infested, In Bengal, the

a s e a s e is widely spread among the natives, aa wel laa in Assam. InBurma,

it is the second disease in occurrence, and in the &st Indian Islands, it a t

one t h e reached an incidence of 10@, In the Phil ippines and in South China,

ancylostomiasis is very frequent. It has also been met in Chantung.

In Australia it is present, especially in North Queensland, where 9% of the children are infested.

In New Guinea, Tutuila and especially Viti Levu (Fiji Islands), infesta-

tion reached 70% among the population before preventive maaures were intro-

duced.

SMla r ly , before.it wacl dealt w i t h , the diseaee was widely 8PrQqd 3n

the southern states of North America (8U of the recruits pr wed to be worm

carriers) . In Honduras, Central America, 8G$ were infested, Also in the

West ~nd ie s , the disease is very cornon. It was very serims, e6p&cislly in

h e r t o R i o o before sanitation was improved. The same can be said .of Venezuela

and Colombia where infection had reached PO$, In t h e tropical region of Braa i l

the infestation is reportedly SG$. It sekms that in'the Americas the: t l f e c t i o n

reaches i t s most southern limits'in t h e north of Argentina.

In bhe Mediterranean Region the disease is widely spread. Althou"~ there

are several papers on mcyloatomiasis prepared by representatives a t the Ninth

Session of the Regional Committee for the Eastern ~editerrenean''', a s-

dealing with the prevalence of the disease is c a e d for, and may be found at

the end of t h i s paper, pages 21 ' - 24.

The hookworms of man belong in the zoological classification to the

Phylum Nemthelminthes:

F a y : ancylostmidae Looss, 1905

Sub-families: ancylostominae, and necatorinae

Genus: ancylostoma Dubhi, 1843, ~replin, 1845

The following synonym, are given here to show that ancylostoma was intro-

duced by Crepljn in 1845, prior t o awlostoma which was introduced in 1885

by Luta o

Agchylostoma DubM, 1843 Anchylostormun Diesing, 1851

-lostoma Luts, 1885

Diploodon Molin, - 1863.

Thus accordjng to t he law of nomenclature, the correct spel l ing in this case

is llancylostonma" and not t t ~ l o s t o m a " as is mentioned frequently in recent

l i t e r a tu r e ,

The defini t ion of ancyloatoma ia as follows:

Anterior extremity bent dor~ally ; buccal capsule lnfundibular , one t o three pairs of venternl t ee th a t t he oral margin, a d two triangular lancets

in the depth of t h e capsule. The duct of the dorsal. oesophageal g l a d wuna

h a ridge on the dorsal w a l l of the capsule, and opens at the bottom of a

deep notch on its oral margin, Male: bursa1 formula -; ventral. ray cleft,

extarno-lateral separate, externo-dorsal arising from a common trmnk with the

dorsal, dorsal bifurcate, each branch being tridigitable; epicules e q d , ;

gubernacuEum present, Female: w l v a h poster ior third of body. Parasites

of the intestine of mammals,

Type Species

A.duode,@e (discoveredby Dubini in1843 in~ilan). In man, r*

Felis app, and the pig.

A .brazibense de Fara, 1910. In man, dog, cat, t i ge r , l ion, - leopard, wolf, and sloth bear,

A.caninum (Ecrolani, 1859). In dog, jackal, wolf, fox, t i ge r , - and s loth bear,

(b) Necatarinae

Anterior extre~tr bent dorsally; buccal. capsule sub-globular with

se&unar ventral c u t t h g plates at the oral margin, and in the depth two

triangular sub-ventral lancets, and two sub-dorsal ( lateral) lancets; duct of

the dorsal oesophageal glands opens on t he end of a cone proJecting into the

buccal cavity, e bursa symmtricpl, with the following formla - ventral

ray cleft , externo-lateral and la te ra l s arise from a common trunk, medico-

lateral. and postero-lateral close together, externo-dorsal narrowed a t i t s

base and arises from a common trunk with the dorsal, dorsal doubled, each

branch being bidigitatej spicules equal and one of them at t h e t i p ; gaberna-

cu lm absent. Female t vulva near the middle of the body Parasites of

man, chimpanzee, and pig ,

Type of species: N, W ~ ~ C & ~ U S (stiles, 1902). Male, 8 female, - 10 mm. In man and pig,

Life-cycle: The worms with thei r powerful buccal capsules &.hold of

the mucous membrane and suck the blood and tissue juices with vigour. Each

female necator producea 5,000 t o 10,000 eggs per day, while each female

ancyloatoma &posits ovartwico as many. Yet the bodtes of tho worms contain

on t he average only about five per cent of t h i s number of eggs at one tima.

The eggs average about seventy by thirty-eight microns in ne~a tor , and sixty

by thlulty-eight mjcrona in nncylostomas, but t h o species cannot be identified

reliably by eggs in the faeces. They are in the four-celled stage when

freshly gassed and do not develop further u n t i l exposed to a i r , They require

nourishment, and if t h e temperature is favourable and there are no adverse

conditions, the embryoa hatch in less than twenty-four hours, lChe aeriation

of the faeces which is required for the development of the larvae, is affected

in the tropics by the dung-beetles which disturb the h u m excrement, mhing

them with the soi1,

As is known, t h e hatched larvae (250-300 microns x 17 microns), the so-

called rhabditifom larva, posseso an oesophagus with an anterior thick portion

connected by a needle-like region wi th a pobrterios bulb, a character which

distinguishes them from "filariform" larvae which have a long cylindrical

oesophagus typically without a terminal bulb: the so-called f i la r i form lama.

After about three days of feeding and growth, the lama sheds i t s cbticula,

then grows up t o a m a x i m of 0.5 t o 0.6 m, i n length with a corresponding

increase in diameter, Usually between t h e f i f t h and eighth day the mouth

becomes closed, t he oesophagus elongates and t h o larvae now become transformed

into the non-feeding filariforrn t ypo ( t h i r d larval stage) . The old c u t i c u l a . I

may bc shed or may remain for some t h o as a protective covering around t he

yomgworm, This stage is infective for man as soon as it i s freed o f t h e

old cuticuln, but ft may remain viable in the soil up to fifteen weeks, It

m y migrate several inches radially, but seldom burrows below the tap h m s ,

A Wmm&knowledge of the anatomy of the lama of ancylostoma i s essential

f o r thc: study of the epidemiology of t he diaeaso. During investigations

carried out in t h e Province of Egypt, United Arab Republic, ( H a l a w m i : un-

published report) , it 'was essential in tho first place to t r a j n t he technicians

on how to differentiate the hookworm larvae obtained in s o i l culture from the

larvae of s t rona lo ides ,

Stronwloidcs stercoralis is primarily adapted to warn climatest In general, its distribution and development parallel. tho human hookworms but in

certain regions i ts incidence is considembly less than that of tho hookworms

and in other areas i t s incidence is greator, Very f ~ w basic surveys have been

made to establish i t s actual distribution in warm climates. Infection rates

up to twenty per cent of surveyed populations have been reported (Dasling, 1911;

Faust, 1936). In the Province of Egypt, United Arab Republic, the incidence

does not exceed J - 2%. The f ree- l iving larvae of hookworm in all stages are

distinguishable from the r h a b a t i f om larvae of s t r o n ~ l o i d e a by t he long mouth

cavity. The fi larifom lama of strongyloides is distinguished from hookworm

larva by means of thc notch h the caudal e x t ~ e d t y of t h e strongyloides l ama .

Lnrvno bf many strongyloidos of domes$ic animals, e,g., oesophagostomes and

t r i c h o s t r o n ~ l a s , arc distinguishablc by their long, filamenous t a i l s . The

larvae of hookworm arc fur ther d i s t i n ~ i s h e d from stronwloides larvae by the

shorter oesophagus,

3. BIOmGY OF LARVAE

Knowledge of the b i o l o a of the larvae of hookworm explains the mode of

distribution of the disease in the count~ies of the tropics and sub-tropics,

The larvae require fo r development :

(a) suitable s o i l ;

(b)' f avourable temperature ;

( c) oxygen for respiration;

(d) shade for and

( e) moisture,

! he optimum temperature is between 70' and 85'~. (20 - 30'~)

On account of temperature, ancylostomiasis is more prevalent in Upper

E w t than in Lower E g y p t , While in Beheira Province, in the North, we f i n d

t h e incidcncc approximately 12 - 1/43, In t he South, in Souhag, it is on the

average 42$, and in Quena, 30,8$,

Lower temperatures retard, and finally stop the dovalopmcnt of l a m p ;

higher temperatures decrease hatching and increase Inrval mortality, This

may oxplain why in Aswan Province, under thc scorching sun, tho incidence is

no moro than 1.M. When kxposed. t o n hot sun or to oupe'~ficicl1 drying of soi l ,

they retrcat into crevices' in iho u p & r lay&.

'L'hq Larvaa have the ab i l i ty t o migrate vertically rur n rcw inches, or

even two or three feet in loose-texture soil, but do pot migrate laterally t o

aw great extant; Tho larvae are at t ractud by heat ( ~ h a l d ) ' . They arc I .

s t rongly a t t r ac t ed by moderate heat ,and are stimulated t o activity by contact

wi th objects; it is these reactions which cause the,larvne to burrow i n t o the

skin of animals,

m o infective larvae subsist on s$ored food in tho* bodiea, ae they dto

not feed thcmaclvcs , Theruf ore, movement exhausts a great deal of t he f~od,

and the more active t h ~ y are, the soonar the i r food supply is used and t h e

soonar they die, Vertical migration, even through a few hchos, exhauats a

great dc,d of t h e i r stored nourishment, In t h e tropics it was Sound thak,

through thc alternations of sun and shade, of heat and coolness, and also

disturbancas by rain, inaects, etc., which stimulate them t o frequent movemeAL,

t h e i r span of lifu is not nearly ns long as it was thougkt to bo; about 9%

of thc larvae d i e in f i f t a c n to twenty days, and almost Ell1 nro dead ,in Porty-

two days. On the other hand, larvae kept in water in o coil place and left

undietwbed, my l ive for eighteen months or more, h r v a o t h a t hmc had their

rcserve food p e a t l y dcplcted, although still alivo, m y not hcve enough e n e r a . :,

t o penetrate the sk in of a host ,

4 MODE OF INFECTION

The normal mode of infection ia via t h e skin. This important discovew

was made by. Looss in khc School of Nedicfne of Cairo i n 1898, He h b s c l f .

acquired the infection when water containing larvae.from.culture was spil led

on his hands. It i s a l s ~ possible f olr the larvae t o cauao infection when

swallmed withfood o r water, although in nature this must bc of relatively raro

occurronco. The iwvnc, after penetratihg t h e skin reach n lymph or 'a vein

in the s k i n and through t he blood stroam reach the lungs and are carried to

the bronchi, trachea and t h o a t , by mans of the c i l i a r y movomont 09 $he

epithelium. They are either cxpectora-bed or s w d l owed.

Tfie l n h a e bury thornsblves in tho v i l l i of t he inkcstinas until t h e .third ...

m o u l t . They tkan"acquire a mouth capsule and attach themselves to the mcosa,

and undergo a fourth moult, !They become adult warns after a h wcoks ,

A s soon as lalvvae ponctrete i n t o t h e skin i t c h i n g occurs in the Z m r

two t h i r d s of t h o body. " In a patient recordod by Khali l and ~nlah'~', itching

was confined to tho buttocks, becauso ha sat on t h e wet p & d while picnicking

in an island in t he Ni lo , nonr k n d i (Cairo). Secondary infootion a t t he site

of penetration resulted. wrexia of intermittent character, not excocdlng 3 8 ' ~

may occur associated with leucocytosis and eosinophilia, Approximately one

week af ter the infection, diarrhoea of a l lergic or toxic nature may take place,

The migration of t he larvae t o t he lungs gives rise t o cough with sputum, s igns

of generalized bronchitis with coarse rales all over t he chest, Eosinophilia

appears in the sputum, Asthma-like attacks and giddiness occur, According

t o Khalil and ~a lah" , i n one pa t i en t haemaglobin remained constant up t o t he

sixteenth day. After three months a 1% reduction was found and a f t e r seven

months 45%, i .e. the patientR s haernoglobin was reduced by 45% (85% - LO$) in

seven months by an infect ion with 345 worms, In another patient, the haemo-

glabin was reduced to 2G$ after four months, by an infection with 384 worms.

The ret iculocytes rise with the onsat of anaemia. High eosinophilia (75%) was detected by them 3n one pa t ien t on the ninth day, declined with the pro-

duction of anaemia (12% af ter seven months) ,

The clinical picture of ancylostomiasis is well known, However, there

are certain pitfalls i n t h e diagnosis, Due t o fa t ty infiltration of the

l i v e r i n mcylostomiasis, coloration of t he skin in severe oaeos appears pale

yellow, Such condition is sometimes t reated f o r l i ver trouble f o r long periods

of time, paving the way for anaemia t o progress and aggravate the condition,

Anaemia with fever may also occur. A t times th5s fever proves to be due to

enter ic infections, associated with nncylostomiasis. Tropical practitioners

areusually aware of t he suscept ibi l i ty of t he ancylostomlasis pat ien t t o enteric

Infections. However, there are sevcro cases of ancylostomiasis associated

wi th pyrexia which i s of unknown or ig in but subsides on expulsion of the worms

and improvemnt of an~emia,

There are cases which simulate duodenal ulcers or gas t r i c ulcers. Entero-

c o l i t i s associated with diarrhoea wi th mucus and blood in t he s too ls m Y

s t a r t one week af ter infection wi th larvae, and persist .

Oedema in cases of severe ancylostoma anaemia occurs frequently. It

tends t o acquire a generalized character. The condition simulates nephrosis,

An investigation of a local ized epidemic of acute ha~kworm disease was (3 1 carried out i n 1944

In June 1944 a localized epidcmlc of acute hookworm disease was met in

t he v i l l age of Kafr Tahanoub, near Shibeen El Kanater in the Province of Egypt,

United Arab Republic. Thirty-five men were severely attacked and suffered

from alarming symptoms. Four of the men died as a result of the infection,

When t h i s question was investigated it was found tha t hookworm disease was t he

sole cause of t h i s catastrophe. The a f f l i c t ed men had been cal led upon t o

evacuate the septic tank of t h e villagel s mosque in October 1943. They carried

out this work whilo naked and romovod the msscs of faecoa f romthe bottom of

t h o tank, They felt severe i t ch ing d u r i n ~ this performance, which increased

after bathing in tha ncighbouring canal. A t n ight .they suffered usually from

attacks of dyspnoen and genoral ur t icar ia . The severity of dyspnoea was

variable. A t times it was oxtr~rnely oppressive and accompanied by a suffo-

cating s ~ n s a t i o n , prccordic?l pain and sovere cough, and a t othcr times it was

milder in charactor, Tho patients began t o complain of thcsc dyspnoeic

a t tacks 2 - 3 days after exposure to infection. The cough porsis tcd in some

cases f o r 1 - 2 waoks and in two cases was complicated by pneumonia which ended

f a t a l l y , A few pnt iants complained of having had fever on t h e flrst and

second days of working i n the sept ic tank, Five patients described eruptions

occurring on tho first and second days which rocallcd t o t he mind the condi-

t ions known as pound i t c h , Another prominent symptom of which t he majority

of the patients complained was diarrhoea e i t h c r alone or associated with t he

qysentcric manifestations, For fu r the r clinical investigations, eighteen

cases of this group were admitted €0 the hospi ta l of t he Institute of Tropical

Nedicinc i n Cairo and kept under observation and troatrnent for two months,

The main syinp.l;oms and points of i n t e r e s t were as follows:

(a) The gastro-intes t inal symptoms wcre mainly flatulence, fullness in

the stomach, anorexia, heartburn, oppression i n the epigastrium and even

gas t ra lg ia , These symptoms began t o mnifcs t themselves two months after

the occurrence of the infection, Threc cases of this series complnbed of

hunger pains and symptom simulating t he duodenal u lcer syndrome, Onc of

them actually suffcred from an attack of hnemorrhagu during h i s stag i n the

hospi ta l ; the X-ray exmination revealed the prescnce of duodenitis. In

a l l three cases the t e s t rncd revealed hyperacidity md a climbing acid curvc,

(b) Dlarrhoeic and dysenteric slymptoms occurred in f i v c casus, which

t o be free from dysentery bacilli, cntarnoeba histolytica and, schisto-

soma mansonieggs, These symptoms ceaaod comple$ely after expulsion of the

ancylostomcs by carbon tetrachloride.

(c) Symptoms of general weakness such as loss of power, cx~essive

fatigue, lack of concentration and progrcssive pal lor , usually followed the

gastro-intestinal symptoms.

( d) The cardio-vascular gympt oms were palp i ta t ion , tachycardia, dyspnoea

on slight exertion and rarely angina-likc attacks. Fainting and timitus

occurred i n advanced cases, Pcins in t h e Legs t h e knees, nwnbnoss and

tingling i n the extremities, and a t t acks of intermittent claudicatf on f ormod

a group of complaints mcntiion~d by most of the patients. Four cnscs of this

series developed oodem of l ogs , and orie case generflized o o d ~ , including I

thc face,

(e) Pyrexia occurred in three cases. One was due t o typhoid and the

other two cases wcre of unknown origin. Tho subfebrile condition in tho two

cases was possibly related ts the severity of t he anaemia, aa it subsided soon

after it was cured. This is a l s o t he experience in a m b e r of other cases

admitted t o hospital . Possibly this febr i l e condition is due to toxic absorp-

tion from the innumerable minute hookworm ulcers present in t he gut, Thcse

cases are part icular ly l i ab le t o the typhoid poup of favexs which run unually a subfebrile prolonged coursc,

5 . THE AETIOLOGY OF OEDFJ4A IN CASES OF ANGYLOSTOMIASIS

Among the pa t i en t s of ICrzfr Tahanoub there were five cases of oedcm which

were associated with particularly scvcre anaemia ( haemoglobin rcmging be twecn

8% and 15%) . It was also noticed tha t i n o ther cases of sevcrc ancylostoma

cnacmia oedema is of common occurrence. Thcrc appears, however, no correla-

t i o n betweon the degree of anaemia and the oedema, as several cases of severe

anaemia without oedema come u n d ~ r observation. In four patients suffering

from ocdern~l there was clinical ovidence of vitamin B1 deficiency as manifested

by the tenclerness of t he calf msclcs, absence of ankle jerks and numbness

and t i ng l ing of the extremities. There was no evidenco of hypoproteinaemia,

no nephrotic or nephri t ic affection as shown by the norm1 urinary f indings

and kidney function t e s t s , t he low figures of t h e blood cholesterol and the

normal blood pressure. A cardiac olemcnt was also excluded becaus~ tho

oedem did not disappear a f t e r r e s t i n t h e hospital. me average blood

vitamin B1, as referred to above, was 41%. Three of t he four pationts

were given a high protein d i e t and i ~ o n f o r four weeks wi.thout an inp3rovcrnent.

The osdem disappeared completely, however, aftw t he administration of a high,

vitamin HI diet including t rygo l in and y e a s t for two weeks. Nevertheless it

cannot bo claimed tha t all cases of hclminthic oedema are due t o vitamin B 1 dcficiericy bcc~use casts w L t h normal. blood vitamin B valucs have been seen,

1 Investigation of those cascs sharsd tha t thdrc: werc.: othur contributing factors,

( 4) such as hypoproteinaemia m d b i lka rz i a l c i rrhosis . I n 1938, Salah reported

t h a t hypoprotehaemia ma9 account f.or helrninthic oedcma because he found low

figures of plasma protein i n twelve out of twncty-two cases. Most of h i s

cases, however, wore n o t pure ancylostoma anaemia because intestinal schisto-

somiasis was prosont as w e l l , There is no doubt t h a t i n t e s t i n a l b i lha rz i a s i s

associated with hepatosplonomegaly causes marked diminution of plaama proteins.

The value of vitamin B i n t he trcatmcnt of the nu t r i t iona l oedema was 1 (7 1 recorded by Carmalt-Jones i n 1932'5' , and by Schneider i n 1936'6'. McKenzie

1939, reported the improvement of oedoma i n two caaes of ancylostoma anaemia

after the administration of vitamin B 1' The f a c t t h a t vitamin B1 possesses

a d-iuretic effect may explain Go a certain decree its value i n the treatment

of osdema generally,

One patient aged twenty-five years from Bafr Tahanoub,presented . . ., a p ic ture

of severe anaemia w i t h haornoglobin of 8% associated with oedema of legs and

face. He was complaining of giddiness, severe dyspnoea, attacks of f i in t ing

and of severe pains i n the extremities. Both the left and r i g h t side .of t h e

hear t were found dilated and the veins of the neck engorged, The calf musclos

were extremely tender, the ankle and knee jerks were l o s t , and there was evi-

dence of impairment of sensation t o l i g h t t ~ u c h . Tkc pa t ien t presented a

picture closely simulating beriberi. Similar cases have 'already been des-

cribed by Chandler in the Dutch East Indies (8)

6, THE QUE3T10N OF VITAMIN DEFICIENCY

I n attenpting to ansrh;r this question, several cases for vftamln A and C

deficiencies were ipvestigated, 300 mgm of v i t a f i n C used t o be given as a

t e s t dose a t 6 a,m, The urine was col lected between 7 a.m. and 1 p,m,, and

t h e amount of vitamin C estimated. In n o m l persons, the vitamin C excro-

tion in We six-hour period is 5 mgm F! . It has bdon estimated i n four-

teen cases of t he Tahanoub s ~ r i e a and found def in i te evidence of deficiency

in nine cases, Ths average f i e r e waa found t o be 1.5 mgm $ , This def i-

ciency m y partly be due to demlnished absorption- because of the associated

gas t roanter i t i s . It has long bcen known t h a t pa t ien ts suffering from gastro-

intostha1 diaoasos excrete sub-normal amounts of vitamin c(lO). Several

authors have reported t he value of adding vitamin C t o i ron therapy i n the

troatrncnt of nutritional nnaemia(l'! As regards vitalrbn A, G a l Nor El

has' investigated t h i s question cxtensivuly m d hna found an average

f f gure of 0.02 mgm % of vitamin A i n the blo6d. The norm1 average i s

Q ,055 m %. 7 . HAEMATOLOGICAL INVESTIGATIONS

During t h e same epidemic t hc usual haematological exavrjnations

were carried out. The bone marrow puncture was performed on most cases of

the It oxhibitod n picture of hypochromic normoblastic eosino-

p k i l i c anaemia, ' Two cases only showed hypoplaatic bone-marrow, The

response of the anaemia to thc iron administration was rather slow ih t h e ' I . I

cases accompanied by oedema, i n k s t i n a l b l ad ing , or winaPy infection, I n

h e a q infections t he eosinophilic response was vary poor and there was a

delayed r i s e after a prolonged course of Iron. The anaemia was found more

or less r e l a t e d t o the nu t r i t i ona l state ra ther than t o t h e intensi ty of

infection, The response t o iron was more rapid in the well-fed individuals.

than in t he poorly, fed,

E N / ~ I c ~ A / T ~ c ~ ,Uiac ,/2 page 11

Such insects as dung-beetles m4x faeces wi th the so i l , thus acting as spreaders

of eggs and means fo r inducing favourable conditions for'larval cultures.

Cockroaches on the other hand d e s t r q mast of the eggs in their gizzards.

According to Chandler they keep down hookworm disease i n Indian mines,

SusceptibUity t o kookwomvariaa according t o race and sex, The white

race i s the moat susceptible, so are females and children.

Occupations which expose individuals are agr icu l tu re and mining.

However, the disease spreads i n rural d i s t r i c t s .. On account of t h e type of

s o i l and other favourable f a c t o ~ s , crops such as coffee, tea, sugar, cocoa

and bananas are conducive t o infect ion. Cotton a d grain cul t ivat ions are

mch less dangerous in drier soil; and cotton soil is unfavourable fox

development of the larvae. Rice and jute are not associated with heavy

hookworm infec t ion , h lbe rq+ra i s ing districts are ideal.

Defecation on the soi3, i s the most important factor for disseminating

hookworm infect ion. Primitive latrines, where f e e t are kept away f rom

pol lut ion lessen greatly the chances of infestation. Shoe waarbg is a

preventive measure of great significance. Even simple sandals or clogs, as

worn i n parts of t h e Middle East and India, are effective,

It i s in t e r e s t i ng t o mention t h a t although not t o be recommended from

the public health point of view, expectoration habits especially as a result

of chewing (betel-nut chewers or tobacco chewf ng) lessens appreciably t he

infection due t o s p i t t i n g out phlegm collecting i n t he mouth, and thus

ge t t ing rid of many of t h e hookworms which invade the b o a ,

10, TW RELATION OF WTAITION TO P ~ S ~ T I S P l

There i s adequate evidence t h a t poor die t retards o r stops t he develop-

ment of resistance t o infectious diseases, and t h a t resistance already present

is quickly l o s t , The main'responsible component i n t he d ie t f o r resistance

i s protein, especially the 'globulin f rac t ion . h e l o s s of res is tance i s

quickly res tored by return t o a good set, Whether t h i s can occur without

fresh contact with an antigen has not been clearly demonstrated, bu t it seems

l i k e l y that when new globulin begins to form i n a depleted animal, t he

s t ruc tura l pattern which makes globulin function as an antibody will s t i l l

be operative,

The e f fec t of diet can easily be demonstrated on intestinal helrrcinthic

infect ion, An adequate diet leads t o the development of immunity, Only

an overwhelming in fec t ion can overcome an animal on adequate d i e t before

immunity has sufficient time t o develop,

EM/RCPACI~C~, D i s c ./2 page 12

In animals or h w n beings on a deficient die t , these i m o l o g i c a l

e f f ec t s develop more slowly, or may fail entirely. One of t he most striking

demonstrations of t h i s w a s the work of Foster and Cort 'I3' on hookworm infeo-

tions i n dogs. After producing a highly r e s i s t an t s ta te over a period of a

number of months, they put the dogs on a poor d i e t t h a t was inadequate in

protein, vitmjns, and minerals and broke t h e i r resistance w i t h i n a few weeks,

After several months on t h i s diet, the dogs were given an infect ion t h a t pro-

duced a very high egg output. When they were then returned t o a good diet ,

the egg production dropped almost to ze ro within six weeks and maw worms were

p a s s e d i n the faeces - a r e a l die tary cure. Not only did the dogs lose t h e i r

resistance t o superinfection when on a poor diet , but a few remaining o ld

worms, which had not produced eggs fo r weeks, began egg production again.

These results have subsequently baen confirmed by other workers.

Epidemiological evidence indicates t h a t repeated small or moderate doses

of hookworm larvae t o human beings induce a s t a t e of high, though seldom i f

ever conrplete res is tance t o heavy infec t ion if the nutrition is good, If, howover, nut r i t ion is pbor, n chronic stake of f a i r l y heavy infec t ion may

pe r s i s t , kept up by constant re-infections. It is probable that t h e general

level of hookworm infect ion i n a locality is dependent as much on the nutr i -

t i o n a l s t a t e as it is on the degree of exposure to infection, Under conditions

of poor nutr i t ion, it i s poss ible t ha t it would take a relatively stronger

antigenic stimulus to induce the body t o apportion some of its inadequate

supply of protein t o the production of nmr modified gamma globulin t o fluzction

as ant ibodies ,

I n the treatment of polycythaemia, ancylost oma in fec t ion was t r i c d

fo r the f i rs t time in 1940 ( 14) on a womn. I n Emt, this type of treatment

was tried (15) on one male pa t ien t suffer ing from the same disease and succeeded

in lowering the haemoglobin to 60%. An i n t e r e s t i ng observation was made on the

s a w pn-ticn+b by Ilaiawnni .in 1956, S t was found that the pni ;knt b c c a a ~ xesi.8 ban

t o the infect ion on the administration of repeated doses t o the extent t h a t

the s too l s contained vew few eggs or none a t a l l . This t ook place while the

pa t i en t was on full diet , containing a fair amount of mat, When* t h e patient,

however, was deprived of meat-eating and kept as fa r as possible on protein

deficient die t f o r a few weeks, in fec t ion with larvae (usually t h e dose 200

larvae), succeeded in producing actult worms. The success of infaction

depended t o a great extent on the ras is tance of the host which in its turn

depended an the t y p e of d i e t .

The production of cantibodies i s evidently dependant on the s t a te of nutrl-

t i o n of the individual. If t h c d ie t is lacking in protein, immunity is pro-

duced only when a cer ta in level of worm-infection is reached. Therofore, the

i ~ o l o g i c a l response broduces quantita'tive effectiveness, It would be higher

in well-nourished than i n poo~ly-nourished individuals. I n the l a t t e r case

one w d d expect less complete inh i l i t ion of reproduction, leas interference

with- es tabl ish&nk of hew worms, and less prompt expulsion 'of 'old worb ,

The diet ha3 a profound effec t on the infccted individual and the corn-

y It is a well-known f a c t t h a t annefiia is the most important pathological

effect of ancylostomiasia, 1% is t he result of the rnechanicd loss caused by

the continuous sucking of blood by the worms, which is similar in i t s effects

towithdrawal of blood by means of a syr inge from experhentax animals. The

blood sucked by the worms is voided without i t s haemoglobin being absorbed by

the intestfnes.

If no adequate diet is obtainable this process leads to severe anaemia,

On the other hand, well-nourished ancylostorna pat ients show a marked hyper-

trophy of the blood-forming t issues , and g striking increase in reticulocytes . Obviously, however, for this response to be effective, there must be an ade-

quate supply of materials needed f o r synthesis of haemoglobin, including both

i ron and protein. 'The deficiency of protein i n the diet renders iron alone

of VET l i t t l e effectiveness, '

This f a c t bears p e a t importance in t he opi-

demiolom of t he disease. Chronic Rookworn disease w i t h serious effects

becomes prevalenk in c o m i t i e s su f f e r i ng from i n a d e q u q of diet* This was

experhental ly demonstrated i n dogs kept on a generally poor d i e t , deficient

i n minerals and vitamins and low in protein; in thusc animals administration

of iron caused l i t t l e , i f aqy, heightened rcsistanco t o heavy hookworm infoc-

tions. In addition t o pro te in and vitamins, f o l i c acid, when combined with \

iron therapy, was found very usefbl i n the treatment of hookworm paomla*

Since poor diet has t h i s double effect of preventing replacement of lost

blood, and of blocking the development of immunity, it is not surprising tha t

a severe hookworm burden i n a community is almbst always associatcd'with poor

economic conditions, f o ~ a good diet, and particularly the amount of protein

in it, a lkos t always closely para l le ls the economic l e v e l .

An Tnteresting observation on the r e l a t i o n o f d i e t t o hookworm disease

i s t h a t i n Egyp t pellagra is s ix times more common in hookworm patients than

in tho general population (16) * '

According t o investigations carried by Halawani, no absolute correlation

between the incidence of ancy1osLomiasi.s and t rue pellagra was obsomrad in t h e

averages of incidence over the period 1938 t o l9$O..

EN/Rc~A/T~c~ .Disc .I2 page 14

Following is a table on the incidence of pellagra and ancylostomiasis i n

the d i o t r i c t s of t h e Province of Egypt , United Arab Republic, per thousand of

population :

Districts

Caixo Alexandria Suez D a n i e t t ~ Behera Garbieh Menouf ieh Qralymb i a Dakahlia Sharkia Giza Bani Suef Fayourn Minia Assiut S ohag Quem Aswan

Ancylostomiasis

-- -- - -

The incidence of pellagra fo l l ows mainly t he consumption of maize (corn) , Its incidence is lowest in c i t i es where wheat is used more frequently for

bread - and highest in the rural areas of tho Delta where miee f l o u r is used

i n larger proportions than wheat. I n Upper Egypt , where millet i s eaten,

pel lagra is of l o w Incidence as s h o w n i n t h e above t ab le . During the years

of the w a r the incidence of pellagra in Egyp t was a t its highest peak,

especially during 1942 when, a t a cer ta in time, there was a great shortage

o f wheat.

Tha incidence of ancglost o~niasis follows the epidemiological factors

which have nlreaqy been montioned. In the northern d i s t r i c t s , where t he

temperature i s lower than in Upper E g y p t , t h e incidence of hookworm disease

is also lower. However, t he provinces such aa t ho Qalyubia and Mcnoufia,

whore thcre is morc poverty, due t o overpopufatiion, than in t h e other pro-

vinces of the north, and whcre mise is more consumed, ancylostomiclsis

appears t o be more in prevalence. The incidence of ancylostomiasis in-

creases an wa go from nor th t o t h e south, being h ighes t in Uppcr Eg;ypt due

t o t he favourable conditions of the soil and of temperature. Aswan scorns

t o be an exc~pt fon , due t o the high degree of desiccation prevai l ing d u r b g

tho groater par t of the year. (~alawani, i n unpublished report) . Reverting t o the effect of diet, thcre i s also the poss ib i l i ty , although

not defini tely established, t h a t coarse fibres, seeds and husks may have a

mechanically i r r i t a t i n g offect on the worms, and t h a t such things as spices,

ga r l i c and onions may also be i r r i t a t i n g tothsm, Possibly, persistent use

of suck substances as i n the curries of India and tho chili of Mcxiao may have

an effect, Ancylostoma species occur primcarilp in carnivorous or omnivorous

hosts whereas necator occurs o n l y i n herbivorous and omnivorous animals.

Dict may also influence the hookworm burden of a c o m i t y by i ts effect

on development of larvae i n the stools. Little defini te information iu

available concerning the effects of various dietary componants in t h i s respect.

Loose, experimenting with his own a n c y l o a t o ~ duodenale infoction obtained poor

larval development in h i s s too ls a f t e r fourteen days on a vege-table diet, even

when t h e faeces wore mixed wi th charcoal (17 .I

(18 1 Immunity in helminth infections wae demonstrated by Stoll , , expcri-

menting with nematode worm haemonchus contortus which inhabits t h e fourth

stomach of r u d m n t s , and sucks t he blood. In his expcrhent, one la& was

infected with for ty-f ive larvae and after s o i l i n g the pasturo a second lamb

became infected also , There was a p e r i o d of accelerating egg output, It

is evidsnt t h a t during this period thero was opportunity fW constantly bigger

re infect ions but, i n sp i te of thie, reinfections ceased abruptly. Not only 'were

no more worms acquired, but those alrea4v present were f o r the m ~ s t p a r t

expelled, cons t i tu t ing what S t o l l called a se l f cure" ,

The evidence from experiments seems t o indicate that the h n i t y is due

t o a reaction against metabolic products, possibly enzymes concerned i n t h e

utilization of food, and t h a t t h e resulting phenomena - stunting of growth,

failure of development t o maturity and inhibition of reproduction are due to

' '19' there seoms to be a interference with nut r i t ion . According t o Chandler

str iking similarity t o t he act ion of ablastin i n trypanosorno infections, and

t o the failure of development of Cor@lobia larvae i n previously inf ccted

skin, although in this case there is no lethal effect on the worms, as was

demonstrated by n o d growth and reproduction of inhibited fourth- stage

larvae transferred from h u n e t o non- imne hosts (20 1

Blood-sucking worms, l i k e Baemonchus and hookworms require much longer

t o stimulato an effective immunity than do worms l i k e Nippostrongylus,

St ronq lo ides and Trichinella, which feed on mucosal calls - a matter of

months as compared with weeks.

In cascs of Oesophagastomum, repeated infections result i n the production

of immunization which manifests i t s e l f by t h e f o r m t i o n of nodulesl' a ~ o u n d the

worms after burrowing into the submucosc,

'EM)RC~A/T,CC~ Disc ./2 page 16

In cmsc of in fec t ions w i t h blood-sucking worms, t o which m i t y devolops

rclativcl.y slowly, and in which the h o s t my suffer severely from loso of blood, it is very important; that t he rate of acquisition of parasite be slow, other-

w i s e t h e h o s t may be ovcrwhelmcd by -the parasites before any r~sistance can

develop, and cvcn in t he cLwly stages of h u n i z a t i o n too l a r g ~ a dose of

worms may prove f a t a l , o r SO drain the pro te in reserves of t ho h o s t t h a t a

rea l ly effective imnnulity cannot develop. T h i s is part icular ly likely t o

happen when the d i e t i s suboptimal,

12. EFFECT OF' ANCYLOSTOMIASIS ON THE OUTPUT OF LABOUR

EKporience has shown t h a t the work-output of people suffer ing f r o m hook-

worm disease is 33% less than the work y i e l d of unaffected persons. It has

been proved t h a t t he production i n the Buxite mines i n Br i t i sh Guiana increased

by 35% subsequent to r idding the labourers of the i r hookworn infection ( 21)

In 1923 work was s t a r t e d i n these mines. A t t h a t time 3.6 -tons of o re

was excava1;ed by each Labourer in A ten-hour working day. This amount in-

creased u n t i l it reached f ive tons. Two nionths subsequent t o Lreatmont of

hoakwokm disease the output rosa to S,l, while four months l a t e r it reachad

6.76 tone i n t h e tun-hour working day.

This example among several shows t h a t the output has increased at first

s i g h t duc t o t r a i n ing as i s usually t h o case in new industries, but it r ~ m i n e d

s ta t ionary nl; f ive tons until thc workmen were t r o n t e d and got r id of t h c i r

hookworms. Subsequent t o this t h c i r haumoclobin s t a r t e d t o r ise, usually by

one p e r c ~ n t everyday and possibly more if t h u i r nu t r i t i on was adequate. A s

t h c i r hnemoglobin and strength was gradually res tored t o .normal, t h e i r output

of work rose according2;y. At this stage thc seriousness of ancylostomiasis

i n mines must be emphasized and invost ignt ions 013 t h i s important problem be

carried out in tho Region.

The e f f e c t s of ancylostomiasis on t h e physique is w e l l known. It s tun ts

the growth and also a f f ec t s the degreo of in te l l igence , Affected children

are two ycars and a half less $ n t e l l i g u n t t h a n normal childrcn. T h i s means

t h a t an affected cht2d eleven years o f ago i s equal i n inte l l igence t o a

child of c igh t ycars, A s a r e s u l t of this intellectual deficiency the

individual loses the i n i t i a t i v e t o work and fox this reason s ~ c k s the pro-

t e c t i on o f his family. Moreover h i s character degenerates and he tends t b

I I I I Tdrl, EFFECTS OF sMITAi2Y 11@20VEW,IITS ON THE P1DVALHCE OF ANCYLOSTO1:a.AAIS

Environmental sani tat ion i s the nos t ef fcctivc: and l a s t ing rneasuro against tho spread of ancylostominsin . I n campaigns n~ainut hookworm disonsu c onductod

by t he Rockefeller Foundation and other agencies i n South America and the West

Indies, san i ta t ion of a d i s t r i c t .preceded the mass-treatment of t he population.

The campaign i s car r ied out as follows:

(1) The hookworm treatment and tlze sanf ia t ion un i t s take charge of treat-

ment asld control work i n the d i f fe ren t in fes ted areas, Each u n i t consis ts of

a medical doctor , two microscopists, about e igh t field off icers and three

off ice clerks,

(2) The f i e l d officers are sent a few weeks ahead of t h e u n i t of canpaign

treatment to carry out pioneering work, such as propaganda and health education

work. Each f i e l d o f f i ce r i s assigned t o a district where he makes a houw -to house

census and a t the same time inspects the la t r ines and classifies them,

(3) Before starting any treatment, san i ta t ion measures should be estab-

lished i n the district s h months in advance. ,The f i e ld of f icers then collect

specimens of faeces f-rom the inhabitants of the d i s t r i c t and take them to be

examined i n the laboratory of t h e unit.

(4) A l l the infested persons are then asked t o meet the medical director

of the u n i t a t a convenient place, such as a school, a public building o r a

market, t o undergo a physical examination. According t o t h i s examination the

doctor prescribes the dose of the drugs required f o r each individual.

5 ) The f ie ld off icers o r nurses receive the amount of drugs required

and administer them t o the pa t i en t s i n their homes, or in a school, O i l of

chenopod-ium and thy-mol were t he dmgs used f o r t h e canrpaign treatment of hook-

worm disease i n Jamaica (in 1934). Seven days a f t e r the treatment, t h e s too ls

were examined by Willyt s Floatat ion method, and those found negative were given

c e r t i f i c a t e s t o this ef fec t , which were valid for three months, By means of

heal th education, people became interested i n W i n g t h e i r homes sanitary and

building t h e i r own l a t r ines . Those who were p a r t i a l l y o r t o t a l l y unable t o

f i nd the mans fo r building t h e i r own l a t r i n e s were helped f inancial ly by the

l o c a l boards of health, which are the heal th committees of the Provincial

Boards. These boards can levy certain taxes t o support san i ta t ion and other

matters of public i n t e r e s t , The average cure ate reported a f t e r treatment

with o i l of chenopodium ( two doses of 20 minims) . The second dose given after

a two-hour interval was sixty per cent, and eighty per cen t after t h e second

treatment. The outcome of t h e hookworm campaign i n Jamaica has shown that

the disease can be controlled by treatment and san i ta t ion ,

Diseases such as those of tho en te r i c group and @sentries have decreased

in prevalence due t o sanitation of t m s and rural d i s t r i c t s . It was a l so

fbund t h a t af-ter such a campaign, the capacity of labourers f o r work was ( 22) considerably increased .

E E I I / X C ~ A / T ~ C ~ .Disc, /2 page 16

Yhe effect of san i ta t ion on the incidence of pnrns i t i c diseases was demon-

strated in an Elmt i an v i l l a y o called Bahteem. In 1931, the houses of that

vil lage were provided uf t,h bore-hole 1atrj.nes after a genoral sumey of para-

s i t i c infestation mong the inhabitanbs had been accomplished. In 1936 t h e

same examfnation was carriod out and the following results were reported by

Halczwani ( 2 3 ) ,

Effect of t h e Construction of La t r ines on t h e Percentages of Inci- dence of P a ~ a s i t e s

Name of Parc.site Before Sani ta t ion After Sanitation January 1931 January 1939

% %

Ascaris 70 9 - --

A s reported by deir a t a1!24), ihe In te rna t iona l Health Board of the

liocke'fellcr Foundation, in cooperation with the E y p t i a n Ministry of Public

Health, in conncxion w i t h a study o f hca l th condit ions in t h e Egyptian vi l lages

ins ta l led certain sanitary improvements and developed cer ta in hea l t h services

in some' villages. The v i l l n q e of S id ib is in which a he=KLth centre was estab-

l ished in 1948, had bored hole l a t r ines w i t h cement platforms, installed in

about ninety pcr cent of the housos . ' dc l l s providing unpolluted water were

mde available to all t h e inhalbitnnts, a refuse disposal service was o e t up,

2nd it was giwcn certain o the r san i tnrg or honl-th scrvicen. Othcr nearby

v i l l n g c s wcrc a l s o provided w i t h some of these hrpsovements, but Aghour c l

i'iurba four kj,n_ometres dist::nt, was l e f t as it was f o r control purposes.

The improvements in Sid ib is werc completed in 1950, In order to

determine whether any cffcc t of these imrovemcn-bs could bc observed a f t e r

two pears, s sumcg o f hclminti and prot,oxoan infection in oach v i l l agc was

made in Novembcr <and Deccmbcr 1952 (25' a bout 250 f r c s h s t o o l spacimcns

warc collected from cnch v i l l a g e w i t h about twenty-five f rom each scx in each

of t h c Pollowing age-groups: 1 - 4, 5 - 9 , 10 - 19, 20 - 39 , 40 2nd above.

This work w a s carried o u t In the 1nstitv.te of 1i~acnrch f o r Tropics1 ~ h d i c i n e ,

undcr t h e supervision of tho late Profoasor Asa C, Chandlcr , Two samples

of each specimen wcre col lacted and one only was used for examinntion for

hclrninth eggs, each specimen buing examined by floatation, ancl 1/200 of a

gram being egg-counted by the S t o l l and Hansheer I! #ma11 dropkt mcthod.

In 1950, H e i r ct a2.'26' found a sixty-two pcr ocnt inoidcncc of ascaris

infcction in Sindibis ; no survey was made i n Aghour el Kurba . Chandler s

E M / R c ~ A / T ~ ~ ~ ,Disc ,/2 page 19

figure of fifdcy per cent in 1952 i s , as he belLeved, indicative of a t m c

f a l l i n g off i n the intervening time, and t h i s was due primarily t o the

i n s t a l l a t i o n of the l a t r i n e s in the homes and t h e i r fairly extensive use,

It i s t rue that a l a rge number of t he ascaris infect ions detected i n Sindibis

during the 1948-1950 survey were treated a t t he health cen%re, but Otto and

Gort '27' have given convincing evidence tha t in t h e absence of sanitary improve-

ments a return t o the pre- t reatment~level of infection map be expected after a

period of five t o e igh t months,

Ancylostom incidence r e l a t i ve t o t h e proportions of t he population i n the

various age-groups was seven per oent for females '2nd twelve per cent for males

i n Sindibis, and seventeen f o r females and forty-two percent fo r males in

Aghour e l Kurba, but i n both vi l lages the average egg-count per gram was

extremely low, O n l y six individuals, l e ss than one per cent of t he people

examined, had egg-counts of over 1000 per gram on t he basis of mushy s too l s , (28) According t o t h e calculat ion of Augustine e t al. thc averages of ChandZer

represent a burden of about two pairs of hookworm per person. About half of

the positive cases were detected only by the salt floatation method; In

spi te theref ore of t he relative1.v high incidence f o r a vil lage in Lower Ergpt , which was found i n Aghour 01 Kurba, the infect ions are so light that even

with t he rather poor nutritional s t a tu s in these villages, ancylostomiasis

may bc considered of negl igible public heal th importance. The age and sex

d is t r ibu t ion found by Chandler suggested to him that n f a i r number of Very

light hookworm infections are acquired in t he villages themselves, and the

heavier ones oriLg in the field. Tkc! much Lqrger number of l i g h t in fec t ions

found 51 Aghour el Kurba, as compared wi6h Sindibis, seems t o indicate less

expoaure t o hookworm in the sanitated than i n the unsanitatod v i l l age (29 )

It i s not intended to dwell here on the treatment of hookworm disease

i n de t a i l , but reference can be made to the evolution of drug therapy,

Thyno1 was introduced i n 1880, but was replaced by o i l of chenopodium, and

this l a t t e r drug was again replaced by ca-bon te t rachlor ide by Hall in 1923,

and thus the extinguisher of fire became the extinghisher of ancylostondasis , However, its t ox i c i ty t o the l ive r i n cases of calcium deficiency made i t s

general use dangerous , Since 192 5 , t e trachloroe thylcn~, . which is highly

efficient and of very low toxicity, has largely replaced carbon tetrachloride,

A dose of three t o f o u r cc, removes seventy-five t o ninety per cent of t h e

hookworms, and completely cures about two-thfrds of t h e patients, A a p e t i -

t i on of t he treatment may be ne~ded aftcr an i n t e rva l of one woek,

E M / ~ C ~ A / T ~ C ~ .Disc m/2 page 20

Hexylresorcinol crystoida i n hard ge la t in capsules containing 0-2 grams,

is somewhat less effective but very useful during pregnancy and illness, because

of i t s inon-toxicity . It was employed in pat ients with low haemoglobin, who

were not responding to i ron therapy on account of the large munber of worms and

depletion of protein. The administrat ion of crystoids reduced t h e number of

worms in patients in whom other drugs were cont~a indica ted , thus helping them

recover, respond to iron therapy and f o l i c acid and be amenable t o treatment wi th

more offactiv~ c h g s to oxpel thc mi-n%indcr of -Ll>c rrmms*(Ilaln~~ani, unpublished repor t ) .

Another drug that has shown promise i n dogs i s N-butyl chloride, which is

effective against ascaris and whip worms also, but has not yet come i n t o general

use f o r human infections.

This kind of attack on hookworm was introduced by Darling and tniended

to t r e a t a whole populat ionwhose incidence is v e r y high, Campaign treatment

of the infected individuals is undertaken after establishing the diagnosis by

microscopy. The diagnosis in itself is not d i f f i cu l t , but obtaining specimens

from t h e whole population i n cer tain primitive communities usually present

great difficulties. If all the members of a community are treated at once,

preferably during a dry or cold season, when rapid reinfection from an alreaqy

badly in fes ted soil cannot occur, t he reduction in infection is s t r ik ing and

durable . In F i j i , mass treatment was accomplished in two years (1922 land 1923) .

The ent i re population was treated, In 1935, L a h e r t (30' reported that clini-

cal hookworm disease was st i l l rare in Fiji; t he p e ~ p l e were heal thier ,

happier, and more prosperous, and hookworm had been eliminated as an important

economic factor .

For t h e control of hookworm, f i v e weapons are available:

(1) Treatment

(2) Dietary slpplements

(3) Protection of the feet

(4) Disinfection of faeces or s o i l

5 ) Prevention o f soil pol lu t ion

Mass treatment gives immediate re l i e f by slowing up t he r a te of reinfection

but, unless it is supported by o t h e r measures, e a p e c i d l y by prevention of s o i l

pol lut ion which is inadequate, since it has not get been and probably w i l l

never be found feasible to eliminate all the wo~ms, reinfection w i l l ,inevitably

follow,

EM/Hc~A/T~c~ ,Disc ,/2 page 21

Cruz and De Me110 'jl' suggested t he wholesale addit ion of i r on t o food, as

a preventive measure, jus t as iodine i s adcled t o water to prevent go i t r e , In Brazil they suggested ferrous sulphate added to casava meal, or iron ammonium

citrate t o beans. For people with hookworm anaemia they recomerdone gram per

day until the haemoglobin is normal, then 0.5 gram for eighty days, and then

0.25 gram fo r eighty more days, Such a programme would not only eliminate

synqtoms but would also permit development of immunity, reduce t h e nuniber of

eggs reaching the s o i l , and eventually lead t o a much lower hookworm burden

even wi thout improvement in sanitary conditions,

16. PK3VALENCE OF ANCYLOSTOMIASIS IN T I E COUNTIIIES OF TIE EASTERN Mi3DITE1WNEAN RF,GION

The Northern Region (Mosul, Erbil, Sulaimnyia and Kirkuk)

This area is considered one of the less endemic areasfbr hookworm disease.

This i s a t t r ibuted to t he low temperature during seven months of the year, 0 ranging between 1 and 10'~. The s o i l in t h a t region is of t he clay.typej

river irrfgati0n.i~ not available except in Mosul, and t h e heavy rains which

pour dawn there during certain seasons play another important r o l e i n reducing

the chance of s o i l in fec t ion , The people wear shoes anduse la t rhes , due to

the ,cold dima-te in %hat area.

The Central and Southern Regions

These include the provinces of Baghdad, Baquba, Ilamadi, Kut, Karbala and

D-jwaniya. The area of t he southern region includes the Liwas: Nasiriyah,

Amara and Basra.

These two regions are t he most favourable places for the development and

propagation of ancylostomiasis.

The .temperature i n t he central region ranges from 5' t o ,L~'c. , In the .

southern region it is yo and 45'~. There t he temperature, the moisture, t h e

s o i l factors, the irrigation, cul t iva t ion of palm trees, and t h e shade are

most favourable f o r the spread o f kookwomn disease. The conditions of

insanitary l iv ing in mud houses ( t h e so-called sarifas), t he promiscuous de-

fecation, the use of human excrement ( i n which larvae l ive 5-15 weeks) before

w i n g completely, for manuring gardens, t he habit of not wearing shoes, f a v m

the spread of mcylostomiasis in these areas, No surveys of the groups of

population are available, but the repor t which has been made available t o the

Eastern k d i t e r r a n e a n Regional Office by the Ministry of Health of Iraq has

quoted the incidence of cases as registered in t h e hosp i ta l and the dispensaries

of the various Liwas. The r e p o ~ t s prepared by Dr, Gamal Nor El Din '12' and

E F ! / ~ I C ~ A / T ~ C ~ . Disc ,/2 page 22

D r . Farjo should be road i n t h e i r entirety, but as an illustration we give here the incidence in 1957 :

Northern Hcgion Central Region Southern Regiori

Mosul 46 Baghdad 1962 Basra 2450 Kirkuk 3 Kut 1152 Nasiriyah 374 Erb il - Kerbala 3343 Amara 614 Sulaimaniya - HiUa 2636

ilamadi 1415 Baquba 462 Diwnniya 3512

Incidence in percentages of m c ~ r l o s t o m i a s i s among school children in

different, Liwas of Iraq, according t o Gama.1 Nor El Din (1954) are as follows:

Mosul 1 Baghdad 3.8 Basra - 38

Kirkuk Kut 2 9 Muntafik 12.5 Exbil 1.5 Kerbala 25.8 Amara 23 Sulaimaniya - Htlla 13.5

D i l s m 14 a 9 Uiwaniya 21 ,5

It i s believed t h a t hookworm disease i s prevalent i n several provinces of

West Pakistan. k i n g 1926 t o 1927, Chandler investigated t h e incidence and

in t ens i t y of the disease on a l a r g e scale in different parts of India. He

found that the pe~centage of infection in Lahore was 16%. In 1953, Dr, Shah

carr ied out extensive investigations i n ~akistan, i n t he v i l l ages of

Shakmgan Thnseol and f ive v i l l ages in Lahore area. He found the incidence

to be 21.6% and 12-92% in t h e two distrj-cts respectively. The in t ens i ty of

infection f o r Shakargar was found t o be 340,3 eggs/gram faeces, whi le t h a t f o r

Lahore was 400.5. The papcr of Dr, Shah comprises i n f o y m t i o n of real

interest, and therefore should be read as n whole,

SWAN - Ancglosto~niasis spreads in t he extreme south of t h c Sudan, mainly in

Equatoria and Bahr E l Ghazal Province where t h o r a i n f a l l is high ,and ty-pical

tropical climatic conditions exist .

Thc t o t a l annual average number of cases, discovered i n routine examina-

t ions in these infectcd areas, is about seven thousand, The time during

which these cases were discovered has not been s ta ted. There i s no swcfal

campaign, ncvcrtheless t h e diseasc is discovcred during routine examination

i n the hosp i ta l s and the pa t ien ts arc t reated w i t h thgrnol.

a E M / : & c ~ A / T ~ c ~ .Disc ,/2 page 24

not provided, u n t i l recently, with an adequate number of treatment uni t s . In

Minia province, t h e staff of the mass treatment and control sect ion of endemic

diseases, carried out a survey in 1958. Tho incidence ranged between 4,h$ 'and 39.7%. me increase was progrcssivc f rom north t o south, due t o the

increasing tcmperature, cul t ivat ion o f sugar- cane and the s ta te of nu t r i t i on

of the population, 'These two surveys i n the two provinces of Sharkia and

Ninia, are very useful and have shown t h e benef i t of es t~ lb l i sh ing t he u n i t s of

the ltrnaso treatment and control of endewf c c l i s e a ~ c s ' ~ . IIowcver, more records

on the in t ens i ty of infection and the brunt of the disease suffered by the

population arc s t i l l required. It i s hopedtha t i n the fhture more data

weighing t he various aspects of nncylostomiaais w i l l be collected i n order t o

obtain a t rue evaluation of the problem i n thc Province o f Egyp t ,

Province of Syria

Ancylostorniasis i s k n m t o be endemic i n ileir ez Zor Governorate in t h e

v i l lages on both banks oP the Euphrates. The incidence v a r i ~ s from three to

one hundred per cent, t he majority being a b m SO$. I n addition, Magatf (32 1 found another focus of aricylostomiasis in t he Hama Governorate, This disease

was detected i n f o u r out of t he e i g h t vi l lages investigated, a l l on the banks

of t he r iver Assi, The incidence o f in fec t ion i n persons investigated was

7%, lo$, 42% and 67% i n Tezin, Eshiha, Kazo and Eddaharia respectively, This

invest igat ion was carr ied out, planned and sponsored by the World Health (33 1 Organization, Regional Off ice f o r tho Eastern Mediterranean in October 1955 .

Ancyloston~aais i n $he Province of Syria i s s t i l l a local ized disease and

should bc combatted before it sprcads further.

3tLar CounLsies of t h e i l e ~ i o n

lieports received f rm the Govornmen-Zs of Aden, Cyprus, Jordan and Frcnc'r~

Somaliland s t a te t h a t ancylostomiasis does not e x i s t as an endemic disease,

LIST OF WFWENCES

Reference t o documents f o r Technical Discussj.ons - Sub-Committee A Regional Cormnittee far t he Eastern Mediterranean.- Ninth Session:

- EN/Rc~A/T~c~ ,Disc ./3 . Inf o m t i o n received from Goverment s . E M / L ~ C ~ A / T ~ C ~ . ~ i s c , / b . Epidemiology of Ancylost omiasis in Egypt, Dr. A , Abdallah,

EM/RCPA/T~C~ ,Disc ./5. Ancylostomiasis , - Clinical and HaemtologicaJ, Aspects. Professor M, Salah,

E M / R C ~ A / T ~ C h ,Disc 4 6 , The Incidence of Ancylost omiasis in Iraq UP. P.D, Farjo.

@f / id~9~ /~ech . ~ i s c ./7 , A History of the Discovery of the Human Hookworm. Dr. Ismail, S , N i l m y ,

E I U ~ / B C ~ A / T ~ C ~ ,~isc ./8. The Heark in Ancylostomjasis , Dr. Ahmed Badran,

E ~ ~ / R c ~ A / T ~ c ~ .Disc ,/p . S tudiea on Ancplos tomLasis in West Pakistan. Dr. Nazir Akmad.

E I ~ / R C ~ A / T ~ G ~ . ~ i s c ./lo. Iiookworrn Infection Survey of Organized CommuniGies', Dr. Nazir Ahmad and Dr. K-,S, Shah.

E I / P ~ C ~ A / T ~ C ~ . ~ i s c ./11. Investigation of fIookworm Disease in Attoch District. Dr. K,S. Shah.

(2) Khalil and Salah, J , of the E g y p t , Med, Assoc. 1935, p,384.

( 3 ) Balawani st a1 J. of the Empt, Med. Assoc, 1944,

(4) Salah, M, Trans, Roy. Soc . Trop, Med. & Elyg , , 31, 4, pp *43~-436~

( 5 Carmalt-Jones, B r i t i s h Med. J. 1932, p ,324,

( 6 ) Schneider . In Vitarnlns in Medicine by Bickne l l and Prescot t, London, 1942 .

(7 ) McXenzie . Deficiency of Vitamin B in Hookworm Anaemia, Lancet, my 30, 1939.

1

(8) Chandler, A ,G , Hookworm Disease. New Y ork. 1929.

( 9 ) Gonder and Miederberger , In Vitamins in Medicine by Bicknel l and Prescott, London, 1942.

(10) Gothlin, G.F. 1931. Quotedby A l t , ChinnmdFarmer, h e r . J. Med. Science, p.233,

(11) Powel, Quar-terly Journal Medicine . April 1944,

(12) Gaml Nor El Din. Ankylostomiasis Survey in Iraq. GM/ML/~,

(13) Foster andCort. J , Hyg, 16:241, 1932, 3 5 t 3 ~ 2 , 1935.

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'WORLD HEALTH O R G A N I Z A T I O N

REGIONAL OFFICE FOR THE EASTERN MEDITERRANEAN

Ninth Session

Agenda i tem 17

-r

ORGANISATION MON MALE DE LA SANTE

BUREAU R ~ G I O M L DE LA

M~DITERRAN~ E ORIENTALE

J ~ M / R c P A / T ~ c ~ ,iliac ./2/~dd .l 8 Sep tembsr 1959

TECHNICAL DISCU5SIONS - SUB-COWTTU A

ANCY LOS TOMTAS IS

1. C H E M O T I ~

(a) Apcording to Bhaduri and ~enyal'l) a h o u t of sixteen a n c y l o s t d a s i s

casea were cured after the first treatment with cashew-nut she l l oil, and three

after the aeoond. me' drug did nut produce any toxic &mptoms.

( 2) ( b) Treatment of severe ancylos tomiasis w i t h tetrachlorethylene . In the treatment of ancrylostmiasis t h i v i m is adopted by some workers that

the first esoential procedure is the treatment of the anaemia; after the

ri3turn of t h e blood picture to normal the vermifuge m y be given, if it is

thaught neceasm, This principle is satisfactory when there is only slight

anaemia, but ,when there is a e v e s anaemia and a heavy hookworm load it is

necessary to give the anthelmintic f irst or a satisfactory responoe to t h e ' I

anti-anaemia treatment w i l l not be obtained, Ae the patients are often very

debjlitated it is advisable t o avoid anthelmintics such as thym01, 031 of

ohonopodium and Ca.rbon tetrachloride on account of their toxicity on fie one

hand and heqlresorcinol on account of its feeble action on the other.

~etraohlorethylene is thsrsfore the drug of choiie.

The authors k e a t e d 80 patients in et hospital in North Viet Nam:

of theae 59 completed tha caurse of traatwnt,

3he clinical criterla of improvement were the lldfuretic crisistt

that occurred two or thrge days after the admirAstrEctSon of the antheldnt ic ,

the disappearance of t h e oedema that followed and the improvement in the

anaemia. However, in all, the pat$ents. t he atools were screened and an egg

CUUII~

Weatment was carried out as follows: an egg count was made before

the treatmnt , A normal midday ma1 was taken but after that only fluid,

A t midnight one hard gela t in capsule contahing 1 fl, of tetrachlmethylene was taken every five minutes up to a t o w of three to six capsules. Next

morning a sal ine purgative o f sodium o r magnesium sulphate, was r,iven, All

the sboo l s passed during the twen-Ly-four hours S o l l o t ~ i n g t h e purgative were

'col lected atid screened, A f t e r ten clays the s -bools were re-examhned f o r ezgs

and, if any were Sound, t h e precedure was repeated,

The d m g is w a l l tolerated and only minor side-ef fec ts such as a

s l i g h t headache, vert igo, a sense of inebr ia t ion, and somnolence, unimportant

when the pa t i en t is i n bed, were observed, In persons w i t h hepatic, renal

and cardiac complications, and i n pregnan-t women, treatment was given with

caution (usually 3 m l .) without i l l - e f f ects ,

'The r e s u l t s of treatment were n o t as spectacular as some ear l ier

workers hawe reported, b u t t h i s was probably because ';;he present authors were

dealing mainly w i t h h e a v infec-ti-ons, but they have effected e l h i n a t i o n of

hundreds of w o r m s even w i t h doses of 3 d,: they quote examples, from t h e i r

tables, in which 3 nit. has produced 800 worms and 6 ml, up t o 1,075 worms.

A cure r a t e of 50 per cent was obtained w i t h a s ing le dose of 3 m l .

and an 85 p c ~ cent cure rate wi th 6 ml.

An advantage is that in weak pat ients totrachlorethylone can be

emplqycd wi,thou-L a purgz-Live,

The e f f ec t on Ascaris in fec t ion was all-so goodj, of 37 pa t ien ts

t reated 26 were cured and in 10 t h e worms were par t ly eliminated,

( c ) In 1954, Sadun and ~ a r a s b h i r a ' ~ ' published t h e i r preliminary resul t s

on the effect of MakZua ( ~ i o s ~ ~ r o s mollis) in t h e treatment of human hookworm,

Tnis i s derived from the berries of t h e p lan t Uiospgros inoll is (Family:

Ebenaceae - .L,ropical hardwood t rees, of which t h o ebony t r ee is an example),

which are common in Thailand. One thousand berries (4,880 gm,) were mixed

with one l i t r e of coconut & i l k and cane sugar, The dose is 3 n i l . per year

of age given on an empty stomach up to a maximum of 75 ni l . The h g as a

purgative, compared t o hexylresorcinol, is f avourable, but result E should be

treated. with great caut ion,

(d) Studies on chemotherapy agslinst hookworm diseases on the effec t of ( LC) I-Broino-B-Naphthol were carr ied out by Kiura , This drug was found

effective in f i f ty-four s choa lbqs (0.5 grn. twice). In a group ofsuvcnteen

patients, doses up t o 4.0 gn,, two t o seven times were given. Complete

disinfestation was achieved wi thou t side-effects in a case of severe anaemia.

Al togc tho r 117 pat ients have hccn t roa ted . side-el"Iacl;s, w1licl1 were

s l i g h t , included s l i g h t nausea, l o s s of appcti.'ce and stomach-ache .

( e ) Elbers, 1 9 ~ 6 ' ~ ' , reports on the good r e s u l t s obtained by using

Vermella in hookworm treatment in Indonesia. Vermella (C.F. Asche & Co. A S , ,

Hamburg-Altona) is a halogen oyvdemative of 1-rflethyl-4-isoprowlbeneoL, It

i s lmch l ess toxic than hexylresorcinol, has no i r r i t a n t e f fec t and has a low

solubility in water and hence i s but l i t t l e resorbed into the system, The

method of treatment was t o administer th ree drag6es or three capsules before

oroakfast and then t o give the same dose on five occasions at intervals of

two hours, On the second day three drag& were given before breakfast and

again two h m s a f t e r breakfast followed in the early afternoon by vigorous

purgation by castor 011, If the first course of treatment was not success-

f u l , a second course was given four or five days l a t e r , It was claimed that

10@ cure r a t e resulted from t h i s treatment.

( f) Smeth e t a1 .(6) tried Mant?midc (Win 5047) o r N- (2, kdichlorobenzyl) -N-

(2-kydraxyethy2) dicliloroacetamide i n Bombay in t h e treatment of 26 adult pat ients suffering f ~ o m severe ancylostomlasis with gross clinical manifestam

t ions of t h e infection, The dose was 750 mgm, thrice daily -for three days,

and t h i s was w e l l tolerated even by anaemic and debi l i ta ted pat ients . Hook-

w m m ova vanished f rom the stool of 22 pat ients ; re-treatment of two of t he

pat ients not cured by t he treatment resulted in clearance of t h e s t o o l s of

one of them and. substant ia l reduction in t h e egg count of t h e other.

( g) Goodwin o t a1 .(7) reported i n 1958 t h a t Bephenium Hydrornaphthoate

against hookworm (Nccator americanus) i n Ceylon in doscs of 2-3 gm. was as

effect ive as the standard dose of tetrachlorethylene (1.8 n i l * ) used in Ceylon

both in hospi ta l pat ients and in the f ie ld , and did not cause the giddiness

and nausea sornethes a s s o c i a t e d w f t h t h e use of the l a t t e r drug. Bephenium

hydroxynophthoate is t h e drug of choice whenever it is necessam t o eliminate

ancylostomes from rnarasmic, anaemic children suffering from chronic diarrhoea

whose precarious condition does not jus 'c iq the use of even a smll dose of

tetrachlorethyJone, Bephenium also proved ac t ive against ascartasis.

Bephanium hydraqynaphthoate is c l e m l y a most valuable antihelmjntic,

whose special advantage lies i n i ts non toxicity, ease of administration and

effectiveness against hookworms and roundwo~ms . It i s good, but probably not

better than tetrachlorethylene, for routine use in healthy subjects, and the

relative pr ice of e i t he r w i l l probably determine which is used in l a rge scale

campaigns,

~ e p heniini one of the aua1;crnary compounds

Soprunov and 'i'endetnick rcported in 1 9 ~ 7 ' ~ ' tha t the t&al of 410 kg.

of spores of predacious 'fungi were brought i n t o the mine which was t reated

five timea during t h e period 1953-1956. 50 t o LOO gm, of t h i s preparation

was u s ~ d $0 one square metre of t he ground, It was effective f o r several

months and was found t o be harmless t o man and t i m b e r i n g , The total i n c i d ~ n c e

of ancylostomiasis was reduced, durin<!pelpcriod of 1953-1956, from 171 cases

t o 34 cases ( i , e . by 7 7 % ) . The reductj-on of f resh cases preceded t he decrease

of the incidence of parasite, which provcs t h e good effec t of anti-larval

measures (trea-tment of .Ghe ground in mine by the sporeb of predacious fungi ) ,

Effect of Sanitaqr l'rczbrnent of Ilumn Excreta by Boating Process

on Anc;ylos-Gomna Larvae and Othor Parasites - Katayama in 195~'~' rdports that: " A simple method of heub troatrlnant of

human excreta used as fertilizer has been devised and p u t into prac-Lice since

1952 zt Kashi-watara-mra, a farm vil1ap;e in Shigo. Prcfccture, as the radical

counter-measure f o r parasit o disease control .

"A sheet-iron container-with a capacity of fourteen Zitres was i n s t a l l e d

under the scat of each demestic privy to rsccive faecal excrement only, The

faecal content is enptied occasionally i n t o a drum-can of 2 0 o r 200 l i t r e a in 0

capacity, and heated up t o 60 C, w i t h f i r e wood, All parasitic ova, patho-

genic bacteria of digestive or$ans and fly-maggots are completely dest-royed

tharoby, and then t h o night-soil is used Tor fa r t i l i za t ion ."

3 , CREEPING &-LUPTIUN

Obsorvakions wcrc made by i l i tchie and ~ing('O) on t h e reactions of t he

larvae of nncylostoma canium 2.nd ancylostoma braa i l iknse -to various drugs and

chorni.cal compounds based on in v i t r o t e s t s . '6Sith 6.3 per cent Fouadin and

2.5 p e r cent didthylcartamazine, ten per cent of the larvae survived f o r twentyd

f o u r hours, Among the compounds which exerted complete lar 'v ic ide 'nct ion in

Five minutes were: acetone, ethyl acetate, ethyl formte, pyridinu and 95 per

cent ethyl alcohol; among those comp1etel;y l a rv i c ida l wi th in thirty minutes

worc ammonium chloride, and sulpkatc, sodium chloride, and sucrose ( saturated

concontration) , Haxylresorcinol 0.06, pex cent in water, killed in less than

90 minutes, wd s-trictanose 2.0 per ccnt, in l e s s than thrce hours, Action

was incomplete c?.fter three hours w i t h oxytetracycline t en per cent, aureonycin

ten p c r cent, ,md several other antibiotics,

For creeping eruption ( of 'I cat-and-dog hookworm") treatment two mgm. per

kgs. throo times daily was described by ~ o r t o n ' l ' ) . The p r u r i t i s usually

bccame normal i n 48-72 hours; i f treatment was interrupted, the prmritis

returned, Tho time required f o r clinical cure rangcd from eight t o t h i r t y

days; average three waeks. One pnt iont had aosinophilia (21 por cent)

together with radiogmphic appearances compatible w i t h Loefflcrls syndx.om

of allergic pneumonitis, he responded t o I ie t ra~an. Of t h o thirteen patients,

nine were clinically cured,

Wilson (I2' used Stltnnose ( C ~ ~ H ~ ~ N S N S ~ N ~ ) in t he treatment of Larva Migrnns

in a two per cent aolut ion intrarmscularl;v, 4 ml, daily fo r s i x days,, Of

seven-ty-five cases, a complete cure was achieved in twenty-'two, in fifty cases

considerable jmprovomht was effecte'd, and in only tkr~e cases was tho t reat-

inent a complete fai lure, In recurrence, t h o lesions were then t rea ted loca l ly

by freezing and the application of ethyl acetate collodion,

4+ DUGNOSIS

Diagnoais in ancylosto~niasis by means of i n t r o d e m l and serological

t e s t s by &wdn e t a1 .(13) showed the following resu l t s :

(1) Prcc ip i t in t e a t s and haemagglutination tests did not serve

satisfactorily,

(2) Protein and polysaccarido fractions were proparad from the adult

anc;vlostoma caninum and tested i n dogs and mn,

(3) Protein f rac t ions used us test ant igens showed rairly satisfying

results,

(4) Polysaccharide fract ion used as a test antigen showed unsatisfactory

result^.

Sasi ot al, (I4' mportod tho extreme sensitivity of test-tube cultivation

method on t h e survey of hookworm and rclated h m n nematodes i n f e c t i o n , The

method is as follows: half a grame of faeces is smoared on a s t r i p of f i l t e r

papor 25 mm x 150 mm, which is put i n t o an 18 mm. diameter test-tubbe with

3 cc. of tap water. The test-tube is owerod t i g h t l y nnd kept at 25'0, for

over a week, when infective larvae are found a t the bottom, %ae are

k i l l e d by heat and examined on a slide. A trained technician usually diag-

noses one to two hundred specimens in four hours.

Studies on the development of ancylostoma larvae in chickon embryo were

made by S m d a and ~ano'l". The larvae of - A . duodenale inorcased in size

and dovelopmnt rather more than those of - A . canhum, especially in t h e

al lantois , i n which t e n days aftor i n j cc t ion there was not o n l y development

of the buccal c~.psule but t he sm of t h e larvae could be determined,

6 . L D ~ ~ I O A C T I V I V I CILiOHIUM CrS1 I N 'ilIU Pl&SU. L&R:ihlT UP' IITJISmIIINKL U L O LOLS ASSOCIATEL, irJTTII HOOK,fO:M INl%CTIdN I"

iloche e t 21, 51 '16) using radioac tivt chromium Cr by labe l l ing pa t ien ts

red c e l l s and measuring chroinium excretion in khc f neces , were able t o ecti-

mate the bata l loss of blood per clry per pa t ien t and also per day per hookworm,

There waa no close re la ti or^ between the amount of blood l o s t ~ " n d the number

of hookworms. II"ilus, one pat ient who harboured at lees t 509 worms (Necator

americanw) bled 7.3 nil. p a r day whereas another w i t h 609 hookworms

(2, americznus) was cnlculxted t o l o s e 15.4 m l , per day, Tho aublzors found

t h e t p a t i e l ~ t s w i t h pure - N . americanus in fec t ion lo s t , on "ce meraze, 0,03 nil,

of b lood per w o r m per day and from examining mixed infections they in te rpo la te

far ancylostomc. duodenale the f i gu re of 0.2 ~ n l l , of blood p e r worm per day,

For prectical purposes the au thor s eive the fo l l owing average figure: +

2,711. - 1.50 d, blood l o s s per day per thousand Hecator ova per grumme

of f aeccs.