Infantile hookworm disease.
ABSTRACT Hookworm infection is common but has rarely been reported in neonates or infants. Two cases of hookworm infestation in early infancy are described. The infants presented with malena, severe pallor, lethargy and failure to gain weight. Initial stool examination was non-contributory and diagnosis was made by upper gastrointestinal endoscopy.
Article: The neglected tropical diseases of India and South Asia: review of their prevalence, distribution, and control or elimination.PLoS Neglected Tropical Diseases 10/2011; 5(10):e1222. · 4.69 Impact Factor
190VOLUME 47__FEBRUARY 17, 2010
hookworms and 2 million children under the age of
4 have hookworm infection(1). It usually occurs in
children when they begin to crawl or walk barefoot
and come in contact with contaminated soil. Infants
are rarely exposed to this infection; description is
available from a few case reports only(2-6). Two
cases of hookworm infection in infants who
presented with massive gastrointestinal bleeding
ookworm infestation is common in
tropical and subtropical countries.
Approximately 7% of Indian population
is estimated to be infested with
Case 1: A twelve weeks old, exclusively breast fed
male infant, belonging to a poor, marginal family
was admitted with complaints of passage of black
tarry stools since the age of six weeks. The baby
required five packed cell transfusions. There was no
history of bleeding from any other site. There was
no history of fever, jaundice or abdominal
distension. His weight was 4.2kg (<3rd percentile,
WHO standards) and length was 55 cm (<3rd
percentile, WHO standards). The child was pale but
hemodynamically stable. Abdomen was soft, liver
was 4 cm below costal margin and span was 6.5 cm.
Rest of examination was normal.
Hemoglobin was 6.2g/dL; TLC was 58000
(eosinophilic leukocytosis / leukemoid reaction)
with differential of N22L35E42M1; platelets were
normocytic normochromic RBCs; prothrombin
time and liver enzymes were normal; bilirubin was
0.8 mg%; total protein was 6.3 g/dL; albumin and
globulin ratio of 1:1 and CRP was negative.
Grossly, two samples of the stool were black tarry
and positive for occult blood but microscopy was
normal. Meckel’s scan and blood pool scan were
Upper gastrointestinal endoscopy showed pale
mucosa with multiple erosions in the duodenum.
There were multiple worms which were attached to
the intestinal wall or moving freely in the lumen. A
worm was extracted endoscopically and proved to
be hookworm (Ancylostoma duodenale). Three
more stool examinations were done later and one
revealed hookworm ova. Mother’s stool was also
examined which showed ova of Ascaris and
C C C C C A A A A A S S S S S E E E E E R R
R E E E E E P P P P P O O O O O R R R R R T T T T T
Infantile Hookworm Disease
VIDYUT BHATIA, MANOJA KUMAR DAS, PAWAN KUMAR AND NARENDRA KUMAR ARORA
From Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India; and *The Inclen Trust International,
Yusaf Sarai, New Delhi, India.
Hookworm infection is common but has rarely been reported in neonates or
infants. Two cases of hookworm infestation in early infancy are described. The
infants presented with malena, severe pallor, lethargy and failure to gain weight.
Initial stool examination was non-contributory and diagnosis was made by upper
Key words: Endoscopy, Hookworm, India Infant, Melena.
Correspondence to: Dr N K Arora,
The Inclen Trust International,
18 Ramnath Building 5th floor,
Yusuf Sarai, New Delhi 110 049,
Received: December 18, 2008;
Initial review: December 30, 2008;
Accepted: January 30, 2009
191VOLUME 47__FEBRUARY 17, 2010
ARORA, et al.
INFANTILE HOOKWORM DISEASE
Trichuris. The infant was treated with 200 mg of
albendazole as single dose. The child passed worms
the next day and the stool color changed to yellow.
Clinically, the child improved. He was discharged
after three days. On follow up after one week,
hemoglobin was 9.2 g/dL and TLC was 9200/mm3
with a DLC of N68 L22 E10.
Case 2: A eight months old exclusively breast-fed
male infant was admitted with complaints of black
tarry stools since 4 weeks of age. The infant had
required 4 packed cells transfusion during last 6
months. There was no history of bleeding from any
other site. There was no history of fever, jaundice,
umbilical cord infection and abdominal distension.
The infant was from a poor family. On examination,
the baby was hemodynamically stable but severely
pale. His weight was 5.8kg (<3rd percentile, WHO
standards) and length was 62 cm (10th percentile,
WHO standards). Abdomen was soft, liver was 2
cm below costal margin and span was 6 cm. Rest of
systemic examination was normal.
Hemoglobin was 6.0g/dL; TLC was 14000 mm3
with differential of P76L22E2; platelets: 343,000/
mm3; peripheral smear showed normocytic
normochromic RBCs; liver enzymes normal; serum
bilirubin: 0.6 mg/dL; serum proteins: 8.2 g/dL;
albumin to globulin ratio 1:1; prothrombin time was
normal; CRP: negative. Grossly, stool was black
tarry, positive for occult blood; microscopic
examination did not show any ova or cyst; Meckel’s
and blood pool scan were non-contributory. UGI
endoscopy showed multiple erosions in duodenal
mucosa with multiple worms attached to the wall.
They looked like hookworms but could not be
removed for microscopic confirmation. Packed
cells were given twice for severe anemia. Infant was
treated with 200 mg single dose of albendazole.
Next morning, infant passed thread like small
worms in stool. Stool color changed to yellowish
after 48 hrs. Clinically the child improved and was
discharged after 96 hrs of therapy; however, the
patient did not come for follow up.
Infantile hookworm disease is a distinct clinical
entity which has only uncommonly been reported
particularly from China, Nigeria, Nepal and
aboriginal communities of Australia(2-6). There are
a few reports of hookworm infestations in infants
from India; two of these reports are among infants
coming from Nepal(3-5,7). Both of our cases were
from North Bihar.
Hookworm infestation of humans usually
occurs when the infective larvae (L3) enter the body
either by penetrating the skin (A. duodenale or N.
Americanus) or by direct oral ingestion (A.
duodenale). The larvae migrate to the circulation
and reach the pulmonary alveoli from where they
enter into the trachea. The L3 then reach the gut
from the circulation after penetrating the pulmonary
alveoli and traversing the trachea. Here they moult
twice before maturing into adult worms. This is the
prepotent/incubation period and is about 5-8 weeks
in adults. This cycle is not clearly understood in
infants. Several routes of hookworm infestation
among infants are postulated but never confirmed.
Infants who become symptomatic before the age of
5-8 weeks, are usually infected with A. duodenale,
and might have acquired this infestation from the
transplacental or the transmammary route(5,6).
Hookworms might also be acquired from
contaminated soil where the babies are usually put
by their mothers while working in fields or from
sandbags/wheat-stem bundles used as diapers made
from contaminated soil. Occasionally infestations
might be acquired through partially wet diapers
which have been washed in larva-infested ponds or
canals and dried on the grassland(6). However, the
exact mechanism by which massive hookworm
infestation occurs in small children is still unclear
and needs investigation.
Although we cannot be certain of the route of
infection in our babies, it does appear that the
infants acquired this infection from their
environment. Both our cases were from a low
socioeconomic background with poor sanitary
facilities. The mother of one of the infants (case 1)
was also infested with other worms. Therefore, the
possibility that they were in contact with
contaminated soil or from contaminated hands of
their mothers is high. We postulate that the period
from entry of the hookworm to the start of
symptoms could be shorter in these infants since the
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INFANTILE HOOKWORM DISEASE
distance L3 larvae has to traverse to reach the gut is
much less in infants as compared to older children
The usual symptoms of infantile hookworm
disease are bloody stools, melena, increasing pallor,
anorexia, listlessness and edema(2-4,6). However the
disease is uncommon and these children might be
suspected to have other diagnosis. In both the cases an
initial stool examination was done and found to be
negative and hence we had suspected portal
hypertension, Meckel’s diverticulum or AV malfor-
mation as the cause for the gastrointestinal bleeding.
We undertook upper GI endoscopy, Meckel’s scan
and blood pool scan to rule out these possibilities.
Sensitivity of stool examination to pick up ova and
cyst increases from 58.6% to 95% upon increase in
number of stool examinations from one to three(8).
Therefore, in retrospect, we feel that all such infants
should be subjected to at least three stool
examinations before proceeding to more invasive
In conclusion, young infants coming from low
socioeconomic families, having poor environmental
hygiene and sanitation and presenting with severe
anemia and melena, should be suspected of having
hookworm disease. The disease can be managed
effectively through simple and well known
Contributors: All authors were involved in reporting,
reviewing, managing the case and drafting the
Competing interest: None stated.
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