TAJ June 2003; Volume 16 Number 1
The Journal of
Gnathostomiasis-A Rare Nematode Infection
M M Rahman 1
Gnathostoma, primarily an animal nematode, is rusty in colour, 2-3 cm long in adult stage, can
infect man by their larval form. Human infection occurs by the third stage larva by consumption
of undercooked or raw fish, poultry, or pork and rarely by skin penetration, In Bangladesh
gnathostomiasis is not reported. But recently a female of 38 year of age of the northern district,
Rangpur has got infected with a species of Gnathostoma, manifested by the appearance of the
farva in anterior chamber of her right eye. The larva was removed from her eye surgically in
living state and the patient was cured.
TAJ 2003; 16(1): 28-29
Cases of gnathostomiasis have been diagnosed in
many countries in Southeast
countries of South America, and parts of Mexico.
Among all four species of human infection of
Gnathostoma, G. spinigirum is the best-understood
species. Its definitive host is dogs, cats, tiger, lions
etc. These animals harbour adult warms in their
stomach wall and eggs are released in the faces.
Cyclops, in fresh water (1st intermediate host) in
gcst these ova and the larva develops up to early
third stage form. Cyclops are eaten by fish (2nd
intermediate host) or directly hy definitive host. A
wide variety of animals, including fish, bird and
mammals serve as second intermediate host to
Gnathostoma. The worms lodge in the gastric wall
of definitive host but in second intermediate host
fish, poultry and human, they such as lodge into
other tissue and don't develop to their adult forms.
Human can acquire larval by ingestion of
definitive host (not common), second or first
intermediate hosts. Since humans are "dead-end-
hosts", the larval are unable to mature into adult
form, thus they migrate throughout the body and
can survive up to 10 years and encysted in any
Individuals infected with gnathostomiasis can
develop symptoms as soon as 24 hours after
ingestion of worm. Symptoms include malaise.
fever, urticaria, vomiting, diarrhea, and epigastric
pain. Cases of gnathostomiasis have been
observed in the lung, eye. face, genitourinary tract.
GIT, auditory and
gnathostomiasis is often diagnosed by the presence
of migratory oedema of creeping eruptions.
Oedema, localized swelling and skin abscesses are
the more common indicators.
Visceral gnathostomiasis can take many and the
parasites can be found in eye (intraocular), GJ
tract, lung, ear, nose CNS etc. Repetition delete
Migratory sub cutaneous nodules are common
with viscera! gnathostomiasis involving CNS.
Although it is not understood how Gnathostoma
are able to enter the eye, they have been know to
cause damage the sensory apparatus of the retina,
leading to irreversible blindness.
Clinical presentation is the key to recognize
gnathostomiasis. Migratory oedema or creeping
eruption is visual sign of the presence of parasite.
History of consumption of related food or
1 Assistant Professor, Department of Microbiology, Rangpur Medical College, Rangpur.
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TAJ June 2003: Volume 16 Number I
traveling to endemic area can provide key
information. A wide array of serological tests-
indirect agglutination and ELISA has been used
for the detection of antibody against the parasite.
Albendazole (400 mg twice daily for 21 days) and
ivermectin (200iig/kg body wt for 1-2 days) have
been shown to be
gnathostomiasis but the treatment of choice is
often surgical removal of the parasite.
A 38 years old female patient of Rangpur, a
northern district of Bangladesh presented with
defective vision, recurrent pain and redness of her
right eye for the last 2 months. On examination her
visual acuity was 6/60 in the affected eye, while it
6/6 was in her left eye.
On slit lamp examination, surprisingly a motile
worm about 1 cm. in length, seen in the anterior
chamber not was/right eye. With application of
topical oxybuprocain, (0.40%) attempt was taken
to paralyze the worm but failed. Then was started
medical treatment of uveitis when worm was
surgically removed from the anterior chamber by
limbal incision and application of viscoelastic
The worm was collected in vial containing
distilled water. The worm was live and its motility
was like a maggot. At first the identity of the
worm was not clear. But when is was magnified
morphology if the worm to be consistent with the
larval stage of Gnathostoma species.
The larva is covered with fine spine like scales all
over the body. The cephalic bulb is globular and
covered with four circular rows of spines. The
head is separated from body by a narrow neck.
The long esophagus is continuous with the
taken reveals details
The Patient does not give history of taking such
food but eating half-boiled egg is not uncommon
in this area. Rare cases have shown that the third
stage larval worm can enter the host by skin
penetration. However, the route of transmission in
this case could not be assumed. On follow-up for
two months the women was all right and her visual
acuity returned to 6/9 within this period.
Fig: Larva of Gnathostoma
So far we know, except this present case, no case
of gnathostomiasis has
Bangladesh. But it does not mean that infection of
Gnathostoma is not
gnathostoma larva is blood is not documented,
unlike microfilaria, which is very common in this
zone of the country. So it is difficult to isolate the
larva from tissue but it could be easily visualized
when ocular involvement present.
involvement may represent the tip of the iceberg
of the prevalence of the disease. So Awareness
should be created among the health personal about
the parasite to diagnose the infection earlier and
thus to avoid serious complications due to
involvement of internal organs like CNS, eye of
auditory area by the parasite.
been reported in
here. Presence of
1. Vargas OF, Alarcon RE, Alvarado AFJ. Human
gnathostomiasis in Mexico. Int J Dermatol .1998;
2. Chattergee KD. Gnathostoma. In Parasitology. 141"
3. Parola P. Gnathostomiasis. Lancet .2001; 358:332.
Ali correspondence to:
M M Rahman
Department of Microbiology
Rangpur Medical College, Rangpur.