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AFRO-NETS> RFI: Tungiasis (aka, Jiggers, Chigoes or Pig Fleas) [3]


  • Subject: AFRO-NETS> RFI: Tungiasis (aka, Jiggers, Chigoes or Pig Fleas) [3]
  • From: Beverley Snell <bev@burnet.edu.au>
  • Date: Thu, 18 Oct 2001 00:16:12 -0400 (EDT)




RFI: Tungiasis (aka, Jiggers, Chigoes or Pig Fleas) [3]
-------------------------------------------------------

One of our Infectious Diseases Physicians, Dr Tony Stewart, provided
this info.

Best wishes,
Beverley Snell
International Health Unit
Macfarlane Burnet Institute for Medical Research & Public Health
P O Box 254 Fairfield Vic Australia 3078
Tel: +61-3-9282-2115 / 9282-2275
Fax: +61-3-9482-3123
mailto:bev@burnet.edu.au


--
Here from Tony Stewart - same address as mine.

There's a bit of info around. Niridazole (Ambilhar) is not available
in US, but has been reported to be completely effective in lysing
imbedded fleas in infected children. The response was quicker when a
second dose was given 1 wk after first. Combination of direct toxic
action on flea and anti-inflammatory action on surrounding tissue was
postulated. Adult Dose: 30 mg/kg PO in juice Pediatric Dose: Adminis-
ter as in adults Contraindications: Documented hypersensitivity;
known G-6-P deficiency Interactions May elevate serum levels of theo-
phylline increasing toxicity (monitor serum levels and reduce dose
prn) Pregnancy: Category C - Safety for use during pregnancy has not
been established. Precautions: May cause nausea, vomiting, and ab-
dominal pain

The information below on tungiasis from the Stanford site:
http://www.stanford.edu/class/humbio103/parasitepages/ParaSites/tungiasis/

Other links I found were:

GENERAL: Tungiasis is an infestation of the skin by the sand flea,
Tunga penetrans. The pregnant female flea burrows under the skin,
sucks blood, swells, and releases eggs. A localized nodule will form
at the point of infestation, possibly causing pain and inflammation.
Complications, though rare, may involve ulceration, gangrene, secon-
dary infection, tetanus, and death. This burrowing flea is endemic to
Latin America, the Caribbean, Africa, and India.

SYNONYMS: Chigoe, jigger, pigue, nigua, pico, bicho de pie ("bug of
the foot"), sand flea.

HISTORY OF DISCOVERY: Gonzalez Fernandez De Oviedo y Valdes noted the
earliest report of tungiasis at the turn of the 16th Century when
Spanish conquerors of the crew of the Santa Maria were shipwrecked on
Haiti and became infested with the disease. A few years later, the
Spanish conqueror Gonzalo Ximenes de Quesada reported an entire vil-
lage in Colombia that had been abandoned by its inhabitants due to
this disease. Consequently, his soldiers became so infected with the
disease that they could barely walk. In the 17th Century, Aleixo de
Abreu, a Portuguese physician working in the Brazilian government,
provided the world with the first scientific description of Tunga
penetrans.

CLINICAL PRESENTATION IN HUMANS: The first evidence of infestation by
this sand flea is a tiny black dot on the skin at the point of pene-
tration. Because the flea is a poor jumper, most lesions occur on the
feet, often on the soles, the toe webs, and around or under the toe-
nails. Among natives who frequently squat, however, the buttocks and
perineum can be involved. A small, inflammatory papule with a central
black dot forms early. Within the next few weeks, the papule slowly
enlarges into a white, pea-sized nodule with well-defined borders be-
tween 4-10mm in diameter. This lesion can range from asymptomatic to
pruritic to extremely painful. Multiple/severe infestations may re-
sult in a cluster of nodules with a honeycomb appearance.

Heavy infestations may lead to severe inflammation, ulceration, and
fibrosis. Lymphangitis, gangrene, sepsis, the loss of toenails,
autoamputation of the digits, and death may also occur. In most
cases, however, this lesion heals without further complications.

Nonetheless, the risk of secondary infection is high. Tetanus is a
common secondary infection that has reported associations with death.

TRANSMISSION: The sand flea is normally found in the sandy terrain of
warm, dry climates. It prefers deserts, beaches, stables, stock
farms, and the soil and dust close to farms.

While both male and female sand fleas intermittently feed on their
warm-blooded hosts, it is the pregnant female flea that burrows into
the skin of the host and causes the cutaneous lesion. She does not
have any specialized burrowing organs; rather, she simply attaches to
the skin by her anchoring mouth and claws violently into the epider-
mis. Since this process is painless, it is thought that the flea may
release some keratolytic enzymes. After penetrating the stratum
corneum, the flea burrows to the stratum granulosum, leaving her pos-
terior end exposed. The "black dot" of the nodule is this posterior
end of the flea sticking out. The opening provides the flea with air
and an exit route for feces and eggs. With its head in the dermis,
the flea begins to feed on the host's blood and enlarges up to 1cm in
diameter. Over the next two weeks, over 100 eggs are released through
the exposed opening and fall to the ground. The flea then dies and is
slowly sloughed by the host's skin.

The eggs hatch on the ground in 3-4 days. In the next 3-4 weeks, they
go through their larval and pupal stages and become adults. The com-
plete life cycle of a T. penetrans lasts about a month.

RESERVOIRS: T. penetrans has many animal reservoirs including: Hu-
mans, cattle, sheep, horses, mules, rats, mice, dogs, pigs, and other
wild animals.

INCUBATION PERIOD: Signs of the bite will appear immediately or
within days.

MORPHOLOGY: T. penetrans is the smallest known flea, with a length of
only 1mm. It is distinguished by its large angular, double-curved
head and its narrow, short thorax region.

MANAGEMENT AND THERAPY: Treatment consists of the physical removal of
the flea by a sharp instrument. The residual cavity should then be
surgically cleaned to remove its entire contents. Afterwards, an an-
tibiotic ointment may be applied to prevent secondary infections.

Certain chemicals have also proven to be effective, including 4 per-
cent formaldyhyde solution, chlorophenothane (DDT), chloroform,
turpentine, and niridazole. These treatments do not physically remove
the flea from the skin, however, and therefore don't result in quick
relief. They also carry their own risk of morbidity.

Physical removal followed by antibiotic ointment and an anti-tetanus
prophylaxis to prevent secondary infection (especially that of teta-
nus) is most effective.

EPIDEMIOLOGY: Originally, the sand flea was only present in Latin
American and the Caribbean. It was most likely introduced into Africa
in 1873 by the infested crew and sand on board the ship Thomas
Mitchell travelling from Brazil to Angola. Within 20 years, the flea
spread from Angola to the West Coast of Africa and throughout the
sub-Saharan region eventually to East Africa and Madagascar. In 1899,
Indian soldiers brought the flea to Bombay, India and Karachi, Paki-
stan.

Today, Tunga penetrans is endemic to Latin America, the Caribbean,
sub-Saharan Africa, India, and Pakistan.

In endemic areas, prevalence ranges from 15-40%. In 1981, the preva-
lence of tungiasis among children in rural Lagos State (Nigeria) re-
corded 40%. Similar prevalence was noted for villages in Southern Ni-
geria and Trinidad.

In other areas, however, cases are sporadic. Travelers may become in-
fected in and import the flea from endemic areas. In the United
States, only 14 cases have been reported since 1989.

Tungiasis has become a neglected health problem in poor communities.

"Growing urbanization, improved housing, and use of appropriate foot-
wear presumably have led to an overall reduction of the occurrence of
tungiasis in many Latin American and African countries. However, it
is still a highly prevalent disease where people live in poverty,
such as in the innumerable shantytowns of big cities of in the rural
hinterland. Those areas share many factors favoring a high attack
rate by T. penetrans: stray dogs and cats, pigs in close vicinity to
living quarters, unpaved streets, mud floors in houses, insufficient
or non-existent sanitation; and infestation with rats and mice espe-
cially in areas without rubbish disposal. Many people, especially
children, mostly walk barefoot or only wear slippers. Illiteracy, ig-
norance, and neglect presumably are other factors favoring the high
prevalence of severe pathology of children living in these circum-
stances. Tungiasis is a disease of the poor." (Heukelbach, 269)

PUBLIC HEALTH AND PREVENTION STRATEGIES: Wearing of shoes is the pri-
mary defense against tungiasis. Shoes should be strongly encouraged
to control the disease in all endemic areas.

Avoidance of contaminated areas, personal cleanliness, and disinfec-
tion of clothing, bedclothes, and furniture can also be important.

Floors/ground sprayed with an insecticide (1% Malathion) is also ef-
fective in reducing the incidence of tungiasis in infested villages.

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