Published Date: 2009-03-27 23:01:04
Subject: PRO/AH/EDR> Angiostrongylus meningitis - Taiwan
Archive Number: 20090327.1193
ANGIOSTRONGYLUS MENINGITIS - TAIWAN
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Fri 27 Mar 2009
Source: Taipei Times [edited]
Angiostrongylus in Thai workers after consuming raw snails
Earlier this month (March 2009), 4 out of 5 Thai workers who ate raw
snails became infected with a potentially deadly parasite
[_Angiostrongylus_], the Department of Health (DOH) said on Wednesday
[25 Mar 2009]. Centers for Disease Control Deputy Director Chou
Jih-Haw said that 3 of the workers were in stable condition, while one
had left Taiwan and the other had not shown any symptoms of illness.
Three of the workers were reported to have been infected with the
parasitic nematode Angiostrongylus cantonensis -- an elongated
cylindrical worm -- early this month and developed symptoms of
eosinophilic meningitis, including headaches, fever and vomiting, Chou
said. The DOH discovered that the trio and some of their friends had
caught apple snails (_Pomacea canaliculata_) in fish ponds in southern
Taiwan and eaten them raw with sauce.
Snails are usually the primary host of the worm, also known as the rat
lungworm -- a parasite endemic to Southeast Asia and the Pacific
region. Humans become infected by ingesting the parasite's larvae,
which are then carried in the blood to the central nervous system.
This can result in eosinophilic meningitis, which is characterized in
the early stages by severe and acute headaches, fever, nausea and
vomiting, and stiffness of the neck, and can result in death or
permanent brain damage.
Chou said that it was once believed that eating giant African snails
could cure certain illnesses and that there were frequent reports in
Taiwan of infections of this type of roundworm.
A 70-year-old man in Kaohsiung was treated for the same conditions in
2007 after eating raw frogs in an effort to cure back pain. Another
case in 2005 saw Hualien's Tzu-Chi Buddhist General Hospital treat a
48-year-old man who had become infected with the parasite after eating
raw snails. In 1998, 8 Thai workers came down with eosinophilic
meningitis as result of eating raw snails and in 1999, Kaohsiung
Veterans General Hospital reported that 9 Thai laborers had been
infected with rat lungworms.
In light of the recent case, the DOH said it would contact Thai
authorities to step up health education to avoid a recurrence of the
ProMED-mail Rapporteur Susan Baekeland
[_Angiostrongylus cantonensis_ is transmitted to humans eating raw
fresh water snails and lettuce contaminated with infected slugs. Human
infection with _Angiostrongylus cantonensis_ is common in Thailand and
is seen especially in the northeastern region, where it is associated
with the habit of eating koi-hoi, which contains raw snail meat
(Eamsobhana P et al. Thai Koi-Hoi Snail Dish and Angiostrongyliasis
Due to Angiostrongylus cantonensis: Effects of Food Flavoring and
Alcoholic Drink on the Third-Stage Larvae in Infected Snail Meat.
Foodborne Pathog. Dis. 2009 Mar 9).
Ocular Angiostrongylus has also been described from Thailand (Sinawat
S et al. Ocular angiostrongyliasis: clinical study of 3 cases. Eye
See Life Cycle at:
<http://www.dpd.cdc.gov/dpdx/HTML/angiostrongyliasis.htm> - Mod.EP
Images of _Angiostrongylus_ at:
Apple snail _Pomacea canaliculata_: