A foodborne parasite detected in two patients in a Chinese hospital has been traced to consumption of raw wild centipedes, according to a case report by the American Journal of Tropical Medicine and Hygiene.
Researchers from the Southern Medical University and Zhujiang Hospital in Guangzhou said it’s the first time the Angiostrongylus cantonensis parasite — often called rat lungworm — has been detected in a centipede species. Centipedes are used in traditional Chinese medicine, though usually in a dried or powder form, which does not transmit the parasite.
Mild infections with A. cantonensis may resolve on their own. But the parasite can penetrate the brain and spinal cord, which can lead to meningitis and, in some instances, paralysis and death.
“We don’t typically hear of people eating raw centipedes, but apparently these two patients believed that raw centipedes would be good for their health,” said Lingli Lu, a co-author of the report who works in the Department of Neurology in Zhujiang Hospital.
Lingli said the patients, a 78-year-old woman and her 46-year-old son, came from the rural countryside where it was believed that consuming raw centipedes offered potential health benefits. Both recovered with treatment.
According to the U.S. Centers for Disease Control and Prevention, A. cantonensis is mainly found in China and Southeast Asia and infections are usually linked to eating raw or undercooked snails. The parasite has been detected in the Caribbean, Hawaii, and more recently, in Louisiana and South Florida.
The Hawaii Department of Health has confirmed at least three cases of rat lungworm disease so far this year.
In Louisiana, it was found in the invasive apple snail, a freshwater snail native to South America that is sometimes consumed as food. In South Florida, the parasite was discovered in the invasive giant African land snail.
In 2017, there were 17 laboratory-confirmed cases of rat lungworm disease statewide.
The researchers in China purchased 20 centipedes from the agricultural market where the patients bought theirs. The immature, or larvae, form of A. cantonensis was detected in seven of them. They infected 20 centipedes with the parasite but the centipedes subsequently died.
Lingli said results could indicate that, while centipedes can be temporary hosts, it is not certain they are able to serve as intermediate hosts, a classification that indicates an ability to carry and spread the parasite over a long period of time.
A study in a Morbidity and Mortality Weekly Report (MMWR) published by the CDC looked at the epidemiologic and clinical features of 12 rat lungworm cases in the continental U.S. from January 2011 to 2017. Six were likely a result of transmission in the southern part of the country. Consumption of raw vegetables was reported in 55 percent of those cases.
In Hawaii, public health officials have said host animals, particularly snails, are frequently found in fresh lettuce and other salad ingredients that are served raw.
“Health care providers, especially those in the southern United States, need to consider angiostrongyliasis in patients with eosinophilic meningitis, particularly those with a history of ingestion of gastropods or raw vegetables contaminated with larvae,” said the report.
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