Turtles Bred for Food in Asia Can Transport Cholera (Turtles infected with the bacteria causing cholera — Vibrio cholerae — have been found in shipments throughout Asia, from Bangladesh to Japan) - via Herp Digest

Global Health, New York Times, 6/14/17 by Donald G. McNeil Jr. 

Soft-shell turtles raised for food in Asia can infect people with cholera and spread the lethal bacteria from place to place, according to a new study.

Cholera infects up to five million people around the world each year, causing rapid, overwhelming diarrhea that leads to an estimated 100,000 deaths annually.

A major outbreak is underway in Yemen and in the Horn of Africa. (That outbreak is not food-related. Cholera is endemic there and is being spread to previously clean sources of drinking water by people forced to flee drought and civil war.)

The new study, by researchers at the Chinese Center for Disease Control and Prevention, was published last week in Applied and Environmental Microbiology, the journal of the American Society for Microbiology.

Large-scale turtle breeding has expanded rapidly in China, the authors noted. At the same time, turtles infected with the bacteria causing cholera — Vibrio cholerae — have been found in shipments throughout Asia, from Bangladesh to Japan.

The scientists made Vibrio bacteria easily detectable by inserting into them genes for bioluminescent proteins, then dipped some turtles into a Vibrio solution for two hours before rinsing them off. The researchers also pumped the solution into the stomachs of some turtles.

Within days, the scientists found the bacteria growing all over the turtles’ shells, limbs and necks, and in the calipash, the gelatinous green layer beneath the shell that is considered a delicacy in Asia. The researchers also discovered the bacteria in the intestines of some turtles.

Vibrio bacteria flourish in the brackish estuaries where shellfish grow. They concentrate in filter feeders, like mussels and oysters, and attach themselves to crabs and shrimp, thriving on the chitin in their shells, according to a 2009 article in the American Journal of Infectious Diseases.

They are not easily removed by rinsing or depuration, a process in which shellfish are stored in sterilized seawater.

One of the last cholera outbreaks in the United States took place in Louisiana in 1986, sickening 18 people. Cases were blamed on both crabs and shrimp; raw oysters were also suspected.

Careless handling — including holding cooked shrimp in boxes that had held raw shrimp — contributed to the outbreak.