Cholera is an acute diarrhoeal disease caused by the bacterium Vibrio cholerae. Photo: VCG

Wuhan in Central China's Hubei Province reported on Thursday four seafood samples tested positive for the O139 type of bacteria that causes cholera. Officials say the latest case is unrelated to the previously confirmed case found at Wuhan University. Personnel and the environment involved with the positive samples have not shown abnormalities after examination, authorities said. 

The four turtle samples contaminated with the virus were found on Wednesday during a daily health inspection work at the Baishazhou Market in Wuhan, local authorities said in a notice issued on Thursday. 

An emergency response was immediately launched to conduct epidemiological survey, environmental sampling and disinfection. 

The shop selling the products has been temporarily shut down for three days, and the contaminated products have been properly disposed of. Persons in contact with the samples all returned negative results for cholera virus. 

Personnel and environment involved with the positive samples have not shown abnormalities after examination, authorities said, and they have reminded other destinations outside of Wuhan that received relevant products of the same batch.

There exist some risks of the cholera bacteria in these products infecting humans, experts noted, but said there is no need to panic. "Cholera is an infection of the digestive tract. So as long as people eat cooked products, there would be no risk of infection," Yang Zhanqiu, deputy director of the pathogen biology department at Wuhan University, told the Global Times on Friday. 

Even if people are infected with cholera, China has long been capable of treating the disease with drugs and other medical facilities, Yang said. 

The incident has not been found to have infected people, and is unrelated to the confirmed case of cholera discovered at Wuhan University on July 9.

The patient showed symptoms of vomiting and diarrhea accompanied by fever, and quickly recovered after effective diagnosis and treatment. No other cases were reported. 

There are only two class-A infectious diseases in China -- plague and cholera. COVID-19 is class-B.

Cholera in China has been under control since 2000 and only sporadic cases have been reported in recent years. China can provide advanced medical treatment and efficacious medicines against the disease, thus it is less likely to see a cholera outbreak nowadays, experts said, noting that there is no need to panic. 

The cholera virus is sensitive to heat, dryness, sunlight and general disinfectants, and can die after 2 hours of drying or 10 minutes at a temperature of 55 C. Boiling kills the virus immediately.

Wuhan authority reminds that summer is a high season for incidences of intestinal diseases, and reminded residents not to eat unclean raw, cold or half-cooked food.

Yang noted that summer creates an environment for various bacteria to grow, not only cholera. However, most of these bacteria will be killed after they are cooked.