How wild animals used for food can lead to disease
Close interactions with wild animals have caused numerous disease outbreaks in humans, including Ebola, SARS and HIV.
Buying, selling, and slaughtering wild animals for food is one way an animal-borne disease may infect people. Viruses can spread more easily if animals in markets are sick or kept in dirty, cramped conditions, such as in stacked cages.
When animals are under duress, viral pathogens can intermingle, swap bits of their genetic code, and perhaps mutate in ways that make them more transmissible between species. In the case of respiratory diseases, such as COVID-19, the virus can jump to food handlers or customers through exposure to an animal’s bodily fluids.
Most people had never heard of the term “wet market,” but the coronavirus pandemic has thrust it into the limelight. A wet market in Wuhan, China, called the Huanan Seafood Wholesale Market, is believed to be the source of COVID-19.
This menu was shared on Twitter by Muyi Xiao.
Somewhat akin to farmer’s markets and found around the world, wet markets are typically large collections of open-air stalls selling fresh seafood, meat, fruits, and vegetables. Some wet markets sell and slaughter live animals on site, including chickens, fish, and shellfish. In China, they’re a staple of daily life for many.
Wet markets also sell wild animals and their meat. The Huanan market, for example, has a wild animal section where live and slaughtered species were for sale: snakes, beavers, porcupines, and baby crocodiles, among other animals.
Other forms of wildlife trade can be risky too, including the exotic pet industry and tapping animals or their parts for traditional medicine or ornamental uses, such as rugs or carvings. Animals used for those purposes may harbor viruses that can sicken preparers and customers.
In August 2007, for example, a drum maker and his child in Connecticut both became ill with anthrax after his home and workplace became contaminated by a goatskin imported from Guinea. Apparently, it carried naturally occurring anthrax spores. People also can get sick from having wild animal pets such as turtles, which may carry salmonella.