We cannot ban the world’s ‘wet’ markets – but we can make them safer

The world had been warned. Experts said repeatedly where and how the next deadly virus would emerge. Yet here we are facing a reality we all knew was coming.

It began, utterly predictably, at a crowded live-animal market. A virus unknown to humans was lurking in a chicken, a pig or a local delicacy.

Then came the spread to humans with zero immunity. With no test, vaccine or proven medicine, the epidemic is with us.

Epidemiologists are not yet in full agreement about the precise animal culprit but there is no doubt the outbreak originated from a local “wet” market selling dead and live animals.

The outbreak resulted from an animal-to-human species-jump – as do three of four new human infectious disease epidemics. HIV/Aids, Ebola,

Zika and bird flu, as well as previous Sars and Mers coronavirus outbreaks, each originated in animals.

Most animal viruses are quickly eliminated by human defences. But it takes just one new viral strain and a vulnerable human host to catalyse an entirely new disease outbreak.

Wet markets put a variety of live animals in proximity to large numbers of handlers, sellers and customers. The resulting contact of humans each year provides millions – if not billions – of opportunities for new strains of coronavirus, influenza or viruses to make their way into us. If wet markets are such a threat to public health, why not ban them? The Chinese government tried this in 2013 and the banned ones were quickly replaced by a raft of potentially more dangerous black markets.

Wet markets are important sources of affordable food for growing urban populations. They are embedded in cultures economies throughout Asia. Making wet markets safer while over time shifting consumer preferences to better sources provides a sensible alternative to an outright ban.

Following the 2003 Sars outbreak, Hong Kong took a series of measures to strengthen regulation of wet markets and their animal supply chains.

Among these were disinfection, reducing faecal contamination, and hygienic slaughtering. Consumers were educated on safe handling of wet market purchases. Similar measures have been implemented in Thailand, Vietnam and Bangladesh.

Targeted surveillance of viruses with epidemic potential could track the effectiveness of such measures and help producers to identify and cull poultry with deadly avian influenza. Future outbreaks are inevitable. The expanding web of risks, from urban crowding, population growth, greater demand, international travel and global warming, will exacerbate this.

Chinese wet markets remain a threat to global health. Its political and public health leaders must not fall into the cycle of short-lived commitment but long-term complacency.

Dr Jonathan Quick is adjunct professor of global health at Duke Global Health Institute and an author on health issues