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Being the most populous country in the world, it is not unexpected that new diseases would emerge from China.

In the last couple of years, diseases like the H1N1, the coronavirus severe acute respiratory syndrome (Sars) and the current Covid-19 broke out in China.

Professor Wanda Markotter, at the University of Pretoria's department of virology, said China was not the only place where new disease outbreaks were emerging.

For instance, the devastating Ebola virus first broke out in the Democratic Republic of Congo in West Africa.

Markotter said: “Around 19% of the world's population lives in China. With such a high population it is understandable that there will be immense pressure on the environment and supply of food.”

The Covid-19 outbreak has been linked to a food market in Wuhan in China where bats are found.

Markotter said bats were reservoirs or natural hosts, “which means they have a high diversity of viruses but they do not become sick. There are several reasons for that. But it has to do with their longevity, reproduction, roosting habits, ability to fly, echolocation, hibernation and maybe unique immunological factors".

“They can control these pathogens but when they do spill over into other animals and humans, we have no defence and we get sick. It is not easy for them to transmit it to humans. The viruses are not present in bats in high amounts and that is why there is usually another animal host involved before jumping to humans.

“There have to be high contact rates with humans and the viruses usually need to adapt to infect human cells. It is a matter of probability.

"The higher the contact rates, the higher the chance of spillover eventually. H1N1 is not linked to bats and with both Sars and Covid-19 it has not been proven that it is a direct infection from a bat that caused the outbreaks.”

She said that while animals could transmit diseases to humans, moving to a more plant-based diet might not be the answer.

“We must remember that properly cooked food or animal products pose no risk for infection. Oversupply of vegan products will put other pressures on the environment that will also disturb the ecosystem with unknown consequences,” Markotter said.

She cautioned against panicking.

“The disease is spread by droplets and will spread globally due to travel and locally between people who have contact. However, we need to recognise that this is a mild disease; most people will survive. The predictions are it will just become one of the circulating flu viruses in the end,” Markotter said.