Hong Kong scientists said a coronavirus they had found in masked palm civets, raccoon dogs and badgers is more than 99 percent the same as human SARS virus. For this reason they believe the SARS virus originated from these wild animals.
The animals are primarily distributed in low-altitude mountainous areas in tropical and subtropical regions. Though omnivorous, they are listed in the viverridae and mustelidae families under the carnivora order. Residents in southern China favor them as "invigorating" wildlife meat. They can be purchased alive at animal markets and restaurants in the cities of Guangdong Province. They are probably caught in the nearby mountains or raised and bred by farmers.
Even though the masked palm civet primarily feeds on fruits and insects, I have seen vendors in the Guangdong region throw pig lungs and other offal that do not have much value as food into the cages for the animals to devour. In recent years, pig farmers in Guangdong have been dogged by diseases caused by coronaviruses. It is possible the coronavirus jumped from pig offal to wild animals such as masked palm civets -- in the same way as cattle caught the mad cow disease from bone meal containing infected protein from goats and sheep.
The coronavirus found in wildlife such as masked palm civets may have mutated from a virus in pigs and other animals. Or a genetic reshuffle may have occurred between a coronavirus in wildlife and a virus that jumped to them from other animals, thereby forming a new virus that eventually infected human beings. Viruses from the coronavirus genus have high mutation and genetic reshuffle rates, and cross-infection between animals are not uncommon.
Therefore, it is still possible for SARS viral bodies with different virulence factors or pathogenicity to attack humanity. Chinese people over the centuries have had a fondness for civet meat. Now they are finally tasting the pain. It's worthwhile to ponder what kind of disease will result the next time wildlife gets back at us.
Hong Kong scientists discovered that wildlife such as masked palm civets did not show any symptoms even though they had the virus in their bodies and antibodies in their blood. All viruses from the coronavirus family feature strict host-specificity. Therefore, human beings may be the only target species made ill by the SARS virus, but the SARS virus can continue to infect the above-mentioned animals without displaying symptoms. Studies are needed on how long these animals will be carrying the virus and whether they will infect human beings. These animals may provide hidden hotbeds for the SARS virus. Will they become disease carriers and lurk permanently in people's living environment, waiting for an opportunity to jump at us?
Liou Pei-pai is a former director of the Taiwan Animal Health Research Institute.
Translated by Francis Huang