Discovery and surveillance of novel or emerging human and animal viruses by surveillance of patients and wild animals: impact on control and management of infectious diseases

Abstract

Almost half of all patients with community-acquired pneumonia have no identifiable aetiological agents. Our research identified a novel Group IIb coronavirus as the cause of SARS from the lung tissue of a patient who died from the atypical pneumonia in 2003. About 70% of new emerging infectious agents originate in animals. Civet cats are the most commonly consumed wild game animal meat in winter and we found civet SARScoronavirus in caged civet cats in wild animal markets. However, surveillance of wild and farmed civet cats for this novel coronavirus proved fruitless, suggesting that civet cats are simply amplification hosts and not the true virus reservoir. Since the recently identified Lyssavirus, Nipah and Hendra viruses, which have emerged to cause outbreaks of human disease in the last 10 years, were found in bats, we focused on these animals as possible SARS-coronavirus reservoirs. A novel bat SARS-coronavirus highly similar to the human and civet virus was subsequently discovered. If wild animal surveillance had been performed systematically before 2003, the SARS-like coronavirus group might have been discovered and Hong Kong might have better prepared for the SARS epidemic. One year after the discovery of the SARS-coronavirus, we also found another novel Group IIa coronavirus in a patient with community acquired pneumonia returning from Shenzhen. Continuous vigilance is required in surveillance for emerging infectious diseases. For known microbes such as the influenza A H5N1 strain causing the present pandemics in poultry and other birds, continuous surveillance may identify the strains with pandemic potential in humans. The results of this microbiological surveillance have clearly contributed to the epidemiological control, diagnosis and management of influenza A H5N1 and SARS-coronavirus.