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# 7018
Early epidemiological and serological investigations led many researchers to suspect that palm civets – small nocturnal mammals, a delicacy often served in Chinese `wild flavor’ restaurants – were a possible reservoir host for the SARS virus that erupted a decade ago in rural Guangdong Province.
This link first appeared in a World Health Organization SARS update (#64 Situation in Toronto, detection of SARS-like virus in wild animals) on May 23rd, 2003 (excerpts follow):
Research teams in Hong Kong and Shenzhen, China have today announced the results of a joint study of wild animals taken from a market, in southern China, selling wild animals for human consumption.
The study detected several coronaviruses closely related genetically to the SARS coronavirus in two of the animal species tested (masked palm civet and racoon-dog). The study also found that one additional species (Chinese ferret badger) elicited antibodies against the SARS coronavirus. These and other wild animals are traditionally considered delicacies and are sold for human consumption in markets throughout southern China.
<SNIP>
Information on the potential role of animals in the transmission of SARS is important to overall understanding of SARS. Much more research is needed before any firm conclusions can be reached. At present, no evidence exists to suggest that these wild animal species play a significant role in the epidemiology of SARS outbreaks. However, it cannot be ruled out that these animals might have been a source of human infection.
This research, led by Dr. Guan Yi, led to the temporary ban on the sale of civets and the closing down of numerous wildlife markets across much of China.
While not conclusive, the case against palm civits grew stronger that fall with the publication of:
Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China.
Guan Y, Zheng BJ, He YQ, Liu XL, Zhuang ZX, Cheung CL, Luo SW, Li PH, Zhang LJ, Guan YJ, Butt KM, Wong KL, Chan KW, Lim W, Shortridge KF, Yuen KY, Peiris JS, Poon LL.
Source
Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital, Hong Kong Special Administrative Region, People's Republic of China. yguan@hkucc.hku.hk
Abstract
A novel coronavirus (SCoV) is the etiological agent of severe acute respiratory syndrome (SARS). SCoV-like viruses were isolated from Himalayan palm civets found in a live-animal market in Guangdong, China. Evidence of virus infection was also detected in other animals (including a raccoon dog, Nyctereutes procyonoides) and in humans working at the same market. All the animal isolates retain a 29-nucleotide sequence that is not found in most human isolates. The detection of SCoV-like viruses in small, live wild mammals in a retail market indicates a route of interspecies transmission, although the natural reservoir is not known.
In January of 2004, when it looked as if SARS might be about to return, China undertook a massive cull of palm civets (see Time Magazine Averting an Outbreak by Karl Taro Greenfeld).
Over the next few years, however, the case against civets grew weaker, as more closely related SARS viruses were detected in bats – suggesting that civets were either secondary, intermediate, or perhaps even incidental hosts.
Bats, civets and the emergence of SARS
Curr Top Microbiol Immunol. 2007;315:325-44.
Wang LF, Eaton BT.
Abstract
Severe acute respiratory syndrome (SARS) was the first pandemic transmissible disease of previously unknown aetiology in the twenty-first century. Early epidemiologic investigations suggested an animal origin for SARS-CoV. Virological and serological studies indicated that masked palm civets ( Paguma larvata), together with two other wildlife animals, sampled from a live animal market were infected with SARS-CoV or a closely related virus.
Recently, horseshoe bats in the genus Rhinolophus have been identified as natural reservoir of SARS-like coronaviruses. Here, we review studies by different groups demonstrating that SARS-CoV succeeded in spillover from a wildlife reservoir (probably bats) to human population via an intermediate host(s) and that rapid virus evolution played a key role in the adaptation of SARS-CoVs in at least two nonreservoir species within a short period.
Since 2007, the case against bats has grown stronger, while the case against civets has become less so. In recent months we’ve seen bats linked to another, emerging coronavirus (see EID Journal: EMC/2012–related Coronaviruses in Bats) out of the Middle East.
This emergent novel coronavirus (dubbed NCoV by the WHO), has public health agencies around the world on high alert (see WHO: Revised NCoV Surveillance Recommendations), although to date only 15 cases have been identified.
Nowhere is this more apparent than in Hong Kong – arguably the city hardest hit by SARS epidemic in 2003 (see SARS And Remembrance) – where their Centre for Health Protection is taking an aggressive, and very public stance against this new viral threat.
While the link between civets and SARS has been diluted over time, the fact is we don’t have a good handle yet on the emerging NCoV. On Monday of this week a WHO update described our knowledge gap this way:
A number of unanswered questions remain, including the virus reservoir, the means by which seemingly sporadic infections are being acquired, the mode of transmission between infected persons, the clinical spectrum of infection and the incubation period.
Given this current dearth of knowledge, overnight Hong Kong announced that their longstanding ban against importing civets remains in place, and that a new ban on importing bats is going into effect.
This from http://www.info.gov.hk.
HK continues import ban on game civet cats
The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department today (March 21) reminded the public that the import of game masked palm civets (also known as Himalayan palm civets or gem-faced civets, or commonly referred to as civet cats) is prohibited.
A spokesman for the CFS said that the import ban on masked palm civets was introduced as a precautionary measure after the outbreak of SARS (Severe Acute Respiratory Syndrome) in 2003 by the Director of Food and Environmental Hygiene.
The spokesman said, "The Government has remained vigilant ever since. We see no justification for relaxing the control."
He pointed out that the import ban would also extend to bats due to the public health threat from novel coronavirus.
No application for importing of the above products had been received over the past decade.
He called on members of the public to exercise caution when contacting, handling or eating wild animals to minimise the risk of zoonotic diseases.
"We will closely monitor the situation and remain vigilant on the latest developments," the spokesman added.
Ends/Thursday, March 21, 2013
Issued at HKT 16:01
Ten years after the SARS epidemic began, there are still many unanswered questions regarding its origins.
Only six months after NCoV was first detected in a patient from Saudi Arabia, it is not surprising that we still know so very little about its place in the natural environment.
Since we don’t know at this stage how much of a threat NCoV may ultimately provide, public health agencies are obliged to take whatever prudent steps they can to prevent the spread or importation of this, or any other emergent threat.
Because they know that the old adage is true.
`When public health works, nothing happens.’
