GUANGZHOU, China, January 5, 2004 (ENS) - Laboratory tests received today have confirmed a case of Severe Acute Respiratory Syndrome (SARS) in a 32 year old man in the southern Chinese province of Guangdong. The patient is a television producer who has been undergoing treatment in isolation at a hospital in the provincial capital, Guangzhou, since December 20.

The World Health Organization (WHO) has decided that this single isolated case does not constitute grounds for issuing a SARS alert or recommending any restrictions on travel or trade.

This is the first confirmed case of SARS in 2004, and the first case not linked to a laboratory accident that has occurred since the initial outbreak of SARS was declared contained on July 5, 2003. Laboratory related cases occurred after that date in Singapore in September and in Taiwan, China in December of last year.

The Guangdong case has been under investigation, with support from the WHO, since December 26, when it was initially reported by Chinese authorities.

Previous diagnostic tests produced inconclusive results. SARS diagnostic tests are limited, so confirmation of positive results by a reference laboratory designated by the World Health Organization is required for a definitive diagnosis.

The confirmatory tests were conducted in Hong Kong by the University of Hong Kong and the Government Virus Unit, Queen Mary Hospital. Both laboratories are members of the WHO Multicentre Collaborative Network for Severe Acute Respiratory Syndrome Diagnosis that collectively identified the SARS coronavirus in mid-April 2003.

A confiscated unlicensed civet cat at a wild game market in Guangzhou. (Photo courtesy Veterinary Services Dept. Perak, Malaysia)

"Further research has found that the S gene sequence of the coronavirus from civet cats and that of the confirmed SARS case in Guangdong were highly homological and were from the same phylogenetic tree," the state news agency Xinhua reported today.

Guangdong immediately announced a ban on the breeding and sale of civet cats, and all civet cats being raised and sold in Guangdong are to be destroyed. Some 10,000 civet cats may have to be killed to prevent any possible spread of SARS, authorities estimate.

In addition, the city's wildlife markets will be closed, Feng Liuxiang, deputy director of the provincial health department, said on national television today.

He prohibited the entry of civet cats into Guangdong from elsewhere in the country, and inspection stations have been established along highways leading to the province to keep them out.

The Guangdong provincial forestry department quarantined 2,030 civet cats from 41 farms in the province today, Xinhua said.

But the World Health Organization hesitated to place the blame on civet cats. "The source of infection for this newly confirmed case remains unclear," WHO said today.

Several lines of investigation last year suggest that SARS may have originated from contact with wild animals sold for human consumption at live markets in southern China, the international health agency said.

Studies conducted last year detected a SARS like virus in some animal species, including the masked palm civet, WHO acknowledged. Retrospective analysis of patient records has linked several of the earliest cases, which began occurring in Guangdong in mid-November 2002, to contact with wild animals.

Live animals for purchase at Qingping Food Market in Guangzhou (Photo credit unknown)

On the other hand, Dr. Hitoshi Oshitani, who leads WHO's response to SARS in the Western Pacific Region, told reporters, "WHO has long maintained that animals could be reservoirs for the SARS coronavirus (CoV), and hence a source of infection."

In a statement distributed before a news conference, WHO said the organization welcomed "a decision by the Chinese authorities to try and minimize contact between humans and the animals thought to be carrying the SARS virus."

While scientists try to trace the origin of the virus, Chinese authorities have introduced several measures to protect public health. The patient has been treated in isolation since his hospitalization on December 20, four days after the onset of symptoms.

All contacts have been traced and followed up. All are reported to be free of symptoms and most have been released from quarantine, suggesting that no further transmission has occurred. Surveillance for additional cases has been intensified in Guangdong and other provinces.

At the request of Chinese authorities, additional teams from the World Health Organization are being sent this week to assist in research aimed at identifying the source of infection and preventing further cases.

The first cases of SARS occurred in Guangdong in mid-November 2002. SARS eventually claimed 349 lives in China. The disease began to spread internationally in late February 2003, eventually causing more than 8,000 cases, with 774 deaths, in 27 countries.