Apr 9, 2003 (CIDRAP News) A World Health Organization (WHO) official today said the peak of the epidemic of severe acute respiratory syndrome (SARS) has passed in places other than China and Hong Kong, despite the continuing increase in cases.
"The peak in most places is behind us," said Dr. Guenael Rodier, WHO director of communicable disease surveillance and response, speaking at a WHO news conference. "On the other hand, there could be transmission chains in other countries which will create new local epidemics. But today, apart from China and Hong Kong, where I can't say that the peak is behind us, for the others it is." A transcript of the conference was posted on the WHO Web site (see link below).
Today WHO reported a total of 2,722 SARS cases with 106 deaths, an increase of 51 cases and 3 deaths since yesterday. New cases included 42 in Hong Kong, 5 in Singapore, 3 in Canada, 1 in mainland China, and 1 in the United states. The Centers for Disease Control and Prevention today reported a total of 154 suspected US cases, with no deaths.
Rodier's comment was one of many SARS developments in recent days, including the following:
- WHO officials said China's Guangdong province, the apparent birthplace of SARS, responded well to the outbreak, but also said better SARS surveillance is needed in rural areas of the province.
- A WHO official said there is a suspected case of SARS in South Africa, which apparently would be the first case on that continent.
- More evidence for the existence of SARS "super spreaders," or super-infectious people, was reported, particularly in Singapore.
- WHO officials said there has been no clear evidence that the antiviral drug ribavirin is effective for patients with severe SARS.
- The Lancet published a report and commentary on the clinical picture of SARS, which included "disproportionally mild" respiratory symptoms and auscultatory findings relative to chest x-ray findings.
- WHO said Hong Kong authorities will allow Block E of the Amoy Gardens apartment complex, site of a large SARS outbreak, to reopen tomorrow, and residents will be permitted to return from quarantine camps after their apartments have been disinfected.
- A Chinese physician accused the Chinese government of covering up the extent of the SARS outbreak in Beijing, according to an Associated Press report. The physician, Jiang Yanong, said there were 106 cases in the city, more than five times the 19 cases reported by the Health Ministry.
A team of WHO experts in China reported that the Guangdong health system responded well to the SARS outbreak, according to a WHO news release. The team expressed confidence that "virtually all probable cases of SARS" presenting at hospitals in the province will be detected. "However, the team found an urgent need to improve surveillance in the countryside to head off new outbreaks in rural areas." The team was concerned about an increase in cases that were not linked to known transmission chains.
In addition, the WHO team voiced concern about the ability of other Chinese provinces to respond to the epidemic. In Beijing, for example, most hospitals don't make daily reports of SARS cases, and systematic contact tracing is lacking, the team reported.
At the WHO news conference, Rodier said in response to a question, "We actually today have a suspected [SARS] case in South Africa." He expressed concern that SARS cases in Africa could go unrecognized at first, leading to hospital outbreaks. "SARS could become in the long run a problem for the developing world," much like tuberculosis, malaria, and other endemic infectious diseases, he said.
The WHO news release said that an outbreak of 20 suspected cases at the Singapore General Hospital might have been caused by a SARS "super spreader." "The health worker considered to be the index case in this cluster of cases may be the fourth 'super spreader' identified in Singapore," the statement said. It appears that "super spreaders" may have contributed to SARS outbreaks around the world, officials said.
Meanwhile, an Associated Press report today said that "all but a handful" of 118 reported SARS cases in Singapore have been traced to Esther Mok, 26, a former flight attendant who became ill in early March after traveling to Hong Kong. Her case was one of the three original SARS cases in Singapore, according to the report. Mok survived the disease, but her parents and her pastor all contracted it and died, the report said.
On the basis of recent cases in Vietnam, WHO epidemiologists still believe that SARS patients do not spread the disease before they have symptoms, according to the WHO news release. No do they see evidence of an incubation period longer than 2 to 7 days in most cases, officials said.
On the treatment front, WHO officials at the news conference said there is little to suggest that ribavirin is effective for SARS. About 60 patients, most of them with severe cases of the disease, have been treated with the antiviral, said Dr. Mark Salter, a WHO medical officer. "None of these individuals have shown any significant improvement that can be attributed directly to the ribavirin," he said. He added that clinicians working with WHO are planning systematic appraisals of ribavirin and other treatments in use.
In the Lancet report, a group of Hong Kong clinicians reported on their analysis of 50 SARS cases. "When compared with chest radiographic changes, respiratory symptoms and auscultatory findings were disproportionally mild," they wrote. They also found evidence that (as reported previously) SARS is associated with a hitherto unknown coronavirus: 45 of 50 SARS patients, but no controls, had evidence of infection with the virus.
At the WHO news conference, Salter said the coronavirus found in SARS patients is similar to, though not the same as, other coronaviruses that infect mice and pigs. While there is no actual evidence that the SARS virus is "a mutated animal virus," it is known that different coronaviruses can infect pigs at the same time and exchange genetic material, he said. "So we may be looking at an infection having occurred in animals which has now changed the virus to allow it to more readily infect human beings," he added.
Transcript of WHO press conference
WHO's Apr 9 news release
WHO case and fatality count
Lancet report on 50 cases (abstract)