Investigations continue as SARS claims more lives.

Worldwide deaths and reported cases of severe acute respiratory syndrome from Nov 1, 2002 to April 7, 2003, according to WHO

By April 7, severe acutev respiratory syndrome (SARS) had claimed 98 lives with 2601 cases reported from 17 countries, according to WHO.

As The Lancet went to press, WHO said that SARS had killed 53 people in China, 23 in Hong Kong, nine in Canada, six in Singapore, four in Vietnam, two in Thailand and one in Malaysia (see commentaries and Fast-Track SARS study on www.thelancet.com)

The hardest hit countries remain China, with 1268 confirmed cases, and Hong Kong, with 883 cases.

WHO welcomed the Chinese government's decision to provide daily updates on numbers of cases and deaths nationwide by province. “Chinese officials have announced that SARS is being made a high priority by the government. A system of alert and response for early detection and reporting of all emerging and epidemic-prone diseases is being put in place”, said WHO.

Although China has reported several new cases and deaths in the past few days. WHO was particularly alarmed by the death of a 53-year-old Finnish staff member of the International Labor Organization (ILO) on April 6 in Beijing. ILO staff were attending an international conference in Beijing. Currently WHO does not know how this staff member contracted SARS. “He had travelled to Beijing via Thailand, where no local transmission has been reported”, said WHO.

Meanwhile Hong Kong continued to report the largest number of new cases, which is placing hospitals under considerable strain. However a spokeswoman for the Hong Kong's Hospital Authority said its hospitals were prepared for 3000 patients with SARS in a worst-case scenario.

Hong Kong's Department of Health said the investigation at the Amoy Gardens estate, where 268 residents were infected, was coming to an end. Health authorities are considering evidence for a oral-faecal route of transmission although no conclusions have been reached. The Department of Health said it had found no evidence of airborne transmission.

China faced renewed criticism by WHO's director-general Gro Harlem Bruntdland for failing to report the initial outbreak in November last year.

Meanwhile WHO's network of 11 laboratories have been working round the clock to develop a diagnostic test. “Three diagnostic tests are now available and all have limitations”, said WHO.

ELISA detects antibodies but only from about day 20 after clinical symptoms appear. “It therefore cannot be used … at an early stage before they have a chance to spread the infection to others”, said WHO.

The immunofluorescence assay detects antibodies reliably from day 10 of infection, but is a demanding and comparatively slow test that requires the growth of virus in cell culture.

PCR is useful to detect SARS virus genetic material in the early stages of infection but produces many falsenegative results.

Last week WHO stepped up precautions and advised citizens not to travel to countries worst hit by SARS.