Analysis of the latest statistics on the global SARS epidemic reveals that at least 10 per cent of people who contract the new virus will die of the disease.The low death rates of about four per cent cited until now by the World Health Organization and others are the result of a statistical difficulty, well known to epidemiologists, that hampers the early analysis of new disease outbreaks. This difficulty is the reason for the apparent rise in death rate - not a change in the SARS virus.
A fatality rate of over 10 per cent puts SARS on a par with some other RNA viruses. Yellow fever and Japanese encephalitis, spread by tropical mosquitoes, between them kill more than 10,000 people a year, even though both have vaccines. Lassa fever kills about 70,000 a year in West Africa, but people mainly catch it from a local mouse.
Because these infections need animal vectors that only exist regionally, ...