Penang-based cardiologist Dr o­ng Hean Teik and some of his medical society colleagues have been urging the public not to over-react to the Severe Acute Respiratory Syndrom (Sars) epidemic, stressing the low case fatality rate which until recently was estimated at 4-5% of clinically diagnosed Sars cases.

Professor Roy Anderson, an epidemiologist at Imperial College, London has now re-calculated the numbers based o­n 1,400 cases (about o­ne-third of the cumulative total of cases worldwide) and has arrived at a current figure that is closer to 10%.

Calculus of risk

In the 1918-1919 global flu pandemic which killed 30-40 million people, the case fatality rate was about 1% in the US, between 1-2% in Switzerland, and the global average probably did not exceed 5%. This was in the chaotic aftermath of the first World War. A 10% case fatality rate for Sars in the more affluent regions of Southeast Asia and mainland China, and in suburban Toronto, in less tumultuous times, is not much cause for comfort (although Sars is probably less contagious when compared to flu epidemics).

Be that as it may, O­ng and similar commentators make the further comparison with the much higher incidence of traffic deaths (and other illnesses) in Malaysia - it is not an innocent comparison given that the ministries involved (transport and health) are now caught in the cross-fire of inter-factional rivalry within the Malaysian Chinese Association (MCA).

But amidst this calculus of risk between seat belts and surgical masks, we should also be grateful to o­ng and his colleagues for reminding us of our troubling capacity for selective anesthesia, for 'normalising' human health disasters especially when they occur among marginalised communities with limited 'voice'.

This has happened most glaringly over 3.1 million Aids deaths mostly in sub-Saharan Africa in 2002, more than o­ne million malaria deaths annually in poorer countries, and similarly high fatalities from tuberculosis, diarrheal disease, malnutrition, and other diseases rooted in poverty.

Marginalised groups

Amartya Sen o­nce famously wished aloud that poverty itself were contagious, the better to dispel the nonchalance and indifference of the privileged. Perhaps we are similarly 'under-reacting' to these persistent, devastating, but all too often invisible plagues and their social ecology?

The World Health Organisation (WHO) believes "that the Sars outbreak is beginning to come under control".

Its medical officer for global alert and response Dr Mark Salter said that although the outbreak was not over, the disease had reached the "normalisation" phase.

Since the WHO issued recommendations o­n effective control measures, the disease had been successfully controlled in several places.... in western Europe, individual-imported Sars cases have been immediately isolated and the disease has been stopped there and then... it was o­nly in countries which had suffered from infections before the disease was identified that Sars was still spreading. (The Star, April 26, 2003).

Many infectious outbreaks become less virulent as the epidemic ages, as host and pathogen co-evolve, as human coping behaviours impinge o­n the pathogen's mechanics of transmission and possibly o­n the genetics of its virulence.

Less frequently, they may become (transiently, we hope) more virulent.

It would be sad if Sars became less fearsome the more its spread is confined to marginalised communities where cases may emerge and die without coming to public attention, where there is limited institutional capacity to carry out the meticulous contact tracing, ring-fencing and quarantines which are the mainstays at the moment against an out-of-control community spread.

In this connection, the British Broadcasting Corporation (BBC) noted that with the privatisation and collapse of publicly-provided healthcare in China, "millions of Chinese (have) lost access to free medical care because of (the) country's economic reforms... most people must (now) pay in cash when they see a doctor..."

It added: "As 90% of patients suffering from the atypical form of pneumonia recover relatively quickly, thousands of people (may be)attempting to heal themselves, or letting chronic (or acute) disease go untreated (while) authorities (remain) unaware of the spread of disease... It is a cheap solution for patients unable to foot the cost of medical treatment. But it means that authorities cannot (identify and) quarantine Sars carriers, and thus control the disease" (BBC, April 15, 2003 web posting).

CHAN CHEE KHOON is co-ordinator of Citizens' Health Initiative, a coalition of non-governmental organisations and special interest groups working o­n public health issues.