SARS: good
news, bad news

THE MEDIA frenzy around SARS has put the whole world on an emotional roller coaster. One day we all get elated with a headline like "SARS virus gene unlocked," with the article promising cures and vaccines in the near future. Then a few days later, we read about a whole province being declared in a state of calamity because of one SARS case.

I don't want to reinforce these terrible mood swings, but let me use a "good news, bad news" format to help us take stock of where we are now, drawing on the more staid (albeit dull) technical reports coming out of medical journals and websites of the World Health Organization and the US Centers for Disease Control.

Let's start off with SARS' infectiousness, especially because we keep hearing about "super-spreaders" or people who seem to pass on infections rapidly. The bad news is that these super-spreaders do exist, not just for SARS but for any disease. Scientists are still trying to figure out why this happens but this phenomenon certainly exists and it may be related to the stage of infection.

The good news is that not everyone who comes down with SARS is a super-spreader. Infections seem to take place only with close contact with patients, with most of the transmission taking place in hospitals. The problem (oops, bad news) is that in many poorer countries, including the Philippines, many patients will probably never reach a hospital and infections will take place in homes and in communities.

Will SARS evolve into a pandemic like that of influenza in 1918 which killed millions? The bad news is that we can't really project that far ahead. The statistics can be alarming, with the way new cases seem to be cropping up each day. The good news is that while the figures do rise rather quickly, they may not be as bad as it seems. When you read the papers or watch TV newscasts, you get the impression that every other person in Hong Kong now has SARS. In reality, the number of probable SARS cases was 1,434 as of April 22, out of a total population of seven million.

This is not to trivialize the suffering that comes with SARS illness and deaths, but let's compare SARS with some other diseases. In some southern African countries, one out of every three adults is now infected with HIV, the virus that causes AIDS, yet the world seems to have forgotten this threat.

One could argue that HIV is transmitted mainly by sex while SARS is a respiratory disease, and thus so much more easily passed on. Well, if we want to use that analogy, then let's look at another respiratory disease, tuberculosis. In the Philippines, each year hundreds of thousands are infected with tuberculosis, with 20,000 dying, but no one seems to worry about TB, until a close friend or relative gets it, or dies. SARS is scary because it's so new, so unfamiliar.

But what about the death rates for SARS? I'm going to reverse my discussion here and start with the good news. Right now the mortality rate is reported to be hovering around 5 percent. That's quite low compared to many other diseases. In fact, I try to console more panicky friends and suggest that instead of thinking of a "5 percent death rate," we could look at SARS in terms of a "95 percent survival rate."

But there's a "bad news" angle to this. The current 5 percent figure is derived by dividing deaths by total cases, which is not a reliable method of computation because many of the cases are still new, and we still don't know if the patient will recover or die. For example, Hong Kong has 1,434 reported cases but only 560 patients can be classified as being "resolved" cases. Of these 560, 461 recovered and 99 died. Now, if you divide 99 by 560, you get a 17.6 percent death rate. Using this method of computation, Canada, with 13 deaths and 65 recoveries, has a similar SARS death rate of 16.6 percent.

We're going to have to wait for a few more weeks to get a more reliable trend, based on more cases. But I worry that as the outbreak spreads out to more impoverished areas, we'll probably get a death rate higher than 5 percent.

I also tend to be more pessimistic because SARS death rates may have a strong correlation to the state of health care services. I've been following newscasts on Chinese television and am quite alarmed with the trend of reports coming from poorer provinces such as Inner Mongolia, with both cases and deaths escalating quite quickly. (All this in spite of China's tendency to under-report cases.)

Death rates from diseases often depend not just on the nature of hospital facilities but on the overall health status of citizens. If a person's immune system is already weakened by having to fight so many diseases -- tuberculosis, for example, in the Philippines -- the probability of death from SARS increases.

This is taking us to the matter of cures. The bad news is that there is no cure yet for SARS. There was some media hype when scientists figured out the SARS virus' genetic structure, with hints that treatment and vaccines would not be far off. We forget that it's been almost 20 years since scientists identified HIV, the cause of AIDS, and we still don't have a cure or vaccine.

There are anti-viral drugs but these only slow down the virus' reproduction. One of these drugs, ribavarin, is being used for SARS patients but technically speaking, these anti-virals are not cures.

The good news is that patients do recover from SARS, even without "cures." SARS is terribly virulent but so are older diseases such as influenza and pneumonia. The SARS virus is a mutated version of the cold virus, which infects millions of people each day. Patients will recover from viral diseases even without drugs. The key is to strengthen the patients' own immune systems.