In 1918, when the fastest transoceanic voyage still took a matter of weeks, a flu epidemic killed 20 million to 40 million people around the world. Eighty-five years later, when thousands of people travel millions of miles every single day, the potential for tragedy is obviously far greater.
You might think that in those intervening years, our means of tracking infectious diseases -- and curing them -- would have progressed just as our means of travel did. But you would be mistaken.
The first cases of severe acute respiratory syndrome, or SARS, appeared about four months ago in southern China. To date, there have been an estimated 2,270 cases worldwide, and 79 people have died. That calculates to an alarmingly high fatality ratio of 1 in 29. The United States has reported 85 cases, which are traceable to recent travel to Asia, without any deaths. We've been lucky.
The spread of this unusually fatal disease is reminiscent of the opening months of the 1918 epidemic. The World Health Organization warns that SARS is transmitted by exposure to respiratory droplets from infected people and by surfaces contaminated with the virus. People are at risk simply through casual contact with one another and, early on, there may be a period in which an infected person shows no symptoms but is contagious. In contrast, the spread of HIV/AIDS requires sexual or blood contact.
These two routes of transmission are often called nonrisk- related and risk-related, respectively; the most appropriate public health responses for each are therefore different.
The promising news is that the infectious agent causing SARS has been narrowed down to one of two viruses. A case definition has been established and diagnostic tests to detect the virus will be forthcoming. Once available, it will be important to get these tests into the hands of public health laboratories around the world. Many people are working hard to ensure this.
The troubling news is that the SARS virus may be a coronavirus -- the family of viruses that cause the common cold. These viruses mutate and thereby change rapidly. Four months into the epidemic, it remains unclear whether the SARS virus is becoming more or less virulent. We can only hope that the case-fatality ratio is decreasing, along with human spread. Only time will reveal these answers.
Also, little if any comprehensive information is available on SARS virus mutations. Do all emerging SARS viruses look alike to our immune systems? Is there one representative strain of virus to study in-depth and target for a vaccine? These are uncharted waters; effective vaccines have not been developed for any common cold virus.
We are in the age of the Internet, personal digital assistants and global positioning devices. We have sequenced the human genome through amazing breakthroughs in science and technology. We also have automated laboratory equipment that can perform the work of thousands of technicians. We have not, however, yet assembled all these readily available parts for the real-time surveillance and analysis of new diseases like SARS.
At present, it is unclear whether SARS will fizzle out or explode into a worldwide airborne epidemic, possibly placing millions of lives at risk.
But it is clear that we need to take more samples and record symptoms quickly. We need to analyze samples within days for significant variations. We need to compile test results in one place and develop a comprehensive picture of the problem. And, if called for, we need to make fast-paced public health and vaccine development decisions with up-to-date information.
Last year, a panel of experts convened by the National Research Council in Washington recommended that we build high-capacity laboratories to manage natural outbreaks like SARS and to combat the germs of bioterrorism. No concrete action was taken, and now, with the war in Iraq, the report seems to have fallen off the political radar screen.
Such ideas are not the stuff of Buck Rogers. We have all the necessary science and technology to have the first high-capacity infectious disease laboratory working within a year, at a cost of perhaps $5 million, a little more than one Predator unmanned spy craft. Over five years, a small network of such laboratories might cost $100 million.
The high-capacity laboratory tools to fight SARS are the same tools needed to fight bioterrorism. What are we waiting for?