Chinese researchers are studying why none of several dozen AIDS patients who shared a hospital ward with people suffering from Severe Acute Respiratory Syndrome, or SARS, acquired the disease despite the fact that some health care workers on the ward did contract SARS, Newsday reports. The patients shared a hospital floor in the city of Gaungzhou, where the SARS outbreak seemed to have peaked in February. "I am wondering why there was no SARS virus coinfection in the AIDS cases," said Zhang Fujie, China's director of AIDS treatment and care. "We are exchanging information with Hong Kong on this. We will continue to try to understand that."
Some AIDS experts in the country are speculating that the antiretroviral drugs given to the AIDS patients might have somehow blocked SARS infection. David Ho, of the New York City-based Aaron Diamond AIDS Research Laboratory, and Yuen Kowk-yung, of the University of Hong Kong, are now exploring the use of anti-HIV drugs to treat SARS.
Another theory being examined is that SARS doesn't actually cause death but that a strong immune response to the SARS virus precipitates the destruction of cells in the lungs and other parts of the body that brings on the pneumonia-like complications. Because AIDS patients have impaired immune systems, their immune responses to the SARS virus are less vigorous and less likely to lead to this complication. That theory is backed by limited evidence showing that treatment with steroids, which diminish immune system responses, has some effectiveness in combating SARS.
Some AIDS experts had previously worried that people with AIDS would be more likely to die from SARS than those with healthy immune systems. Luc Montagnier, head of the Paris-based World Foundation for AIDS Research and Prevention and a codiscoverer of the AIDS virus, had told reporters in Tokyo on April 21 that the SARS death toll among AIDS patients could be significantly higher than the disease's overall 4-5% death rate. Chinese health officials also had suggested that in some villages with large numbers of HIV-positive people, the SARS death rate could rise as high as 40%.