Tracking a Modern Plague

Photo: Rod Searcey

Imagine hunting a killer who constantly changes his appearance. He moves undetected from one area of the world to another. He slips past "security agents" who don't even know what to look for. A frightening scenario from the latest hit action movie? Maybe, but for Dale Hu this is no big-screen adventure - it's job. And the killer is HIV.

As a medical epidemiologist for the federal Centers for Disease Control and Prevention in Atlanta, Hu searches for variant subtypes of the AIDS virus that are capable of slipping unnoticed through screening tests.

Hu is one of two project leaders on the CDC team that began sleuthing in 1994. French researchers had reported on several patients from Cameroon who exhibited the classic signs of AIDS but tested negative for HIV. "The CDC were really concerned that diagnostic tests in the United States might miss this divergent strain, labeled HIV-1, subtype O," Hu says. To prevent this, Hu and colleagues tested samples of serum from blood banks across the country. They did not find any "subtype O" strain. But in July, the CDC reported that the Los Angeles Health Department had treated a woman from a central Afircan country who was diagnosed as having the HIV-1, subtype O strain. So, although the U.S. blood supply is currently safe, the testing continues.

Testing also coutinues around the world. Hu and his team have mounted an exhaustive search for new variant HIV strains in Thaliland, Brazil, Uganda and the Ivory Coast. In each of these countries, they have helped establish collaborative testing efforts with local authorities. Hu speaks five languages, and he has found them invaluable with ministries of health and local researchers. Once a new strain is identified, it is only a matter of months before diagnostic screening tests are developed to catch the new variant.

While in medical school at UC-San Diego, Hu did not see his future in public health. However, since being at the CDC, he has discovered that he loves the work. "It's a very exciting area. I find it rewarding because we can have such a direct effect on public health." But it is also emotionally draining. Hu relaxes by playing volleyball and tennis. He also took up Latin dancing three years ago. "I like the salsa and the merengue," he chuckles. "I suppose it's an unusual combination. But I love it." A Chinese-American AIDS researcher doing the merengue in a Latin American dancehall? Why not?

Meanwhile, Hu keeps working as an international viral detective to ensure that everything is being done to catch this killer -- a chase that is motivated by his constant concern that there is yet another strain out there nobody even knows about.

--Katie Kinnaman, '92