HIV strikes fast, study finds

Duke results point to need for prompt diagnosis, mark shift in AIDS research

HIV infects and attacks the body within days -- much faster than previously thought -- drastically narrowing the window of time when intervention is possible, Duke University researchers have found.

This means clinicians must test more and sooner if they hope to catch an infection before it can be transmitted to someone else.

"We're just going to have to be much more aggressive in identifying the infection early on," said Dr. Peter Leone, the state's HIV/AIDS health director and an associate professor in the UNC-Chapel Hill schools of medicine and public health.

Knowledge of what goes on immediately after transmission of the virus is essential to understanding what kind of vaccine will be effective, a discovery especially important in the wake of two recent failed attempts to find a shot that works.

On Thursday, the National Institute of Allergy and Infectious Disease, the main federal agency in charge of AIDS research, called for scientists to return to a basic question: What happens when the virus is transmitted?

"Design of a vaccine that blocks HIV infection will require enormous intellectual leaps beyond present-day knowledge," concluded a broad team of institute researchers writing in today's edition of the journal Science. The team said the focus of research should be on discovery of a vaccine rather than on clinical trials for evaluating medicines that may or may not work.

The Duke results, which will be published in the August issue of the Journal of Virology, exemplify that type of scientific inquiry.

The research team was led by Dr. Barton Haynes, director of the Center for HIV/AIDS Vaccine Immunology. The center, a consortium of research institutions founded in 2005 with headquarters at Duke, was the beginning of a larger shift in HIV/AIDS research that culminated in Thursday's announcement by the federal institute, Haynes said.

Faster diagnoses

The center's research has significantly changed the way scientists look at HIV. For years, doctors thought the virus was a stealth infection and couldn't be diagnosed for months. Researchers at UNC-CH proved several years ago that the virus can be detected within weeks. Now the Duke team has whittled the time frame further, to days.

"It was stunning to see how quickly the immune system was affected," said Haynes, who is the lead author on the study.

To deal with the shrinking window, clinicians can check for the presence of HIV more often, but the potential for catching cases early enough for intervention looks bleak. The earliest and most infectious stage of HIV has vague and practically unnoticable symptoms.

"It looks like HIV does a lot of damage very early on," Haynes said. "Now we feel that the opportunity to intervene most effectively may range from about five to seven days after infection."

Doctors are going to have to start screening patients for the HIV virus even if they come in with what seems like a headache or a common cold, Leone said.

"We can narrow that window down, but we're never going to be able to identify all of these folks," Leone said. "We just can't."

HIV is the virus that causes AIDS. Worldwide, about 3 million cases of the disease are diagnosed each year.

North Carolina, which identifies about 2,000 cases of HIV a year, is ahead of the game in identifying the infection early. The state pioneered a program six years ago that tests for HIV in the genetic material of patients even if they pass an AIDS test.

Still, Leone said, clinicians need to be recognizing the infection earlier and routinely considering HIV when someone comes in with an illness.