Acute Stages of HIV Have Been Characterized

Researchers recently were able to track the HIV status of high-risk individuals to characterize the acute stages of HIV.

The researchers defined the acute stage as the first 30 days of infection.

The study, which was published in The New England Journal of Medicine, included high-risk individuals from Africa and Thailand who had blood drawn twice weekly for qualitative plasma HIV RNA nucleic acid testing (NAT). This test allows for the early detection of HIV.

"We were able to capture people with HIV infection before they had symptoms and before they had antibodies, which is how a diagnosis of HIV is usually made, and while their viral loads were actually very low," said study principal investigator Merlin Robb, MD. "We're able to define the symptoms and signs during the acute interval, and now we're working intensively on evaluating the relationship between the virus and the host immune response."

According to the study, early events in the infection can impact the future of the disease. Although researchers in the past have found the amount of the HIV virus in the blood increases quickly during acute infection and decreases with time, the duration and type of immune response has not been clear.

Researchers discovered a link between peak viremia and set-point viremia. The viral load set-point begins 18 to 42 days after infection, which is when acute viremia ends.

"This indicates that events during acute infection are abrupt and decisive, meaning they play a role in later disease outcomes over many years of HIV infection in the absence of treatment," Dr Robb said.

Researchers also found that the clinical presentation of the infection had fewer, briefer, and milder symptoms than previously thought.

"Our impression from this finding is that most of these people would not have come into a clinic with complaints and would not have been identified as acutely HIV infected," Dr. Robb said. "It changes the way we need to think about identifying people with acute infection."

Findings from this study prove that intervening in acute HIV infections is possible, but it is not feasible on a large scale yet, the researchers wrote.

"This study is now being re-purposed to allow us to test promising new interventions at the very earliest period of HIV infection with a view to develop approaches to HIV cure," concluded senior paper author Colonel Nelson Michael, MD, PhD.