People who frequently test for HIV remain healthier and much less likely to die than people who wait long periods before getting tested. These data, published online February 22 in the journal AIDS, are the first to examine the link between frequent HIV testing and health outcomes.

Prevention and treatment guidelines in the Netherlands recommend that those who are at ongoing risk for HIV get tested at least yearly for the virus, for those who are confirmed to be positive start treatment with antiretrovirals (ARVs) before their CD4 count drops below 350. These guidelines are in place to both slow ongoing HIV transmission and ensure the health and well-being of those who do become positive.

While data exist to indicate that treating with ARVs earlier results in better outcomes for people with HIV, and that people who find out their positive HIV status tend to reduce behaviors that could infect others, there have been no data to prove that frequent testing offers health benefits to those who become HIV positive.

To test this theory, Luuk Gras, MSc, from Stichting HIV Monitoring in Amsterdam, and his colleagues examined data from 5,494 people who contracted HIV between 2004 and 2008 through sexual contact and who had medical histories available for analysis.

Gras's team separated the participants into three groups. One group included those who tested positive within one year of their last HIV-negative test (frequent testers). Another included those who tested positive between one and two years after their last HIV-negative test (infrequent testers), while the third group included those who were HIV positive at their first HIV test (initially HIV positive).

The group who were initially HIV positive at the first test was far larger than the other two: 4,067 people compared with 561 infrequent testers and 888 frequent testers.

There were also significant demographic differences between those who were initially HIV positive and those who were infrequent and frequent testers. Frequent and infrequent testers were far more likely to be born in the Netherlands and to have been infected through homosexual contact. Conversely, people who were initially HIV positive were more than seven times as likely to be from sub-Saharan Africa as frequent testers and roughly four times as likely as infrequent testers.

The groups also differed in terms of their health status at the time of their HIV-positive diagnosis. CD4 counts were highest and AIDS diagnoses were lowest in frequent testers. Frequent testers had an average CD4 count of 550 at the time of diagnosis, and only 1.5 percent had AIDS. Meanwhile, people who were initially HIV positive had average CD4 counts of 350, and 16 percent had an AIDS diagnosis at the time of their HIV test.

These differences undoubtedly contributed to the dramatic difference that Gras and his colleagues found in the death rate. The rate of death in both frequent and infrequent testers was half that of those who were initially HIV positive.

Disturbingly, the number of people who waited to start ARVs was exceptionally high in all three groups. It was highest in those who were initially HIV positive. Forty-eight percent waited to start ARVs until CD4s dropped below 200. However, 26 and 23 percent of infrequent and frequent testers also waited too long to start ARVs.

Gras's team writes that those who had CD4s of 300 or more at the time of diagnosis but who waited to start treatment until CD4s dropped below 300 were likely to have waited nine months or longer between their HIV diagnosis and their first clinic visit. They comment that reasons for late or infrequent care need to be further explored.

“In summary, our findings illustrate the benefit of repeated testing for HIV,” they conclude. “It shortens the time between infection and diagnosis and improves the likelihood of timely treatment, with prevention of clinical progression to AIDS and death.”