Symptom-based viral load testing detects HIV in MSM

Testing for HIV when flu-like symptoms develop may offer a cost-effective alternative for early detection of HIV infection in men who have sex with men (MSM), reports a study in the journal AIDS. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

"Use of HIV viral load testing in MSM with influenza-like illness prevents more infections than does annual antibody screening alone and is cost-effective," comments Jessie L. Juusola, M.S., of Stanford University, lead author of the new study.

Currently, annual testing for HIV antibody is recommended for all MSM—a high-risk group for HIV infection. Studies estimate that about two-thirds of MSM are actually tested each year. This approach misses some early-stage infections, however, as HIV antibodies may not appear for several weeks.

In a series of simulations, the researchers compared the cost-effectiveness of three alternative strategies for HIV screening:

•Expanded antibody testing—increasing the percentage of MSM who undergo annual antibody testing to 90 percent.
•Viral load testing (measuring the level of HIV in the blood) when symptoms of flu-like illness develop. Flu-like symptoms are common during the acute phase of HIV infection.
•A combination approach including both antibody and viral load testing.

The researchers estimated that, at the current rate of HIV-antibody testing, 538,000 new infections will occur among MSM over the next 20 years. Increasing the percentage of MSM tested to 90 percent per year would reduce the rate of new infections by 2.8 percent. The cost of detecting these extra infections would be about $13,000 per quality-adjusted life-year (QALY) gained—a standard measure of cost-effectiveness. That's well within accepted standards for cost-effective screening programs.

Symptom-based viral load testing would be more expensive than expanded antibody screening. However, it would also be more effective, reducing the rate of new infections by 4.2 percent. Cost per QALY would be about $23,000—also within accepted standards for cost-effectiveness.

The combination approach would reduce the rate of new infections by 5.7 percent, at a cost per QALY of about $30,000. Adding viral load testing to all annual HIV antibody tests would further increase the detection rate, but would be prohibitively expensive: more than $100,000 per QALY.

A key component of the symptom-based screening approach is prompt treatment with anti-HIV (antiretroviral) drugs. Early antiretroviral therapy can suppress HIV replication during the early stage of infection, and thus may be an effective method of reducing transmission.

Based on the results, adding symptom-based viral load testing to annual antibody testing for MSM could prevent more than 30,000 new HIV infections over 20 years, at a cost lower than many interventions accepted as cost-effective. "Targeted viral load testing of symptomatic MSM provides approximately 80 percent of the benefit of universal viral load testing at less than half the cost," Juusola and colleagues add.

Symptom-based screening provides a unique opportunity to improve health outcomes at a reasonable cost, using a strategy that can be easily followed by health care professionals who see MSM. The researchers conclude, "These findings can assist clinicians and MSM in making decisions about the value of testing and can inform policymakers' decisions about how to allocate limited HIV screening resources."

Source: www.aidsonline.com.