The Super Shedders and Other Retrovirus Tales

News from the 10th Conference on Retroviruses and Opportunistic Infections (CROI), the most important HIV medical conference held in the U.S., held this year in Boston in February. Visit www.retroconference.org/2003 for more information.

Super-Shedders

HIV in genital secretions might increase the risk of transmission. British researchers called some men "seminal super-shedders" because of the unusually high amount of virus found in their semen (actually, their "seminal plasma").

They wrote that usually viral load in semen is found less frequently, and at lower levels, than in the blood. The study looked at the semen of men who were not on therapy and had a viral load greater than 400. The majority, 58% of the 73 men, had detectable virus in their semen, but not higher than that found in their blood. A third had a seminal viral load less than 400. (This doesn't mean the virus wasn't there -- it might need to be measured differently, such as using tissue samples.)

This left 12% (nine men) who were super-shedders. Even though their blood viral load was not statistically different from that of the other shedders (the majority group), their semen viral load was significantly higher. Their T-cell counts and AIDS status were also the same as that of the other shedders.

The technology used to measure viral load throughout the body is not available in clinics. Therefore, people may be at greater risk of transmitting HIV without knowing it.

Vaginal Shedding

U.S. researchers found that sub-clinical inflammation (no symptoms or disease) was associated with increased HIV shedding in the vagina, no matter what a woman's viral load was. As with men, this shedding may increase the risk of transmission. They said the finding helps explain transmission despite having a low viral load in the blood. Previously the researchers had found that low viral load in the blood was associated with low shedding in the vagina (and vice versa), and that pro-inflammatory cytokines (a type of cell) associated with cervical ulcers increase shedding. The study looked at 60 vaginal samples.

Protection Against HIV

Researchers found that a virus discovered about 10 years ago may protect people with HIV against disease progression and death. GBV-C is closely related to hepatitis C virus. Researchers found that men co-infected with GBV-C had an 80% survival rate, while the guys who weren't had a 36% survival rate. However, the survival for the men who had been infected with GBV-C but had cleared the virus was only 16%. The study looked at stored blood samples over a 10-year period from 271 men in MACS (Multicenter AIDS Cohort Study).

Another group of researchers reported that GBV-C in the test tube almost completely suppresses HIV. The idea of infecting HIV-positive people with GBV-C to protect them is tantalizing, but can't be considered until the mechanisms and dangers are understood. The advantage of continuous infection was compared to having an extra 300 T-cells. GBV-C hasn't been found to cause any symptoms of disease, another reason why it's intriguing as a weapon for people with HIV.

Six Months

Researchers looked at data from 13 cohorts (groups of patients). Just getting T-cells above 25 after six months of therapy cut the risk of death in half. Overall, where people are at six months after starting therapy was more closely related to survival than where they were when they started. Researchers concluded that, "It matters where you are, not where you came from!"

EuroSIDA -- Surviving

Thanks to therapy, deaths related to HIV/AIDS were cut by 10% for each six-month period after September 1998. So was the development of AIDS itself. Doctors gathered the information from a European database of 8,551 patients. They found that even people with less than 20 T-cells had a significantly greater survival in the HAART era (highly active antiretroviral therapy) than before it.

More AIDS Cases

AIDS cases went up one percent between 1999 and 2001, the first increase since 1993.

HIV infection also went up, by 8% for the 25 states that report HIV cases. HIV went up by 10% among heterosexuals and 14% among gay men. These numbers did not include states with large numbers of HIV-positive people, like New York and California.

Officials from the U.S. Centers for Disease Control and Prevention (CDC), who reported the findings, said that:

• Approximately 1/3 of 900,000 people with HIV in the U.S. are unaware of their infection, increasing the risk of transmission.

• Medical providers should make rapid HIV testing more routine so that infections are found more quickly.

• More counseling is needed for people who know that they're positive.

CDC researchers also listed possible reasons for increased risk-taking. These include the sense that effective therapy is lowering fear of infection and lack of first-hand knowledge or memory of the "dark days" when people often died.