A recent analysis investigated the relationship between HIV and syphilis -- specifically, to find out what syphilis infection may mean for people with HIV in terms of HIV viral load and risk of transmission.
"There have been outbreaks of syphilis in multiple urban areas in the last ten years, and we continue to have high rates of syphilis among men who have sex with men. In some cities, more than half of new syphilis infections are among men with HIV. We wanted to investigate what viral loads are like close to the time of syphilis acquisition," said lead author Melanie Taylor, MD, MPH from the Centers for Disease Control and Prevention.
Both HIV and syphilis are "reportable" infections -- all new cases are documented and reported to public health departments. Taylor and colleagues analyzed HIV and syphilis surveillance registry data from New York City, Washington D.C., Philadelphia and Phoenix.
Over two years, 3,060 cases of syphilis were reported. More than half (1,675) of the people who tested positive for syphilis had a match in the HIV surveillance registry (i.e., they had already been diagnosed with HIV). Among all co-infected people, 86% (1,442) were men who have sex with men.
Most of those who were co-infected reported an HIV viral load collected within six months of their syphilis diagnosis -- over half of the sample had a detectable viral load. (The median viral load was 25,101 copies/ml3 and viral loads ranged from 206 - 3,590,000 copies/ml3 around the time when participants were infected with syphilis.) Younger people co-infected with HIV and syphilis were more likely to have detectable HIV viral loads: 81.9% of people ages 17-24 had detectable viral loads while 49.2% of people ages 35-44 were detectable.
This excerpt was cross-posted with the permission of BETAblog.org. Read the full article.