High infectivity of early HIV infection in men who have sex with men in San Francisco.

Journal of Infectious Diseases

PubMedID: 25542958

Hollingsworth TD, Pilcher CD, Hecht FM, Deeks SG, Fraser C. High infectivity of early HIV infection in men who have sex with men in San Francisco. J Infect Dis. 2015;211(11):1757-60.
We estimate the relative transmission rate in early versus later infection amongst men who have sex with men (MSM) in San Francisco, USA, by studying the characteristics of a sample of transmitters, recruited through newly infected MSM between 1996 and 2009. Of 36 transmitters identified, 9 were recently infected based on testing history and serologic testing. The odds ratio of transmitting during early infection was 15.2 (95% CI 6.3-33.4, p<0.001) unadjusted and 8.9 (95% CI 4.1-19.4) when adjusting for self-reported antiretroviral treatment. This high transmissibility could be due to both high infectiousness and high rates of partner change or concurrency.