HIV/STI co-infections, syphilis incidence, and hepatitis B vaccination: the Buenos Aires cohort of men who have sex with men

Abstract

In a previous cohort study among 327 men who have sex with men (MSM) in Buenos Aires, an HIV incidence rate of 3.9 per 100 persons-year was reported. Using data from this study, we determined: (a) HIV/STI co-infections; (b) clinical manifestations of incident HIV infections; (c) syphilis incidence and its associated risk factors; and (d) adherence and immune response to hepatitis B virus (HBV) vaccine. During the cohort study, 12 incident HIV infections were found. Within this group, HIV infection alone was most frequent (42%), followed by co-infection of HIV/HBV (33%), and triple co-infection of HIV/HBV/syphilis (25%). The most frequent clinical manifestations among incident HIV cases were: pharyngitis, fever, lymphadenopathy, asthenia, and myalgia. Seven new syphilis infections were detected yielding an incidence rate of 2.4 (95% CI=1.07 − 4.73) per 100 persons-year. Sex work was the only significant risk factor associated with syphilis seroconversion (hazard rate=10.93, p-value=0.033). Only 7% of cohort participants reported having received HBV vaccine. Ninety-percent of the 204 cohort members who agreed to be vaccinated completed the HBV vaccination schedule with an immune response rate of 85%. Our findings suggest the need to increase the access to serologic testing for STI and HBV immunization, as well as the developing of effective HIV/STI behavioral and educational prevention programs among MSM in Buenos Aires.

Keywords:

• HIV
• syphilis
• HBV
• HCV
• MSM
• co-infection
• Argentina

Acknowledgements

We would like to thank all MSM volunteers in this study. This project was financially supported by Work Unit Number 62787A S17 H B0002 and CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina. The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or any of the other organizations listed.

Doctor Silvia Montano is an employee of the US Government. This work was prepared as part of her official duties. Title 17 U.S.C. § 105 provides that “Copyright protection under this title is not available for any work of the United States Government”. Title 17 U.S.C. § 101 defines a US Government work as a work prepared by a military service member or employee of the US Government as part of that person's official duties.