Background High rates of HIV co-infection have been observed in recent syphilis epidemics, and persons diagnosed with HIV and early syphilis (ES) within a short period of time may be an appropriate focus for targeted HIV control strategies. Targeted control strategies seek to prevent HIV transmission by focusing specifically on those most likely to transmit, i.e., high viral load or concurrent STIs. To implement targeted HIV control in Baltimore, Maryland, we sought to characterise persons newly diagnosed with HIV who also received an ES diagnosis.

Methods Using retrospective public health surveillance data of newly diagnosed HIV cases reported to the Baltimore City Health Department from 2009 to 2011, we measured the proportion of persons with ES diagnoses. Chi-square tests were used to assess differences in age (> = 30 vs. < 30), gender, and sexual orientation by infection (HIV only vs. ES-HIV).

Results Of the 811 persons with newly diagnosed HIV, 104 (12.8%) also received at least one ES diagnosis between 2009 and 2011, 95% of whom were male. Compared to persons receiving only an HIV diagnosis, persons receiving both HIV and ES diagnoses were more likely to be younger (35.8% vs. 69.2%, p < 0.001, respectively) and men who have sex with men (MSM) (24.3% vs. 62.5%, p < 0.001, respectively). When controlling for sexual orientation, younger age was significantly associated with ES among men who have sex with women (MSW) (28.0% vs. 64.7%, p < 0.01, respectively) and females (25.9% vs. 80.0%, p = 0.02, respectively); however, among MSM, age was no longer statistically significant (62.8% vs. 70.8%, p = 0.25, respectively).

Conclusions A substantial proportion of persons newly diagnosed with HIV were also recently infected with syphilis, with young age strongly associated with ES among non-MSM. In addition to MSM, women and MSW under 30 years old may be appropriate foci for targeted control.