Impacts of Sexually Transmitted Disease/HIV Outreach Sites on the Effectiveness of Detecting New Infections in Baltimore City, 2015 to 2018

Background Effectiveness of sexually transmitted disease (STD)/HIV mobile van outreach programs has been shown to assist in identifying new cases of syphilis and HIV among high-risk populations. However, specific types of mobile outreach testing and their varying abilities to assist in STD/HIV case identification have not been thoroughly explored. Methods We analyzed data from the Baltimore City Health Department syphilis and HIV testing intake interviews and subsequent laboratory results for clients at any of the 6 different Baltimore City Health Department mobile outreach testing setting types between 2015 and 2018. A total of 8098 syphilis and 7946 HIV testing encounters were included. Cross-tabulation and proportion estimates were used to obtain the volume of new syphilis and HIV diagnoses across the different mobile outreach testing setting types. Multivariable firth logistic regressions for rare events were used to obtain odds ratios for new syphilis diagnoses across the different mobile outreach setting categories. Results Testing at street corners yielded the highest proportion of new syphilis cases (0.83%), whereas at community centers, it produced the highest proportion of new HIV cases (0.48%). The adjusted odds for new syphilis were 2.14 among street corners compared with community centers. Conclusions The findings indicated that street corners were the most successful at detecting new syphilis cases, whereas community centers were the most successful at detecting new HIV cases. However, because of the small number of new cases detected and low uptake per testing event between 2015 and 2018, STD/HIV mobile testing does not seem to be effective overall.