Recent HIV Infection among men who have sex with men and transgender women in Tijuana

ABSTRACT OBJECTIVE To characterize recent HIV infections among newly diagnosed men who have sex with men and transgender women in Tijuana. METHODS Limiting Antigen (LAg)-Avidity testing was performed to detect recent HIV infection within a cohort of newly-diagnosed men who have sex with men and transgender women in Tijuana. Logistic regression was used to determine characteristics associated with recent infection. A partial transmission network was inferred using HIV-1 pol sequences. Tamura-Nei 93 genetic distances were measured between all pairs of sequences, and the network was constructed by inferring putative transmission links (genetic distances ≤ 1.5%). We assessed whether recent infection was associated with clustering within the inferred network. RESULTS Recent infection was detected in 11% (22/194) of newly-diagnosed participants. Out of the participants with sequence data, 60% (9/15) with recent infection clustered compared with 31% (43/139) with chronic infection. Two recent infections belonged to the same cluster. In adjusted analyses, recent infection was associated with years of residence in Tijuana (OR = 1.5; 95%CI 1.01-1.09), cocaine use (past month) (OR = 8.50; 95%CI 1.99-28.17), and ever experiencing sexual abuse (OR = 2.85; 95%CI 1.03-7.85). DISCUSSION A total of 11% of men newly diagnosed with HIV who have sex with men and transgender women in Tijuana were recently infected. The general lack of clustering between participants with recent infection suggests continued onward HIV transmission rather than an outbreak within a particular cluster.

Prevalence of HIV/STIs and correlates with municipal characteristics among female sex workers in 13 Mexican cities / Prevalencia de VIH/ITS y correlaciones con carácterísticas municipales entre trabajadoras sexuales en 13 ciudades mexicanas

Abstract: Objective: To identify correlates of HIV/STI prevalence among 13 cities with varying sizes of female sex worker (FSW) populations and municipal characteristics in Mexico. Materials and methods: FSWs underwent interviews and testing for HIV, syphilis, gonorrhea and chlamydia. Logistic regression explored variations in HIV/STI prevalence. Results: Among FSWs (n=1 092), prevalence across 13 sites was: HIV: 0.4% (range: 0%-1.4%): syphilis: 7.8% (range: 0%-17.2%); chlamydia: 15.3% (range: 5.7%-32.2%); gonorrhea: 2.9% (range 0%-13.8%), and any HIV/STI: 23% (range: 9.9%-46%). Municipalities with high human development scores and a lower municipal marginalization index had higher odds of combined HIV/STI prevalence. After controlling for site-specific variability in municipal characteristics, greater risk of HIV/STIs was associated with lower education, having a spouse diagnosed or treated for an STI, unaffordability of condoms, and having non-Mexican clients. Conclusions: Prevalence of HIV/STIs varies across Mexican municipalities indicating the need for surveillance to identify hotspots for targeted resource allocation.

Resumen: Objetivo: Identificar correlaciones de la prevalencia de VIH / ITS entre 13 ciudades con diferentes tamaños de población de trabajadoras sexuales y características municipales en México. Material y métodos: Las trabajadoras sexuales fueron entrevistadas y recibieron pruebas de VIH, sífilis, gonorrea y clamidia. La regresión logística exploró las variaciones en la prevalencia del VIH/ITS. Resultados: Entre las trabajadoras sexuales (n = 1 092), la prevalencia en 13 sitios fue: VIH: 0.4% (rango: 0-1.4%): sífilis: 7.8% (rango: 0-17.2%); clamidia: 15.3% (rango: 5.7-32.2%); gonorrea: 2.9% (rango 0-13.8%) y cualquier VIH/ITS: 23% (rango: 9.9-46%). Los municipios con altos puntajes de desarrollo humano y menor índice de marginación municipal tuvieron una mayor probabilidad de prevalencia combinada de VIH/ITS. Después de controlar la variabilidad específica del sitio en las características municipales, el mayor riesgo de VIH / ITS se asoció con menor educación, tener un cónyuge diagnosticado o tratado para una ITS, imposibilidad de conseguir condones y tener clientes no mexicanos. Conclusiones: La prevalencia de VIH/ITS varía entre los municipios mexicanos, lo que indica la necesidad de una vigilancia para identificar hotspots para la asignación selectiva.

Estimaciones de prevalencia del VIH por género y grupo de riesgo en Tijuana, México: 2006 / Estimating the 2006 prevalence of HIV by gender and risk groups in Tijuana, Mexico

Objetivo: Estimar la prevalencia para 2006 de HIV/sida entre población general de 15 a 49 años de edad y en los grupos de riesgo, en la ciudad de Tijuana, México. Métodos: Se obtuvieron datos demográficos del censo mexicano de 2005 y la prevalencia del VIH, de la literatura. Se construyó un modelo de prevalencia del VIH para la población general y de acuerdo con el género. El análisis de sensibilidad consistió en estimar los errores estándar del promedio-ponderado de la prevalencia del VIH y tomar derivados parciales respecto a cada parámetro. Resultados: La prevalencia del VIH resultó ser de 0.54% (N = 4,347) (rango 0.22-0.86% [N = 1750-6944]). Esto sugiere que 0.85% (rango 0.39-1.31%) de los hombres y 0.22% (rango 0.04-0.40%) de las mujeres podrían ser VIH-positivos. Los hombres que tienen sexo con hombres, las mujeres trabajadoras sexuales usuarias de drogas inyectables (UDI), las mujeres trabajadoras sexuales-no UDI, mujeres- UDI y los hombres-UDI, contribuyeron a las proporciones más elevadas de personas infectadas por el VIH. Conclusiones: El número de adultos VIH-positivos entre subgrupos de riesgo en la población de Tijuana es considerable, lo que denota la necesidad de enfocar las intervenciones de prevención en sus necesidades específicas. El presente modelo estima que hasta uno de cada 116 adultos podría ser VIH-positivo.

OBJECTIVE: Estimate the 2006 HIV prevalence among adults aged 15-49 from the general population and at-risk subgroups in Tijuana, Mexico. METHODS: Demographic data was obtained from the 2005 Mexican census and HIV prevalence data was obtained from reports in the literature. We developed a population-based HIV prevalence model for the overall population and stratified it by gender. Sensitivity analysis consisted of estimating standard errors in the weighted-average point prevalence and calculating partial derivatives of each parameter. RESULTS: HIV prevalence among adults was 0.54% (N = 4347) (range 0.22-0.86% [N = 1750-6944]). This suggests that 0.85% (range 0.39-1.31%) of men and 0.22% (0.04-0.40%) of women could have been HIV-infected in 2006. Men who have sex with men (MSM), followed by female sex workers who are injection drug users (FSW-IDU), FSW-non IDU, female IDU, and male IDU were the most at risk groups of infected individuals. CONCLUSIONS: The number of HIV-infected adults among at-risk subgroups in Tijuana is significant, highlighting the need to design tailored prevention interventions that focus on the specific needs of certain groups. According to our model, as many as 1 in 116 adults could potentially be HIV-infected.