Background: HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. Methods: A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. Results: The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. Conclusions: The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

Background: Male sex workers are at high-risk for acquisition of sexually transmitted infections (STIs), including human immunodeficiency virus (HIV). We quantified incidence rates of STIs and identified their time-varying predictors among male sex workers in Mexico City.Methods: From January 2012 to May 2014, male sex workers recruited from the largest HIV clinic and community sites in Mexico City were tested for chlamydia, gonorrhea, syphilis, hepatitis, and HIV at baseline, 6-months, and 12-months. Incidence rates with 95% bootstrapped confidence limits were calculated. We examined potential time-varying predictors using generalized estimating equations for a population averaged model.Results: Among 227 male sex workers, median age was 24 and baseline HIV prevalence was 32%. Incidence rates (per 100 person-years) were as follows: HIV [5.23; 95% confidence interval (CI): 2.15–10.31], chlamydia (5.15; 95%CI: 2.58–9.34), gonorrhea (3.93; 95%CI: 1.88–7.83), syphilis (13.04; 95%CI: 8.24–19.94), hepatitis B (2.11; 95%CI: 0.53–4.89), hepatitis C (0.95; 95%CI: 0.00–3.16), any STI except HIV (30.99; 95%CI: 21.73–40.26), and any STI including HIV (50.08; 95%CI: 37.60–62.55). In the multivariable-adjusted model, incident STI (excluding HIV) were lower among those who reported consistently using condoms during anal and vaginal intercourse (odds ratio = 0.03, 95%CI: 0.00–0.68) compared to those who reported inconsistently using condoms during anal and vaginal intercourse.Conclusions: Incidence of STIs is high among male sex workers in Mexico City. Consistent condom use is an important protective factor for STIs, and should be an important component of interventions to prevent incident infections.

Men who have sex with men (MSM) are disproportionately affected by syphilis, HIV, and syphilis/HIV coinfection. Antiretroviral therapy (ART) prevents HIV transmission but does not impede the spread or acquisition of syphilis. Information about syphilis/HIV coinfection among MSM is scarce. We aimed to determine the prevalence of syphilis/HIV coinfection in a national sample of MSM who attend meeting places (such as movies, clubs, gay bars, saunas, shopping malls, and others referred to by the same MSM participants of the study) in Mexico to evaluate factors associated with syphilis, and to compare the prevalence rates of syphilis between the current survey and DGE data. We performed a laboratory diagnosis to determine the rates of syphilis and HIV among the included MSM. The national and regional prevalence of syphilis was calculated. HIV and coinfection prevalence were determined only for the survey. All prevalence rates included _95%CIs. Descriptive, bivariate, and multivariate analyses were performed. The national prevalence rates of syphilis, HIV, and coinfection were 15.2%, 10.2%, and 5.7%, respectively. The region with the highest prevalence rate was Mexico City (39.4%). The center region, minimal “goods” (i.e., a minimal number of material possessions such as a car or dryer, etc., which served as a proxy for low economic income level), use of “inhalant drugs”, “HIV infection”, “sexual intercourse” only with men, “rewarded sex”, and “youngest age at first sexual encounter or debut” were risk factors for syphilis. In general, regional prevalence of syphilis was higher in the survey (2013) and DGE data from 2019 than in the DGE data from 2013. Similar to other countries, Mexico needs to assess elements around not only syphilis and HIV infections but also syphilis/HIV coinfection, and preventive measures focusing on MSM are needed.

Adolescents and young people are particularly vulnerable to contracting STIs, including HSV-2; furthermore, vaginal shedding of HSV-2 during pregnancy can cause vertical transmission and neonatal herpes. To evaluate the seroprevalence of HSV-2 and vaginal HSV-2 shedding in adolescent and young pregnant women, a cross-sectional study was carried out in 496 pregnant women—adolescents and young women. Venous blood and vaginal exudate samples were taken. The seroprevalence of HSV-2 was determined by ELISA and Western blot. Vaginal HSV-2 shedding was assessed by qPCR of the HSV-2 UL30 gene. The seroprevalence of HSV-2 in the study population was 8.5% (95% CI 6–11), of which 38.1% had vaginal HSV-2 shedding (95% CI 22–53). Young women presented a higher seroprevalence of HSV-2 (12.1%) than adolescents (4.3%), OR = 3.4, 95% CI 1.59–7.23. Frequent alcohol consumption was significantly associated with HSV-2 seroprevalence, OR = 2.9, 95% CI 1.27–6.99. Vaginal HSV-2 shedding is highest in the third trimester of pregnancy, but this difference is not significant. The seroprevalence of HSV-2 in adolescents and young women is similar to that previously reported in other studies. However, the proportion of women with vaginal shedding of HSV-2 is higher during the third trimester of pregnancy, increasing the risk of vertical transmission.

Objective. To determine the prevalence of SARS-CoV-2 antibodies among healthcare workers (HCW) and to identify factors associated with infection. Materials and meth­ods. A cross-sectional study was conducted in a Covid-19 hospital in Morelos, Mexico. Antibodies against SARS-CoV-2 spike and nucleocapsid proteins were detected by ELISA. A bivariate and multivariable Poisson regression model were performed to identify factors associated with infection. Results. Among all participants, 31% had anti-SARS-CoV-2 antibodies, while only 13.1% had reported a history of positive RT-PCR. Individuals who reported cohabiting with someone with Covid-19, and those who had a previous RT-PCR test, were more likely to be seropositive. Laboratory personnel had the lowest seroprevalence (12.0%), while social workers had the highest (35.7%). Conclusions. The results of this study show the seroprevalence of SARS-CoV-2 antibodies among HCW in a hospital in Mexico, and underline the importance of serological tests for a better estimate of prevalence in health systems where only symptomatic cases are recorded.

Objetivo. Evaluar la diversidad morfológica y dinámica de la microbiota vaginal en adolescentes y jóvenes embarazadas. Material y métodos. Se analizaron muestras de exudado vaginal tomadas en cada visita prenatal. Se utilizó tinción de Gram para la caracterización morfológica y los criterios de Nugent para diagnosticar vaginosis bacteriana (VB). Resultados. De 501 embarazadas, 31.1% presentó VB. Ser soltera, alto consumo de alcohol y tener tres o más parejas sexuales fueron factores de riesgo; el uso previo de antibióticos y antecedentes de infección urinaria fueron protectores. En 173 participantes con seguimiento, se observó una disminución de los morfotipos Mobiluncus y Gardnerella y un aumento de Lactobacillus. La VB disminuyó de 37.0 a 7.7% entre la primera y tercera visita. El 50.0% de las embarazadas con VB y 64.7% con microbiota intermedia restablecieron a microbiota normal en la siguiente visita, mientras que 5% con microbiota normal desarrolló VB. La incidencia de VB fue de 8.03 casos/100 mujeres/trimestre y la persistencia de 32.8%. Conclusiones. La prevalencia e incidencia de VB fue alta entre las adolescentes y jóvenes embarazadas. La microbiota vaginal durante el embarazo es variable. Aunque tiende a normalizarse, una proporción evoluciona a VB, representando un riesgo significativo de complicaciones.