HIV Pretreatment Drug Resistance Trends in Mexico City, 2017-2020.

In response to increasing pretreatment drug resistance (PDR), Mexico changed its national antiretroviral treatment (ART) policy, recommending and procuring second-generation integrase strand-transfer inhibitor (INSTI)-based regimens as preferred first-line options since 2019. We present a four-year observational study describing PDR trends across 2017-2020 at the largest HIV diagnosis and primary care center in Mexico City. A total of 6688 baseline protease-reverse transcriptase and 6709 integrase sequences were included. PDR to any drug class was 14.4% (95% CI, 13.6-15.3%). A significant increasing trend for efavirenz/nevirapine PDR was observed (10.3 to 13.6%, p = 0.02). No increase in PDR to second-generation INSTI was observed, remaining under 0.3% across the study period. PDR was strongly associated with prior exposure to ART (aOR: 2.9, 95% CI: 1.9-4.6, p < 0.0001). MSM had higher odds of PDR to efavirenz/nevirapine (aOR: 2.0, 95% CI: 1.0-3.7, p = 0.04), reflecting ongoing transmission of mutations such as K103NS and E138A. ART restarters showed higher representation of cisgender women and injectable drug users, higher age, and lower education level. PDR to dolutegravir/bictegravir remained low in Mexico City, although further surveillance is warranted given the short time of ART optimization. Our study identifies demographic characteristics of groups with higher risk of PDR and lost to follow-up, which may be useful to design differentiated interventions locally.

Characteristics and growth of the genetic HIV transmission network of Mexico City during 2020.

INTRODUCTION: Molecular surveillance systems could provide public health benefits to focus strategies to improve the HIV care continuum. Here, we infer the HIV genetic network of Mexico City in 2020, and identify actively growing clusters that could represent relevant targets for intervention. METHODS: All new diagnoses, referrals from other institutions, as well as persons returning to care, enrolling at the largest HIV clinic in Mexico City were invited to participate in the study. The network was inferred from HIV pol sequences, using pairwise genetic distance methods, with a locally hosted, secure version of the HIV-TRACE tool: Seguro HIV-TRACE. Socio-demographic, clinical and behavioural metadata were overlaid across the network to design focused prevention interventions. RESULTS: A total of 3168 HIV sequences from unique individuals were included. One thousand and one-hundred and fifty (36%) sequences formed 1361 links within 386 transmission clusters in the network. Cluster size varied from 2 to 14 (63% were dyads). After adjustment for covariates, lower age (adjusted odds ratio [aOR]: 0.37, p<0.001; >34 vs. <24 years), being a man who has sex with men (MSM) (aOR: 2.47, p = 0.004; MSM vs. cisgender women), having higher viral load (aOR: 1.28, p<0.001) and higher CD4+ T cell count (aOR: 1.80, p<0.001; ≥500 vs. <200 cells/mm3 ) remained associated with higher odds of clustering. Compared to MSM, cisgender women and heterosexual men had significantly lower education (none or any elementary: 59.1% and 54.2% vs. 16.6%, p<0.001) and socio-economic status (low income: 36.4% and 29.0% vs. 18.6%, p = 0.03) than MSM. We identified 10 (2.6%) clusters with constant growth, for prioritized intervention, that included intersecting sexual risk groups, highly connected nodes and bridge nodes between possible sub-clusters with high growth potential. CONCLUSIONS: HIV transmission in Mexico City is strongly driven by young MSM with higher education level and recent infection. Nevertheless, leveraging network inference, we identified actively growing clusters that could be prioritized for focused intervention with demographic and risk characteristics that do not necessarily reflect the ones observed in the overall clustering population. Further studies evaluating different models to predict growing clusters are warranted. Focused interventions will have to consider structural and risk disparities between the MSM and the heterosexual populations.

Syphilis infection markers among HIV positive individuals in the Mexico City HIV/AIDS Program / Marcadores de infección por sífilis de individuos VIH positivos en el Programa de VIH/SIDA de la Ciudad de México

Abstract: Objective: The aim of this study is to evaluate the prevalence of T. pallidum infection markers in HIV-positive individuals receiving highly active antiretroviral therapy (ART) in the Mexico City HIV/AIDS Program, as well as predictive characteristics. Materials and methods: The reverse serologic algorithm method was used for the T. pallidum diagnosis, and applied to 2 383 HIV-positive individuals. Sociodemographic characteristics, sexual practices, previous syphilis diagnosis, and length of antiretroviral treatment, were evaluated. Variables significantly associated with syphilis markers were analyzed using a logistic regression model. Results: Prevalence of "active or resolved" and "probable active" infection markers were 44.2 and 28.8%, respectively. Predictive factors were: Clínica Especializada Condesa Iztapalapa (CECI), previous syphilis diagnosis, men in who have sex with men (MSM), and receptive sex practices. Conclusions: The prevalence of T. pallidum infection markers was the highest ever reported in Mexico, and was related to specific sexual practices as well as previous syphilis diagnosis, elements which require preventive measures in the Mexico City HIV/AIDS Program.

Resumen: Objetivo: Evaluar las prevalencias de marcadores de infección por T. pallidum en personas que viven con VIH y reciben tratamiento antirretroviral en el Programa de VIH/SIDA de la Ciudad de México, así como sus características asociadas. Material y métodos: Se siguió el método del algoritmo reverso para el diagnóstico de T. pallidum aplicado a 2 383 individuos VIH positivos, quienes contestaron un cuestionario sobre características sociodemográficas, prácticas sexuales, diagnóstico previo de sífilis y tiempo de tratamiento antirretroviral. Las variables significativamente asociadas con los marcadores de sífilis se analizaron mediante un modelo de regresión logística. Resultados: Las prevalencias de marcadores de infección "activa o resuelta" y "probablemente activa" fueron 44.2 y 28.8%, respectivamente. Las características asociadas con los marcadores fueron Clínica Especializada Condesa Iztapalapa (CECI), diagnóstico previo de infección por sífilis, hombres que tienen sexo con hombres (HSH) y prácticas sexuales receptivas. Conclusiones: Las prevalencias de marcadores de infección por T. pallidum fueron altas y estuvieron relacionadas con prácticas sexuales específicas y con el diagnóstico previo de sífilis, características que requieren medidas preventivas dentro del programa.

Syphilis Infection Markers Among HIV Positive Individuals In The Mexico City HIV/AIDS Program.

OBJECTIVE: The aim of this study is to evaluate the prevalence of T. pallidum infection markers in HIV-positive individuals receiving highly active antiretroviral therapy (ART) in the Mexico City HIV/AIDS Program, as well as predictive characteristics. METHODS: The reverse serologic algorithm method was used for the T. pallidum diagnosis, and applied to 2,383 HIV-positive individuals. Socio-demographic characteristics, sexual practices, previous syphilis diagnosis, and length of antiretroviral treatment, were evaluated. Variables significantly associated with syphilis markers were analyzed using a logistic regression model. RESULTS: Prevalence of "active or resolved" and "probable active" infection markers were 44.2% and 28.8%, respectively. Predictive factors were: Clinic Specialized Condesa Iztapalapa (CECI), previous syphilis diagnosis, MSM, and receptive sex practices. CONCLUSIONS: The prevalence of T. pallidum infection markers was the highest ever reported in Mexico, and was related to specific sexual practices as well as previous syphilis diagnosis, elements which require preventive measures in the Mexico City HIV/AIDS Program.

Pretreatment HIV drug resistance spread within transmission clusters in Mexico City.

BACKGROUND: Pretreatment HIV drug resistance (HIVDR) to NNRTIs has consistently increased in Mexico City during the last decade. OBJECTIVES: To infer the HIV genetic transmission network in Mexico City to describe the dynamics of the local HIV epidemic and spread of HIVDR. PATIENTS AND METHODS: HIV pol sequences were obtained by next-generation sequencing from 2447 individuals before initiation of ART at the largest HIV clinic in Mexico City (April 2016 to June 2018). Pretreatment HIVDR was estimated using the Stanford algorithm at a Sanger-like threshold (≥20%). Genetic networks were inferred with HIV-TRACE, establishing putative transmission links with genetic distances <1.5%. We examined demographic associations among linked individuals with shared drug resistance mutations (DRMs) using a ≥ 2% threshold to include low-frequency variants. RESULTS: Pretreatment HIVDR reached 14.8% (95% CI 13.4%-16.2%) in the cohort overall and 9.6% (8.5%-10.8%) to NNRTIs. Putative links with at least one other sequence were found for 963/2447 (39%) sequences, forming 326 clusters (2-20 individuals). The inferred network was assortative by age and municipality (P < 0.001). Clustering individuals were younger [adjusted OR (aOR) per year = 0.96, 95% CI 0.95-0.97, P < 0.001] and less likely to include women (aOR = 0.46, 95% CI 0.28-0.75, P = 0.002). Among clustering individuals, 175/963 (18%) shared DRMs (involving 66 clusters), of which 66/175 (38%) shared K103N/S (24 clusters). Eight municipalities (out of 75) harboured 65% of persons sharing DRMs. Among all persons sharing DRMs, those sharing K103N were younger (aOR = 0.93, 95% CI 0.88-0.98, P = 0.003). CONCLUSIONS: Our analyses suggest age- and geographically associated transmission of DRMs within the HIV genetic network in Mexico City, warranting continuous monitoring and focused interventions.

Evaluation of HIV, STI and CD4 results among voluntary attendees at the HIV/AIDS program of Mexico City.

OBJECTIVE:: To describe results of HIV, sexually transmitted diseases (STI) and CD4 counts at the HIV-specialized Condesa Clinic (CC) in Mexico City. MATERIALS AND METHODS:: Individuals who requested voluntary counseling and testing at CC were studied. We identified antibodies against HIV, syphilis, hepatitis C, and hepatitis B HBsAg. CD4 cell counts and viral load of HIV positive individuals were also obtained. Late HIV infection diagnosis was established if CD4 counts were lower than 200 cells/µL. RESULTS:: Global seroprevalence of HIV, syphilis, HBsAg, and anti HCV markers was of 20.1, 6, 1 and 1, respectively. Men displayed higher seroprevalence of infection markers than women. Among men, HIV infection was related to age and with all STI markers. Late HIV diagnosis was 31.8%. The risk of late HIV diagnosis was higher among women and it increased as age increased. CONCLUSIONS:: Differences between genders regarding HIV and STIs prevalence as well as risk factors for HIV infection and late HIV diagnosis were observed.

Evaluation of HIV, STI and CD4 results among voluntary attendees at the HIV/AIDS program of Mexico City / Evaluación de resultados de VIH, ETS y CD4 en asistentes al programa de VIH/SIDA de la Ciudad de México

Abstract: Objective: To describe results of HIV, sexually transmitted diseases (STI) and CD4 counts at the HIV-specialized Condesa Clinic (CC) in Mexico City. Materials and methods: Individuals who requested voluntary counseling and testing at CC were studied. We identified antibodies against HIV, syphilis, hepatitis C, and hepatitis B HBsAg. CD4 cell counts and viral load of HIV positive individuals were also obtained. Late HIV infection diagnosis was established if CD4 counts were lower than 200 cells/μL. Results: Global seroprevalence of HIV, syphilis, HBsAg, and anti HCV markers was of 20.1, 6, 1 and 1, respectively. Men displayed higher seroprevalence of infection markers than women. Among men, HIV infection was related to age and with all STI markers. Late HIV diagnosis was 31.8%. The risk of late HIV diagnosis was higher among women and it increased as age increased. Conclusions: Differences between genders regarding HIV and STIs prevalence as well as risk factors for HIV infection and late HIV diagnosis were observed.

Resumen: Objetivo: Describir resultados del programa VIH/SIDA de la Clínica Especializada Condesa (CC). Material y métodos: Se identificaron anticuerpos contra VIH, sífilis y hepatitis C, así como HBsAg del virus de la hepatitis B. Se hizo un conteo de CD4 y carga viral en los positivos a VIH asistentes a la CC. El conteo CD4 menor a 200 células/μL definió el diagnóstico tardío de la infección por VIH. Resultados: La prevalencia de VIH, sífilis, HBsAg y virus de la hepatitis (HCV) fue de 20.1, 6, 1 y 1, respectivamente. Los hombres mostraron prevalencias mayores de infección que las mujeres y en ellos la infección por VIH estuvo relacionada con la edad y con los marcadores de ITS. El diagnóstico tardío de VIH fue de 31.8% y su riesgo fue mayor en las mujeres y se incrementó conforme la edad. Conclusión: Se encontraron diferencias de género en las prevalencias de VIH e ITS, en los riesgos de infección por VIH y en el diagnóstico tardío de esta infección.

Comparison of two diagnostic algorithms for the identification of patients with HCV viremia using a new HCV antigen test.

BACKGROUND: Patients exposed to hepatitis C virus (HCV) may develop chronic infection with viremia. The diagnosis of this condition requires the use of several laboratory tests in algorithms tailored to the population and resources available for each laboratory. AIM: We compared the diagnostic efficacy of two diagnostic algorithms for the identification of viremic patients with HCV. One based on confirmation of reactive antibody results with molecular techniques (reverse transcription polymerase chain reaction, RTPCR) and the other based on the use of a new HCV core antigen test (HCV Ag). Material and methods. We measured levels of anti-HCV, HCV Ag and viral load (trough RT-PCR) in parallel, in 211 samples (53 antibody positive, 158 antibody negative). Using the three results available for each sample we simulated the diagnostic performance of the two algorithms and compared them to the results of RT-PCR as gold standard. RESULTS: Both algorithms showed a high degree of concordance for viremic patients. The percentage of correctly classified patients was 99.05% for the algorithm based on RT-PCR and 98.10% for the HCV Ag algorithm. The HCV core Ag test showed a clinical sensitivity of 0.917 and showed a good correlation to the results of molecular biology. Spearman rank correlation coefficient (ρ) of 0.97 (95% CI 0.95 to 0.99, p < 0.0001). CONCLUSION: An algorithm incorporating HCV Ag as confirmatory test for anti-HCV results is a feasible alternative to the use of molecular techniques in laboratories that do not have access to them or require faster turn around times.