SARSCoV-2 antibody prevalence and titers in persons living with HIV cared for at a large tertiary reference center in Mexico City.

OBJECTIVE: To assess SARS-CoV-2 antibody prevalence and titers in people living with HIV (PLWHIV) on antiretroviral treatment (ART) enrolled at a tertiary reference hospital in Mexico. METHODS: Two plasma aliquots per person, used for HIV viral load follow-up between 01/2020 and 09/2021, were used to assess total anti-N and neutralizing SARS-CoV-2 antibodies. Sociodemographic, clinical, and SARS-CoV-2 exposure risk information were collected. The risk associated with SARS-CoV-2 exposure and associations with antibody titers were analyzed with logistic, Cox, and linear multivariable models. RESULTS: 803 PLWHIV participated; 233 had detectable SARS-CoV-2 antibodies (prevalent cases), and 132 seroconverted (incident cases). Overall, the adjusted prevalence was 46.45%, with an incidence rate of 3.78 cases/100 person-months. Factors associated with prevalent cases included lower age, location (western zone of Mexico City and the neighboring Mexico State), use of public transport, attendance at meetings without social distancing, and higher CD4 + T cell counts (p < 0.05; multivariable logistic model). BNT162b2 vaccination reduced incident cases (Cox adjusted HR = 0.4; p = 0.013). Notably, previously infected and vaccinated individuals showed maximization of neutralizing activity (p < 0.001). No associations between SARS-CoV-2 neutralization and HIV-related variables (CD4 + T cell counts, viral load, number of years in viral suppression, ART regimen) were found in multivariable analysis. CONCLUSIONS: SARS-CoV-2 infection was associated with community risk rather than HIV-associated variables in PLWH on ART and clinical follow-up. Antibody neutralization activity in vaccinated participants was maximized with previous SARS-CoV-2 infection.

Seroepidemiology of SARS-CoV-2 in healthcare personnel working at the largest tertiary COVID-19 referral hospitals in Mexico City.

INTRODUCTION: We performed a longitudinal SARS-CoV-2 seroepidemiological study in healthcare personnel of the two largest tertiary COVID-19 referral hospitals in Mexico City. METHODS: All healthcare personnel, including staff physicians, physicians in training, nurses, laboratory technicians, researchers, students, housekeeping, maintenance, security, and administrative staff were invited to voluntarily participate, after written informed consent. Participants answered a computer-assisted self-administered interview and donated blood samples for antibody testing every three weeks from October 2020 to June 2021. RESULTS: A total of 883 participants (out of 3639 registered employees) contributed with at least one blood sample. The median age was 36 years (interquartile range: 28-46) and 70% were women. The most common occupations were nurse (28%), physician (24%), and administrative staff (22%). Two hundred and ninety participants (32.8%) had a positive-test result in any of the visits, yielding an overall adjusted prevalence of 33.5% for the whole study-period. Two hundred and thirty-five positive tests were identified at the baseline visit (prevalent cases), the remaining 55 positive tests were incident cases. Prevalent cases showed associations with both occupational (institution 2 vs. 1: adjusted odds ratio [aOR] = 2.24, 95% confidence interval [CI]: 1.54-3.25; laboratory technician vs. physician: aOR = 4.38, 95% CI: 1.75-10.93) and community (municipality of residence Xochimilco vs. Tlalpan: aOR = 2.03, 95% CI: 1.09-3.79) risk-factors. The incidence rate was 3.0 cases per 100 person-months. Incident cases were associated with community-acquired risk, due to contact with suspect/confirmed COVID-19 cases (HR = 2.45, 95% CI: 1.21-5.00). CONCLUSIONS: We observed that between October 2020 and June 2021, healthcare workers of the two largest tertiary COVID-19 referral centers in Mexico City had similar level of exposure to SARS-CoV-2 than the general population. Most variables associated with exposure in this setting pointed toward community rather than occupational risk. Our observations are consistent with successful occupational medicine programs for SARS-CoV-2 infection control in the participating institutions but suggest the need to strengthen mitigation strategies in the community.

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.