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.

The Population Impact of Late Presentation With Advanced HIV Disease and Delayed Antiretroviral Therapy in Adults Receiving HIV Care in Latin America.

Late presentation to care and antiretroviral therapy (ART) initiation with advanced human immunodeficiency virus (HIV) disease are common in Latin America. We estimated the impact of these conditions on mortality in the region. We included adults enrolled during 2001-2014 at HIV care clinics. We estimated the adjusted attributable risk (AR) and population attributable fraction (PAF) for all-cause mortality of presentation to care with advanced HIV disease (advanced LP), ART initiation with advanced HIV disease, and not initiating ART. Advanced HIV disease was defined as CD4 of <200 cells/µL or acquired immune deficiency syndrome. AR and PAF were derived using marginal structural models. Of 9,229 patients, 56% presented with advanced HIV disease. ARs of death for advanced LP were 86%, 71%, and 58%, and PAFs were 78%, 58%, and 43% at 1, 5, and 10 years after enrollment. Among people without advanced LP, ARs of death for delaying ART were 39%, 32%, and 37% at 1, 5, and 10 years post-enrollment and PAFs were 20%, 14%, and 15%. Among people with advanced LP, ART decreased the hazard of death by 63% in the first year after enrollment, but 93% of these started ART; thus universal ART among them would reduce mortality by only 10%. Earlier presentation to care and earlier ART initiation would prevent most HIV deaths in Latin America.

Immunologic Effects of Maraviroc in HIV-Infected Patients with Severe CD4 Lymphopenia Starting Antiretroviral Therapy: A Sub-Study of the CADIRIS Trial.

BACKGROUND: We aimed to describe the mechanisms of immunological recovery and the effects of blocking CCR5 in patients starting ART with advanced HIV-infection. METHODS: This was a sub-study of a 48 week double-blind, clinical trial where patients starting ART with CD4+ cell counts <100 cells/uL were randomized to receive maraviroc or a placebo. CD4+ and CD8+ cell maturation phenotypes, expression of PD-1 and CCR5, and activation indices were measured at weeks 0, 4, 12, 24, and 48. The reactivity of CD4+ and CD8+cells with peptides of CMV and MTb, and with Staphylococcal enterotoxin B (SEB) was assessed by intracellular expression of IFNγ, TNFα, and CD40 ligand at weeks 0, 4, and 12 of ART. RESULTS: Forty patients were included in the study (Maraviroc = 22; placebo = 18). Sustained increases in CD8+ cells and in proportions of CCR5+ CD4+ and CD8+ cells were observed in the maraviroc arm. Early increases in the proportions of activated (CD38+, HLA-DR+), PD-1+ CD4+, and CD8+ cells and more matured CD8+ cells, were observed in the maraviroc arm. T cell responses to CMV, MTb, and SEB did not differ by treatment arms. CONCLUSIONS: During antiretroviral therapy in advanced HIV infection, maraviroc retains mature, activated CCR5+ cells in circulation without impact on CD4+ T cell recovery or T cell reactivity to antigen or superantigen.

Monitoring of HIV treatment in seven countries in the WHO Region of the Americas.

OBJECTIVE: To determine the prevalence of adequate monitoring and the costs of measuring CD4+ T-lymphocytes (CD4+ cell) and human immunodeficiency virus (HIV) viral load in people receiving antiretroviral therapy (ART) in seven countries in the WHO Region of the Americas. METHODS: We obtained retrospective, longitudinal data for 14 476 adults who started a first ART regimen at seven HIV clinics in Argentina, Brazil, Chile, Haiti, Honduras, Mexico and Peru between 2000 and 2011. We estimated the proportion of 180-day periods with adequate monitoring, which we defined as at least one CD4+ cell count and one viral load measurement. Factors associated with adequate monitoring were analysed using regression methods. The costs of the tests were estimated. FINDINGS: The median follow-up time was 50.4 months; the proportion of 180-day periods with adequate CD4+ cell counts was 69% while the proportion with adequate monitoring was 62%. Adequate monitoring was more likely in participants who were older, who started ART more recently, whose first regimen included a non-nucleoside reverse transcriptase inhibitor or who had a CD4+ cell count less than 200 cells/µl at ART initiation. The cost of one CD4+ cell count ranged from 7.37 United States dollars (US$) in Argentina to US$ 64.09 in Chile; the cost of one viral load measurement ranged from US$ 20.34 in Brazil to US$ 186.28 in Haiti. CONCLUSION: In HIV-infected participants receiving ART in the WHO Region of the Americas, CD4+ cell count and viral load monitoring was often carried out less frequently than regional guidelines recommend. The laboratory costs of monitoring varied greatly.

A literature review of reporting standards of HIV progression models.

OBJECTIVE: We conducted a systematic review of HIV progression models to identify the mathematical structures used, the main research questions and key model aspects in terms of quality and robustness. METHODS: We searched for articles published before February 2009 that described models of HIV progression in humans. We included two strategies of search with and without MeSH terms. We classified the models by their mathematical structure and research question. We created a checklist of desirable features of the models, reviewed and classified the articles to inform our conclusions. RESULTS: Among 3491 articles found, 93 met the inclusion criteria. Among the selected articles, 60 used transition models, 25 applied differential equations, and eight had other structures. We did not find a relation between the type of question explored and the modeling method used. None of the studies complied with the complete set of items in the checklist, but 6.5% cover at least 90% of them. CONCLUSION: There is an enormous heterogeneity of HIV modeling exercises in terms of methods used and topics addressed, as well as in the presentation of key aspects of the articles in terms of quality and robustness.