Search

Summary: Background: Household transmission studies seek to understand the transmission dynamics of a pathogen by estimating the risk of infection from household contacts and community exposures. We estimated within/extra-household SARS-CoV-2 infection risk and associated factors in a household cohort study in one of the most vulnerable neighbourhoods in Rio de Janeiro city. Methods: Individuals ≥1 years-old with suspected or confirmed COVID-19 in the past 30 days (index cases) and household members aged ≥1 year were enrolled and followed at 14 and 28 days (study period November/2020–December/2021). RT-PCR testing, COVID-19 symptoms, and SARS-CoV-2 serologies were ascertained in all visits. Chain binomial household transmission models were fitted using data from 2024 individuals (593 households). Findings: Extra-household infection risk was 74.2% (95% credible interval [CrI] 70.3–77.8), while within-household infection risk was 11.4% (95% CrI 5.7–17.2). Participants reporting having received two doses of a COVID-19 vaccine had lower extra-household (68.9%, 95% CrI 57.3–77.6) and within-household (4.1%, 95% CrI 0.4–16.6) infection risk. Within-household infection risk was higher among participants aged 10–19 years, from overcrowded households, and with low family income. Contrastingly, extra-household infection risk was higher among participants aged 20–29 years, unemployed, and public transportation users. Interpretation: Our study provides important insights into COVID-19 household/community transmission in a vulnerable population that resided in overcrowded households and who struggled to adhere to lockdown policies and social distancing measures. The high extra-household infection risk highlights the extreme social vulnerability of this population. Prioritising vaccination of the most socially vulnerable could protect these individuals and reduce widespread community transmission. Funding: Fundação Oswaldo Cruz, CNPq, FAPERJ, Royal Society, Instituto Serrapilheira, FAPESP.

Summary: Background: HIV incidence estimation is critical for monitoring the HIV epidemic dynamics and the effectiveness of public health prevention interventions. We aimed to identify sexual and gender minorities (SGM) with recent HIV infections, factors associated with recent HIV infection, and to estimate annualised HIV incidence rates. Methods: Cross-sectional multicentre study in HIV testing services in Brazil and Peru (15 cities). Inclusion criteria: 18+ years, SGM assigned male at birth, not using pre-/post-exposure prophylaxis. We identified recent HIV infection using the Maxim HIV-1 LAg-Avidity EIA assay as part of a recent infection testing algorithm (RITA). Annualized HIV incidence was calculated using the UNAIDS/WHO incidence estimator tool. Multivariable logistic regression models were used to estimate factors associated with recent HIV infection. Trial registration: NCT05674682. Findings: From 31-Jan-2021 to 29-May-2022, 6899 individuals participated [Brazil: 4586 (66.5%); Peru: 2313 (33.5%)]; 5946 (86.2%) cisgender men, 751 (10.9%) transgender women and 202 (2.9%) non-binary/gender diverse. Median age was 27 (IQR: 23–34) years. HIV prevalence was 11.4% (N = 784/6899); 137 (2.0%) SGM were identified with recent HIV infection. The overall annualized HIV incidence rate was 3.88% (95% CI: 2.86–4.87); Brazil: 2.62% (95% CI: 1.78–3.43); Peru: 6.69% (95% CI: 4.62–8.69). Participants aged 18–24 years had higher odds of recent HIV infection compared to those aged 30+ years in both countries. Interpretation: Our results highlight the significant burden of HIV epidemic among SGM in large urban centres of Brazil and Peru. Public health policies and interventions to increase access to effective HIV prevention methods such as PrEP are urgently needed in Latin America. Funding: Unitaid, WHO (Switzerland), Ministry of Health from Brazil and Peru.

Introdução: O diagnóstico de IVA pelo HIV exige alta suspeição, devido ao período de soroconversão, sendo necessários exames de 4ª geração ou carga viral em indivíduos com quadro clínico sugestivo ou exposição sexual recente, sobretudo no contexto de início de PrEP ou PEP. O início precoce da terapia antirretroviral (TAR) em pessoas com IVA pode reduzir reservatórios virais, sendo de potencial interesse em pesquisas de cura funcional. Nosso trabalho objetiva descrever o perfil de indivíduos com IVA acompanhados no Rio de Janeiro, Brasil. Métodos: Coorte prospectiva, incluiu sequencialmente pessoas ≥ 18 anos diagnosticadas com IVA pelo HIV de 2013-2023 acompanhadas em centro no Rio de Janeiro, Brasil. Foram coletados dados sociodemográficos, clínicos, comportamentais e laboratoriais. Realizamos uma análise descritiva das características no atendimento inicial. Participantes foram submetidos a TCLE e o projeto foi submetido ao Comitê de Ética em Pesquisa local. Resultados: Dos 103 participantes, 91% eram homens cis (96% HSH, n = 89/93), 7% travestis/mulheres trans (TMT), 1% não binárie e 1% mulher cis, majoritariamente com idade < 30 anos (65%), autodeclarados pretos/pardos (59%) e de escolaridade pós-secundária (58%). Enquanto 58% apresentaram síndrome retroviral aguda, o diagnóstico de IVA ocorreu no acompanhamento de PrEP/PEP em 34%. A mediana de log de carga viral HIV pré-tratamento foi 4.7, com CD4 de 577 cél/mm3, sendo 74% com CD4/CD8

Summary: Background: By October 30, 2022, 76,871 cases of mpox were reported worldwide, with 20,614 cases in Latin America. This study reports characteristics of a case series of suspected and confirmed mpox cases at a referral infectious diseases center in Rio de Janeiro, Brazil. Methods: This was a single-center, prospective, observational cohort study that enrolled all patients with suspected mpox between June 12 and August 19, 2022. Mpox was confirmed by a PCR test. We compared characteristics of confirmed and non-confirmed cases, and among confirmed cases according to HIV status using distribution tests. Kernel estimation was used for exploratory spatial analysis. Findings: Of 342 individuals with suspected mpox, 208 (60.8%) were confirmed cases. Compared to non-confirmed cases, confirmed cases were more frequent among individuals aged 30–39 years, cisgender men (96.2% vs. 66.4%; p

Summary: Background: COVID-19 serosurveys allow for the monitoring of the level of SARS-CoV-2 transmission and support data-driven decisions. We estimated the seroprevalence of anti-SARS-CoV-2 antibodies in a large favela complex in Rio de Janeiro, Brazil. Methods: A population-based panel study was conducted in Complexo de Manguinhos (16 favelas) with a probabilistic sampling of participants aged ≥1 year who were randomly selected from a census of individuals registered in primary health care clinics that serve the area. Participants answered a structured interview and provided blood samples for serology. Multilevel regression models (with random intercepts to account for participants’ favela of residence) were used to assess factors associated with having anti-S IgG antibodies. Secondary analyses estimated seroprevalence using an additional anti-N IgG assay. Findings: 4,033 participants were included (from Sep/2020 to Feb/2021, 22 epidemic weeks), the median age was 39·8 years (IQR:21·8-57·7), 61% were female, 41% were mixed-race (Pardo) and 23% Black. Overall prevalence was 49·0% (95%CI:46·8%-51·2%) which varied across favelas (from 68·3% to 31·4%). Lower prevalence estimates were found when using the anti-N IgG assay. Odds of having anti-S IgG antibodies were highest for young adults, and those reporting larger household size, poor adherence to social distancing and use of public transportation. Interpretation: We found a significantly higher prevalence of anti-S IgG antibodies than initially anticipated. Disparities in estimates obtained using different serological assays highlight the need for cautious interpretation of serosurveys estimates given the heterogeneity of exposure in communities, loss of immunological biomarkers, serological antigen target, and variant-specific test affinity. Funding: Fundação Oswaldo Cruz, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ), the European Union's Horizon 2020 research and innovation programme, Royal Society, Serrapilheira Institute, and FAPESP.

The Ad26.COV2·S (Janssen/Johnson & Johnson) COVID-19 vaccine, has been rarely associated with vaccine-induced immune thrombocytopenia and thrombosis (VITT). We investigated the prevalence of anti-PF4 antibody positivity, thrombocytopenia, D-dimer elevation, plasmatic thromboinflammatory markers, and platelet functional assays following Ad26.COV2·S vaccination in Rio de Janeiro, Brazil. From July to September 2021, participants were assessed prior, 1, and 3 weeks post-vaccination. Platelet count and D-dimer were measured at each visit and anti-PF4 at week 3. A positive anti-PF4 prompted retrospective testing of the sample from week 0. Individuals with new thrombocytopenia or elevated D-dimer, positive anti-PF4, and 38 matched controls without laboratory abnormalities were evaluated for plasmatic p-selectin, tissue factor, and functional platelet activation assays. 630 individuals were included; 306 (48.57%) females, median age 28 years. Forty-two (6.67%) presented ≥1 laboratory abnormality in week 1 or 3. Five (0.79%) had thrombocytopenia, 31 (4.91%) elevated D-dimer, and 9 (1.57%) had positive anti-PF4 at week 3. Individuals with laboratory abnormalities and controls showed a slight increase in plasmatic p-selectin and tissue factor. Ten individuals with laboratory abnormalities yielded increased surface expression of p-selectin, and their ability to activate platelets in a FcγRIIa dependent manner was further evaluated. Two were partially inhibited by high concentrations of heparin and blockage of FcγRII with IV.3 antibody. Plasma obtained before vaccination produced similar results, suggesting a lack of association with vaccination. Vaccination with Ad26.COV2·S vaccine led to a very low frequency of low-titer positive anti-PF4 antibodies, elevation of D-dimer, and mild thrombocytopenia, with no associated clinically relevant increase in thromboinflammatory markers and platelet activation. [ABSTRACT FROM AUTHOR]