Seroprevalence of SARS-CoV-2 and Vaccination Coverage among Residents of a Lower-Middle-Class Population in the Federal District, Brazil.

Estimating seroprevalence and vaccination coverage against COVID-19 is crucial to the development of well-targeted public health policies at the local level. Here, we estimated seroprevalence and vaccination coverage in a lower-middle-class population in Brazil. We conducted an observational, cross-sectional, population-based survey from 24 September to 19 December 2021. CMIA tests were used to detect anti-SARS-CoV-2 IgG against the N-protein. The overall seroprevalence was 24.15% (177/733), and vaccination coverage was 91.40% (670/733); 72.09% (483/670) were fully vaccinated. Among vaccinated participants, seroprevalence was 24.77% (95% CI 21.50-28.04; 166/670), with a prevalence ratio (PR) of 1.03 (95% CI 0.98-1.08; p-value 0.131). Among participants who received an mRNA vaccine with S-based epitope (485), seroprevalence was 16.29% (95% CI 13.04-19.85; 79/485). Among unvaccinated participants, seroprevalence was 17.46% (95% CI 10.04-28.62; 11/63). Finally, in spite of the political climate and other possible causes for vaccine hesitancy, the positive Brazilian culture towards vaccination might have curbed hesitancy.

Replacement of the Gamma by the Delta variant in Brazil: Impact of lineage displacement on the ongoing pandemic.

The coronavirus disease 2019 (COVID-19) epidemic in Brazil was driven mainly by the spread of Gamma (P.1), a locally emerged variant of concern (VOC) that was first detected in early January 2021. This variant was estimated to be responsible for more than 96 per cent of cases reported between January and June 2021, being associated with increased transmissibility and disease severity, a reduction in neutralization antibodies and effectiveness of treatments or vaccines, and diagnostic detection failure. Here we show that, following several importations predominantly from the USA, the Delta variant rapidly replaced Gamma after July 2021. However, in contrast to what was seen in other countries, the rapid spread of Delta did not lead to a large increase in the number of cases and deaths reported in Brazil. We suggest that this was likely due to the relatively successful early vaccination campaign coupled with natural immunity acquired following prior infection with Gamma. Our data reinforce reports of the increased transmissibility of the Delta variant and, considering the increasing concern due to the recently identified Omicron variant, argues for the necessity to strengthen genomic monitoring on a national level to quickly detect the emergence and spread of other VOCs that might threaten global health.

Syphilis and other sexually transmitted infections among waste pickers in Brasilia, Brazil.

There are millions of waste pickers worldwide that are predominantly located in low- and middle-income countries. They survive on sorting and selling reusable orrecyclable materials discarded by society.While sorting, they are exposed to occupational risks and hazards, including cuts from sharp objects and medical wastes, that could be contaminated by infectious diseases. Because of these exposures, a study was conducted to determine the prevalence of syphilis and other sexually transmitted infections (STI's) among waste pickers. A cross-sectional study using a semi-structured questionnaire and blood samples for serological tests were collected. A total of 1,025 waste pickers were interviewed. Most participants were women (67.54%), without a partner (70.11%), were an average of 40 years old, and had between 3 and 4 children. There were 755 samples collected for syphilis, 791 for HIV, 866 for hepatitis B, and 859 for hepatitis C. Of these samples, 28 (3.70%) waste pickers had reagent serology for syphilis, 6 (0.75%) for HIV; 6 (0.69%) for acute hepatitis B and 1 (0.11%) for hepatitis C. Overall, this study identified the serological status of waste pickers; this information can be used to encourage waste pickers to seek health treatment for STIs and receive education to understand the risks associated with being exposed to medical waste or syringes.

Knowledge, attitudes, and practices related to Leptospirosis among urban slum residents in Brazil.

Leptospirosis disproportionately affects residents of urban slums. To understand the knowledge, attitudes, and practices regarding leptospirosis, we conducted a cross-sectional study among residents of an urban slum community in Salvador, Brazil. Of the 257 residents who were interviewed, 225 (90%) were aware of leptospirosis and more than two-thirds of respondents correctly identified the modes of disease transmission and ways to reduce exposure. However, study participants who performed risk activities such as cleaning open sewers had limited access to protective clothing such as boots (33%) or gloves (35%). Almost all respondents performed at least one activity to prevent household rat infestation, which often included use of an illegal poison. Our findings support the need for interventions targeted at the individual and household levels to reduce risk of leptospirosis until large-scale structural interventions are available to residents of urban slum communities.