Low prevalence of anti-Orthopoxvirus neutralizing antibodies in an urban population of Brazil.

Since 1999, Vaccinia virus (VACV) has been described as a causative agent of bovine vaccinia (BV), a zoonotic disease that occurs mainly in rural areas of Brazil. However, the circulation of VACV in urban environments and its associated burden has been poorly explored. Moreover, the current monkeypox (mpox) outbreak has raised questions regarding the immune status of the worldwide population previous vaccinated against smallpox. Hence, we conducted a cross-sectional study to better understand the prevalence of anti-OPV neutralizing antibodies (NA) and related exposure factors in a susceptible urban population of Brazil. A total of 372 individuals were sampled, yielding an overall seroprevalence of 16.9% (CI95% = 13.4-21.1), and antibodies titers ranging from 100 to 800 neutralizing units/mL. The prevalence of NA among individuals potentially vaccinated against smallpox (≥36 years old [yo]) was 24.9% (IC 95% = 19.5-31.2), and among those unvaccinated (<36yo) was 6.7% (IC 95% = 3.7-11.8). Interestingly, contact with horses was pointed out as an exposure factor for the presence of NA, however, the multivariate logistic regression analysis indicated that age ≥36yo and the presence of vaccine take were independently associated with the presence of anti-OPV NA. Our findings suggest that vulnerable populations could be subclinically exposed to VACV in urban areas, drawing attention to alternative routes of zoonotic VACV exposure. Our data is also important for better strategies to mitigate zoonotic OPV infections mainly among vulnerable populations.

Detection of SARS-CoV-2 RNA on public surfaces in a densely populated urban area of Brazil: A potential tool for monitoring the circulation of infected patients.

The world is experiencing the worst global health crisis in recent decades since December/2019 due to a new pandemic coronavirus. The COVID-19 disease, caused by SARS-CoV-2, has resulted in more than 30 million cases and 950 thousand deaths worldwide as of September 21, 2020. Determining the extent of the virus on public surfaces is critical for understanding the potential risk of infection in these areas. In this study, we investigated the presence of SARS-CoV-2 RNA on public surfaces in a densely populated urban area in Brazil. Forty-nine of 933 samples tested positive (5.25%) for SARS-CoV-2 RNA, including samples collected from distinct material surfaces, including metal and concrete, and distinct places, mainly around hospital care units and public squares. Our data indicated the contamination of public surfaces by SARS-CoV-2, suggesting the circulation of infected patients and the risk of infection for the population. Constant monitoring of the virus in urban areas is required as a strategy to fight the pandemic and prevent further infections.

Circulation of vaccinia virus in southern and south-eastern wildlife, Brazil.

We evaluated 345 wild animals from southern and south-eastern Brazil to understand their role in vaccinia virus (VACV) transmission cycle. VACV DNA was detected in rodents, marsupials, chiroptera and cingulate, expanding the knowledge of VACV host range in wildlife that could potentially act as source of infection in rural and urban areas.