Impact of COVID-19 RT-PCR testing of asymptomatic health care workers on absenteeism and hospital transmission during the pandemic.

Background: Reducing the transmission of SARS-CoV-2 from asymptomatic and pre-symptomatic patients is critical in controlling the circulation of the virus.

Methods: This study evaluated the prevalence of Reverse transcription polymerase chain reaction (RT-PCR) positivity in serial tests in 429 asymptomatic health care workers (HCW) and its impact on absenteeism. HCW from a COVID-19 reference hospital were tested, screened, and placed on leave.

Genetic diversity and HIV-1 incidence estimation among cocaine users in São Paulo, Brazil.

We describe HIV-1 incidence and the prevalence of genetic subtypes among cocaine users in São Paulo, Brazil. A cross-sectional HIV-1 survey was carried out among 839 current cocaine users attending seven drug treatment units in the São Paulo metropolitan area from 1997 to 1998. HIV-1 subtyping was performed among 41 positive individuals using the heteroduplex mobility assay and DNA sequencing.