Prevalence of virological and serological markers of SARS-CoV-2 infection in the population of Ribeirão Preto, Southeast Brazil: an epidemiological survey.

INTRODUCTION: This epidemiological household survey aimed to estimate the prevalence of the current and past SARS-CoV-2 infections in Ribeirão Preto, a municipality of southeast Brazil. METHODS: The survey was conducted in two phases using a clustered sampling scheme. The first phase spanned May 1-3 and involved 709 participants. The second phase spanned June 11-14, 2020, and involved 646 participants. RESULTS: During the first phase, RT-PCR performed on nasopharyngeal swabs was positive at 0.14%. The serological tests were positive in 1.27% of the patients during the first phase and 2.79% during the second phase. People living in households with more than five members had a prevalence of 10.83% (95%CI: 1.58-74.27) higher than those living alone or with someone other. Considering the proportion of the positive serological test results with sex and age adjustments, approximately 2.37% (95%CI: 1.32-3.42) of the population had been cumulatively infected by mid-June 2020, which is equivalent to 16,670 people (95%CI: 9,267-24,074). Considering that 68 deaths from the disease in the residents of the city had been confirmed as at the date of the second phase of the survey, the infection fatality rate was estimated to be 0.41% (95%CI: 0.28-0.73). Our results suggest that approximately 88% of the cases of SARS-CoV-2 infection at the time of the survey were not reported to the local epidemiological surveillance service. CONCLUSIONS: The findings of this study provide in-depth knowledge of the COVID-19 pandemic in Brazil and are helpful for the preventive and decision-making policies of public managers.

Molecular surveillance of the on-going SARS-COV-2 epidemic in Ribeirao Preto City, Brazil.

The Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of an unprecedented worldwide pandemic. Brazil demonstrates one of the highest numbers of confirmed SARS-CoV-2 cases, and São Paulo State is the epicenter of the pandemics in the country. Nevertheless, little is known about the SARS-CoV-2 circulation in other cities in the State than São Paulo city. The objective of this study was to analyze phylogenetically SARS-CoV-2 strains circulating in city of Ribeirão Preto at the beginning of the pandemic and during the actual second wave. Twenty-nine nasopharyngeal SARS-CoV-2 RNA positive samples were sequenced by nanopore technology (18 obtained at the initial period of the pandemic and 11 during the second wave) and analyzed them phylogenetically. The performed analysis demonstrated that the majority of the strains obtained in the initial period of the pandemic in Ribeirão Preto belonged mainly to the B1.1.33 lineage (61.1%), but B.1.1 (27.8%) and B.1.1.28 (11.1%) lineages were also identified. In contrast, the second wave strains were composed exclusively by the Brazilian variant of concern (VOC) P.1 (91%) and P.2 (9%) lineages. The obtained phylogenetic results were suggestive of successive SARS-CoV-2 lineage substitution in this Brazilian region by the P.1 VOC. The performed study examines the SARS-CoV-2 genotypes in Ribeirão Preto city via genomic surveillance data. The obtained findings can contribute for continuous long-term genomic surveillance of SARS-CoV-2 due to the accelerated dynamics of viral lineage substitution, predict further waves and examine lineage behavior during SARS-CoV-2 vaccination.

Outcomes of HIV-associated Burkitt Lymphoma in Brazil: High treatment toxicity and refractoriness rates - A multicenter cohort study.

BACKGROUND: Although the increased use of combined antiretroviral therapy (cART) has decreased the incidence of lymphomas HIV-associated, Burkitt lymphoma (BL) incidence remains stable. Reported outcomes on HIV-associated BL from developed countries seem to corroborate that the regimens do not need to be tailored to the HIV-positive population. MATERIALS AND METHODS: This is a retrospective multicenter cohort study from Brazil, including HIV-positive patients aged 15 years and above diagnosed with BL. RESULTS: A total of 54 patients were included. Median age was 39 years (range, 15-64). At diagnosis, advanced disease was found in 86% and 52% had a CD4+ count lower than 200 cells/mm3. Five patients died before starting any regimen. Among the remaining 49 patients, most were treated with Hyper-CVAD (53%) and CODOX-M IVAC (18%). Rituximab was used in frontline in only 16% of the patients. Primary refractory disease was found in 14%. A treatment-related mortality of 38.7% and a complete response rate of 44.9% were found. At 4 years, estimated overall survival (OS) was 39.8%. All relapsed and primary refractory patients eventually died. Remaining patients died from infections (24/34), despite antimicrobial prophylaxis and associated cART. CONCLUSION: Early mortality and toxicity were higher in our cohort than in developed countries. A faster diagnosis, better understanding of the biology of the disease, establishment of low toxicity regimens, inclusion of rituximab and improvement of supportive care may decrease the mortality of HIV-associated BL in developing countries.