A higher number of SARS-COV-2 infections in quilombola communities than in the local population in Brazil.

The historical and social vulnerability of quilombola communities in Brazil can make them especially fragile in the face of COVID-19, considering that several individuals have precarious health systems and inadequate access to water. This work aimed to characterize the frequency of SARS-COV-2 infections and the presence of IgM and IgG SARS-CoV-2 antibodies in quilombola populations and their relationship with the presence of risk factors or preexisting chronic diseases in the quilombola communities. We analyzed the sociodemographic and clinical characteristics, serological status, comorbidities, and symptoms of 1,994 individuals (478 males and 1,536 females) from 18 Brazilian municipalities in the State of Sergipe of quilombola communities, which were evaluated at different epidemiological weeks, starting at the 32nd (August 6th) and ending at the 40th (October 3rd) epidemiological week. More than 70% of studied families live in rural areas and they have an extreme poverty social status. Although we found a higher number of SARS-COV-2 infections in quilombola communities than in the local population, their SARS-CoV-2 reactivity and IgM and IgG positivity varied across the communities investigated. Arterial hypertension was the most risk factor, being found in 27.8% of the individuals (9.5% in stage 1, 10.8% in stage 2, and 7.5% in stage 3). The most common COVID-19 symptoms and comorbidities were headache, runny nose, flu, and dyslipidemia. However, most individuals were asymptomatic (79.9%). Our data indicate that mass testing must be incorporated into public policy to improve the health care system available to quilombola populations during a future pandemic or epidemic.

Does In-Person Visiting Affect the Number of COVID-19 Cases in Prisons?

Even with the current advances that have been made in regard to COVID-19, such as a better understanding of the disease and the steady growth in the number of vaccinated individuals, it remains a challenge for humanity. Dealing with the disease in prison settings has been particularly difficult. This study sought to discover whether in-person visiting affected the number of cases of SARS-CoV-2 infection in the penitentiaries in the state of Sergipe (Brazil). We conducted a two-phase study (when visiting was suspended and after it recommenced) in seven penitentiaries in Sergipe using immunochromatography and nasopharyngeal swab testing to evaluate whether visiting affects the number of COVID-19 cases. In the first phase (n = 778), 57.6% of inmates reported risk factors and 32.5% were positive for COVID-19 (18.9% IgM, 24.2% IgG, 1% antigen). In the second phase, 19.6% tested positive (13.9% IgM, 7.9% IgG, 0.2% antigen). The occurrence of positive cases of COVID-19 and positive results (IgM and IgG) were significantly higher in the first phase. In the second phase, 56.7% of inmates had received visits and 18.7% were positive for COVID-19 (14% IgM, 7% IgG). Among those who had not received visits, 20.9% tested positive (13.8% IgM, 9.2% IgG, 0.5% antigen). There was no significant difference in positive cases/results between inmates that had and had not received visits. These findings suggest that, under the conditions assessed, visiting does not seem to affect the number of COVID-19 cases in prisons and reinforces the importance of sanitary measures to control dissemination.

Rapid diagnosis of COVID-19 in the first year of the pandemic: A systematic review.

BACKGROUND: COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health threat and remains a challenge for modern medicine. Rapid and accurate diagnosis of COVID-19 is vital for proper disease and outbreak management. Our review aimed to analyze scientific articles published in the literature addressing the rapid tests available for COVID-19 diagnosis at the first year of the pandemic. METHODS: A systematic review was performed from October 22 to 27, 2020, searching data published in PubMed and Google Scholar databases, using subject headings or keywords related to point of care and rapid test diagnostic for SARS-CoV-2 and COVID-19. RESULTS: The first survey identified 403 articles, but only 23 met the defined criteria for the systematic analysis. The sensitivity and specificity parameters were assessed in 19 studies, and the data suggested that there was lower sensitivity in the period 1 to 7 days after the emergence of symptoms (∼38%) higher sensitivity at 8 to 14 days (∼90%), and the highest at 15 to 39 days (∼98%). Accuracy was reported in six studies, reporting values above 50%. Only three studies reported a possible cross-reaction. CONCLUSIONS: Our findings indicate that the rapid tests used in the first year of the pandemic were tested with a small number of samples and not adequately validated. And the studies that described them were conducted with little scientific rigor.

SARS-CoV-2 has been circulating in northeastern Brazil since February 2020: evidence for antibody detection in asymptomatic patients.

We screened stored samples collected before COVID-19 had been reported in Brazil. 989 samples were tested for SAR-CoV-2 antibodies using two different methods; 16 (1.6%) were positive (7 (43.8%) IgM, 3 (18.8%) IgG and 6 (37.5%) IgG/IgM positive), suggesting SARS-CoV-2 had circulated before the first reported COVID-19 case in Brazil.

Seroprevalence of SARS-CoV-2 IgM and IgG antibodies in an asymptomatic population in Sergipe, Brazil.

OBJECTIVE: To estimate the prevalence of SARS-CoV-2 antibodies in an asymptomatic population in the state of Sergipe, Brazil.
. METHODS: This cross-sectional study with stratified sampling (sex and age) included serological immunofluorescent tests for IgM and IgG on samples from 3 046 asymptomatic individuals. Sample collection was performed in wet-markets of the 10 most populous cities of Sergipe, Brazil. Exclusion criteria included symptomatic individuals and health workers. The presence of comorbidities was registered.
. RESULTS: Of the 3 046 participants, 1 577 (51.8%) were female and 1 469 (48.2%) were male; the mean age was 39.76 (SD 16.83) years old. 2 921 tests were considered valid for IgM and 2 635 for IgG. Of the valid samples, 347 (11.9% [CI 10.7%-13.1%]) tested positive for IgM and 218 (8.3% [CI 7.2%-9.4%]) tested positive for IgG. Women over 40 had the highest prevalence for IgM (group C, p=0.006; group D p=0.04). The capital Aracaju displayed the highest prevalence for both antibodies; 83 (26.3% [CI 21.6%-31.6%]) tested positive for IgM and 35 (14.6% [CI 10.4%-19.7%]) for IgG. The most prevalent comorbidities were hypertension (64/123 individuals) and diabetes (29/123).
. CONCLUSIONS: A high prevalence of SARS-CoV-2 antibodies was found among asymptomatic persons in Sergipe. Women over 40 showed the highest rates. The capital, Aracaju, displayed the highest seroprevalence. Surveys like this one are important to understand how the virus spreads and to help authorities to plan measures to control it. Repeated serologic testing are required to track the progress of the epidemic.

OBJETIVO: estimar la prevalencia de anticuerpos dirigidos contra el SARS-CoV-2 en una población asintomática del estado de Sergipe, Brasil. MÉTODOS: estudio transversal con muestreo estratificado (por sexo y edad) que incluyó pruebas serológicas de inmunofluorescencia para IgM e IgG en muestras de 3 046 individuos asintomáticos. La recolección de muestras se realizó en los mercados húmedos de las 10 ciudades más pobladas de Sergipe, Brasil. Se excluyó a los individuos sintomáticos y a los trabajadores de la salud. Se registró la presencia de comorbilidades. RESULTADOS: De los 3 046 participantes, 1 577 (51,8%) eran mujeres y 1 469 (48,2%) varones; la edad promedio fue de 39,76 (SD 16,83) años. Se consideraron válidas 2 921 pruebas para la IgM y 2 635 para la IgG. De las muestras válidas, 347 (11,9% [CI 10,7%-13,1%]) resultaron positivas para IgM y 218 (8,3% [CI 7,2%-9,4%]) para IgG. Las mujeres mayores de 40 años tuvieron la mayor prevalencia de IgM (grupo C, p=0,006; grupo D, p=0,04). Aracaju, la capital del estado, mostró la mayor prevalencia para ambos anticuerpos; 83 (26,3% [CI 21,6%-31,6%]) resultaron positivas para IgM y 35 (14,6% [CI 10,4%-19,7%]) para IgG. Las comorbilidades más frecuentes fueron la hipertensión (64/123 individuos) y la diabetes (29/123). CONCLUSIONES: Se encontró una alta prevalencia de anticuerpos contra el SARS-CoV-2 en personas asintomáticas en Sergipe. Las mujeres mayores de 40 años mostraron las tasas más altas. La capital, Aracaju, mostró la mayor seroprevalencia. Las encuestas como esta son importantes para comprender cómo se propaga el virus y para ayudar a las autoridades a planificar medidas de control. Se requieren pruebas serológicas repetidas para dar seguimento al progreso de la epidemia.

Seroprevalence of SARS-CoV-2 IgM and IgG antibodies in an asymptomatic population in Sergipe, Brazil

[ABSTRACT]. Objective. To estimate the prevalence of SARS-CoV-2 antibodies in an asymptomatic population in the state of Sergipe, Brazil. Methods. This cross-sectional study with stratified sampling (sex and age) included serological immunofluorescent tests for IgM and IgG on samples from 3 046 asymptomatic individuals. Sample collection was performed in wet-markets of the 10 most populous cities of Sergipe, Brazil. Exclusion criteria included symptomatic individuals and health workers. The presence of comorbidities was registered. Results. Of the 3 046 participants, 1 577 (51.8%) were female and 1 469 (48.2%) were male; the mean age was 39.76 (SD 16.83) years old. 2 921 tests were considered valid for IgM and 2 635 for IgG. Of the valid samples, 347 (11.9% [CI 10.7%–13.1%]) tested positive for IgM and 218 (8.3% [CI 7.2%–9.4%]) tested positive for IgG. Women over 40 had the highest prevalence for IgM (group C, p=0.006; group D p=0.04). The capital Aracaju displayed the highest prevalence for both antibodies; 83 (26.3% [CI 21.6%-31.6%]) tested positive for IgM and 35 (14.6% [CI 10.4%-19.7%]) for IgG. The most prevalent comorbidities were hypertension (64/123 individuals) and diabetes (29/123). Conclusions. A high prevalence of SARS-CoV-2 antibodies was found among asymptomatic persons in Sergipe. Women over 40 showed the highest rates. The capital, Aracaju, displayed the highest seroprevalence. Surveys like this one are important to understand how the virus spreads and to help authorities to plan measures to control it. Repeated serologic testing are required to track the progress of the epidemic.

[RESUMEN]. Objetivo. Estimar la prevalencia de anticuerpos dirigidos contra el SARS-CoV-2 en una población asintomática del estado de Sergipe, Brasil. Métodos. Estudio transversal con muestreo estratificado (por sexo y edad) que incluyó pruebas serológicas de inmunofluorescencia para IgM e IgG en muestras de 3 046 individuos asintomáticos. La recolección de muestras se realizó en los mercados húmedos de las 10 ciudades más pobladas de Sergipe, Brasil. Se excluyó a los individuos sintomáticos y a los trabajadores de la salud. Se registró la presencia de comorbilidades. Resultados. De los 3 046 participantes, 1 577 (51,8%) eran mujeres y 1 469 (48,2%) varones; la edad promedio fue de 39,76 (SD 16,83) años. Se consideraron válidas 2 921 pruebas para la IgM y 2 635 para la IgG. De las muestras válidas, 347 (11,9% [CI 10,7%-13,1%]) resultaron positivas para IgM y 218 (8,3% [CI 7,2%-9,4%]) para IgG. Las mujeres mayores de 40 años tuvieron la mayor prevalencia de IgM (grupo C, p=0,006; grupo D, p=0,04). Aracaju, la capital del estado, mostró la mayor prevalencia para ambos anticuerpos; 83 (26,3% [CI 21,6%-31,6%]) resultaron positivas para IgM y 35 (14,6% [CI 10,4%-19,7%]) para IgG. Las comorbilidades más frecuentes fueron la hipertensión (64/123 individuos) y la diabetes (29/123). Conclusiones. Se encontró una alta prevalencia de anticuerpos contra el SARS-CoV-2 en personas asintomáticas en Sergipe. Las mujeres mayores de 40 años mostraron las tasas más altas. La capital, Aracaju, mostró la mayor seroprevalencia. Las encuestas como esta son importantes para comprender cómo se propaga el virus y para ayudar a las autoridades a planificar medidas de control. Se requieren pruebas serológicas repetidas para dar seguimento al progreso de la epidemia.

Repulsive Guidance Molecules a, b and c Are Skeletal Muscle Proteins, and Repulsive Guidance Molecule a Promotes Cellular Hypertrophy and Is Necessary for Myotube Fusion.

Repulsive guidance molecules (RGMs) compose a family of glycosylphosphatidylinositol (GPI)-anchored axon guidance molecules and perform several functions during neural development. New evidence has suggested possible new roles for these axon guidance molecules during skeletal muscle development, which has not been investigated thus far. In the present study, we show that RGMa, RGMb and RGMc are all induced during skeletal muscle differentiation in vitro. Immunolocalization performed on adult skeletal muscle cells revealed that RGMa, RGMb and RGMc are sarcolemmal proteins. Additionally, RGMa was found to be a sarcoplasmic protein with a surprisingly striated pattern. RGMa colocalization with known sarcoplasmic proteins suggested that this axon guidance molecule is a skeletal muscle sarcoplasmic protein. Western blot analysis revealed two RGMa fragments of 60 and 33 kDa, respectively, in adult skeletal muscle samples. RGMa phenotypes in skeletal muscle cells (C2C12 and primary myoblasts) were also investigated. RGMa overexpression produced hypertrophic cells, whereas RGMa knockdown resulted in the opposite phenotype. RGMa knockdown also blocked myotube formation in both skeletal muscle cell types. Our results are the first to show an axon guidance molecule as a skeletal muscle sarcoplasmic protein and to include RGMa in a system that regulates skeletal muscle cell size and differentiation.