ABSTRACT
BACKGROUND: There are several ecological studies, but few studies of the prevalence of SARS-COV-2 at high altitude. We aimed to estimate the population-based seroprevalence of SARS-COV-2 in three settings of Cusco at the end of the first wave among adults. METHODS: A population-based survey was conducted in September 2020, in three settings in the region of Cusco: (1) Cusco city at 3,300 meters above the sea level (m.a.s.l.), (2) the periphery of Cusco (Santiago, San Jerónimo, San Sebastián, and Wanchaq) at 3,300 m.a.s.l., and (3) Quillabamba city, located at 1,050 m.a.s.l. People aged ≥ 18 years within a family unit were included. The diagnosis of SARS-CoV-2 infection was based on identifying anti- SARS-CoV-2 total antibodies (IgM and IgG) in serum using the Elecsys Anti-SARS-CoV-2 chemiluminescence test. RESULTS: We enrolled 1924 participants from 712 families. Of the total, 637 participants were anti-SARS-CoV-2 seropositive. Seroprevalence was 38.8% (95% CI [33.4%-44.9%]) in Cusco city, 34.9% (95% CI [30.4%-40.1%]) in the periphery of Cusco, and 20.3% (95% CI [16.2%-25.6%]) in Quillabamba. In 141 families (19.8%; 95% CI [17.0%-22.8%]) the whole members were positive to the test. Living with more than three persons in the same house, a positive COVID-19 case at home, and a member who died in the last five months were factors associated with SARS-COV-2 seropositivity. Dysgeusia/dysosmia was the symptom most associated with seropositivity (aPR = 2.74, 95% CI [2.41-3.12]); whereas always wearing a face shield (aPR = 0. 73; 95% CI [0.60-0.89]) or a facial mask (aPR = 0.76, 95% CI [0.63-0. 92) reduced that probability. CONCLUSIONS: A great proportion of Cusco's city inhabitants presented anti-SARS-CoV-2 antibodies at the end of the first wave, with significant differences between settings. Wearing masks and face shields were associated with lower rate of seropositivity; however, efforts must be made to sustain them over time since there is still a high proportion of susceptible people.
Subject(s)
Altitude , Coronavirus Infections , Pandemics , Pneumonia, Viral , Betacoronavirus , COVID-19 , Cross-Sectional Studies , Humans , SARS-CoV-2ABSTRACT
O oeste do estado de São Paulo responde por cerca de 40% da produção estadual de batata-doce, mesmo sem a adoção, pelos agricultores da região, de tecnologias fundamentais para o aumento da produtividade. Este trabalho avaliou o impacto de viroses sobre variáveis da produção de batata-doce. O experimento foi conduzido em área comercial no município de Presidente Prudente, São Paulo, Brasil, utilizando plantas de Ipomoea batatas L, grupo rosada, cv. Canadense. Como material de propagação foram utilizadas mudas livres de vírus produzidas em viveiros e mudas originadas de lavoura comercial infectada por vírus. Na colheita foram demarcadas três parcelas de 10 x 4 m em cada uma das metades do campo (com e sem vírus), quando se avaliou, aleatoriamente, número, massa, comprimento e diâmetro dos tubérculos de dez plantas localizadas na área central de cada parcela. As parcelas sem vírus produziram cerca de 50% a mais e o dobro em massa (kg) de tubérculos colhidos em relação aos provenientes das parcelas com vírus. Os tubérculos obtidos das plantas não infectadas apresentaram maior massa (p < 0,01), comprimento (p < 0,01) e diâmetro médio (p < 0,05) do que os colhidos das plantas infectadas. Foi constatada também uma frequência de 65% de tubérculos com classificação 2A (150 a 299 g) para o grupo rosada-CEAGESP, que representa 70% do volume comercializado no CEAGESP, o que confere maior lucratividade ao produtor.(AU)
The Western region of São Paulo State, Brazil, is responsible for approximately 40% of the production of sweet potato (Ipomoea batatas L.) in the state, even under low-technology. The study aimed to evaluate the impact of viruses on sweet potato production variables. The experiment was conducted in Presidente Prudente, São Paulo, Brazil, in a commercial sweet potato crop of pink group, cv. Canadense, with and without virus. In three randomly chosen plots of 10 x 4 m in each half of the field (with and without virus), ten central plants were randomly collected. The number, weight, length and diameter were evaluated. The plots without virus produced 50% more tubers and 100% more weight during harvesting. Tubers obtained from virus-free seedlings showed a greater mass (p < 0.01), height (p < 0.01) and mean diameter (p < 0.05) than those harvested from infected plants. From free-of-virus seedlings, 65% of tubers were classified as 2A (150 to 299 g), the standard that represents 70% of the trading volume at a Food Market place, which provides greater profitability to the producer.(AU)
