Background: A population study is an important tool that can be used to understand the actual epidemiological scenario of the Covid-19 in different territories, identify its magnitude, understand its transmission dynamics, and its demographic, geographical, and social distribution. Objective: The aim of this study was to determine the prevalence and dynamics of SARS-CoV-2 infection in the population of two Brazilian cities during the pandemic first wave and subsequent socioeconomic and health effects. Materials & methods: This paper described the methodological procedures adopted and the prevalence of the SARS-CoV-2 infection in the population. A household survey was conducted between October and December 2020, in two historic cities of Brazil's mining region. Anti-SARS-CoV-2 antibody was detected using the Wondfo® rapid test. The face-to-face interview consisted of administration of a questionnaire containing registration data, sociodemographic and economic variables, living habits, general health condition, mental health, sleep habits, and eating and nutrition. Results: We evaluated 1,762 residents, of which 764 (43.4%) were in Mariana and 998 (56.6%) in Ouro Preto. For both cities, 51.9% of the interviewees were female, with a predominance of the age range 35 to 59 years old (47.2%). The prevalence of the SARS-CoV-2 infection was 5.5% in all cities, 6.2% in Ouro Preto, and 4.7% in Mariana. The prevalence was similar between cities (P>0.05). Conclusion: The study was effective in verifying the seroprevalence of infection by the virus and its findings will enable further analyses of the health conditions of the population related to social isolation and the risk of infection with SARS-CoV-2.

OBJETIVO: Descrever a confiabilidade/validade de um questionário semi-estruturado para avaliar comportamento de risco para as infecções sexualmente transmissíveis entre adultos com doença mental crônica. MÉTODO: Estudo-piloto transversal em um hospital psiquiátrico e um centro de atenção psicossocial. Dados clínicos, comportamentais e sociodemográficos foram coletados por entrevistas semi-estruturadas/prontuários médicos. Cento e vinte pacientes foram selecionados aleatoriamente a partir de listas pré-definidas de ambos os centros, enquanto 89 (74%) foram entrevistados, indicando uma taxa de não-participação de 26%. Protocolo, participação, consentimento e outros fatores foram avaliados. A entrevista semi-estruturada foi avaliada em sua confiabilidade (intra e inter-observador) e validade de construto, por repetição aleatória (razão 1:1), com até uma semana de intervalo. A confiabilidade foi estimada pelo percentual de concordância/coeficiente Kappa (intervalo de confiança 95%). A validade de construto foi avaliada pelo modelo Grade of Membership. RESULTADOS: Os coeficientes Kappa variaram de 0,40-1,00 para a maioria das variáveis. A análise Grade of Membership gerou três perfis de vulnerabilidade. O perfil um representou principalmente mulheres em relacionamentos estáveis que não usavam preservativo; o perfil dois revelou principalmente homens em relacionamentos estáveis, mas múltiplos comportamentos de risco; o terceiro perfil indicou uma alta proporção de uso de substâncias lícitas e/ou ilícitas. CONCLUSÕES: A confiabilidade e validade de construto indicaram que a entrevista foi adequada para captar os comportamentos de risco nesta população.

OBJECTIVE: To describe reliability/validity of a semi-structured questionnaire designed to assess risk behavior to sexually transmitted diseases among adults with chronic mental illness. METHOD: A cross-sectional pilot study was conducted in one psychiatric hospital and one mental health outpatient clinic. Clinical, behavioral and demographic data were collected from semi-structured interviews and medical charts. One-hundred and twenty patients were randomly selected from pre-defined lists in both centers while 89 (74%) were interviewed, indicating 26% nonparticipation rate. Protocol, participation rates, consent form and feasibility issues were assessed. The semi-structured interview was evaluated with regard to reliability (intra- and inter-rater) and construct validity by randomly repeating the interviews in a 1:1 ratio up to one-week interval. Reliability was estimated by percent agreement and Kappa statistics (95% confidence interval). Construct validity was assessed by Grade of Membership model. RESULTS: Kappa statistics ranged from 0.40 to 1.00 for most variables. Grade of Membership analysis generated three profiles. Profile one was represented by mostly women with no condom use in stable relationships; profile two revealed mostly men in stable relationship but with multiple risk behaviors; while profile three indicated a higher proportion of licit or illicit substance use. CONCLUSIONS: Reliability and construct validity assessment using Grade of Membership analysis indicated that the semi-structured interview was suitable for capturing risk behavior among patients with chronic mental illness.