COVID-19 vaccination and case fatality rates: a case report in a Brazilian municipality.

Vaccination campaigns played a crucial role in reducing the incidence of COVID-19. However, a scant number of studies evaluated the impact of vaccination on case fatality rates (CFRs), including in Brazil. Our study aimed to compare CFRs according to vaccination status among subjects living in Arapongas (Paraná State, Brazil), considering the age composition of the population. Several strategies adopted by the Arapongas City Hall to minimize the spread of the virus were also elaborated upon. We accessed the 2021 database of the Arapongas Municipal Health Department, in which a total of 16,437 confirmed cases and 425 deaths were reported. The CFR was calculated as the ratio between COVID-19 deaths and the number of confirmed cases. Differences in age composition between unvaccinated and fully vaccinated individuals were observed in our study. Considering that CFR is a crude indicator and is highly sensitive to the age composition of the population, we adopted the average age distribution of confirmed cases among the three vaccination statuses (unvaccinated, partially, and fully) as a standard age distribution. The age-standardized CFR for unvaccinated and fully vaccinated groups were 4.55% and 2.42%, respectively. Fully vaccinated individuals showed lower age-specific CFRs in all age groups above 60 years than unvaccinated populations. Our findings strengthen the role of vaccination as a critical measure for preventing deaths among infected people and is particularly important to the ongoing reassessment of public health interventions and policies.

Probabilistic survival modeling in health research: an assessment using cohort data from hospitalized patients with COVID-19 in a Latin American city.

Probabilistic survival methods have been used in health research to analyze risk factors and adverse health outcomes associated with COVID-19. The aim of this study was to employ a probabilistic model selected among three distributions (exponential, Weibull, and lognormal) to investigate the time from hospitalization to death and determine the mortality risks among hospitalized patients with COVID-19. A retrospective cohort study was conducted for patients hospitalized due to COVID-19 within 30 days in Londrina, Brazil, between January 2021 and February 2022, registered in the database for severe acute respiratory infections (SIVEP-Gripe). Graphical and Akaike Information Criterion (AIC) methods were used to compare the efficiency of the three probabilistic models. The results from the final model were presented as hazard and event time ratios. Our study comprised of 7,684 individuals, with an overall case fatality rate of 32.78%. Data suggested that older age, male sex, severe comorbidity score, intensive care unit admission, and invasive ventilation significantly increased risks for in-hospital mortality. Our study highlights the conditions that confer higher risks for adverse clinical outcomes attributed to COVID-19. The step-by-step process for selecting appropriate probabilistic models may be extended to other investigations in health research to provide more reliable evidence on this topic.

COVID-19 vaccination and case fatality rates: a case report in a Brazilian municipality / Vacinação contra a COVID-19 e taxas de letalidade: relato de caso em uma cidade brasileira / Vacunación contra el COVID-19 y tasas de letalidad: reporte de caso en una ciudad brasileña

Vaccination campaigns played a crucial role in reducing the incidence of COVID-19. However, a scant number of studies evaluated the impact of vaccination on case fatality rates (CFRs), including in Brazil. Our study aimed to compare CFRs according to vaccination status among subjects living in Arapongas (Paraná State, Brazil), considering the age composition of the population. Several strategies adopted by the Arapongas City Hall to minimize the spread of the virus were also elaborated upon. We accessed the 2021 database of the Arapongas Municipal Health Department, in which a total of 16,437 confirmed cases and 425 deaths were reported. The CFR was calculated as the ratio between COVID-19 deaths and the number of confirmed cases. Differences in age composition between unvaccinated and fully vaccinated individuals were observed in our study. Considering that CFR is a crude indicator and is highly sensitive to the age composition of the population, we adopted the average age distribution of confirmed cases among the three vaccination statuses (unvaccinated, partially, and fully) as a standard age distribution. The age-standardized CFR for unvaccinated and fully vaccinated groups were 4.55% and 2.42%, respectively. Fully vaccinated individuals showed lower age-specific CFRs in all age groups above 60 years than unvaccinated populations. Our findings strengthen the role of vaccination as a critical measure for preventing deaths among infected people and is particularly important to the ongoing reassessment of public health interventions and policies.

As campanhas de vacinação desempenharam um papel crucial na redução da incidência da COVID-19. No entanto, um número escasso de estudos avaliou o impacto da vacinação nas taxas de letalidade, inclusive no Brasil. Este estudo teve como objetivo comparar as taxas de letalidade de acordo com a situação vacinal dos residentes do Município de Arapongas (Paraná, Brasil), considerando a composição etária da população. Várias estratégias adotadas pela Prefeitura Municipal para minimizar a propagação do vírus também foram elaboradas. Acessou-se a base de dados de 2021 da Secretaria Municipal de Saúde de Arapongas, onde foram notificados 16.437 casos confirmados e 425 óbitos. A taxa de letalidade foi calculada como a razão entre as mortes por COVID-19 e o número de casos confirmados. Este estudo inédito observou diferenças na composição etária entre indivíduos não vacinados e totalmente vacinados. Considerando que a taxa de letalidade é um indicador bruto e altamente sensível à composição etária da população, adotou-se a distribuição etária média dos casos confirmados entre os três níveis vacinais (não vacinados, parcialmente vacinados e completamente vacinados) como distribuição etária padrão. A taxa de letalidade padronizada por idade para os não vacinados e completamente vacinados foi de 4,55% e 2,42%, respectivamente. Indivíduos completamente vacinados apresentaram menores taxas de letalidade específicas por idade em todas as faixas etárias acima de 60 anos em comparação às populações não vacinadas. Estes achados fortalecem o papel da vacinação como uma medida essencial para a prevenção de mortes entre pessoas infectadas e é de particular importância para a reavaliação contínua das intervenções e políticas de saúde pública.

Las campañas de vacunación juegan un papel clave en la reducción de la propagación del COVID-19. Sin embargo, pocos estudios evalúan el impacto de la vacunación en las tasas de letalidad, incluso en Brasil. Este estudio tuvo por objetivo comparar las tasas de letalidad según el estado de vacunación de los residentes de Arapongas (Paraná, Brasil) a partir de la composición por grupo de edad de la población. El Ayuntamiento Municipal aplicó varias estrategias para mitigar la propagación del virus. Se accedió a la base de datos de 2021 del Departamento de Salud de Arapongas, donde se reportaron 16.437 casos confirmados y 425 defunciones. Se calculó la tasa de letalidad como la relación entre las muertes por COVID-19 y el número de casos confirmados. Este estudio inédito evaluó las diferencias en la composición por grupo de edad entre individuos no vacunados y los individuos totalmente vacunados. Teniendo en cuenta que tasa de letalidad es un indicador bruto y muy sensible a la composición por grupo de edad de la población, se adoptó la distribución estándar por grupo de edad de los casos confirmados entre los tres niveles de vacunación (no vacunados, parcialmente vacunados y totalmente vacunados). La tasa de letalidad estandarizada por edad para los no vacunados y los totalmente vacunados fue del 4,55% y del 2,42%, respectivamente. Los individuos totalmente vacunados tenían más baja tasa de letalidad por grupo de edad en todos los grupos de edad superiores a los 60 años en comparación con las poblaciones no vacunadas. Estos hallazgos confirman el papel de la vacunación como una medida esencial de prevención de muertes entre los infectados y es importante para la reevaluación en curso de las intervenciones y políticas de salud pública.

The impact of COVID-19 vaccination on case fatality rates in a city in Southern Brazil.

BACKGROUND: Recent studies have established that vaccination plays a significant role in reducing COVID-19-related deaths. Here, we investigated differences in COVID-19 case fatality rates (CFRs) among vaccinated and unvaccinated populations, and analyzed whether the age composition of confirmed cases has a significant effect on the variations in the observed CFRs across these groups. METHODS: The study considered 59,853 confirmed cases and 1,687 deaths from COVID-19, reported between January 1 to October 20, 2021, by the Health Department of Londrina, a city in Southern Brazil. We used Negative Binomial regression models to estimate CFRs according to vaccination status and age range. RESULTS: There are significant differences between the CFR for fully vaccinated and unvaccinated populations (IRR = 0.596, 95% CI [0.460 - 0.772], P < .001). Vaccinated populations experience fatality rates 40.4% lower than non-vaccinated. In addition, the age composition of confirmed cases explains more than two-thirds of the variation in the CFR between these 2 groups. CONCLUSIONS: Our novel findings reinforce the importance of vaccination as an essential public health measure for reducing COVID-19 fatality rates in all age groups. The results also provide means for accurately assessing differences in CFRs across vaccinated and unvaccinated populations. Such assessment is essential to inform and determine appropriate containment and mitigation interventions in Brazil and elsewhere.

Meteorological parameters and cases of COVID-19 in Brazilian cities: an observational study.

Meteorological parameters modulate transmission of the SARS-Cov-2 virus, the causative agent related to coronavirus disease-2019 (COVID-19) development. However, findings across the globe have been inconsistent attributed to several confounding factors. The aim of the present study was to investigate the relationship between reported meteorological parameters from July 1 to October 31, 2020, and the number of confirmed COVID-19 cases in 4 Brazilian cities: São Paulo, the largest city with the highest number of cases in Brazil, and the cities with greater number of cases in the state of Parana during the study period (Curitiba, Londrina and Maringa). The assessment of meteorological factors with confirmed COVID-19 cases included atmospheric pressure, temperature, relative humidity, wind speed, solar irradiation, sunlight, dew point temperature, and total precipitation. The 7- and 15-day moving averages of confirmed COVID-19 cases were obtained for each city. Pearson's correlation coefficients showed significant correlations between COVID-19 cases and all meteorological parameters, except for total precipitation, with the strongest correlation with maximum wind speed (0.717, <0.001) in São Paulo. Regression tree analysis demonstrated that the largest number of confirmed COVID-19 cases was associated with wind speed (between ≥0.3381 and <1.173 m/s), atmospheric pressure (<930.5mb), and solar radiation (<17.98e+3). Lower number of cases was observed for wind speed <0.3381 m/s and temperature <23.86°C. Our results encourage the use of meteorological information as a critical component in future risk assessment models.

Risk factors associated with COVID-19-induced death in patients hospitalized in intensive care units (ICUs) in a city in Southern Brazil.

OBJECTIVES: The aim of this research was to address risk factors associated with death after hospitalization in intensive care units (ICUs) in 728 COVID-19 patients in Londrina, the second most populated city in the State of Paraná - Brazil, between March and December 2020. METHODS: Statistical analysis, including multiple logistic regression was performed to identify risk factors associated with death in these patients. RESULTS: The results showed that age (60 years or more, O.R. = 3.13, C.I. 95% [2.02; 4.84]), days in the ICU (11 days or more, O.R. = 1.76, C.I. 95% [1.16; 2.66]), neurological diseases (O.R. = 2.15, C.I. 95% [1.07; 4.31]), pneumopathy (O.R = 2.19, C.I. 95% [1.01; 4.82]), diabetes (O.R. = 1.55, C.I. 95% [1.03; 2.32]), and kidney disease (O.R. = 2.27, C.I. 95% [1.18; 4.70]) were associated with increased risk for death from COVID-19. CONCLUSION: Knowing the risk factors associated with death after ICUs hospitalization is useful for identifying the most vulnerable groups, as well as for defining vaccination priorities, considering its scarcity in many parts of the world, mainly in underdeveloped countries, including Brazil.