RESUMO
Background: The true incidence of SARS-CoV-2 infection in Costa Rica was likely much higher than officially reported, because infection is often associated with mild symptoms and testing was limited by official guidelines and socio-economic factors. Methods: Using serology to define natural infection, we developed a statistical model to estimate the true cumulative incidence of SARS-CoV-2 in Costa Rica early in the pandemic. We estimated seroprevalence from 2223 blood samples collected from November 2020 to October 2021 from 1976 population-based controls from the RESPIRA study. Samples were tested for antibodies against SARS-CoV-2 nucleocapsid and the receptor-binding-domain of the spike proteins. Using a generalized linear model, we estimated the ratio of true infections to officially reported cases. Applying these ratios to officially reported totals by age, sex, and geographic area, we estimated the true number of infections in the study area, where 70% of Costa Ricans reside. We adjusted the seroprevalence estimates for antibody decay over time, estimated from 1562 blood samples from 996 PCR-confirmed COVID-19 cases. Findings: The estimated total proportion infected (ETPI) was 4.0 times higher than the officially reported total proportion infected (OTPI). By December 16th, 2021, the ETPI was 47% [42-52] while the OTPI was 12%. In children and adolescents, the ETPI was 11.0 times higher than the OTPI. Interpretation: Our findings suggest that nearly half the population had been infected by the end of 2021. By the end of 2022, it is likely that a large majority of the population had been infected. Funding: This work was sponsored and funded by the National Institute of Allergy and Infectious Diseases through the National Cancer Institute, the Science, Innovation, Technology and Telecommunications Ministry of Costa Rica, and Costa Rican Biomedical Research Agency-Fundacion INCIENSA (grant N/A).
RESUMO
INTRODUCTION: Breast cancer is the leading cause of cancer-related deaths among women worldwide. In Costa Rica, it ranks first in incidence and fourth in terms of mortality. However, there is a lack of comprehensive information on treatment patterns and outcomes for breast cancer patients in Costa Rica. METHODS: This study utilized data from the National Tumor Registry, which was merged with the Costa Rica Social Security Fund (CCSS) to ensure comprehensive access to clinical information. The study is prospective and focused on patients diagnosed with breast cancer between January 2008 and December 2012. This combined dataset allowed for a more comprehensive analysis of patient characteristics, treatment patterns, and outcomes related to breast cancer in Costa Rica. RESULTS: Among the 4775 patients diagnosed during this period, 3160 met the inclusion criteria for our study. The average age at diagnosis was 59.1 years, with 32.5% of patients being over the age of 65. Most of the patients (55.4%) identified themselves as homemakers, while 46.5% underwent core needle biopsy for diagnosis. Approximately 60% of women were diagnosed with early-stage disease (IA, IIA, and IIB), while 1.7% had metastatic disease, mainly affecting the bone. The mean interval between diagnosis and surgery was 72 days. Most patients (88.7%) received surgery as their initial treatment, and over half (54.4%) received some form of adjuvant therapy. Additionally, 85.6% of patients completed their prescribed treatment. CONCLUSION: This study provides a comprehensive and detailed description of the characteristics and treatment patterns among breast cancer patients in Costa Rica. The findings contribute to our understanding of the disease in this population and can serve as a foundation for further research and improvement in breast cancer management and care.