9to the MSP and BS risk categorization guidelines. Results: Of the total, 56 workers had a positive diagnosis of COVID-19, of which seven women (asymptomatic) showed levels <1 to the immunoassay for antibodies. Of the 51 workers with a negative RT-PCR result, 3 showed elevated antibody titers. The sensitivity of the test was 89.3%, the specificity 94.1% and the accuracy 91.6%. No correlation was observed between the global level of antibodies and age (r 0.09; p 0.52) as well as with comorbidities. Finally, workers with persistent symptoms had levels of antibodies. Conclusion:The anti-N antibody detection test for SARS-CoV-2 had a good diagnostic performance, showing some false negatives to RT-PCR, confirming its usefulness for seroprevalence studies. Antibody levels were higher in workers with persistent symptoms.

Introduction: Faced with COVID-19, hospitals were reorganized in the Paraguayan health system where the predominant financing is out-of-pocket expenses. Objectives: to analyze the out-ofpocket expenditure in the Encarnacion integrated respiratory hospital. Materials and methods: Quantitative, observational, descriptive study between August 2020 and February 2021. It included a non-random sample of 95 cases. A telephone survey was applied to a key informant. The dependent variables were: out-of-pocket expense, expense / income ratio, and expense / hospital days ratio. The independent ones were: sex, elderly, admission to ICU, medical insurance and diagnosis of COVID-19. Excessive spending was defined as greater than 0.1 of income and catastrophic as greater than 0.25 of income. The significant association was determined by Chi2 and Mann-Whitney tests (p <0.05). Results: 97.8% had out-of-pocket expenses mainly for medications and disposables. The average total expense was Gs 1.98 million, the average daily expense was Gs 215.4 thousand and the expense / income ratio was 1.13. In intensive care, the average total expenditure was 7.18 million Gs (the maximum was 18.41 million Gs), the average daily expenditure was 666.8 thousand Gs (the maximum was 2.85 million Gs per day) and the expense / income ratio 3.83. The expense was excessive in 87% of the cases and catastrophic in 52% of the cases. The expense was significantly associated with age over 60 years, having been admitted to the ICU and the diagnosis of COVID-19, not with sex or with insurance. Conclusion:The financial protection mechanisms were insufficient to avoid excessive and catastrophic expenses during hospitalization.

Introduction: Due to the different epidemiology of COVID-19 in different regions of the world, it is important to know the impact of health variables specific to each country. Objective:To evaluate the role of history of BCG vaccination and recent history of dengue among risk factors for hospitalization of patients with COVID-19.Methods: Observational, cross-sectional study that recorded sociodemographic and clinical variables by means of structured interview in patients diagnosed with COVID-19 in four health institutions in Paraguay (September to December 2020). Logistic regression models evaluated factors associated with outcome.Results: 397 patients were included. The frequency of hospitalization was higher in male patients, age > 40 years, lower income, obesity, hypertension and diabetes mellitus. There was less hospitalization among health personnel and in those who reported bronchial asthma. Male sex (ORa 3.72; arterial hypertension (ORa 2.46;, income (ORa 1.98; 95%CI 1.03-3.80), healthcare worker (ORa 0.20; 95%CI 0.11-0.37) and bronchial asthma (ORa 0.40; 95%CI 0.20-0.82) were influential in the multivariate analysis. In certain models studied by logistic regression, those who reported a history of BCG vaccination were associated with a lower frequency of hospitalization. History of symptomatic dengue fever was not among the relevant variables related to outcome.Conclusions: Among several COVID-19 severity prediction models, BCG vaccination history may be associated with hospitalization rates.