[Internal validity of a rapid test for COVID-19 antigens in a nursing home]. / Validez interna de una prueba rápida de detección de antígenos COVID-19 en una residencia de mayores.

INTRODUCTION: RT-qPCR is the reference test for the detection of SARS-CoV-2 infection, however, rapid antigen detection tests (RADT) are now available. In this work, the internal validity of the RADT was evaluated in the context of an outbreak in a nursing home. METHODS: Nasopharyngeal exudate samples were analyzed by RADT and RT-qPCR from 61 residents of a nursing home. The sensitivity and specificity of RADT with respect to RT-qPCR was calculated. RESULTS: Specificity was 100% (95% CI 54.1-100.0), while sensitivity in asymptomatic people was 70.3% (95% CI 53.0-84.1) and in symptomatic people 83.3% (95% CI 51.6-97.9). CONCLUSIONS: The RADTs are sufficiently sensitive and specific to be used as screening tests in nursing homes, especially in situations of outbreaks or suspected outbreaks due to the presence of symptoms.

Prevalence of SARS-CoV-2 infection in general practitioners and nurses in primary care and nursing homes in the Healthcare Area of León and associated factors.

OBJECTIVE: To evaluate the prevalence of and factors associated with SARS-CoV-2 infection in general practitioners and nurses from primary care centers and nursing homes in the Healthcare Area of León (Spain). MATERIALS AND METHODS: Cross-sectional study in a convenience sample of professionals from 30 health centers and 30 nursing homes from the primary care management division of the Healthcare Area of Leon. The work center, type of profession, COVID-19 infection, level of exposure, compliance with preventive measures, isolation (if required) and diagnostic tests carried out were collected. The determination of infection was made by differentiated rapid diagnostic test (dRDT), using a finger-stick whole-blood sample. The association of variables with infection was assessed by multivariable non-conditional logistic regression. The true prevalence of SARS-CoV-2 infection was calculated according to two scenarios for RDT (Sensitivity=0.6 and Specificity=0.985; Sensitivity=0.8 and Specificity=1). RESULTS: The true prevalence of SARS-CoV-2 infection was between 4.9% and 11.0%. The observed prevalence was 5.9% and was higher in nursing homes than in primary care centers (9.5% vs. 5.5%). No statistically significant differences were observed by sex, type of professional, level of exposure or compliance with preventive measures. CONCLUSIONS: The prevalence of SARS-CoV-2 infection in this group is low. A high number of professionals remain susceptible to SARS-CoV-2 infection and therefore protective measures should be taken, especially for professionals working in nursing homes.