Search for asymptomatic carriers of SARS-CoV-2 in healthcare workers during the pandemic: a Spanish experience

Objective: determine the percentage of healthcare workers (HCW) carrying SARS-CoV-2 in high exposure areas of the hospital. Design: cross- sectional study during April 15-24th in Hospital Costa del Sol (Marbella, Spain), excluding HCW with previous COVID19. Setting: hospital based, focused on patient care areas COVID19. Participants: 498 subjects, 80% women. Participation was offered to all the HCW of Emergencies, Intensive Care and Anesthesia, Internal Medicine and Pneumology. Other units not directly involved in the care of these patients were offered to participate. Intervention: naso and oropharyngeal PCR determination was performed together with IgG and IgM antibody determination by immunochromatography. On the day of sampling, a health questionnaire was answered, reporting symptoms on the same day and in the previous fourteen days. Main outcome measures: percentage of HCW with positive PCR for SARS-CoV-2, percentage of HCW with positive IgG for SARS-CoV-2. Results: Two individuals were detected with PCR for SARS-CoV-2 positive (0.4%). Both were asymptomatic on the day of sampling, but one of them had had a CoVID-19 compatible picture in the previous two weeks and had positive IgG and IgM; therefore, only one subject was truly asymptomatic carrier (0.2%). 9 workers with positive IgG (1.8%) were detected. Conclusions: the prevalence of asymptomatic carriers among health workers of the services directly involved in the care of patients with CoVID-19 was very low in our center. This type of strategy can be one more tool in controlling the pandemic.