Asymptomatic SARS-CoV-2 infection among healthcare workers in a non-COVID-19 teaching university hospital.

BACKGROUND: During the COVID-19 pandemic, most of the published reports on COVID-19 emphasized that health care workers (HCWs) get infected more than the general population representing one of the most vulnerable groups. However, that the real percentage of HCWs infected by SARS-CoV-2 in Egypt remains unknown. The researchers conducted the current study to assess seroprevalence of SARS-CoV-2 IgG among HCWs working in a hospital with no SARS-CoV-2 patients, and to identify the potential factors associated with SARS-CoV-2 IgG seropositivity. DESIGN AND METHODS: The current study is a cross-sectional study carried out among 455 HCWs at Cairo University Hospital. The researchers administered a questionnaire shortly before the SARS-CoV-2 rapid test is performed using closed-ended question format to obtain information on demographic data of the study participants including age, sex, specialty, clinical information including questions about medical conditions, and. history of previous exposure with a confirmed or suspected case of COVID-19, and history of COVID-19- compatible symptoms during the previous 14 days (cough, sore throat, runny nose, fatigue, shortness of breath, fever, headache, vomiting, diarrhea, anosmia, ageusia, and chills). RESULTS: We screened 455 HCWs for SARS-CoV-2 antibodies, 31.4% were in the high-risk group, and 68.6% in the low-risk group. The overall IgG seroprevalence was 36 (7.9%) (95% CI 5.8 to 10.8). The IgG seroprevalence was significantly higher in low-risk group 11% (35/312) versus high-risk group 0.7% (1/143), p<0.001. CONCLUSIONS: Low seropositivity rates for SARS-CoV-2 among HCWs is suggestive of lack of immunity and we are still far from herd immunity.