Factors preventing SARS-CoV-2 transmission during unintentional exposure in a GP practice: a cohort study of patient contacts; Germany, 2020
Two general practitioners (GPs) with SARS-CoV-2 infection provided in-person patient care
to patients of their joint medical practice before and after symptom onset, up until SARS CoV-2 laboratory confirmation. Through active contact tracing, the local public health
authorities recruited the cohort of patients that had contact with either GP in their putative
infectious period. In this cohort of patient contacts, we assess the frequency and determinants
of SARS-CoV-2-transmission from GPs to patients. We calculated incidence rate ratios (IRR)
to explore the type of contact as an explanatory variable for COVID-19 cases. Among the
cohort of 83 patient contacts, we identified 22 (27%) COVID-19 cases including 17 (21%)
possible, three (4%) probable and two (2%) confirmed cases. All 22 cases had contact with
a GP when the GP did not wear a mask, and/or when contact was ≥10 min. Importantly,
patients who had contact <10 min with a GP wearing a facemask were at reduced risk (IRR
0.21; 95% CI 0.01–0.99) of COVID-19. This outbreak investigation adds to the body of evi dence in supporting current guidelines on measures at preventing the transmission of
SARS-CoV-2 in an outpatient setting.
