Infection(4) Contact(4) English(4) headache(3) IgA(3) preventative measures(3) reported(3) participated(3) SARS-CoV-2(3) hospital(3) Nasopharyngeal swab(3) Endemic(3) tested(3) Allen(3) with COVID-19(3) serology(3) Symptoms(3) Fever(3) positive(3) less(3) reported symptom(3) IgG(3) cough(3) PCR(3) sore throat(3) proportion(3) offered(3) cross-sectional(3) Prevalence(3) questionnaire(3)