Data Collection
A questionnaire was distributed to each participating staff who had
verbally consented. This questionnaire was self-completed to gather
information on basic demographics, including gender, age, and current
residential address showing the district they are living in. Name of the
staff and their contact numbers were recorded for contact tracing
purposes if more assessments are needed after the serology test. Other
details obtained include epidemiological factors for infection (possible
contact with COVID positive patients, COVID clusters, or traveling to
foreign countries) and clinical factors (fever, cough, sore throat,
runny nose, or other specified symptoms). Participants were asked to
write down the exact date of symptom onset and last travel or close
contact date if present. The list of COVID clusters mentioned in the
questionnaire was based on the daily statement released by our State
Disaster Committee at the end of March 2020.27