Assessment of Rapid SARS-CoV-2 Testing with Lateral Flow Immunoassay among Asymptomatic Healthcare Workers in Makati Medical Center

Aims: Corona Virus Disease-19 (COVID-19) is a global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While the gold standard for diagnosis is still reverse transcription Polymerase Chain Reaction (RT-PCR), it is not readily available. Serologic testing is considered to be a faster method of identifying individuals who may have been exposed and developed antibodies against SARS-CoV-2.

Methodology: This was an ambirectional observational study aimed to determine the prevalence of exposure to COVID-19 infection among asymptomatic healthcare workers in Makati Medical Center, a tertiary hospital in the Philippines, using rapid antibody testing (lateral flow immunoassay) in May 2020.

Results: A total of 1557 asymptomatic healthcare workers were included in the study. Majority belonged to the paramedical group (52%). Twenty (1.3%) healthcare workers were IgM positive while 17 (1.1%) tested positive for IgG. Three healthcare workers (0.2%) tested positive for both antibodies. Participants with history of being quarantined who tested positive for either IgM or IgG were significantly higher compared to those who tested negative for both antibodies (55%, 33.3%, 41.2% vs 28.5%, p = 0.036). Those with diabetes had 6.8 times higher risk of being IgM positive and IgG negative (p=0.001). In addition, those with diabetes were more likely (13.6 times) to be positive in both tests (p=0.034).

Conclusion: There was a low prevalence (2.6%) of COVID-19 infection among healthcare workers of Makati Medical Center. Among those with positive serologic test, diabetes mellitus, history of exposure and history of quarantine were risk factors associated with COVID-19 infection.