Serology surveillance of anti-SARS-CoV-2 antibodies among asymptomatic healthcare workers in Malaysian healthcare facilities designated for COVID-19 care

Abstract

IntroductionHealthcare workers (HCW) are presumed to be at increased risk of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection due to occupational exposure to infected patients. We aim to determine the prevalence of anti-SARS-CoV-2 antibodies among asymptomatic HCW.MethodsWe prospectively recruited HCW from the National Public Health Laboratory and two COVID-19 designated public hospitals in Klang Valley, Malaysia between April 13th and May 12th, 2020. Quota sampling was applied to ensure adequate representation of the HCW involved in provision of care for patients directly and indirectly. All participants had worked in the respective healthcare facility for at least 30 days prior study enrollment. HCW who were previously confirmed with COVID-19 infection or listed as “patient under investigation” were excluded. A self-administered questionnaire was used to capture sociodemographic information, history of contact with COVID-19 cases within the past month, clinical signs and symptoms and adherence to universal precautions. Blood samples were taken to test for anti-SARS-CoV-2 antibodies by surrogate virus neutralization test.ResultsA total of 400 HCW were recruited, comprising 154 (38.5%) nurses, 103 (25.8%) medical doctors, 47 (11.8%) laboratory technologists and others (23.9%). The mean age was 35±7.8 years, with females predominant (74%). A majority (68.9%) reported direct contact with COVID-19 patients, body fluids of COVID-19 patients and/or contaminated objects and surfaces in the past month within their respective workplaces. Nearly all claimed to adhere to personal protection equipment (PPE) guidelines (97%-100% adherence) and hand hygiene practice (91%-96% adherence). None (95% CI: 0, 0.0095) of the participants had anti-SARS-CoV-2 antibodies detected, despite 135 (33.8%) reporting respiratory symptoms one month prior to study recruitment. One hundred and fifteen (29%) participants claimed to have contact with known COVID-19 persons outside of the workplace.ConclusionOur finding of zero seroprevalence among asymptomatic HCW suggests a low risk of asymptomatic COVID-19 infection in our healthcare setting; which is at expected levels for a country with an incidence of 26 per 100,000. The adequacy of PPE equipment and strict adherence to infection prevention and control measures offers considerable protection during contact with COVID-19 cases and should be ensured to prevent future nosocomial transmission.

COVID‐19 prevalence among health‐care workers of Gastroenterology department: An audit from a tertiary‐care hospital in India

“…Several studies have reported 0–17.4% COVID‐19 prevalence among HCWs 2–14 . However, very few have evaluated the impact of COVID‐19 on specific medical departments 17,18 .…”

“…Several studies have reported 0-17.4% COVID-19 prevalence among HCWs. [2][3][4][5][6][7][8][9][10][11][12][13][14] However, very few have evaluated the impact of COVID-19 on specific medical departments. 17,18 Repici et al, in a multicenter study from Italy, reported a very low risk of COVID-19 among HCWs in the gastrointestinal endoscopy units.…”

“…Second, we did not perform IgM assay, which might have led to missing some of the recent COVID‐19‐positive cases. However, IgM assay has low sensitivity and specificity, as well as considerable heterogeninity 2 . The IgG assay used in this study targets the S1 spike protein, which is more specific to COVID‐19 compared to the nucleocapsid protein‐based IgG assay 25,26 .…”

“…However, IgM assay has low sensitivity and specificity, as well as considerable heterogeninity. 2 The IgG assay used in this study targets the S1 spike protein, which is more specific to COVID-19 compared to the nucleocapsid protein-based IgG assay. 25,26 Third, we did not compare the COVID-19 prevalence with other medical departments.…”

“…Health‐care workers (HCWs) constitute a special subgroup of the population, which is at a substantial risk of infection and is an important disease transmission source. Previous studies have reported COVID‐19 seroprevalence rates of up to 17.4% among the HCWs 2–14 . Moreover, an increasing number of reports have demonstrated that HCWs are affected by COVID‐19 with significant morbidity and mortality.…”