Publication

Abstract : The COVID-19 pandemic is posing a severe challenge to the fragile healthcare systems of low- and middle-income countries like India. The state of Kerala was the first to report COVID-19 in India, on 30th January 2020, in a medical student who had returned from Wuhan, China [[1]]. The quantum of cases reported, even after 5 months (as on 14th July 2020) is only 8930 with 36 deaths. The ‘Kerala model’ of response to the COVID-19 pandemic was to trace, quarantine, test, isolate and treat all travellers from foreign countries as well as neighbouring states, coupled with lockdown. We hypothesize that, because of this practice, the state has succeeded in preventing community spread in the last 5 months. This is evidenced by the fact that there has been no surge in hospital admissions due to influenza-like illness or COVID-19 clusters or outbreaks in occupational settings. In the background of community transmission, there is always a high risk of transmission to the healthcare worker (HCW) from pre-symptomatic and asymptomatic patients reporting with non-COVID illness, especially in non-COVID-19 hospitals [[2]]. Identifying infected HCWs, including asymptomatic ones, is important to reduce nosocomial spread [[2]]. Seroprevalence of SARS-CoV-2 antibodies in HCWs in non-COVID-19 hospitals can act as a surrogate marker for community transmission in the populations for which they cater. Our study aims to understand the prevalence of asymptomatic infection among HCWs in our university hospital to verify the existence of community transmission in the population. Between 11th and 24th July 2020, healthcare workers in a 1200-bed university teaching hospital were recruited in this prospective, cross-sectional, monocentric study. Ours being a non-COVID-19 hospital, all patients diagnosed with COVID-19 were transferred to the government-designated COVID-19 hospital. All participants completed a standardized form regarding their role, duration of exposure, nature of work, use of personal protective equipment, and signs and symptoms suggestive of COVID-19 over the previous 5 months, and were grouped into high-, intermediate- and low-risk groups. Serum samples from consenting HCWs were tested for SARS-CoV-2 IgG/total antibodies on either the ElecsysR Anti-SARS-CoV-2 total antibodies assay (Roche Diagnostics, Rotkreuz, Switzerland) on a Cobas e 411 analyser or Abbott SARS-CoV-2 IgG (Abbott Laboratories, Chicago, USA) on ARCHITECTR i2000sr platform, according to the manufacturers' instructions. All HCWs who were positive for IgG/total antibodies were interviewed using an extended questionnaire to determine how they acquired the infection. All positive samples were tested by Abbott IgG, Roche total antibody and VITROS Anti-SARS-CoV-2 IgG and total antibody assay (Ortho-Clinical Diagnostics, Rochester, NY, USA), to rule out false-positive results. The positive HCWs were retested for IgG and total antibodies after 14 days, and their nasopharyngeal swabs were tested by reverse transcriptase polymerase chain reaction (RT-PCR) for SARS CoV-2 targeting RdRP and E-gene regions (ViroQ SARS-CoV-2 Kit, BAG Diagnostics, GmbH, Germany). A descriptive analysis of the data was performed. Fisher's exact test was used wherever applicable.