Prevalence of SARS-CoV-2 Antibodies in Laboratory Healthcare Workers at Assiut University Hospital, Egypt.

Background: COVID-19 is an illness caused by a novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Laboratory healthcare workers (LHCWs) are at highest risk for COVID-19 infection due to direct exposure to COVID-19 patients and/or infected samples. Objectives: Our primary objective in this study was to evaluate SARS-CoV-2 Ab testing as a screening tool for detecting COVID-19 infection among asymptomatic LHCWs. Our secondary aims were to establish the relationship between exposure to COVID-19 infection and subsequent asymptomatic disease and working in different areas of the laboratory. Method: The detection of SARS-CoV-2 antibodies was done by different methods (rapid testing, electrochemiluminescence, and chemiluminescent microparticle immunoassay). The study included 199 asymptomatic LHCWs at Assiut University Hospital, Egypt, from different laboratory areas including molecular biology, microbiology, parasitology, and outpatient clinic laboratories in addition to LHCWs involved in automation, phlebotomy, rotating physicians, and those working in the sample receiving area. Results: The incidence of SARS-CoV-2 antibodies by rapid testing and immunoassay among asymptomatic LHCWs was 29.6% and 24.4%. Laboratory phlebotomists (55.6%) were most likely to be exposed to positive patients and samples, followed by those working in the sample receiving area (32%), LHCWs in the automation area (29.6%), rotating doctors (28.6%), and LHCWs in the diagnostic molecular biology laboratory (15.4%). The sensitivities of the rapid test and SARS-CoV-2 total antibody were 94.1% and 92%, whereas the specificities were 92.6% and 91%. Conclusion: Rapid serological testing is an effective screening method for the detection of SARS-CoV-2 infection among asymptomatic LHCWs and the identification of the groups of workers who have a significantly higher seroprevalence than the rest of the laboratory population.

The rate of SARS-CoV-2 among asymptomatic non-immunised low-risk parturient women between the two waves.

This study was conducted to evaluate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and immunity among asymptomatic non-immunised low-risk parturient women and their newborns. A cross-sectional study conducted in a tertiary hospital during the nadir period of new cases in Egypt. All asymptomatic pregnant, low risk and non-immunised women were included. All eligible participants had been subjected to SARS-CoV-2 nasopharyngeal swabs according to CDC and sampling of maternal and umbilical blood to evaluate the presence of coronavirus disease 2019 (COVID-19) IgM and IgG antibodies by immunochromatographic assay. Two cases out of 171 (1.2%) parturient women were tested positive for PCR swab to COVID-19 infection. Furthermore, COVID-19 IgG and IgM antibodies testing showed that 67.8% of women were negative for both IgG and IGM, 24.6% were positive for IgG only, 4.1% were positive for IgM only, while 3.5% were positive for both IgG and IgM. Regarding neonatal testing for immunity, 28.1% of the neonates were positive to IgG only and none for IgM.The rate of positive PCR patients among asymptomatic low-risk parturient women was 1.2%. About quarter of women had got herd immunity as evident by positive IgG antibodies. IgG antibodies transferred to the neonates in almost all cases.Impact StatementWhat is already known on this subject? Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global public health emergency. Asymptomatic pregnant women with coronavirus disease can transmit their infection to their newborn, family members and the health care providers.What do the results of this study add? The study showed very low (1.2%) prevalence of COVID positive cases among asymptomatic pregnant women admitted to our facility. Only two cases out of 171 parturient women tested PCR positive for COVID-19 infection (1.2%). SARS-Cov-2 IgG and IgM antibodies testing showed, about a quarter (24.6%) were positive for IgG antibodies, 4.1% were positive for IgM antibodies, while 3.5% were positive for both IgG and IgM. On the other hand, 28.1% of the neonates were positive to IgG only and none of the newborns had had IgM antibodies in their cord blood.What are the implications of these findings for clinical practice and/or further research? The first wave of COVID-19 pandemic in Egypt left behind at least a quarter of pregnant women with a positive antibody denoting some immunity. This immunity is usually transmitted to the neonates in almost all cases.