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s Indian Journal of Medical Microbiology 39 (2021) S1–S133 SEROPREVELANCE SURVEY OF HEALTHCARE WORKERS IN A COVID CARE HOSPITAL IN MUMBAI, INDIA Seema Rohra, Aruna Poojary, Pritam Pardeshi, Priyanka Patil. Breach Candy Hospital Trust Background:Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV2), spreads mainly through respiratory droplets, aerosols and indirectly through contaminated fomites. Healthcare workers (HCWs) are particularly at risk of infection when caring for such patients. Demonstration of antibodies especially IgG helps to identify the prevalence of SARS CoV2 infection. Methods:The study was conducted in a 212 bed hospital in Mumbai with a 52 bed isolation facility for COVID 19 patients which included 16 intensive care monitoring beds. The study was conducted between the 3rd and 4th week of July 2020. SARS-CoV2 Total (IgA, IgM & IgG) and IgG antibodies were performed from serum samples using the chemiluminescence on the VITROS 3600 (Orth clinical diagnostics, USA). The target antigen was the spike protein. Past history of SARS-CoV2 infection by way of PCR was also noted. The cut off optical density (OD) value used for both antibodies was greater than 1. Results:A total of 473 HCWs were tested for total and IgG antibodies. Of these, 294 (62.15%) had been previously tested for SARS-CoV2 PCR either as symptomatic HCWs or as those in high risk contact with positive cases.179 (37.85%) HCWs never went through a PCR. Of these, 28/179(15.64%) HCWs seroconverted indicating asymptomatic past infection. Among the 294 HCWs who were tested by PCR, 88(29.93%) were positive. 22.72% (20/88) PCR positive HCWs did not seroconvert and produce either antibodies. Of the 207 HCWs who were PCR negative, 52(25.12%) seroconverted with either one of the antibodies. Conclusions:The study observed high rates of seroconversion among those who had never tested (15.64%) and those who were PCR negative (25.12%) indicating a high prevalence of infection among HCWs. Another concern observed was that 22.72% of the PCR positive HCWs did not produce antibodies even after 4 weeks. https://doi.org/10.1016/j.ijmmb.2021.08.254 A PROSPECTIVE STUDY TO DETERMINE THE RATE OF SARS-COV-2 POSITIVITY AMONG WOMEN ADMITTED FOR DELIVERY Iqra Anjum, Mohammed Khaleel, Maimoona Mustafa, Ms Pavani. Deccan College of Medical Sciences Background:SARSCoV-2 has radically influenced the health care workers, especially Obstetricians who are at high-risk COVID-19 transmission due to the nature of their specialty as a result of exposure to infectious particles, hence they have to be judg emental in taking up pregnant females. As the Obstetrical population has to go through a unique challenge during this pandemic, the aim of the study was to know the incidence of SARSCoV-2 positivity rate in pregnant women admitted to hospital for delivery. Furthermore, infected patients may be asymptomatic on admission and may easily transmit the disease during delivery. Methods:The study protocol was approved by the Institutional Review Board and Ethics Committee. It was conducted between September and November 2020 at Deccan College of Medical Sciences, includes 75 pregnant women who were screened for SARS -CoV-2 positivity upon admission to the hospital for delivery. Detection of SARS-CoV-2 in Nasopharyngeal and oropharyngeal samples was performed by Real-Time Reverse Transcriptase PCR (RT-PCR) method, targeting Screening Envelope (E) gene and Confirmatory gene RNA dependent RNA polymerase gene (RdRp). Results:Out of 75 women; two (2) women had mild symptoms of fever and shortness of breath on admission respectively, on testing tested positive for SARSCoV-2. Of the other 73 women admitted without symptoms screened for SARSCoV-2, two (2) were found to be positive for SARS-CoV-2. Although this prevalence has limited generalizability to geographical regions with lower rates of infection, it underscores the risk of Covid-19 among asymptomatic obstetrical patients. S73 Conclusions:Health care professionals have to be meticulous about taking precautionary potential steps regarding COVID-19 status of the patient to determine hospital isolation practices and control measures which also includes judicious use of Personal protective equipment. Access to such clinical data from the laboratory provides an important opportunity to protect mothers, babies, and health care teams during these challenging times. https://doi.org/10.1016/j.ijmmb.2021.08.252 SELF-COLLECTED SALIVA: DIAGNOSTIC POTENTIAL FOR SARS-COV-2 TESTING IN A RESOURCE LIMITED SETTING Santosh Karade, Kavita Bala Anand, Prashant Jindamvar, Sourav Sen, Sourabh Bobdey. Armed Forces Medical College, Pune Background:The gold standard for diagnosis of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection is reverse transcriptase real time polymerase chain reaction (RT-PCR) using respiratory samples. Collection of oronasopharyngeal swab (OP/NP) requires a trained health care worker (HCW) and appropriate biosafety conditions. There is need for a simpler strategy for sample collection without compromising the sensitivity. Saliva sample can be collected without any intervention of HCW. Therefore, the primary objective of the study was to evaluate efficacy of SARS -CoV-2 RT-PCR using self-collected saliva specimen. Methods:This pilot study was carried out at an ICMR approved molecular laboratory. The study population consisted of adults reporting to Flu OPD and hospitalized suspected COVID-19 cases. After obtaining consent, 3-5 ml of saliva was submitted in a universal sterile container by participants. Parallel (OP/NP) swab in viral transport medium (VTM) was also collected as per national guidelines. Both specimens were subjected to RNA extraction and SARS-CoV-2 RT PCR using ICMR approved kit. Cycle threshold value of Envelope_Sarbeco gene (“E”), HKU Orf 1b gene (“HKU”) and Actin (Internal control) obtained for saliva and OP/NP swab were tabulated. Results:Saliva and OP/NP swab in parallel were collected from 85 individuals. The mean age of study population was 35.2 yr and 81% were male. The overall sensitivity and specificity of RT PCR on saliva sample was 95.6% and 92.5%. The concordance between ‘E” and “HKU” Ct value obtained by OP/NP and Saliva RTPCR was 97.64% and 95.29%. The positive and negative predictive value of the novel method was 93.5% and 94.9% respectively. Conclusions:Saliva collection requires lesser logistic requirement and saves VTM. Self-collected saliva is a reliable biological sample and promising tool for SARS-CoV-2 testing in resource limited setting. Saliva RT-PCR could be costeffective measure for laboratory capacity building. https://doi.org/10.1016/j.ijmmb.2021.08.253