LAUSR

Background:The Coronavirus disease 2019 (COVID 19) pandemic has resulted in reduced performance of non-emergent surgeries and procedures across the nation. About four-fifth of COVID-19 infections remain asymptomatic. With an incu- bation period of 7-14 days, patients can also remain in the pre-symptomatic stage. Hence, knowledge of the prevalence of disease among the asymptomatic is important to prevent spread of disease to the health care professional as well as for patient safety. The present study sought to assess the frequency of positivity of COVID 19 among pre -procedural/pre-operative patients. Methods:A retrospective study of all asymptomatic pre-procedural cases was conducted from 10th June 2020 till 10th November 2020. Nasal swabs were collected from patients 48 hours before procedures (including elective and emer- gency surgeries, patient scheduled to receive chemotherapy, radiotherapy, patients undergoing biopsy, endoscopy). RT - PCR test was done for all samples. Case-specific data, results of all PCR tests, and answers to screening questions (about symptoms, exposure, and travel) were obtained Results: 5320 tests were conducted during the study period. Of these, data could be analysed for 2117 tests done. 51.1% were male patients and the median age group of the cohort was 46 years. 254 of 2117 (11.9%) belonged to the paediatric age group. Of 2117, 35 samples were rejected because of sample leakage or improper labelling. Out of the remaining 2082 samples;338 were positive;1606 were negative, and 138 inconclusive. We received second sample for 117 of the 138 inconclusive samples of which 18 were positive, 93 were negative and 6 remained inconclusive. Thus, the total positivity was 17.1%. Conclusions:This study confirms the high proportion of asymptomatic patients with COVID -19 positivity;and suggests the value of screening by RT-PCR during COVID-19 pandemics.