Audit of SARS-CoV-2 RT-PCR Testing Turnaround Time and Operational Determinants in a Centralized Laboratory in a Resource-Limited Setting

Background: Prolonged SARS-CoV-2 RT-PCR turnaround time (TAT) undermines isolation decisions, bed allocation and infection control, especially in centralized, resource-limited laboratories serving large urban networks. We audited TAT performance and operational determinants in a high-throughput COVID-19 RT-PCR laboratory receiving samples from 3 hospitals, 22 urban health posts (UHP) and multiple community camps across Navi Mumbai.Methods: In this retrospective record-based audit, all 210,179 upper respiratory swabs processed between August 2022 and January 2023 were analyzed for total TAT using routine timestamps, and a stratified subset of 1,600 samples underwent detailed phase-wise and operational factor assessment. Result: Overall, 197,558 samples with complete core timestamps were included in TAT analysis; median total TAT was 20.5 hours (interquartile range 8 hours), and 67.01% and 98.75% of reports were issued within 24 and 48 hours, respectively. TAT varied markedly by source, with median values of 10 hours for inpatients, 20 hours for UHP, 22 hours for outpatients and 32 hours for camps. In the detailed subset, median referral and within-laboratory TAT were 3.5 and 16.5 hours respectively, with pre-analytical steps contributing the longest segment.Conclusion: Delayed reporting beyond 24 hours occurred in 28.6% of audited samples and was strongly associated with camp origin, large batch size, reagent shortages and equipment downtime, while test platform and repeat runs were not independently significant. Targeted interventions focusing on pre-analytical workflow, scheduling of sample dispatch, batch size management and supply-chain resilience could further reduce TAT in similar centralized RT-PCR networks.