Root Cause Analysis of Invalid Internal Control in COVID-19 RT-PCR Testing: A Learning Experience

Abstract

Introduction: Laboratory diagnosis of Corona Virus Disease- 2019 (COVID-19) plays a major role in diagnosing and treating infection. The corner stone in strategic public health interventions and breaking the chain of transmission was diagnostic laboratory testing and case-based data. The purpose of the study was to establish quality control standards for RT-PCR testing laboratory by performing Root Cause Analysis (RCA) of invalid Internal Control (IC). Aim: The aim of the study was to estimate the percentage of invalid IC and to describe the most probable associated factors. Materials and Methods: This cross-sectional observational study was conducted at the RT-PCR laboratory in Microbiology department of Govt. Kilpauk Medical College and Hospital for a period of one month, October 2021. The nasopharyngeal and oropharyngeal swabs collected for COVID-19 testing were included in the study. A detailed check-list was prepared by the author for evaluating of invalid IC. Results: All the variables of RT-PCR test were categorised as pre-analytical, analytical and postanalytical phases and each and every component was assessed as per the protocol. Out of 23500 samples included in the study, a positive test result for COVID-19 was obtained in 164 (0.69%) and a negative result in 22533 (95.89%) patients. Around 803 (3.41%) samples included in the study showed an invalid IC. Conclusion: Current observation showed that an invalid IC could be caused by any factors starting from sample collection to reporting. Major causes for an invalid IC were due to improper extraction and sample collection.

Keywords

• corona virus disease-2019
• internal control
• quality control
• rt-pcr test