Laboratory Diagnosis of SARS Corona Virus-2 Infection: Single Centre Experience of First 12,000 Samples DC09-DC12
Dr. Sourav Sen,
Department of Microbiology, Armed Forces Medical College, Pune, Maharashtra, India.
Introduction: First spotted in Wuhan, China, World Health Organisation declared the deadly outbreak caused by novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) as global pandemic on March 11, 2020. With over 72 million cases globally till December 2020, countries need to gear up to detect, isolate and treat Corona Virus Disease-2019 (COVID-19) cases. Laboratories play a crucial role in diagnosis thereby instituting early contact tracing and quarantine measures. The laboratory based COVID-19 diagnostic testing data may help in formulating strategies to contain the spread of infection.
Aim: To describe key patient variables of the respiratory samples processed for SARS-CoV-2 by Real Time Polymerase Chain Reaction (RT-PCR) at a diagnostic laboratory.
Materials and Methods: In this descriptive, single centre study carried out at ICMR approved COVID-19 diagnostic laboratory, nasopharyngeal swabs received in Viral Transport Medium (VTM) were tested for SARS-CoV-2 infection by RT-PCR. Key patient variables, like age, gender, symptoms and sample positivity rate were tabulated. The demographic and clinical data of samples tested were summarised by medians and Interquartile Range (IQR) for continuous variables and by proportions for categorical variables.
Results: A total of 12,187 samples were received between 21st March to 8th July 2020. The data from 11,196 individuals were complete and were included in the analysis. Overall, 2,053 samples were tested positive for SARS-CoV-2 indicating positivity rate of 18.33%. Sample positivity was highest (63.91%) among high-risk contacts of a laboratory confirmed case. The maximum number of samples tested belonged to age group of 21-40 years and male predominance was observed.
Conclusion: Although social distancing, mask usage, hand hygiene and respiratory etiquettes are important measures for containment of COVID-19, strengthening and capacity building of laboratory network is crucial for mitigating the pandemic.