Detection of SARS-CoV2 by a Commercial RNA Detection Kit: a Public Health Laboratory Experience

• Published in: International journal of infectious diseases Vol. 116; p. S42
• Main Authors: Farhana, N., Choudhury, R., Khanam, F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2022; Published by Elsevier Ltd; Elsevier
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2021.12.100

There is a critical shortage of the commercial SARS-CoV2 detection kits and a major problem for testing capacity in Bangladesh since December, 2019 to combat the Covid19 pandemic. So this study was aimed to assess SARS-CoV2 detection with a commercial RNA detection kit by the qualitative real time PCR from respiratory specimens (nasal or throat swab) of Covid19 suspected cases. This cross sectional study was done by convenience sampling from Munshiganj district and four different hospitals in Dhaka city from 28 November 2020 to 4 December 2020. Nasal or throat swab samples were collected from Covid19 suspected cases and sent to NIPSOM RT-PCR lab, National Institute of Preventive and Social Medicine (a public health laboratory), NIPSOM, Mohakhali, Dhaka, Bangladesh. A commercial kit [Adaltis MOLGen SARS-CoV-2 (3Genes) RealTime PCR, Italy] containing the primer and probe set in fluorimeter channel was used to detect three genes of SARS-CoV-2: RNA-dependent RNA polymerase (RdRp), envelope (E) and nucleocapsid (N) with endogenous internal control (IC). Threshold cycle (Ct) value was selected at ≤40 for each positive gene and detection of at least two different genes (RdRp and E gene or N gene) was interpreted as SARS-CoV2 positive. A total of 1061 samples of Covid19 suspected cases within 4 to 98 years of age were included in this study and male female ratio was 1.33:1. Among 1061 samples, 299 (28.18%) were tested positive for SARS-CoV2 with mean age of 43.33 years and male was found predominantly. Of them, 94.98% were positive for RdRp, E and N genes whereas all (100%) were found positive for only RdRp and E gene. Here, the Ct value of IC ranged within <20 to 40 and 44.48% was found at Ct 30–35 followed by 36.79% at Ct 25–30 and 10.37% at Ct 35–40. For individual RdRp gene, E gene and N gene, highest Ct values were at 30–35 with 26.42%, 30.43% and 28.87% respectively. To address accurate and safely diagnosis of SARS CoV-2, this commercial RNA detection kit will help during the COVID-19 pandemic.