Cost and performance analysis of efficiency, efficacy, and effectiveness of viral RNA isolation with commercial kits and Heat Shock as an alternative method to detect SARS-CoV-2 by RT-PCR

In late 2019 a new virus reported in Wuhan, China, identified as SARS-CoV-2 spread rapidly challenging the healthcare system around the world. The need for rapid, timely and accurate detection was critical to the prevention of community outbreaks of the virus. However, the high global demand for reagents during the years 2020 and 2021 generated a bottleneck in kits used for detection, greatly affecting developing countries, lagging their ability to diagnose and control the virus in the population. The difficulty in importing reagents, high costs and limited public access to the SARS-CoV-2 detection test led to the search for alternative methods. In this framework, different commercial nucleic acid extraction methodologies were evaluated and compared against heat shock as an alternative method for SARS-CoV-2 detection by RT-PCR, in order to determine the diagnostic yield and its possible low-cost compared to other methodologies. Nasopharyngeal samples were used where the diagnostic efficiency of the alternative method was 70 to 73%. The evaluation of the discriminatory efficacy of the method took the sensitivity and specificity to establish its cut-off point, being 0.73 to 0.817, which allows discriminating between COVID-19 positives and negatives. As for the diagnostic effectiveness expressed as the proportion of subjects correctly classified, it is between 80 and 84%. On the other hand, in terms of the costs necessary to carry out the detection, the alternative method is more economical and accessible in terms of direct cost close to 47 and 49 USD, and indirect cost around 35 and 50 USD compared to the commercial methods available in this comparison and evaluation, being possible its implementation in developing countries with high infection rates, allowing access to the diagnostic test with a reliable and low-cost method. Keywords: COVID-19, RT-PCR, Viral RNA.