Large-scale PCR testing of SARS-CoV-2 is relevant to control outbreaks of a new coronavirus infection. In order to minimize the spread of COVID-19, it is important to identify and isolate carriers of the coronavirus as quickly as possible. Many regions have a number of difficulties related to PCR assays (small number of trained specialists, large volume of tests, enormous expenses of health care facilities for the purchase of reagents, laboratory plastic, etc.).
AIM OF THE STUDY
To reduce reagent consumption and to accelerate the time of results delivery using the Hypercube mathematical model.
MATERIAL AND METHODS
The study was conducted at the Department of Fundamental and Clinical Biochemistry with Laboratory Diagnostics, Samara State Medical University, Ministry of Health of Russia. During the scientific work 81 samples of respiratory smears were analyzed using OT-PCR method and the method of pooled mixing was tested.
RESULTS
In group one, 27 people were examined as part of a weekly preventive check-up for the SARS-CoV-2 virus. Three positive groups were identified, with one positive sample identified by mathematical exclusion. In group two, samples from outpatients with symptoms of acute respiratory infections and diagnosed pneumonia were examined. Five positive groups of 9 were obtained. A mathematical elimination method yielded 4 positive samples. Additional PCR staging was required to identify true positive samples, starting with RNA isolation. In group three, samples from medical staff of a specialised covid hospital at risk of COVID-19 infection in the workplace were examined and all samples were negative.
CONCLUSIONS
The studied mathematical algorithm «hypercube» is an attractive science-based solution to reduce the total number of tests in order to reduce the costs of health care facilities, and offers maximum speed of testing and results delivery. The combined testing method is appropriate for groups with low probability of SARS-CoV-2 infection (preventive examinations of organised groups, students, aeroplane flights, sports teams, etc.). This technique is not recommended in persons with severe symptoms of acute respiratory infections and a diagnosis of community-acquired pneumonia, due to the increased number of rounds of RNA isolation and amplification.
