CORONAVIRUS DISEASECOVID-19: NEW POSSIBILITIES OF DIAGNOSIS

Abstract

The аim of research – to determinine the diagnostic expediency of using lung condensateas a bioenvironment for the detection of SARS-CoV-2 virus in children with coronavirusdisease COVID-19.Materials and methods. The study was conducted on the basis of infectious diseasesdepartments of the Chernivtsi Children’s Regional Clinical Hospital during December2021 to January 2022. Verifi cation of coronavirus disease COVID-19 was performed bypolymerase chain reaction with reverse transcriptase (set COVID-19 Multiplex RT-PCRin real time regime from Labsystems Diagnostics Oy) with simultaneous detection of threemajor genes ORF1ab, nucleus (E) and envelope (E). The material for the study werenasopharyngeal swabs and pulmonary expiratory. Results. We examined 32 hospitalized children diagnosed with COVID-19 with a meanage of 10,43 ± 0,72 (min = 3, max = 17). The share of boys was 34,4%, girls – 64,6%(p = 0,05), which indicates the practical absence of diff erences in gender. Biomaterialcollection – nasopharyngeal swabs and pulmonary expiration were performed on 6,71± 0,58 (min = 2, max = 16) day of the disease. SARS-CoV-2 virus RNA was detected in46,8% of patients, which almost coincided with the PCR results of 40,62% (p> 0,05).Estimating viral load, the mean value of cycles for PCR of nasopharyngeal smear was30,86 ± 1,39, and for pulmonary expiration – 32,39 ± 1,26. Taking into account theaverage values, depending on the detected gene, it was found that the number of cyclesfor the smear gene E constituted 30,06 ± 1,37 (min = 19, max = 38), the N gene – 30,93 ±1,33 (min = 20, max = 38) for the ORF1ab gene 31,6 ± 1,48 (min = 20, max = 40). Thenumber of cycles for the condensate gene E is 32,6 ± 1,24 (min = 25, max = 38); geneN – 33,36 ± 1,09 (min = 28, max = 39), for ORF1ab – 34,08 ± 1,06 (min = 28, max = 39).The results of the correlation analysis of paraclinical examination of children hospitalizedfor coronavirus disease COVID-19 showed that the use of PCR smear test, comparedwith Ig M, increased the risk of infection with a chance ratio (OR) of 2,27 (95% CI1,26-4,08), relative risk (RR) 1,47 (95% CI 1,01-2,15), absolute risk (R) 0,20. Whenreceiving a positive test result, the post-test probability of a positive result increased12,8%, with a negative one – the result decreased 7,5%. Estimating viral load for geneE, OR = 2,8 (95% CI 1,58-4,98), RR = 1,66 (95% CI 1,22-2,28), R = 0,25, for genes N,ORF1ab OR = 3,2 (95% CI 1,79-5,71), RR = 1,77 (95% CI 1,29-2,44), R = 0,28.Conclusions. At comparative analysis of PCR, performed in diff erentbioenvironmentsof children, the obtainedresults are evidence of better specifi city in the detection of thepathogen when using a traditional smear of the nasopharyngeal mucosa compared withthe use of pulmonary expiratory. However, the study of exhaled condensate can be usedto reduce the isolation time of patients.