Akademik Veri Yönetim Sistemi
25th ESCV 2023, Milan, İtalya, 30 Ağustos - 02 Eylül 2023, ss.72
BACKGROUND-AIM
The most commonly used and reliable test for diagnosis of SARS-CoV-2 and influenza virus is reverse transcribed polymerase chain
reaction (RT-PCR). Quality of the sample, viral load and analytical sensitivity are critical for the test performance.
Aim: To compare the efficiencies of self-collected clinical samples of saliva (S) and nasal swab (ScN) with
healthcare-worker-collected nasopharyngeal swab (HCW-NP) for SARS-CoV-2 + Influenza A/B RT-PCR test.
METHODS
Three clinical samples (S, ScN, HCW-NP) were collected from 404 SARS-CoV-2 and influenza virus infection suspected symptomatic
cases (214 female, 190 male; median age 37), who attended Ege University and Erciyes University Hospital between November
11th 2021 – March 25 th 2022. Samples were tested with SARS-CoV-2/Influenza A/B RNA test (Cobas® SARS-CoV-2 & Influenza A/B
on Cobas 6800 System; Roche Molecular Systems, USA). According to the algorithm based on identified criteria, SARS-CoV-2 or
Influenza virus infection status of all patients was determined. The criteria, compatible with the prospectus, were determined by
us. Positive and negative predictive values (PPV, NPV), sensitivity, specificity and coefficient of variation values (CV) of S, ScN and
HCW-NP samples were analyzed. Interrater reliability of the results obtained from three different specimen types were calculated
based on Cohen’s Kappa values. Pearson correlation coefficient values were used to calculate the correlation of cycle threshold (Ct)
results for three different positive specimen types.
RESULTS
SARS-CoV-2 and Influenza-A infection rates were 42% (n=170) and 7,9% (n=32), respectively. Especially S has a good PPV, NPV,
sensitivity and specificity values, also S and ScN have almost perfect correlation (all Kappa values ε0.81; p<0.001) with HCW-NP. But
Ct value correlations were weak (all values of “r”: <0.55; p<0.001). All CV results showed that precision of the test was appropriate
(all CV values δ6%).
CONCLUSIONS
Saliva and ScN could be alternatives to each other for qualitative results. Weak Ct value correlations didn’t affect this situation.
Considering the compatibility of the results, these easily collectable specimen types will provide fast, effective and early diagnosis
with the correct protocol.