Portal de Periódicos da CAPES

COVID-19

2023; De Gruyter; Volume: 61; Issue: s1 Linguagem: Inglês

10.1515/cclm-2023-7041

1437-4331

Nicola J. Camp, C Rether, J Krech, A Noessler, Mary Beth Happ, U Marr, Hylemariam Mihiretie Mengist, Zubair Khalid, Fentahun Adane, Tengchuan Jin, Lech Chrostek, Katarzyna Janicka, Ewa Gruszewska, Bogdan Cylwik, Kok Beng Gan, Michał Kralisz, Marcin Kazberuk, Anatol Panasiuk, Sumi Yoon, Yong Deok Lim, Oh Joo Kweon, Tae Soo Kim, M Lee, O Tsuprykov, P. Lodemann, Susanne Merkel, Abeer A. Al‐Masri, John Frank, Francisco Javier Turrubiates‐Hernández, Samuel García‐Arellano, Fabiola Márquez‐Sandoval, N Vega-Magaña, Guillermo González‐Estevez, Laura Elena Herrera-Jiménez, F Ferro-Abella, Guillermina Muñoz-Ríos, José Francisco Muñoz‐Valle,

BACKGROUND-AIMDiagnosis of SARS-Cov-2 infection is mainly performed by detection of viral genetic material in nasopharyngeal swabs using a polymerase chain reaction (PCR) technique.During the pandemic, not only symptomatic patients have been tested, but also asymptomatic individuals have been screened prior to travel, hospitalization or a surgical procedure.This has increased the workload in all laboratories.The objectives of the study were to evaluate the efficiency of the pooling technique for diagnosing SARS-COV-2 infection as well as to test the sensitivity of the BD Max System (Becton Dickinson) in detecting positive specimens contained in pools. METHODSNasopharyngeal swabs were collected in E-Swab Liquid Amies preservation medium COPAN.We used the instrument BD MAX System (Becton Dickinson), which performs nucleic acid extraction and real time polymerase chain reaction (RT-PCR) and two different kits were evaluated.Only samples from individuals with low probability of being infected with SARS-CoV-2 were pooled.We consider a positive individual sample only if the ct-value of at least one gene target is less than 35. RESULTS962 samples were analysed in 201 pools in a frame time of three months from March until June 2022.Each pool contained maximum 5 samples and a final volume of 750 µl.We had 26 positive pools.All samples contained in positive pools were tested again individually and we obtained in total 30 positive samples.The prevalence of positive cases was 3.12%.The ct-values of the positive pools and positive individual samples were compared and the differences for each gen target (N1, N2 and N) were calculated.The mean difference (ct-pool / ct-sample) was 3,0 (1,3 -4.4) for N gen target, 2,6 (0,5 -6,1) for N1 gen target and 3,0 (1,5 -5,6) for N2 gen target.The correlation of ct-values of pools and positive samples was (r 0.952 for N, r 0,977 for N1 and r 0,984 for N2).We stablished therefore that pools with ct-values above 38 could be considered as negative. CONCLUSIONSThe data demonstrate excellent repeatability and reliability of the pooling technique.Pooling of nasopharyngeal specimens can be used with BD Max System (Becton Dickinson) to shorten turnaround time and reduce laboratory consumption.