ABSTRACT
Accurate and early diagnoses are prerequisites for prompt treatment. For coronavirus disease 2019 (COVID-19), it is even more crucial. Currently, choice of methods include rapid diagnostic tests and reverse transcription polymerase chain reaction (RT-PCR) using samples mostly of respiratory origin and sometimes saliva. We evaluated two rapid diagnostic tests with three specimen types using viral transport medium (VTM) containing naso-oropharyngeal (NOP) swabs, direct nasal and direct nasopharyngeal (NP) samples from 428 prospective patients. We also performed RT-PCR for 428 NOP VTM and 316 saliva samples to compare results. The sensitivity of the SD Biosensor Standard Q COVID-19 antigen (Ag) test kit drastically raised from an average of 65.55% (NOP VTM) to 85.25% (direct nasal samples), while RT-PCR was the gold standard. For the CareStart kit, the sensitivity was almost similar for direct NP swabs; the average was 84.57%. The specificities were ≥95% for both SD Biosensor Standard Q and CareStart COVID-19 Ag tests in all platforms. The kits were also able to detect patients with different variants as well. Alternatively, RT-PCR results from saliva and NOP VTM samples showed high sensitivities of 96.45% and 95.48% with respect to each other as standard. The overall results demonstrated high performance of the rapid tests, indicating the suitability for regular surveillance at clinical facilities when using direct nasal or direct NP samples rather than NOP VTM. Additionally, the analysis also signifies not showed that RT-PCR of saliva can be used as an choice of method to RT-PCR of NOP VTM, providing an easier, non-invasive sample collection method. IMPORTANCE There are several methods for the diagnosis of coronavirus disease 2019 (COVID-19), and the choice of methods depends mostly on the resources and level of sensitivity required by the user and health care providers. Still, reverse transcription polymerase chain reaction (RT-PCR) has been chosen as the best method using direct naso-oropharyngeal swabs. There are also other methods of fast detection, such as rapid diagnostic tests (RDTs), which offer result within 15 to 20 min and have become quite popular for self-testing and in the clinical setting. The major drawback of the currently used RT-PCR method is compliance, as it may cause irritation, and patients often refuse to test in such a way. RDTs, although inexpensive, suffer from low sensitivity due to technical issues. In this article, we propose saliva as a noninvasive source for RT-PCR samples and evaluate various specimen types at different times after infection for the best possible output from COVID-19 rapid tests.
ABSTRACT
As coronavirus disease 2019 (COVID-19) cases arose globally, active case finding by performing throat swab test proposed high risk for the healthcare workers. Saliva had recently been reported to show positive detection means for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and proposed advantages of self-collection, less requirement of transport media, and reduced nosocomial transmission risk. However, support evidence regarding its diagnostic value was still lacking and varied widely in specimen collection method. This systematic review aimed to assess the diagnostic value of salivary specimens (SS) for COVID-19 detection using reverse transcription polymerase chain reaction (RT-PCR) assay compared with throat swab specimens (TSS), while putting into consideration confounders such as patients’ initial condition, specimen collection method, and transport media used. Six databases were used for identifying relevant studies. Final search yielded 19 eligible studies which was reviewed based on the major outcome: diagnostic agreement, sensitivity & specificity, and viral load comparison. The use of SS as an alternative to TSS showed to be promising although specimen collection method needed to be standardized. SS was comparable to TSS in detecting COVID-19 using RT-PCR assay, especially in symptomatic or confirmed cases. More Randomized controlled trials (RCTs) were still needed to clearly demonstrate the ability of SS to capture asymptomatic cases in the setting of mass surveillance, where patients would self-collect the specimen at ease. © 2022, Intelektual Pustaka Media Utama. All rights reserved.