SARS-COV-2 detection in saliva and nasopharyngeal swabs using RT-PCR was similar

Abstract

The World Health Organization has declared the widespread spread of SARS-CoV-2 and its associated disease (COVID-19) a public health emergency. The standard gold test for detecting the virus is the RT-PCR, performed from nasopharyngeal swab (NPS) samples. However, this test may be uncomfortable for the patient and requires specific training and attire from the health professional responsible for collecting the sample. Therefore, the search for alternative ways to collect samples that may be used in the diagnosis of COVID-19 is relevant. This study aimed to compare the results obtained from NPS and saliva samples. NPS and saliva samples were collected from 189 symptomatic outpatients suspected of COVID-19, who came to Piquet Carneiro Polyclinic. RNA extraction was performed using the Bio-Gene DNA/RNA Viral Extraction kit (Bioclin®). Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) reactions used the Molecular SARS-CoV-2 (E / RP) kit (Bio-Manguinhos). The results indicated that 142 showed a non-detectable result (ND), while 47 showed a detectable result (D). Among the 142 "ND", 137 (94.4%) saliva samples obtained the same result, while 5 samples (3.4%) were "D". Among the 47 "D" swab samples, 35 (74.4%) showed the same result in the saliva samples. The sensitivity of the saliva test was 0.74 and the specificity was 0.97. The positive predictive value was 0.88 while the negative predictive value was 0.92. The results showed that detection of Sars-CoV-2 using saliva samples showed high sensitivity and specificity compared to nasopharyngeal swabs.

Salivary SARS-CoV-2 RNA for diagnosis of COVID-19 patients: A systematic review and meta-analysis of diagnostic accuracy

“…All studies were published in 2020–2022 and were conducted in Argentina [31] , Belgium [32] , Bangladesh [33] , Brazil [14] , [34] , [35] , [36] , [37] , Canada [38] , [39] , [40] , [41] , [42] , Ethiopia [43] , France [44] , [45] , Greece [46] , India [47] , Iran [48] , Italy [49] , Japan [50] , [51] , [52] , [53] , Mexico [54] , [55] , Pakistan [56] , Philippines [57] , South Korea [58] , Thailand [59] , Turkey [60] , [61] , United Arab Emirates [62] , United Kingdom [63] , United States of America [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] . The total number of participants was 14,043, and the age varied between 18 and 106 years old.…”

“…The total number of participants was 14,043, and the age varied between 18 and 106 years old. Twenty-two studies only included patients who had symptoms of COVID-19 [14] , [31] , [33] , [34] , [37] , [43] , [47] , [48] , [50] , [51] , [53] , [54] , [55] , [57] , [59] , [60] , [61] , [65] , [68] , [70] , [71] , [73] , seventeen studies included symptomatic and asymptomatic patients [32] , [35] , [36] , [38] , [39] , [41] , [42] , [44] , [45] , [46] , [49] , [58] , [62] , [63] , [64] , [66] , [69] , one study included only asymptomatic patients [52] , and four studies did not report these data [40] , [56] , [67] , [72] . Other sources of information regarding demographics, characteristics of the population, and characteristics of the samples are available in Table 2 .…”

“… Author Country Population Symptoms Diagnosis RNA extraction kit PCR-Kit Target gene for RT-PCR test Swab type Swab type Saliva collection N Age Abdollahiet et al Iran 80 (emergency unit’s triage) 56.5 ± 16.8 [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , …”

“… NR Oro-Nasopharyngeal Whole saliva (drooling method) Guimarãeset et al Brazil 189 39.6 ± 12.3 Symptomatic patients Viral RNA detection with PCR from NPS Bio-Gene DNA/RNA Viral Extraction, by Bioclin SARS-CoV-2 molecular kit, by Bio-Manguinhos SARS-CoV-2 envelope gene Nasopharyngeal Whole saliva (spit) Hansonet et al United States of America 353 (drive-through test center) 35 [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] , [58] , [59] , [60] , …”

COVID-19 on Oral Health: A New Bilateral Connection for the Pandemic

“…It has been described that SARS-CoV-2-positive patients harbor virus particles within acellular and cellular fractions of saliva, making their saliva a valuable tool for diagnosis [183,184]. SARS-CoV-2 RNA saliva-based detection showed a concordance of 96.1% with nasopharyngeal swabs, which serve as the diagnostic gold standard for SARS-CoV-2, with a very high sensitivity and specificity of detection [24,69,185]. Saliva samples from this were self-collected, which might represent a considerable advantage due to its ease of application, particularly in situations where resources in the healthcare system are constrained (when compared to nasopharyngeal swabs) [186][187][188].…”