Researchers from Rutgers New Jersey Medical School investigated the persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human saliva in a recent study published in the journal PLOS ONE.
Accurate and timely SARS-CoV-2 infection detection has proven important in the management of coronavirus disease 2019 (COVID-19). Salivary and nasal swabs are two commonly used non-invasive ways for testing infection with little to no supervision, allowing COVID-19 testing to become more prevalent. Several tests on nasal and pharyngeal samples revealed a decrease in viral shedding as well as a decrease in culturable virus within the first week of COVID-19 symptoms. However, only a few studies have looked at how long SARS-CoV-2 is detectable in salivary samples versus nasal swabs beyond the first week of symptoms.
Concerning the research
The current investigation looked at whether salivary testing could detect the prolonged presence of SARS-CoV-2 and its potential infectiousness.
The researchers evaluated viral load trends in salivary and nasal specimens as part of an observational group trial of treatment and diagnostic approaches in COVID-19 patients. Patients enrolled at University Hospital in New Jersey were eligible to participate. These subjects were 18 years or older, tested positive for SARS-CoV-2 using a nasopharyngeal (NP) swab, and agreed to supply nasal and saliva samples.
Participants who were scheduled to be treated for COVID-19 during their hospital stay were observed. All participants from the parent trial who provided a known length since symptom start and a nose, as well as a saliva sample for at least one study time point, were included in the substudy. The overall assessment included paired saliva-nasal swab analyses that referred to the time of COVID-19 symptom onset for all eligible participants. The study gathered samples such as self-collected saliva, anterior nasal swabs, and NP swabs.
To escape the grind, one couple rode 15,000 kilometers from Finland to Singapore.
Results
From June 2020 to August 2021, 140 people were recruited for the study, with 44 people excluded. Approximately 147 nose and saliva swabs were analyzed as paired observations across the entire research among the remaining 96 participants. Out of the 96 participants in the overall study group, 28 qualified for the longitudinal analysis since they had more than one point collected.
The average patient age among the 96 participants in the entire analytic group was 54.7 years, with 53% males and 55% Hispanics. The typical baseline sample collection occurred seven days after the onset of symptoms. The majority of individuals who had at least one comorbidity, such as obesity or hypertension, were exposed to another person with SARS-CoV-2 symptoms, or needed supplementary oxygen during their hospital stay.
Important time periods in the study were more than five days, indicating the minimum suggested isolation period for SARS-CoV-2 and more than nine days when patients were declared no longer SARS-CoV-2 infectious due to a lack of culturable virus in nasal or NP specimens. The researchers discovered that dyspnea was more common in the five to nine-day and 10-14-day gap populations, whereas all other symptoms were comparable. those in later phases were more likely to require oxygen support than those in earlier times. Furthermore, participants who were recruited less than five days following symptom start were more likely to be Black, smokers, and to have chronic renal disease.
Overall, saliva testing detected significantly more SARS-CoV-2 infections within five days, after five days, after nine days, and after 14 days of SARS-CoV-2 symptoms. Furthermore, the overall median N2-target Ct values for salivary samples were found to be sooner than for nasal samples. Furthermore, Ct values were higher in salivary specimens than in nasal specimens for all time periods, including those after 14 days of symptoms.
The rates of SARS-CoV-2 positive after five days were equal in salivary samples and NP swabs. Furthermore, the total Ct values did not differ significantly between NP viral transport medium (VTM) swabs and direct saliva samples. Furthermore, no difference in median Ct values or the number of tests yielding Ct values less than 30 were seen between saliva samples and NP swabs throughout all time periods studied.
What is the role of dysbiosis in Parkinson’s disease?
Conclusion
The study findings underlined the evidence for the detection of SARS-CoV-2 in salivary samples vs nasal specimens after the first week of symptom onset, including virus propagation. These findings, according to the researchers, support the inclusion of salivary testing in later stages of the disease course to improve the yield of SARS-CoV-2 diagnosis, as well as the potential of a prolonged oral infectious duration in allowing the detection of saliva-based assessment in individuals with COVID-19 diagnosis.
