While the low sensitivity of rapid antigen tests arises from not isolating the viral RNA from the swab samples and amplification of the DNA before detection, the two indigenously developed tests follow these two vital steps, the reason why the sensitivity and specificity are far superior than that of the rapid antigen tests.
In a mass-screening study of 1,924 asymptomatic persons, self-collected saliva samples had sensitivity (92%) and specificity (over 99.9%) comparable to nasopharyngeal specimens — sensitivity 86% and specificity over 99.9%. The true concordance probability between the nasopharyngeal and saliva tests was estimated at 0.998. In a mass-screening study of 1,924 asymptomatic persons using nasopharyngeal and self-collected … Continue reading COVID-19: Saliva is a viable alternative to nasopharyngeal specimen in asymptomatic persons
If speed, low cost and constraints of molecular testing capacity are the reasons why many States have embraced rapid antigen testing, the test has low sensitivity. Yale University's saliva test, which was granted emergency use authorisation by FDA, is a rapid, inexpensive, non-invasive and highly sensitive test. India will gain much by adopting the saliva … Continue reading With over 900 COVID-19 deaths per day for over a week, India crosses 50,000 toll
A rapid, inexpensive saliva test developed by Yale School of Public Health in partnership with NBA has high sensitivity. The testing protocol has been made available through “open source”. The SalivaDirect test does not use any preservative at time of collection, uses commonly available reagents, and does not need equipment for nucleic acid extraction. In … Continue reading FDA approves rapid, inexpensive saliva test for coronavirus
Researchers at the Mumbai-based Tata Memorial Centre have used Raman Spectroscopy to detect RNA viruses present in saliva samples. It is a proof-of-concept study to analyse non-infectious RNA viruses using conventional Raman Spectroscopy without using any additional reagent to enhance the signal. If Israel developed a spectroscopy-based one-minute breathe analyser to detect coronavirus, a team … Continue reading Detecting RNA virus in saliva samples using Raman Spectroscopy
The novel coronavirus SARS-CoV-2 can also be present in saliva, according to a study carried out on 12 patients admitted in hospitals. The presence of live virus in saliva was confirmed by positive culture. The virus found in saliva can spread the infection. The novel coronavirus SARS-CoV-2 can also be found in saliva, according to … Continue reading Coronavirus: Saliva of COVID-19 patients contain virus, study finds
If researchers had earlier reported the presence of Zika virus in urine and saliva samples (besides semen, blood and breast milk), a new study has been able to find infectious Zika virus particles in urine and saliva samples of two patients during the acute phase of infection. While in theory the presence of Zika virus … Continue reading Infectious Zika virus found in saliva and urine