Utility of Saliva for Detecting Influenza A Virus by cost effective
extraction free SYBR Green-Based PCR
Abstract
Respiratory specimens collected via nasopharyngeal and throat swabs are
the recommended method of choice for the molecular detection of the
Influenza A virus. However, they often cause discomfort to patients and
require trained healthcare workers. This study aimed to validate a
cost-effective nucleic acid extraction-free PCR method using SYBR-Green
chemistry with saliva samples to diagnose respiratory illnesses caused
by Influenza A viruses. This study enrolled symptomatic pediatric and
adult patients with influenza-like illness. A SYBR-Green based nucleic
acid amplification test was used with CDC-recommended primers specific
for detecting Influenza A viruses. Results from saliva PCR tests were
compared with those of standard TaqMan chemistry-based PCR detection
from nasopharyngeal swabs. The sensitivities of saliva PCR tests with
and without nucleic acid extraction were 83% and 82%, respectively.
Both the methods showed a specificity of 98%. Overall, the sensitivity
and specificity of saliva as a sample using the developed
SYBR-Green-based PCR for Influenza A virus detection were 90% and 98%,
respectively. Given the high sensitivity, specificity, positive and
negative predictive values, likelihood ratios, agreement percentage, and
kappa statistics, this study concluded that saliva is a potential
specimen for diagnosing Influenza A virus infection by extraction free
nucleic acid amplification testing.