2021 · Expert review of molecular diagnostics · paywalled
A review on human body fluids for the diagnosis of viral infections: scope for rapid detection of COVID-19
Adigal et al.
The finding, in our words
This review evaluates saliva, tears and exhaled breath as alternatives to nasopharyngeal swabs for COVID-19 diagnosis, recommending optical spectroscopy and electronic nose techniques for rapid detection of viral biomarkers in these more readily accessible body fluids.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
The study found that self-collected dried saliva on FishburneTabs achieved 92% accuracy for viral RNA detection compared to standard liquid saliva samples. This method supports decentralised testing by enabling reliable sample storage and transport for upper respiratory infections.
This review establishes that microsampling across blood, saliva, urine and stool matrices offers validated workflows and regulatory recognition for human biomonitoring comparable to conventional methods. It finds that these decentralised approaches enhance participant acceptability and enable screening in remote or low-resource settings.
The COVID-19 pandemic accelerated adoption of decentralised testing and self-collected saliva specimens, but revealed challenges with variable diagnostic accuracy and lack of internationally standardised processing protocols. Stricter regulatory oversight and robust diagnostic stewardship are needed to balance broad access with clinical performance.
This review summarises how incorporating saliva and urine into home-based point-of-care systems expands diagnostic accessibility for dengue virus, aligning with the WHO REASSURED framework for affordable and rapid testing.
Oral sponge saliva RT-PCR achieved 95% sensitivity and 95% specificity compared with nasopharyngeal swabs in 3,488 symptomatic and asymptomatic adults, while buccal swab performance varied with infection history and symptoms. The rapid antigen test showed 66.9% sensitivity overall, increasing to 97% in high viral load samples. Oral sponge collection permits self-sampling without laboratory pre-analytical steps, offering a robust method for decentralised SARS-CoV-2 screening.