Daily Dose: Use of Multiple Specimen Types in RSV Testing

Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.

On March 27, 2023, we reported on a systematic review and meta-analysis published in the Journal of Infectious Diseases that aimed to quantify specimen and diagnostic testing-based underascertainment of adult respiratory syncytial virus (RSV) infection.

The study

Researchers searched publication databases from January 2000 through December 2021 for studies including adults using/comparing more than 1 RSV testing approach. A total of 154 studies met inclusion criteria, and enrolled patients included those with lower or upper respiratory tract infections or exacerbation of an underlying cardiac or pulmonary disease. When reported (59 studies), study participants were more frequently hospitalized patients (66%). Among all studies included, the most common upper respiratory samples were nasopharyngeal swabs (NPS, 102 studies), followed by nasopharyngeal aspirate (NPA, 48 studies) and oropharyngeal swab (OPS, 36 studies). The most frequently used diagnostic approach was real-time polymerase chain reaction (RT-PCR), with 68.5% (113 studies) of studies using multiplex platforms and 15.8% (26 studies) using singleplex platforms.

The results

Researchers found that, compared to RT-PCR, other methods were less sensitive: rapid antigen detection test (RADT; pooled sensitivity, 64%), direct fluorescent antibody (DFA; 83%), and viral culture (86%). Compared to singleplex PCR, investigators observed that multiplex PCR's sensitivity was lower (93%).

Compared to nasal/NPS RT-PCR alone, adding sputum RT-PCR increased the rate of RSV detection by 52% (detection rate ratio [DRR] 1.52, 95% CI 1.15-2.01) and the addition of OPS RT-PCR increased the rate by 28% (DRR 1.28, 95% CI 1.11-1.49). The addition of paired serology testing increased the rate of detection by 42% (DRR 1.42, 95% CI 1.19-1.70) when compared with rates observed with NPS RT-PCR alone.

Note from authors

“Our review indicates that, while RT-PCR using NPS is the most sensitive currently available diagnostic methodology, the addition of other testing approaches—including collection of different specimens and potentially use of serology—substantially boosts RSV detection and these results should be considered when estimating disease burden and the subsequent economic value of RSV immunization of adults."

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