BACKGROUND
Rapid influenza diagnostic tests (RIDTs) have long been used in clinical
settings to identify patients infected with influenza. Studies have
shown that point-of-care RIDTs reduce the use of antibiotics and improve
clinical outcomes, but in many cases test performance is
unreliable.1 Although specificity is consistently over
90%, some studies report sensitivity rates as low as
17.8%.2 New advances in technology have improved
overall sensitivity, but performance is still inconsistent and false
negatives are fairly common. 3-6
The COVID-19 pandemic resulted in federal policy that allowed rapid
antigen testing in homes, schools, and other community settings for the
first time. This policy shift occurred, however, without formal
evaluations of performance characteristics of specific over-the-counter
tests in community settings. Many academic institutions conducted
routine SARS-CoV-2 rapid antigen testing and experienced high
specificity and varying sensitivity, similar to observations in clinical
settings when testing for influenza.2
In the aftermath of the pandemic,
we are likely to see the emergence of additional rapid testing
technologies intended for school or community use. In addition to
bolstering existing disease surveillance systems that are often reliant
on clinical data, the near real-time results in densely populated
settings like kindergarten-12th grade (K-12) schools
may help to contain outbreaks of influenza and other respiratory
viruses. Accordingly, it is necessary to evaluate performance
characteristics of rapid tests in community settings. Such information
can be essential to educating the public on how best to interpret
results. Thus, we conducted a detailed analysis of performance
characteristics of Sofia Influenza A+B Fluorescent Immunoassay (FIA) to
identify factors that could influence the sensitivity and specificity of
RIDTs for K-12 students in a community setting.
METHODS