Suboptimal performance of rotavirus testing in a vaccinated community population should prompt laboratories to review their rotavirus testing algorithms in response to changes in disease prevalence

Abstract

Rotavirus vaccine has reduced disease prevalence in many countries. Consequently, we aimed to assess the reliability of a rotavirus immunoassay in the community population of Auckland and Northland, New Zealand. Between 22 October 2015 and 31 December 2016, 2873 fecal samples were tested by enzyme immunoassay (EIA, Rotascreen II, Microgen, UK) from 2748 patients (median age 8 years, range 0–101 years). Eighty-nine (3.1%) samples were reactive; 86 samples were tested by a second method. Rotavirus was confirmed in 49/86 (57%). Positive rotavirus EIAs were more likely to be confirmed in samples from cases ≥1 year of age (positive predictive value [PPV] 61%, 95% confidence interval [CI] 50–72%, P = 0.049) and in spring/summer (PPV 67%, 95% CI 55–78%, P = 0.003). Reactive rotavirus tests required confirmatory testing regardless of demographic, vaccine, or seasonal factors; a review of rotavirus testing algorithms may be necessary in other vaccinated community populations.