High Viral Load and Respiratory Failure in Adults Hospitalized for Respiratory Syncytial Virus Infections

Abstract

A prospective study among adults hospitalized for polymerase chain reaction-confirmed respiratory syncytial virus infections (n = 123) showed frequent occurrence of lower respiratory-tract complications causing respiratory insufficiency (52.8%), requirement for assisted ventilation (16.3%), and intensive care unit admission/death (12.2%). High viral RNA concentration was detected at time of hospitalization, including in patients who presented later than 2 days of illness (day 1-2, 7.29 ± 1.47; day 3-4, 7.28 ± 1.41; day 5-8, 6.66 ± 1.87 log10 copies/mL). RNA concentration was independently associated with risk of complications and respiratory insufficiency (adjusted odds ratio 1.40 per log10 copies/mL increase, 95% confidence interval, 1.03-1.90; P = .034). Our data indicate the need and provide a basis for clinical research on antiviral therapy in this population.

Keywords: RSV; respiratory failure; viral load.

Figure 1.

RSV RNA concentration at time of presentation, shown according to presence (gray box-plot) or absence (white box-plot) of underlying major comorbidities. Dotted line indicates the 25th percentile of viral RNA concentration in this cohort (6.49 log₁₀ copies/mL); day 1 (n = 44), day 2 (n = 36), day 3–4 (n = 27), day 5–8 (n = 16). “Major comorbidities,” as defined in the Charlson Index (see Table 1). Specimen used for diagnosis: nasopharyngeal aspirate, n = 99; nasopharyngeal flocked swab, n = 24; RNA concentrations measured were not significantly different. Abbreviations: cp, copies; RSV, respiratory syncytial virus.