863 - Outcomes of Healthcare-Associated Respiratory Viral Infections in a Pediatric Hospital: A Historical Cohort Study

Background: Healthcare-associated respiratory viral infections (HARVI) occur frequently at pediatric hospitals. The spectrum and attributable outcomes of these infections are unknown.

Methods: Using a matched historical cohort design, HARVI cases identified between July 2013 and June 2018 at a large pediatric referral hospital in Dallas, Texas were defined as patients who tested positive for one of eight respiratory viruses during their hospitalization, had new respiratory symptoms develop during hospitalization, and had symptom onset on a hospitalization day that was greater than the maximum incubation period for the specific respiratory virus. Controls were matched 1:1 for index time, meaning that the control had a hospital length of stay that was at least as long as the length of stay in the matched case prior to viral testing. Controls were also matched for year and month of infection as well as hospital unit and/or age. The primary outcome was additional length of stay following infection or index time. Additional outcomes included transfer to intensive care, need for intubation, hospital charges, and all cause in-hospital mortality.

Results: Over the 5-year study period, 317 definite HARVI were identified (0.62 per 1,000 admitted patient days), and only 287 (91%) had a matched control to be included in analysis. Among these cases and matched controls, the median time to index time was 19 days (IQR 10-39 days). The most common causative viruses where rhinovirus/enterovirus (188, 65.5%), RSV (30, 10.5%), parainfluenza virus (28, 9.8%), and seasonal coronaviruses (27, 9.4%). Fewer cases than controls were in an intensive care unit at index time (101 [35.2%] vs. 156 [54.4%]) The mean additional length of stay following index time was shorter in cases than controls (35.2 days vs. 48.1 days, difference = -12.9 days, 95% CI -20.95 to -4.82 days).

Conclusion: Hospital length of stay for cases with HARVI was not longer than for those without HARVI. Possible explanations include confounding and selection bias. Further studies with carefully selected controls are needed.