Methods: The Department of Infection Control at Cohen Children's Medical Center provided a prospectively prepared list of patients who tested positive for PIV types 1, 2, 3, and 4 using a polymerase chain reaction (PCR) assay (xTAG Respiratory Viral Panel, Luminex) for the time period March 2010 through October 2012. Patients with more than one test result within a 100 day period were studied. A retrospective medical review abstracted patient age, immunocompromised (IC) state, and illness severity. Days from the first positive test to the first negative test were calculated using Proc ICLifetest in SAS 9.4. For each factor, survival was compared using a generalized log-rank test.
Results: For the 77 patients studied, the median time from the first positive (day 0) to the first negative test was 3 days (95% CI, 2-15) and 92% were negative by days 15-23. The median time to first negative for the 35 patients < 3 years and the 42 patients ≥ 3 years was 2 days (95% CI, 2-12) and 4 days (95% CI, 4-15), respectively (difference not significant). Of the 75 patients for which the status was known, 45% (n=34) were IC. The duration of positive PCR in non-immunocompromised patients, 3 days (95% CI, 2-11), did not significantly differ from IC patients, 4 days (95% CI, 4-15). The median duration of positive PCR for the 26 patients with moderate to severe disease, 3 days (95% CI, 2-3) was significantly shorter than for the 34 patients with uncomplicated infection, 10 days (95% CI, 10-15) (p < 0.0192). Illness severity was unknown in 17 patients.
Conclusion: Fifty percent of patients became PCR negative by 3 days after the positive result and 92% were negative by days 15-23. There was no significant difference in the duration of PIV detection based on patient age or IC status. Patients with uncomplicated infection had a longer duration of positivity compared to those with moderate to severe infection.
S. Tong, None
L. Rubin, None