Factors associated with prolonged respiratory virus detection from PCR of nasal specimens collected longitudinally in healthy children in a U.S. birth cohort.

BACKGROUND: Respiratory viral shedding is incompletely characterized by existing studies due to the lack of longitudinal nasal sampling and limited inclusion of healthy/asymptomatic children. We describe characteristics associated with prolonged virus detection by PCR in a community-based birth cohort.

METHODS: Children were followed from birth to 2 years of age in the PREVAIL cohort. Weekly nasal swabs were collected and tested using the Luminex Respiratory Pathogen Panel. Weekly text surveys were administered to ascertain the presence of acute respiratory illnesses defined as fever and/or cough. Maternal reports and medical chart abstractions identified healthcare utilization. Prolonged virus detection was defined as a persistently positive test lasting >4 weeks. Factors associated with prolonged virus detection were assessed using mixed effects multivariable logistic regression.

RESULTS: From a sub-cohort of 101 children with >70% weekly swabs collected, a total of 1489 viral infections were detected. Prolonged virus detection was found in 23.4% of viral infections overall, 39% of bocavirus infections, 33% of rhinovirus/enterovirus infections, 14% of RSV A infections, and 7% of RSV B infections. No prolonged detection was found for influenza A or B, coronavirus 229E or HKU1, and parainfluenza 2 or 4 virus infections. First lifetime infection with each virus, and co-detection of another respiratory virus were significantly associated with prolonged detection, while symptom status, child sex, and child age were not.

CONCLUSIONS: Prolonged virus detection was observed in 1 in 4 viral infections in this cohort of healthy children and varied by pathogen, occurring most often for bocavirus and rhinovirus/enterovirus. Evaluating the immunological basis of how viral co-detections and recurrent viral infections impact duration of virus detection by PCR is needed to better understand the dynamics of prolonged viral shedding.