RSV significant cause of severe LRTIs among preterm infants

The presence of respiratory syncytial virus, either alone or with other viruses, increased the severity of pediatric lower respiratory tract infections in a study of preterm infants, according to recent findings.

Renato T. Stein, MD, PhD, of Pontifical Catholic University of Rio Grande do Sul in Brazil, and colleagues evaluated 303 infants born at ≤35 weeks gestational age who were followed for 1 year to determine the incidence of severe lower respiratory tract infection (LRTI) associated with RSV infection that required hospitalization.

Overall, 58.1% of patients had a single LRTI during follow-up, 37.6% had more than one LRTI during follow-up, and 36.4% were severe and required hospitalization. Forty-five of 162 patients tested by PCR for the identification of infecting viruses experienced a severe LRTI. Of those with severe LRTI, RSV was the most commonly isolated virus (66.7%). There was a nearly 10% prevalence of severe RSV-associated LRTIs among the whole population, and nearly half had concomitant positive PCRs for other viruses.

Overall, 461 LRTI events were detected and 432 were tested for viral identification by PCR and 21.1% were negative for all tested viruses. Of 341 samples that tested positive for any virus, 47.2% were coinfections.

Of all samples tested, RSV was the most prevalent (33.1%) and the most prevalent among positive tests (41.9%). More than half of the RSV infections (57.3%) were coinfections and 47.6% were with human rhinovirus.

“The data reported in this study confirm the association of RSV infection with severe LRTI in children born at 35 weeks gestational age or less during their first year of life and provide additional data that suggest that antibody specific for RSV may be protective in young children,” the researchers wrote. “The finding that coinfection of RSV with other viruses increases the severity of LRTIs, as evidenced by longer mean hospital stays among these preterm infants, is quite important, and provides even further relevance to policies that indicate adequate prophylaxis for susceptible infants for whom RSV infection may be accompanied by an increased risk for significant morbidity and mortality.”

Disclosure: The study was funded in part by AbbVie. Five researchers report financial ties with AbbVie. One researcher reports financial ties with Abbott Brazil.