Hospitalizations due to acute respiratory tract infections caused by human metapneumovirus in Costa Rican children.

Background: Human metapneumovirus (hMPV) is a leading cause of acute respiratory infection in children, particularly early in life. Despite this, there are few prospective hMPV studies in Latin American children and this is the only of that kind in Costa Rica.

Methods: We conducted an observational descriptive prospective study at the only national tertiary referral pediatric hospital of the country. We included children < 13 years of age with a laboratory-confirmed hMPV episode of acute respiratory tract infection requiring hospitalization from September 1, 2015, to September 30, 2017. Diagnosis was confirmed by direct immunofluorescence assay and/or polymerase-chain reaction.

Results: One hundred and eighty-eight patients were analyzed. One hundred and sixteen (62%) were male. About 65% were < 15 months of age; median age was 12 months (interquartile range [IQR] = 6-23). Median hospital stay was 5 days (IQR = 3-8). The most common underlying conditions were prematurity (21.8%;41), recurrent wheeze-asthma (22,8%;43), and low birth weight (17%;32). About 52.6% patients received intravenous antibiotics. Complications occurred in 37.5%, among which, ventilatory failure occurred in 17% (32), shock 4.2% (8), and pleural effusion 1.6% (3). Forty-five (23.9%) patients needed high-flow nasal cannula (average of 3.4 days [standard deviation (SD) = 2.08]). Fifty-four (28.7%) children required pediatric intensive care unit admission. Twenty-eight (14.8%) of them were on assisted mechanical ventilation for a mean duration of 6.3 days (SD = 6.03). Ten patients went home with requiring supplementary oxygen; no deaths occurred.

Conclusions: hMPV-associated hospitalizations in Costa Rican children are associated with significant morbidity. A concerning finding in our study was the high proportion of patients requiring antibiotic therapy, either on admission or during hospitalization. This should prompt us to antimicrobial stewardship interventions.