Circulation and clinical presentation of Metapneumovirus infection among pediatric inpatients with acute respiratory infection (ARI)

Abstract

Abstract: 

Human Metapneumovirus (HMPV) was discovered in 2001. This virus is an important pathogen that causes ARI in children under 5 years old, for this reason many health-care centers are including its detection in the respiratory virus panel. Since the clinical presentation of ARI is common for all of the respiratory viruses, the participation of the virology laboratory becomes crucial to establish the etiologic diagnosis.

 The objective of this study was to assess the circulation of HMPV and describe the clinical and epidemiological characteristics of the infection in a cohort of inpatients admitted at the pediatric ward of Sanatorio Allende (Córdoba, Argentina).

A descriptive analysis, previously approved by the Institution´s Ethical Committee, was conducted. 1311 consecutive respiratory samples, routinely taken from inpatients under 5 years old with diagnosis of ARI from May 2017 through December 2019, were included. Samples were tested by direct immunofluorescence for respiratory syncytial virus, influenza, parainfluenza, adenovirus and HMPV. Specimens were taken from day 1 to 7 (median 4), from the beginning of symptoms. 

Out of the 1311 respiratory samples, 634 (48.4%) were positive for any of the assayed agents. HMPV was found in 53/634 samples (8.4%), with an increased incidence towards the end of winter and during spring. The median age was 10 months (range: 0-60 months), and 47% were girls. Forty-nine per cent (26/53) were admitted to the pediatric intensive care unit. The main signs and symptoms were: lower airway sounds (rhonchi and crackles 82%; stridor 43%), fever ≥38ºC (70%) and coughing (59%). Radiological findings at the admission were: interstitial infiltrate (22%), parahilar infiltrate (22%) and parenchymatous condensation (14%). The median of hospitalization days was 5 (2-18) and 86% of patients required oxygen therapy. At discharge, 55% of children were diagnosed as bronchiolitis.

The circulation of HMPV was proved in the studied population, justifying the detection of this viral pathogen, otherwise those inpatients would have remained without an etiological diagnosis. An opportune diagnosis directly impacts in improving the patient management and prevents the unnecessary use of antibiotics.