Human metapneumovirus (hMPV) infection in immunocompromised children

Background: Human metapneumovirus (hMPV) is a major cause of upper and lower respiratory tract infection (URTI, LRTI) in children. The prognosis of hMPV is unclear in immunocompromised patients. Objectives: To describe the characteristics of hMPV infection in immunocompromised pediatric patients and to review the literature. Study design: This retrospective study included 39 immunocompromised children (age 0-18 years) with proven hMPV infection attending two tertiary pediatric medical centers in 2004-2014. Demographic, clinical, laboratory, and radiological data were collected from the medical files. Results: Median age was 6 years. Seven patients had primary immune deficiency and 32, secondary immune deficiency, including 9 patients who underwent hematopoietic stem cell transplantation (HSCT). Most cases (92%) occurred in January-May. Twenty patients (51%) had lower respiratory tract infection and 17 (44%), upper respiratory tract infection; 2 patients (5%) had fever only. Presenting symptoms were fever (70%), cough (54%), and rhinorrhea (35%). Severe lymphopenia (<1000 lymphocytes/mL) was noted in 64% of patients and elevated liver enzyme levels in 49%. Seventeen patients had pneumonia: bilateral and alveolar in 13 patients, each. HSCT was not associated with more severe disease. Respiratory failure occurred in 6 patients, of whom 4 died (10% of cohort). All children who died had severe lymphopenia. On multivariate analysis, bacterial or fungal co-infection was the only major risk factor for death. Review of the literature showed variable clinical presentations and severity in pediatric patients with hMPV infection. Conclusions: Infection with hMPV may be associated with relatively high morbidity and mortality in immunocompromised children. Death was associated with bacterial and fungal co-infection. (C) 2016 Elsevier B.V. All rights reserved.