title: Severe metapneumovirus infections among immunocompetent and immunocompromised patients admitted to hospital with respiratory infection.
abstract: Human metapneumovirus (hMPV) is considered an important cause of acute respiratory infections. hMPV can cause morbidity in hematopoietic stem cell transplant recipients and recent research has demonstrated that it is an important virus in patients admitted to hospital with respiratory infections and suspected of having pandemic 2009 influenza A (H1N1pdm09) virus. The purpose of this study was to investigate infections caused by hMPV in two groups of patients admitted to hospital: Immunocompromized patients with a potential risk of severe outcomes and immunocompetent patients with severe acute respiratory syndrome. A total of 288 samples were tested: 165 samples were collected from patients with suspected influenza A (H1N1) pdm09 infection during the first pandemic wave in 2009; and 123 samples were collected from patients of a hematopoietic stem cell transplantation program in 2008-2009. Amplification of the hMPV genes was performed by polymerase chain reaction. This was followed by sequencing and phylogenetic analysis. hMPV was detected in 14.2% (41/288) of all samples: 17% (28/165) of immunocompetent patients with suspected H1N1 infection and 10.6% (13/123) among hematopoietic stem cell transplant recipients. hMPV accounted for 12.1% (8/66) of immunocompetent adults patients with severe respiratory infections (median age, 55.9 years). Two hMPV subtypes were identified, A2 (26.9%; 7/26) and B2 (73.1%; 19/26) but no difference was observed between the patient groups in terms of age or immunosuppression level. This study highlights the significance of hMPV in immunocompetent adult patients with severe infections and further investigations are recommended for understanding the impact of this virus.
authors.affiliation: Medicine Department, Clinical Virology Laboratory, Infectious Diseases Unit, Sao Paulo Federal University, Sao Paulo, SP, Brazil.
authors.forename: Juliana Sinohara
authors.initials: JS
authors.lastname: Souza
authors.forename: Aripuana
authors.initials: A
authors.lastname: Watanabe
authors.forename: Emerson
authors.initials: E
authors.lastname: Carraro
authors.forename: Celso
authors.initials: C
authors.lastname: Granato
authors.forename: Nancy
authors.initials: N
authors.lastname: Bellei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006761:Hospitals; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D008297:Male; D029121:Metapneumovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008875:Middle Aged; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D012367:RNA, Viral