[Clinical and epidemiological characteristics of respiratory infections caused by human metapneumovirus in pediatric patients].
BACKGROUND
Human Metapneumovirus (hMPV) was first identified in 2001 in respiratory samples from children and adults with acute respiratory tract infection. The aim of this prospective study was to determine the clinical and epidemiological characteristics of pediatric patients with an acute respiratory tract infection and exclusive isolation of hMPV in respiratory samples (December 2005-January 2007).


METHODS
All respiratory tract samples were submitted to rapid antigen detection against respiratory syncytial virus (RSV) and influenza A and B viruses. To isolate respiratory viruses, samples were inoculated in various cell lines using the shell vial culture assay. To isolate hMPV, the LLC-MK2 cell line was used. Only antigen-negative samples were studied for the presence of hMPV.


RESULTS
Over the study period, 32 hMPV were isolated from different patients, accounting for 1.7% of all samples studied for this virus (only RSV-negative samples, 1,791) and 1.5% of all samples studied. Peak incidence was found between December and March of the two years studied. Of the 32 patients in whom hMPV was detected, 17 (53.2%) were female and 15 (46.8%) male. Mean age was 12.5 months (range, 1 month-4 years). The most frequent clinical symptoms were fever (90.6%), cough (87.5%), rhinorrhea and bronchiolitis (46.8%). Three patients (9.4%) were hospitalized.


CONCLUSIONS
Respiratory infection caused by hMPV is considered an emergent disease in pediatric patients. The clinical manifestations are very similar to those of RSV infection; hence, only virological study can establish the definite etiological diagnosis.
Reina
Jordi
J
Unidad de Virología, Servicio de Microbiología, Hospital Universitario Son Dureta, Palma de Mallorca, España. jreina@hsd.es
Ferrés
Francesc
F
Mena
Aina
A
Figuerola
Joan
J
Alcoceba
Eva
E
D000208:Acute Disease; D000956:Antigens, Viral / Q000032:analysis; D001249:Asthma / Q000453:epidemiology; D002675:Child, Preschool; D021821:Communicable Diseases, Emerging / Q000453:epidemiology* / Q000821:virology; D015897:Comorbidity; D003371:Cough / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D029121:Metapneumovirus / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D018184:Paramyxoviridae Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology
D000956:Antigens, Viral