Infants and Children with Lower Respiratory Tract Infections May Have Human Meta

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Title: Significant Number of Infants and Children with Lower

Respiratory Tract Infections May Have Human Metapneumovirus

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N Engl J Med 2004;350:443-50.

01/29/2004 10:43:00 AM

By Joene Hendry

Human metapneumovirus was identified in 20% of cases of lower

respiratory tract infection in a group of 321 otherwise healthy

children. From an overall population of 2009 infants and children

treated between 1976 and 2001 at the Vanderbilt Vaccine Clinic,

Nashville, Tennessee, United States, E. Crowe, Jr., MD, and

colleagues conducted an analysis using reverse transcription

polymerase chain reaction (RT-PCR) on 248 nasal-wash specimens

available from 321 children with lower respiratory tract infections

from no identified cause. Of the 248 tested samples, 49 were positive

for human metapneumovirus. Infants younger than 6 months accounted

for 25% of these infections and another 49% of these infections

occurred among infants between 6 months and 1 year of age. The

hospitalisation rate was 2%; 78% of infections occurred between

December and April; and the male to female ratio for these infections

was1.8 to 1. Human metapneumovirus was also detected in 15% of

samples collected from 261 patients with upper respiratory tract

infection. Conversely, testing of 86 nasal-wash specimens from

children without respiratory symptoms revealed 1 positive specimen

for human metapneumovirus. The researchers found human

metapneumovirus infection associated with bronchiolitis in 59%, with

pneumonia in 8%, with croup in 18%, and with an exacerbation of

asthma in 14% of the cases. Clinical features included cough in 90%,

coryza in 88%, fever in 52%, irritability in 43%, anorexia in 33%,

wheezing in 22%, diarrhoea in 17% and vomiting in 10%, while 77% had

rhinitis, 52% had wheezing, 51% had an abnormal tympanic membrane,

39% had pharyngitis, 20% had rhonchi and 8% had rales. " An

association between the presence of a virus and symptoms of

respiratory tract disease does not necessarily establish causation, "

the authors write, " Nevertheless, the clinical, demographic,

radiographic, and genetic evidence suggests that there is a strong

association between human metapneumovirus and lower respiratory tract

infection in otherwise healthy children. "