Metapneumovirus is a leading cause of respiratory tract infection in infants
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《英国医生杂志》
Scott Gottlieb
In a substantial proportion of lower respiratory tract infections in children where no virus can be cultured, human metapneumovirus infection is a leading cause of the infection in the first years of life. The resulting spectrum of disease is similar to that seen with respiratory syncytial virus.
In 2001, researchers in the Netherlands first isolated the new virus from children and adults with acute respiratory tract infection. This RNA virus is closely related to avian pneumovirus. In a new study, researchers sought to define more clearly the aetiological role of this virus in lower respiratory tract infections in previously healthy young children (New England Journal of Medicine 2004;350:443-50).
Researchers led by Dr John V Williams, of Vanderbilt University Medical Center in Nashville, Tennessee, tested nasal wash specimens for human metapneumovirus. Specimens had been obtained over a 25 year period from otherwise healthy children presenting with acute respiratory tract illness.
The researchers examined results from office visits by 2009 infants and children prospectively seen from 1976 to 2001. No cause was identified in 321 children who made 408 visits for lower respiratory tract illness by. Of these children, specimens from 248 were available. Forty nine specimens (20%) contained human metapneumovirus RNA or viable virus. Thus, 20% of all lower respiratory tract illnesses previously negative for virus were attributable to human metapneumovirus, which means that 12% of all lower respiratory tract illnesses in this cohort were probably due to this virus.
On the basis of these data, it seems that infection in the major target population梟amely, previously healthy young infants梚s somewhat less common than infection with respiratory syncytial virus but more common than infection with parainfluenza virus. The mean age of children infected with human metapneumovirus was 11.6 months. The ratio of male to female was 1.8 to 1, 78% of illnesses occurred between December and April, and the rate of admission to hospital was 2%.
The virus was associated with bronchiolitis in 59% of cases, pneumonia in 8%, croup in 18%, and an exacerbation of asthma in 14%. The researchers also detected human metapneumovirus in 15% of samples from 261 patients with upper respiratory tract infection but in only 1 of 86 samples from children without symptoms.
In an accompanying editorial, Dr Kenneth McIntosh and Dr Alexander J McAdam, both of the Children抯 Hospital and Harvard Medical School in Boston, write that the diseases caused by human metapneumovirus are most similar to those caused by respiratory syncytial virus. Infection with human metapneumovirus is probably somewhat less likely in infants younger than 2 months of age, and overall it is probably somewhat less severe than infection with respiratory syncytial virus. The frequency and severity of disease in elderly people is still not well delineated.
"Human metapneumovirus should quickly be given a prominent position on the list of respiratory pathogens," they write. "This means that we should make widely available the tools that allow the virus to be detected in patients with serious respiratory infections; learn more about its role in disease, particularly in hosts other than children, and about its spread in the community and in hospitals; and as soon as possible, develop the means to prevent and treat human metapneumovirus infection."(New York)
In a substantial proportion of lower respiratory tract infections in children where no virus can be cultured, human metapneumovirus infection is a leading cause of the infection in the first years of life. The resulting spectrum of disease is similar to that seen with respiratory syncytial virus.
In 2001, researchers in the Netherlands first isolated the new virus from children and adults with acute respiratory tract infection. This RNA virus is closely related to avian pneumovirus. In a new study, researchers sought to define more clearly the aetiological role of this virus in lower respiratory tract infections in previously healthy young children (New England Journal of Medicine 2004;350:443-50).
Researchers led by Dr John V Williams, of Vanderbilt University Medical Center in Nashville, Tennessee, tested nasal wash specimens for human metapneumovirus. Specimens had been obtained over a 25 year period from otherwise healthy children presenting with acute respiratory tract illness.
The researchers examined results from office visits by 2009 infants and children prospectively seen from 1976 to 2001. No cause was identified in 321 children who made 408 visits for lower respiratory tract illness by. Of these children, specimens from 248 were available. Forty nine specimens (20%) contained human metapneumovirus RNA or viable virus. Thus, 20% of all lower respiratory tract illnesses previously negative for virus were attributable to human metapneumovirus, which means that 12% of all lower respiratory tract illnesses in this cohort were probably due to this virus.
On the basis of these data, it seems that infection in the major target population梟amely, previously healthy young infants梚s somewhat less common than infection with respiratory syncytial virus but more common than infection with parainfluenza virus. The mean age of children infected with human metapneumovirus was 11.6 months. The ratio of male to female was 1.8 to 1, 78% of illnesses occurred between December and April, and the rate of admission to hospital was 2%.
The virus was associated with bronchiolitis in 59% of cases, pneumonia in 8%, croup in 18%, and an exacerbation of asthma in 14%. The researchers also detected human metapneumovirus in 15% of samples from 261 patients with upper respiratory tract infection but in only 1 of 86 samples from children without symptoms.
In an accompanying editorial, Dr Kenneth McIntosh and Dr Alexander J McAdam, both of the Children抯 Hospital and Harvard Medical School in Boston, write that the diseases caused by human metapneumovirus are most similar to those caused by respiratory syncytial virus. Infection with human metapneumovirus is probably somewhat less likely in infants younger than 2 months of age, and overall it is probably somewhat less severe than infection with respiratory syncytial virus. The frequency and severity of disease in elderly people is still not well delineated.
"Human metapneumovirus should quickly be given a prominent position on the list of respiratory pathogens," they write. "This means that we should make widely available the tools that allow the virus to be detected in patients with serious respiratory infections; learn more about its role in disease, particularly in hosts other than children, and about its spread in the community and in hospitals; and as soon as possible, develop the means to prevent and treat human metapneumovirus infection."(New York)