Human metapneumovirus was first identified as a cause of respiratory infection in 2001. It now appears to be infecting more and more children, Italian researchers report.

Dr. Nicola Principi of the University of Milan and colleagues note in the Journal of Medical Virology that there have been increasing reports of human metapneumovirus, or hMPV, infection, but there has been little information on how kids are being affected.

To investigate further, the researchers examined nasal swabs from children younger than 15 years old seen in the emergency room at the Institute of Pediatrics in Milan for any medical reason during a 6-month period. Samples from 1505 children were collected.

Forty-two children (3 percent) showed evidence of hMPV infection. Respiratory syncytial virus (RSV) was detected in 143 (9 percent) and influenza virus in 230 (15 percent).

Overall, hMPV was seen only in patients with acute respiratory infection, while the other viruses were found in patients with a variety of conditions.

Questionnaires completed by parents showed that households in which there were children with hMPV or influenza had significantly more medical visits and lost significantly more work or school days than those in which children had RSV infections.

While the rate of hMPV infection was relatively low, the researchers suggest the disease “may have a significant clinical and socioeconomic impact on children and their families.”

In fact, Principi told Reuters Health, hMPV causes “a great number of respiratory infections in the family when a child is ill,” as the flu virus does.

Consequently, “Prevention of infections due to hMPV seems necessary, and studies regarding the production of a vaccine are probably needed.”

SOURCE: Journal of Medical Virology, January 2005.