New findings, reported in the journal Respiratory Research, about how the bird flu virus binds to the respiratory tract and lung suggest children may be particularly susceptible to avian influenza.
John Nicholls and colleagues at the University of Hong Kong and Adelaide Women and Children’s Hospital, in Australia, used chemicals that attach to types of sugar on the surface of cells to look at the way different influenza viruses attack cells in the upper and lower respiratory tract, including the lungs.
Molecules of a sugar called sialic acid on the cell surface act as chemical beacons for the influenza viruses. Different types of sialic acid attract different types of influenza virus. Once the virus finds sialic acid, it can attach and infect the cell. The distribution of sialic acid molecules affects how likely the virus is to find cells to infect.
The researchers found that the type of sialic acid that binds bird flu was particularly common in the lower respiratory tract of children, which could explain why children are especially vulnerable to bird flu.