LONDON (Reuters) - Travel restrictions and other measures help limit the spread of the new H1N1 virus but officials are largely ignoring the best way to stop the bug: focusing on children's hygiene, a researcher said.

Citing a review of 51 studies examining different ways to contain respiratory virus epidemics, Tom Jefferson of the Cochrane Library said encouraging children to do simple things like wash their hands is most effective.

"I don't really understand why some governments are obsessed with popping pills and giving injections," Jefferson, who led the review, said in a telephone interview.

"The evidence is clear," he added. "Hand washing offers protection against a lot of things, not just respiratory viruses."

The review of published studies from around the world suggested that frequent hand washing, using gloves, gowns and masks with filtration, and isolating people believed to be sick help reduce transmission of viral respiratory diseases.

It also found that the greatest potential for preventing disease from spread came from focusing on children, not adults, Jefferson said.

"The main thing is if you teach children to wash their hands in schools, that is the biggest benefit to the whole of society," he said.

One large study, for example, looking at 4,332 children in poor Pakistani households found children who washed their hands with soap several times daily had 50 percent fewer episodes of illnesses such as pneumonia or cough than the others.