Flies More Germ-Laden Than Suspected

Another blow to their reputation:

The house fly and the blowfly together harbour more than 600 different bacteria, according to a DNA analysis.

Many are linked with human infections, including stomach bugs, blood poisoning and pneumonia.

Flies can spread bacteria from place-to-place on their legs, feet and wings, experiments show. In fact, every step taken by a fly can transfer live bacteria, researchers said.

''People had some notion that there were pathogens that were carried by flies but had no idea of the extent to which this is true and the extent to which they are transferred," Prof Donald Bryant of Penn State University, a co-researcher on the study, told BBC News.