Christopher Columbus wasn't responsible for the spread of lice in the New World, according to US and French researchers.

Teams in Marseilles and Florida have separately examined two lice-ridden Peruvian mummies dating back to the early 11th century - almost 500 years before the Italian explorer arrived in the Caribbean.

''The DNA from these parasites showed that the animals predated the arrival of Columbus by hundreds of years,'' said David L. Reed of the Florida Museum of Natural History.

Reed said that his studies, combined with those of the French Institute for Infectious Diseases in Marseilles, ''showed that these parasites had been feeding off pre-Colombian peoples for at least 10,000 years''.

''That doesn't absolve European explorers of other germ spreading, of course,'' Reed added, referring to the outbreaks of smallpox, measles, chicken pox and scarlet fever that would eventually decimate native tribes.