The World Health Organization said Turkish officials had now documented 18 human cases of H5N1 avian influenza infection and said three children had died. One boy who was found to be infected without being sick had begun to show symptoms, WHO officials said.

“Human cases have now been reported from nine of the country’s 81 provinces”, the WHO said.

The two newest patients are young children, aged four and six, WHO said.

“Both have a documented history of direct contact with diseased birds”, it said.

“Altogether, agricultural officials have confirmed poultry outbreaks in 11 provinces and are investigating possible outbreaks in an additional 14 provinces across the country”.

The more birds are infected, the more likely that people could become infected through close contact. Experts said as cold weather forced animals and people indoors together, especially in rural areas, animal-to-human infections could become even more common.

A British lab found that two of the first Turkish victims were infected with a slightly mutated strain of H5N1.

Although it did not seem t be more dangerous, the mutation in theory could help the virus more easily pass from a chicken to a human.

The good news was that the virus seems sensitive to the few drugs available to treat patients, WHO said. --- Reuters.