Egyptian girl infected with bird flu - WHO

(Adds case unusual in summer weather, came after 2-month lull)

By Cynthia Johnston

CAIRO, June 8 (Reuters) - A 10-year-old girl from southern Egypt has been infected with the deadly H5N1 bird flu virus and is in "very critical" condition, a World Health Organisation official said on Friday.

The fresh infection came after a nearly two-month warm weather lull in human cases in the most populous Arab country, and brought the number of confirmed avian influenza cases in people in Egypt to 35, of which 14 have died.

"There is a new human case just reported by the Ministry of Health. She is a 10-year-old female. She has a history of contact with backyard birds," John Jabbour, an official with the World Health Organisation in Cairo, told Reuters.

Egypt's state news agency MENA reported that the girl, from the southern town of Qena, was on a respirator in a Luxor hospital. Jabbour said the girl, who fell ill on June 1 but whose diagnosis and life-saving treatment was delayed, was not stable enough to be transferred to Cairo.

Bird flu first hit Egypt in 2006 and did extensive damage to the poultry industry and the economy as a whole. Egypt has the highest number of confirmed human bird flu cases outside Asia.

Most of those who have fallen ill in Egypt were reported to have had contact with sick or dead household birds, primarily in northern Egypt where the weather is typically cooler than in the south.

But in a sign of a change in how the disease may be occurring in Egypt, all but two of the past 11 human cases have occurred in central or southern parts of the country.

Bird flu experts in Egypt have said they would typically expect fewer human cases of the disease during Egypt's sweltering summer months, and in 2006 there was a roughly 5-month summertime lull in human cases between May and October.

"This is an unusual case during this weather and these temperatures," Jabbour said of the girl's case.

Experts fear that the bird flu virus might mutate or combine with the highly contagious seasonal influenza virus and spark a deadly pandemic which could circle the globe and kill millions.

Around five million households in Egypt depend on poultry as a main source of food and income and the government has said this makes it unlikely the disease can be eradicated. The government still finds it hard to enforce restrictions on the movement and sale of live poultry.