CAIRO (Reuters) - Two Egyptian women died of bird flu onMonday, bringing to four the number of fatalities from thevirus in the most populous Arab country in less than a week asEgypt emerged from a warm-weather lull in avian flu cases.

All four deaths involved women and were believed to haveresulted from exposure to sick or dead backyard birds.

Firdaus Mohamed Hadad of Menoufia province in the NileDelta region north of Cairo was taken to hospital on Saturdayand died early on Monday, Egypt's Health Ministry said in astatement.

"She suffered from a high fever and difficulty breathingand had a pulmonary infection after coming into contact withbirds suspected of being infected with avian flu," thestatement said. "She was placed on a respirator but died atdawn on Monday."

Later, John Jabbour, an Egypt-based World HealthOrganisation official, told Reuters a second woman had died ofbird flu in northern Egypt. The health ministry identified thewoman as Hanem Ibrahim from Damietta, also in the Nile Delta.

The four Egyptian deaths from bird flu over the past weekbroke a 5-month pause in human cases in Egypt and brought to 19the number of Egyptians who have died of the deadly H5N1 birdflu virus since it emerged in Egypt in early 2006.

It is also the third winter that the virus has struck afterlying low during Egypt's hot summers, when it is much lesslikely to spread from one carrier to another.

On Sunday, a 25-year-old Egyptian woman died of bird flu inthe Nile Delta city of Mansoura while another woman, OlaYounis, died of bird flu on Wednesday in Beni Suef provincesouth of Cairo, the first case of this winter season.

Jabbour said the high fatality rate in the recent cases waslikely due to a delay in diagnosis after patients and theirfamily members denied exposure to infected birds.

"All of the new cases have exposure to sick or deadbackyard birds. ... The problem is the delay in reporting thatthey have been exposed," he said. Patients are most likely tosurvive if they start treatment with Tamiflu early aftersymptoms occur.

Around 5 million households in Egypt depend on poultry as amain source of food and income, and the government has saidthis makes it unlikely the disease can be eradicated despite alarge-scale poultry vaccination programme. WHO officials havesaid the bird flu virus was now considered endemic in Egypt.

Deaths from bird flu now total more than 210 worldwidesince 2003 and have been reported in several African and Asiancountries, as well as in Turkey and Azerbaijan. Egypt, with 43confirmed human cases, has been the single hardest-hit countryoutside of Asia.

Health experts fear the virus could mutate into a form thatspreads easily from one person to another, possibly triggeringa pandemic that could kill millions.

(Writing by Cynthia Johnston; Editing by Stephen Weeks)