Turkish officials said today none of the latest human victims of bird flu were in a life-threatening condition and international experts said the outbreak could be controlled.
Prime Minister Tayyip Erdogan claimed the crisis was under control.
Two teenagers died last week from bird flu in eastern Turkey - the first reported deaths from the virus outside China and Southeast Asia.
Their dead sister is also a suspected victim and dozens of Turks have rushed to hospitals for bird flu tests.
The World Health Organization says there is no evidence so far of human-to-human transmission of the virus, but experts fear the H5N1 strain could mutate enough to allow it to pass easily from person to person and spark a pandemic.
Turkey has now confirmed 15 people with bird flu infections since last week, most in eastern, central and northern parts of the country.
Speaking by telephone from Ankara, the leader of a World Health Organisation (WHO) team sent to investigate, Guenael Rodier, said: "I have a sense that what is going on in Turkey can be brought under control relatively easily."
Another senior WHO official also told the same news conference that genetic testing on virus samples taken from both human cases and animals showed them to be very similar, pointing to poultry being the source.
Victims contract the disease from close contact with infected poultry.
The rash of cases in Turkey is the first time the virus has been detected in people outside east Asia since it reemerged in late 2003. It is known to have killed at least 76 people in that time.
Turkey reported another human case of bird flu today in the central province of Sivas, but said none of the people infected with the virus were in a critical condition.
"So far H5N1 has been detected in 15 cases and two of them have died. We don't see any new cases in the east, the focus is shifting to central Turkey," health ministry official Turan Buzgan said.
Health experts say the outbreak in Turkey is the worst since one in Hong Kong in 1997 when 18 people were infected and six died before it was subdued.
The outbreak has cast a cloud over Turkish celebrations of the Muslim Eid al-Adha festival, a major national holiday.
Snow and freezing temperatures in the east of the country are also hampering efforts to tackle the virus and may be allowing it to survive for longer.
Four people were taken to hospital with suspected bird flu in the town of Aydin near the Aegean coast - one of Turkey's most important tourism centres - adding to concerns the outbreak will harm country's important tourist trade.
Authorities in neighbouring countries sprayed cars crossing from Turkey with disinfectant and checked luggage as they tried to stem the spread of bird flu.
The authorities have sent teams of veterinarians in protective white body suits to a number of regions to cull poultry, seen as the best method of checking the disease.
Authorities said 12 of 23 people undergoing tests for bird flu in Istanbul had tested negative. There is concern the deadly virus could hit a teeming city of 12 million which is the country's commercial hub and gateway to Europe from Asia.
Turkey has stepped up an information campaign on how to deal with birds and called on locals to comply with culling regulations, particularly in the poor mainly-Kurdish southeast.
Sermons at mosques are also urging precaution. "We weren't aware of any danger from eating chicken," said Sirin Altintas, an unemployed 36-year-old, as he paced a hospital corridor in Van concerned for six-year-old son undergoing tests.