KUNMING - The number of confirmed dengue fever cases in an outbreak of the disease in a prefecture of Southwest China's Yunnan province has risen to 581, but experts say the epidemic has been contained.

There have been no deaths reported since the disease was first reported in Dai autonomous prefecture of Xishuangbanna on Aug 15, according to a statement released by Yunnan's health department.

The cases include 14 originating from neighboring countries, including Myanmar, Laos and Thailand, the statement said.

Of the confirmed cases, 409 had been cured, 116 remain hospitalized and 56 others have been quarantined at home for treatment.

Dengue is a mosquito-borne, potentially fatal disease that affects between 50 and 100 million people in tropical and subtropical regions every year, causing fever and muscle and joint aches.

A third-level emergency response has been launched and various measures taken for the treatment of the patients as well as disease prevention and control, sources with Xishuangbanna's information office said, adding that local residents had been mobilized to fight the epidemic.

Experts warned that the epidemic would prevail at a relatively high level for quite a long time, though the rapidly rising trend has been initially contained.