KUNMING - The number of confirmed dengue fever cases rose to 123 in a prefecture of Southwest China's Yunnan province as of Tuesday afternoon, local health officials said Wednesday.

The total included four cases originating outside the province, and there have been no serious cases or deaths since the disease was first reported in the area on Thursday last week, according to health authorities in the Dai autonomous prefecture of Xishuangbanna.

Nine patients infected with dengue fever were hospitalized between 8 am and 4 pm on Tuesday, and two were discharged from the hospital, authorities added.

No new cases were reported in the prefecture on Tuesday.

Of the confirmed cases, 41 were hospitalized and the others were treated at home or in clinics.

Provincial health authorities have dispatched experts to the prefecture to help control the outbreak. Local government also organized residents to kill mosquitos to prevent an epidemic.

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.