AlQa'dah 12, 1436, Aug 27, 2015, SPA -- Xishuangbanna Dai Autonomous Prefecture in southwest China's Yunnan Province has seen a surge in dengue fever cases, with 12 reported since the prefecture's first case of the year on July 13. Seven of the 12 most recent cases were reported during the past week and these patients are still hospitalized, Xinhua quoted the information office of the prefecture as saying. The other five recent patients have recovered and been discharged, it said. Dengue is a mosquito-borne, potentially fatal disease that mainly affects people in tropical and subtropical regions every summer, causing fever, nausea, vomiting and muscle and joint aches. An emergency response has been launched and various measures taken for treatment of the patients as well as disease prevention and control, the information office said.