BEIJING - China's southern province of Guangdong has reported a sharp rise in mosquito-transmitted dengue fever cases in the past two months, with dozens of people still in hospital, state media said on Monday.

Experts blamed recent humid and hot weather and inadequate anti-mosquito efforts in the area for the recent increase, the Guangzhou-based Southern Metropolis Daily said.

Most of the more than 70 infections so far this year have been reported since June, and over 20 patients were still being treated in a hospital in the provincial capital Guangzhou, prompting local authorities to issue an epidemic warning, state television said.

But officials also urged residents not to panic, noting the outbreak was caused by the least deadly of dengue virus' four forms and none of the Guangdong cases has been fatal.

An endemic viral disease most common in the tropics, dengue is carried by the Aedes Aegypti mosquito, which transmits the virus that can cause fever, severe headache, joint and muscular pains, vomiting and rashes.

The newspaper said a bigger outbreak sickened more than 1,000 people in Guangzhou in 2002. None of those cases were fatal.

Small-scale outbreaks of dengue fever have been reported occasionally in Guangdong and the southeastern province of Fujian since the 1990s, the Xinhua news agency said.