Guangdong province reported 1,431 new cases of dengue fever on Sunday, bringing the total to 21,527, local health authorities said on Monday.

The number was rising quickly, with more than 1,000 new cases found each day last week. One fatality was reported by the provincial health and family planning commission on Sunday, bringing the death toll in the province to six.

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