ISLAMABAD: Islamabad has reported 17 more cases of dengue fever during the past 24 hours on Thursday. According to the district health officer (DHO), 17 patients with dengue hemorrhagic fever were reported in rural and urban areas of the federal territory. The DHO said that nine cases were reported in urban areas of Islamabad and eight from rural areas. The mosquito-borne disease has killed 20 lives in the area in the current season so far. Overall 4,581 dengue fever patients have been reported in this season so far. Dengue is a mosquito-borne viral infection that is common in warm, tropical climates and often peaks during rainy seasons, states the World Health Organisation (WHO). Once bitten by a dengue-infected mosquito, the virus takes four-10 days to affect the body. Its symptoms can be mild, similar to the common flu, or severe such as fever, headaches, pain behind the eyes and nausea.