IV (intravenous) drip in the hand of a patient being treated for dengue fever in hospital in Dhaka, Bangladesh, 9th October 2023. Dengue fever is a mosquito-borne disease caused by the dengue fever virus. Symptoms can range from a mild fever and joint pain to spontaneous bleeding of the skin and circulatory failure, which are often fatal. This outbreak began in April 2023 and by November 2023 over 300,000 people had been infected and more than 1,500 people had died, making it the countrys worst recorded outbreak of the disease so far. Outbreaks of dengue fever are increasing in frequency due to climate change.