In short. In 2025, 10,391 cases of dengue were registered in Bali, most of them in Badung and Denpasar. It is spread by the Aedes mosquito, which bites in the daytime and lives in the house: in the bathroom, under the bed, in wardrobes. The signs: a sudden fever of 39–40 for two to seven days, pain behind the eyes, in the muscles and joints, a rash, and no runny nose; an NS1 test the same day. The most dangerous day or two come when the fever has dropped: shock is possible. Go to hospital with severe abdominal pain, vomiting more than three times a day, fast breathing, bleeding gums, blood in vomit or black stool. Bring the fever down only with paracetamol and drink plenty of fluids, ibuprofen and aspirin increase bleeding. Prevention under the Ministry's "3M plus" rule: empty and cover water containers once a week, repellent in the daytime, screens.
How many people fall ill. According to the provincial health service, 10,391 cases of dengue were registered in Bali in 2025, most of them in Badung and Denpasar, as Bali Post wrote. From January to May 2026 there were 1,167 cases and two deaths, Detik reported, and by July 1,588. The year is calmer than the last, but the mosquito has not gone anywhere, and the peak falls in the rainy season from November to April.
Who bites. Dengue is spread by the Aedes mosquito, and it is not an evening biter: according to the Ministry of Health leaflet it bites from morning until the end of the day, sometimes at night too, and lives in dark, cool corners of the house, in the bathroom, under the bed and in wardrobes. It breeds in clean standing water: flower saucers, vases, barrels, the bucket under an air conditioner, old tyres by the fence.
Symptoms. A sudden rise in temperature to 39–40 degrees that lasts from two to seven days, pain behind the eyes, in the muscles and joints, headache, weakness, nausea, a rash. What sets dengue apart from a cold is no runny nose or cough with a very high temperature, and an ache that is called "bone-breaking". The diagnosis is made with a blood test: in the first days of the illness a rapid NS1 antigen test is done in any clinic and laboratory on the island, later they look at platelets.
Three phases and the most dangerous day. The Ministry describes the illness this way. The first phase, fever, lasts two to seven days. The second, critical: the temperature falls and it seems you have recovered, but it is in this day or two that dengue shock is possible, when plasma leaves the blood vessels. The third, recovery. So a drop in temperature is not a signal to go back to work, but a signal to watch yourself more closely for another two days.
When to go to hospital. The danger signs from the Ministry of Health leaflet: severe abdominal pain, vomiting three times a day or more, fast breathing, bleeding gums and nosebleeds, blood in vomit or black stool, sudden weakness, restlessness or sluggishness, cold hands and feet. With any of them go straight to the emergency room, in Indonesian IGD. Two days of high temperature in a row the Ministry counts as a reason to see a doctor without waiting for anything else. How to call an ambulance and where to go is in the guide to emergency numbers, and hospitals are in the guide to hospitals.
What not to do. Do not bring the temperature down with ibuprofen, aspirin and other non-steroidal drugs: the Ministry writes directly that they increase bleeding. Only paracetamol, and plenty of fluids: water, electrolytes, coconut water, broth. Antibiotics are useless against dengue, it is a virus. If you are treating a child, the threshold for going to hospital is lower: children go into shock faster.
How not to fall ill. The Ministry's "3M plus" rule: empty and clean water containers once a week, cover tanks and barrels, remove or bury rubbish where water collects. Plus: repellent on bare skin in the daytime, screens on windows, light clothing with long sleeves in the evening, spray in dark corners of the house. A villa with a pond and a garden is beautiful, but the saucers under the pots are worth emptying every week. A dengue vaccine is registered in Indonesia, and it is something to discuss with a doctor, especially for those who have already had the illness.
What this means for you. A high temperature without a runny nose in Bali means an NS1 test the same day, paracetamol and water, no ibuprofen. A drop in temperature is not the end of the illness but the two most careful days. Abdominal pain, vomiting, blood or weakness mean the emergency room right away. At home, once a week empty the water from everything where it stands: the mosquito lives not in the jungle but in your bathroom.