Dengue: Why Can the Risk Increase Even After the Fever Subsides?

# Adrian Mercer

With the monsoon season underway, the risk of dengue is once again rising in Nepal. According to the latest regional data from the World Health Organization, Nepal reported 732 dengue cases in July 2026, an increase of 109 percent compared with the 351 cases recorded in June. The sharp rise is a clear reminder that dengue should not be dismissed as an ordinary seasonal fever.

Dengue is a viral infection transmitted through the bite of infected Aedes mosquitoes. Its risk is no longer confined to the Tarai or areas with consistently high temperatures. In recent years, urbanisation, water-storage practices, rainwater accumulation in containers, changing temperature and humidity patterns, and greater human mobility have contributed to the expansion of dengue into wider geographical areas.

According to the World Health Organization, about half of the world’s population is now at risk of dengue, with an estimated 100 million to 400 million infections occurring each year. Many infected people develop no symptoms, while others experience illness ranging from mild fever to severe and potentially life-threatening disease.

The most common symptom of dengue is high fever. Other symptoms may include severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, fatigue and skin rash. Symptoms usually appear four to 10 days after the bite of an infected mosquito and may last for two to seven days.

However, one important misconception must be addressed: a fall in fever does not always mean that the patient is recovering.

Warning signs of severe dengue can sometimes appear after the fever begins to subside. Persistent abdominal pain, repeated vomiting, bleeding from the nose or gums, blood in vomit or stool, unusual weakness, extreme restlessness, cold or pale skin, intense thirst or difficulty breathing should be treated seriously. In such cases, waiting at home can be dangerous, and the patient should be taken to a health facility immediately.

Another issue that receives excessive attention during dengue illness is the platelet count. A falling platelet count can be an important laboratory finding, but the condition of a patient cannot be assessed on the basis of a single number alone.

Doctors also evaluate blood pressure, circulation, bleeding, hydration status, changes in haematocrit, persistent vomiting, abdominal pain and other warning signs. A low platelet count therefore should not lead patients or families to draw conclusions on their own or seek unverified treatment through social media.

Testing for dengue also depends on the stage of illness. During the early phase, tests that detect the virus or the NS1 antigen may be useful, while antibody-based tests can be applied at later stages depending on the clinical situation. The appropriate test should be selected according to the number of days since symptoms began and the overall medical assessment.

There is no specific antiviral medicine that cures dengue in all patients. In uncomplicated cases, adequate rest, sufficient fluid intake and medical monitoring remain the main pillars of care.

Paracetamol may be used for fever and pain under appropriate medical guidance. Aspirin and medicines such as ibuprofen should be avoided when dengue is suspected because they may increase the risk of bleeding.

Fluid management is equally important. Patients should drink water, soups and other suitable fluids as tolerated. In severe cases, intravenous fluids may be required under hospital supervision. Both insufficient and excessive fluid administration can create complications, which is why patients with severe dengue need careful clinical monitoring.

Prevention remains more effective than treatment.

The Aedes mosquito that transmits dengue is active during the daytime as well as around dawn and dusk. Sleeping under a mosquito net at night alone therefore does not eliminate the risk.

Open buckets, water tanks, flowerpot trays, discarded tyres, bottles, cans, rooftop containers and stagnant water around homes can all become breeding sites. Water-storage containers should be covered, emptied and cleaned at least once a week, unnecessary standing water should be removed, and waste should be properly managed.

Wearing clothing that covers much of the body, using window and door screens, and applying appropriate mosquito repellents can also help reduce exposure.

Dengue control cannot be achieved by health ministries or municipalities alone. A breeding site in one household can put several neighbouring families at risk. Search-and-destroy campaigns therefore need to become a regular practice not only in homes, but also in schools, offices, construction sites, hospitals and public spaces.

Nepal has been moving towards a multisectoral approach to dengue prevention and control. Yet the ultimate success of any national strategy depends on what happens at the community level. Expanding hospital capacity alone cannot solve the problem if mosquito breeding environments remain widespread.

The central message is straightforward: in dengue, monitoring the fever alone is not enough. Warning signs that appear after the fever falls can be even more important.

Timely medical assessment, proper fluid management, avoidance of medicines that increase bleeding risk, and regular elimination of mosquito breeding sites can significantly reduce the risk of severe illness and death.

The real fight against dengue does not begin in the hospital. It begins at home and in the community, by preventing water from becoming a breeding ground for mosquitoes.