Frequent outbreaks of dengue in Nepal – causes and solutions: a narrative review

Dengue is a viral illness caused by dengue virus, a flavivirus transmitted by the bite of female Aedes aegypti and Aedes albopictus . In the year 2022, Nepal witnessed the largest ever dengue outbreak in the country. Dengue cases were reported from all seven provinces, affecting all 77 districts of the country. As of 31st December 2022, altogether 54 784 dengue cases have been identified, with Bagmati province reporting the highest. The country’s capital, Kathmandu, reported the highest burden of dengue cases (26%). The high degree of pre-monsoon rainfall because of climate change and mismanaged waste disposal system were the main cause of the 2022 dengue outbreak in Nepal. Furthermore, unplanned urbanization, Aedes vector expansion, open border policy with India, inefficient dengue surveillance system, and insufficient preventive efforts by the government are the causes of frequent dengue outbreaks. Awareness among the general public regarding vector control measures, improved surveillance of acute febrile illness, utilization of vector risk mapping techniques, and establishment of temperature-based early warning systems are utmost to halt future dengue outbreaks in Nepal.