Rising Heat and Dengue Risk in Nepal's Mid Hills

The risk of dengue fever has been growing in Nepal's mid hills. This is due to rising temperatures, which create ideal conditions for mosquitoes to thrive. To understand this better, researchers looked at satellite data and temperature trends from 2001 to 2020. They focused on two types of mosquitoes that spread dengue: Aedes aegypti and Aedes albopictus. These insects are sensitive to temperature changes, so tracking these shifts is crucial for predicting and controlling outbreaks. The study split the years into two parts: 2001 to 2010, when dengue started to appear, and 2011 to 2020, when it spread rapidly. The findings showed that about half of Nepal has suitable temperatures for dengue transmission for at least one month each year. In some areas, this risk lasts up to nine months. This pattern has stayed mostly the same over the past two decades. However, in hilly regions and around big cities like Kathmandu and Pokhara, the suitable temperature period has extended to six months for both mosquito types. This means more people are at risk of dengue each month. The study also found that the population exposed to these suitable temperatures has increased. Compared to the early 2000s, more people are now living in areas with suitable temperatures for six months or longer each year. This increase is significant: 18% more for Aedes aegypti and 20% more for Aedes albopictus. These findings are important for health officials. They provide a clear picture of where and when dengue is most likely to spread, helping them to plan better control measures. However, it's important to note that while temperature is a key factor, it's not the only one. Other factors, like rainfall and human behavior, also play a role in dengue transmission. So, a comprehensive approach is needed to effectively manage and control the disease.