New Study Finds Warming World Will Increase Spread of Dengue Fever
At a Glance
- A warming climate will contribute to the spread of the mosquitoes that carry Dengue viruses.
- The risk will increase worldwide, but particularly in the southeastern United States, coastal China and Japan and inland Australia.
- More than 400 million contract the disease each year and about 22,000 die.
Climate change could in part put more than 6 billion people at risk of contracting the dangerous and often deadly Dengue fever by 2080, a new study says.
Dengue viruses are mosquito-borne diseases that typically affect people living and traveling in more than 100 countries in the tropics, according to the Center for Disease Control and Prevention. Currently, about 3 billion people live in areas at risk for Dengue, with up to 400 million becoming ill each year. Some 22,000 die of the disease.
Researchers used climate change projections from the Intergovernmental Panel on Climate Change (IPCC) to forecast the spread of the mosquitoes that carry the Dengue virus as the climate warms.
While a warming climate will be a major factor in the spread of mosquitoes that carry Dengue — making places like the southeastern United States, coastal areas of China and Japan and inland regions of Australia more vulnerable — other factors including urbanization and socioeconomic change will have an even greater impact on the increased number of people at risk.
“What was most surprising was actually how much less spread we predict in comparison to previous Dengue maps. While climate change is likely to contribute to Dengue expansion, factors including population growth and increasing urbanization in tropical areas will play a much larger role in shaping who will be at risk in the future," co-lead author Oliver Brady of the London School of Hygiene & Tropical Medicine said in the press release.
The greatest shifts in Dengue risks are expected in Africa, particularly in the Sahel and Southern Africa.
Simon I. Hay, director of Geospatial Science at the Institute for Health Metrics and Evaluation and professor of Health Metrics Sciences at the University of Washington says the shift will be particularly difficult for those most economically disadvantaged.
“We found that the population at risk of dengue will grow substantially and disproportionately in many areas that are economically disadvantaged and least able to cope with increased demands on health systems," he said.
“Mitigation strategies must focus on dengue endemic areas, not just the risk of expansion to Western nations," he added. "Taking action now by investing in trials of novel vaccines and mosquito control, curbing carbon emissions and planning for sustainable population growth and urbanization are crucial steps for reducing the impact of the virus.”
Because there are four different Dengue viruses, a person can become ill four times in his or her lifetime from the disease.
Symptoms of the illness can be mild or severe and include nausea and vomiting, rash and aches and pains. Most people recover within a week. About one in 20 people who exhibit symptoms will develop severe Dengue, which could result in shock, internal bleeding and even death. A person previously infected with one or more of the four viruses is more likely to develop severe symptoms.
There is no treatment for the virus other than resting, getting plenty of fluids and taking acetaminophen, known by the brand names Tylenol and Paracetamol. Patients are warned to avoid taking aspirin or ibuprofen because of the risk of excessive bleeding.