More than 8 billion people could be at risk of malaria and dengue fever by 2080 if greenhouse gas emissions continue to rise unabated.
A new study states that malaria and dengue fever could spread to billions of people, according to new projections.
The researchers in fact predict that up to 4.7 billion more people could be threatened by the world's two most important mosquito-borne diseases, compared to 1970-99 figures.
The figures are based on projections of a population growth of about 4.5 billion over the same period and a temperature increase of about 3.7 °C by 2100.
The study, conducted by the London School of Hygiene & Tropical Medicine (LSHTM) and published in the journal Lancet Planetary Health, found that if emission levels continue to increase as they are currently doing, the effect on global temperatures over the next 50 years could lengthen transmission seasons (seasons in which transmission of mosquito-borne diseases is favored) by more than a month for malaria and four months for dengue.
Felipe J Colón-González said, "This work strongly suggests that reducing greenhouse gas emissions could prevent millions of people from contracting malaria and dengue. The results show that low-emission scenarios significantly reduce the duration of transmission, as well as the number of people at risk. Action to limit global temperature rise well below 2°C must continue."
According to the World Health Organization, malaria kills more than 400,000 people each year, mostly children in Sub-Saharan Africa, where in 2019, more than 90 percent of the estimated 230 million cases occurred in Africa. Currently, artemisinin-based combination therapy is the best available treatment for the most dangerous form of malaria, from P. falciparum, which accounts for 90 percent of cases.
Dengue has no specific treatment. The disease is underreported due to underdiagnosis, with nearly half of the world's population at risk. It is estimated that dengue infects 100 to 400 million people each year, killing 20,000 of them.
Dengue is a disease that can be treated in many countries.
Some countries, such as Eritrea, Sudan and Colombia, have seen a significant resurgence of malaria in recent years. So too, the number of cases of dengue reported to WHO has increased more than eightfold in the past two decades, from 505,430 in 2000 to 5.2 million in 2019, he added.
Colón-González said:"Current efforts to control malaria and dengue rely largely on controlling mosquito populations and reducing contact between mosquitoes and people. Although mosquito reduction campaigns can be effective, they are difficult to sustain, particularly in low-income countries, where scarce resources must be allocated between control and treatment.".