By Checky Abuje
More than 8bn people could be at risk of malaria and dengue fever infections by 2080 as a result of the global warming. A new study has found that if greenhouse gas emissions continue at the current rate, temperatures will increase leading to rise of conditions that encourage malaria-carrying mosquito.
According to new research projections, malaria and dengue fever will spread to new locations and reach billions of people at the current climate change. About 4.7 billion more people could be threatened by the world’s two most mosquito-borne diseases, compared with 1970-99 figures.
These latest figures are based on projections of population growth of about 4.5 billion over the same period, and a temperature rise of about 3.7C by 2100. The study finds that to save millions of people from mosquito-borne diseases; the world must reduce global heating.
The research was conducted by the London School of Hygiene & Tropical Medicine (LSHTM).
According to the study, if greenhouse emissions continue to rise at current rates, the effect on global temperatures could lengthen transmission seasons by more than a month for malaria and four months for dengue over the next 50 years.
Climate change increases the risk of illness through increasing temperature, more frequent heavy rains and runoff, and the effects of storms, thus affecting human health through extreme changes in the weather and environment. This can increase existing health problems, as well as creating new ones.
The transmission of malaria is heavily influenced by environmental events. Changes in temperature, humidity, rainfall, and other climatic conditions are crucial in dictating the transmission of malaria, such as the lifespan of the mosquito and the development of malaria parasites in the insect.
Mosquito-borne diseases are benefiting from the increasing temperatures and the other climatic changes they induce. The warmer climate is facilitating the geographical distribution of mosquito-borne diseases such as malaria, as well as the risk of transmission.
It is estimated that Malaria kills more than 400,000 people every year. According to the World Health Organization, it is revealed that there were 229 million cases of malaria worldwide in 2019 and about 409,000 lost their lives to the disease.
The most affected by malaria are children under five (who accounted for 67% of all malaria deaths in 2019), and those in Africa (who accounted for 94% of all cases in the same year).
Other diseases carried by mosquitoes, such as Dengue fever are also becoming more prevalent as a result of global climate crisis . The disease is under-reported, with almost half the world’s population at risk. Dengue is estimated to infect 100 million to 400 million people every year, killing 20,000.
Global health organizations and leaders need to emphasize the importance of implementing strategies to curb climate change in order to prevent an increase in many health problems.
Felipe J Colón-González, assistant professor at LSHTM said: “This work strongly suggests that reducing greenhouse gas emissions could prevent millions of people from contracting malaria and dengue.
“The results show low-emission scenarios significantly reduce the length of transmission, as well as the number of people at risk. Action to limit global temperature increases well below 2C [3.6F] must continue.”
“But policymakers and public health officials should get ready for all scenarios, including those where emissions remain at high levels. This is particularly important in areas that are currently disease-free and where the health systems are likely to be unprepared for major outbreaks.”
Some countries, such as Eritrea, Sudan, and Colombia, have seen a significant resurgence of malaria, said Rachel Lowe, associate professor at LSHTM and another author of the study. The number of dengue cases reported to WHO increased more than eightfold over the last two decades, from 505,430 in 2000 to 5.2m in 2019, she added.
“Our findings stress the importance of increased surveillance in potential hotspot areas to monitor the emergence of diseases,” she said.
The LSHTM study factors in various levels of greenhouse gas emissions, population density, and altitude. But researchers have acknowledged that some other key factors have not been taken into account, including the evolution of the disease and vector, or the development of more effective drugs and vaccines. Malaria vaccine trials are ongoing. A vaccine for dengue has been licensed in some countries.
Colón-González said: “Current malaria and dengue control efforts largely rely on controlling mosquito populations and reducing contact between mosquitoes and people. While 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.”