Dengue fever to spread in the US, Africa and even the Mediterranean

Dengue fever to spread in the US, Africa and even the Mediterranean as ‘climate change and population growth put SIX BILLION people in danger zones by 2080’

  • Researchers in the UK and US made the predictions in a scientific paper
  • They calculated which regions would become suitable for Aedes mosquitoes
  • The blood-sucking bugs can spread dengue fever, Zika and yellow fever
  • Poorer but currently unaffected areas of Africa are likely to be worst hit

Mosquito-borne dengue fever could sweep deeper into the US, China, Japan and inland Australia over the next 60 years because of climate change.

Scientists say warmer and wetter weather coupled with more people moving into tropical areas as the global population rises will put greater numbers at risk.

Currently the infection, which is incurable and causes fever, vomiting, rashes and pain, is best known for spreading through south Asia, Africa and South America.

But as many as six billion people – around 80 per cent of today’s world population – will live alongside disease-spreading mosquitoes by 2080, the researchers said.

The virus could even spread as far north as the Mediterranean and put people in Spain, Portugal, Italy and Greece in danger.

The Aedes aegypti mosquito (pictured) can only survive by drinking mammals’ blood and is best able to fly in regions with temperatures consistently above 15°C (59°F) (stock image)

The World Health Organization estimates dengue fever causes 100million infections around the world every year, and 10,000 deaths.

Infections are more than 30 times higher than they were 50 years ago and almost half the world’s 7.5billion population is at risk.

But the at-risk group could almost double in size again if the predictions of researchers at the London School of Hygiene and Tropical Medicine and University of Washington come true.

The researchers said their prediction was milder than past research which has suggested the disease will spread through Europe, but still showed a rising risk.

Dr Oliver Brady, an assistant professor at LSHTM said: ‘While climate change is likely to contribute to dengue expansion, factors including population growth and increasing urbanisation in tropical areas will play a much larger role in shaping who will be at risk in the future.’

Dr Brady and his team made their predictions by analysing which environments around the world looked likely to become suitable for dengue-carrying mosquitoes.

The Aedes mosquito thrives in warmer climates between 15°C (59°F) and 32°C (90°F), becoming less able to fly if temperatures fall below this range.

And the bugs also survive best if they’re near people or livestock and have a constant supply of blood to feed off.

So as the world’s population and temperature rises, and more of that population moves into warmer areas, the mosquitoes’ optimum environments will expand, researchers said.

In maps released with the paper in Nature Microbiology scientists showed how the distribution of Aedes mosquitoes could change. In the model for next year, India and South Asia and West Africa are the worst affected – shown by red highlights

A model for 2080 shows more of the centre of Africa has become red, some low-risk yellow shading has appeared in the Mediterranean, further north in the US and further south in Australia. Meanwhile, South Asia appears slightly paler in comparison to 2020, but the problem has worsened in South America

By 2080 some 60 per cent of the global population – expected to reach more than 10billion in the 2050s – will be at risk of catching dengue fever.

The same mosquitoes also spread yellow fever, Zika and chikungunya.

More of the south-eastern United States will be affected by 2050, as well as coastal regions of Japan and China, inland Australia, higher altitudes in Argentina and Mexico.

Southern Africa and the Sahel – between the Sahara and Savanna deserts – will be among the regions which see the biggest spike in dengue risk, the experts said.

‘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,’ said study said co-author Dr. Simon Hay, from the University of Washington.

‘Mitigation strategies must focus on dengue-endemic areas, not just the risk of expansion to Western nations.

‘Taking action now by investing in trials of [new] vaccines and mosquito control and planning for sustainable population growth and urbanization are crucial steps for reducing the impact of the virus.’

The team’s research was published in the journal Nature Microbiology. 


The World Health Organization is underestimating how many people will die because of climate change, experts claim.

Researchers from the London School of Hygiene and Tropical Medicine and the University of Washington picked apart the WHO’s warning that global warming will lead to the deaths of an extra quarter-of-a-million people per year between 2030 and 2050.

This translates to approximately one in every 200 deaths – around 55million people die each year – but the true toll is now expected to be significantly higher, although the study authors couldn’t put a number on it.

As well as heat stress and malaria, people will also die because of extreme weather events, migration and reduced farm productivity, they said.

And rising temperatures and intense weather around the world will endanger the lives of ‘many millions of people’. 

‘We think the impact is more difficult to quantify,’ Sir Andrew Haines, who reviewed various climate change predictions from international organisations, told CNN.

‘There is also population displacement and a range of additional factors like food production and crop yield, and the increase in heat that will limit labor productivity from farmers in tropical regions that wasn’t taken into account among other factors.’  

Sir Andrew’s article was written alongside climate change expert, Professor Kristie Ebi, from the University of Washington.

They said food shortages alone could lead to more than half a million (529,000) adults dying every year by 2050.

And the World Bank estimates 100million more people will be thrust into ‘extreme poverty’ – which the UN defines as deprivation of food, water, sanitation and healthcare – in the next 11 years, putting their lives at risk. 

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