What's Making Your Zika Risk Spike?

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What does climate change have to do with the spread of disease-carrying mosquitoes? Quite a bit, according to a study in Nature Microbiology. Factors like greenhouse gas emissions, a rise in travel, and more people living in urban areas create habitats for the blood-sucking insects — so much so that, by the year 2050, nearly half of the world’s population will likely be at increased risk for Zika virus, yellow fever, dengue, chikungunya, and other diseases carried by mosquitoes.

For this study, an international group of researchers examined factors that contribute to the spread of mosquitoes (climate change, human travel, and urbanization, for example) and developed a prediction model for two types of mosquitoes that spread disease — Aedes aegypti and Aedes albopictus. These mosquitoes typically live in tropical, subtropical, and some temperate climates.

First, the researchers gathered information about mosquito populations in Europe and the United States from the 1970s and 1980s. Then, they looked at current-day mosquito populations and predicted the suitability of the insect habits using various climate models and the projected growth of cities, human migration, etc. for 2020, 2050, and 2080.

In recent years, Aedes aegypti, also called the yellow fever mosquito, has spread over long distances and the spread of Aedes albopictus, also known as the tiger mosquito, has been more localized. In the United States, Aedes aegypti mosquitoes have spread north at a rate of about 150 miles per year. Aedes albopictus mosquitoes have spread faster in Europe and slower in the United States. The CDC provides a potential range map for these mosquitoes.

In the short term — the next 5 to 15 years — human movement is expected to drive the spread of mosquitoes, but the environmental impact of climate change and urbanization are likely to have long-term effects on mosquito populations throughout the world. Mosquito-borne diseases are a serious threat and, according to the World Health Organization, cause millions of deaths each year.

The best way to stop the spread of these diseases is, well, to prevent mosquito bites in the first place. Try these tactics:

  • Say bye-bye to birdbaths and outdoor planters and pet bowls. Standing water provides a breeding ground.
  • Repair window screens and door screens so that mosquitoes can’t get inside your house.
  • Use an insect repellent containing 15 to 30 percent DEET.
  • Avoid spending time outdoors at dawn and dusk when mosquitoes are most active.