Study: Mosquitoes in Dry Climates More Attracted to Human Blood

Category: Health


Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. dense / dɛns / (adj) – having a lot of things or people close together

    The dense forest is filled with tall trees.

  2. evolve / ɪˈvɒlv / (v) – to slowly change or develop from one state to a more advanced one

    The company evolved from a startup to a multinational business.

  3. speculate / ˈspɛk yəˌleɪt / (v) – to guess why something happened or what will happen next

    The police speculate that the suspect committed the crime to get revenge.

  4. urbanization / ˌɜr bə nəˈzeɪ ʃən / (n) – the process of forming cities and making them larger and more populated

    Worsening air pollution is one of the negative effects of fast urbanization.

  5. outbreak / ˈaʊtˌbreɪk / (n) – a sudden start and spread of a disease

    There’s usually an outbreak of mosquito-borne diseases during rainy seasons.


Read the text below.

A team of international researchers conducted a study to determine why certain mosquitoes developed a preference for human blood.

According to study co-author Noah Rose, mosquitoes found in dense human populations in cities with intense dry seasons evolved to have a stronger preference for human blood. The researchers speculate that the evolution happened because humans living in these cities tend to store water, which mosquitoes depend on for survival.

For the study, the researchers examined Aedes aegypti mosquito populations from 27 locations across Africa. These mosquitoes have a strong preference for human hosts and are well-known carriers of dengue and Zika viruses.

The researchers collected egg samples of the mosquitoes for three years and conducted laboratory tests on each population. They found that urbanization increased mosquitoes’ tendency to bite humans, but it did not have a major effect. Professor Carolyn McBride explained that it is only when these extremely populated cities experience long and hot dry seasons that mosquitoes become more interested in feeding on humans.

The researchers predict that rapid urbanization in Africa will cause mosquitoes to further evolve. This evolution may result in more human-biting mosquitoes in several populated cities by 2050.

The researchers added that understanding why these mosquitoes prefer to bite humans is crucial in forecasting outbreaks and preventing millions of deaths caused by mosquito bites each year.

Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

• Do you find it surprising that urbanization increased mosquitoes’ tendency to bite humans? Why or why not?
• Aside from mosquitoes’ biting preferences, what factors should scientists study (e.g. mosquitoes’ ability to become carriers of disease)? Explain.

Discussion B

• Do you think outbreaks can ever be completely prevented? Why or why not?
• Who do you think should be responsible for managing an outbreak (e.g. governments, health institutions)? Discuss.