Hesperian Health Guides

How Mosquitoes Cause Illness

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HealthWiki > A Community Guide to Environmental Health > Chapter 8: Health Problems from Mosquitoes > How Mosquitoes Cause Illness

Three serious illnesses carried by mosquitoes are malaria, dengue fever, and yellow fever. Each of these illnesses has different signs and is carried by a different kind of mosquito with different breeding habits. But these diseases can be prevented in the same ways because they are all passed from mosquitoes to people.

Prevent mosquito bites

How mosquito-borne diseases spread
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Mosquito bites person who has malaria, dengue, or yellow fever
Same mosquito bites healthy person
Mosquito bites sick person
Healthy person gets sick
Mosquito bites other people, spreading disease

All mosquito-borne illnesses can be prevented by preventing mosquito bites. To prevent mosquitoes from breeding, see Community Mosquito Control. To reduce the danger of being bitten:

  • Wear clothes that completely cover the arms, legs, head, and neck (long sleeves, pants and skirts, and a head covering).
  • Use mosquito coils and repellents like citronella, neem oil, or basil leaf. Repellents are especially important for children because they can prevent mosquito bites even when other preventive steps are not taken.
  • Use screens on windows and doors.
  • Use mosquito netting and bednets treated with insecticide to prevent bites while you or your children sleep. Tuck the edges of the nets under the bed or sleeping mat so there are no openings. In many places, pregnancy care programs offer bednets at low cost or no cost to women and young children. To be effective, bednets must be re-treated every 6 to 12 months. Also use a net when sleeping outdoors.

Note: Bednets are most effective for malaria, and less effective for dengue and yellow fever.