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How do insecticide-treated bed nets help prevent malaria?

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trypanosome — parasitic disease *Trypanosoma brucei* in a blood smear (Giemsa-stained light photomicrograph).

Insecticide-treated bed nets are a primary tool for preventing malaria, a parasitic disease transmitted by mosquitoes. These nets function by providing a physical barrier that prevents mosquitoes from biting individuals while they sleep, thereby reducing the transmission of the parasite.1

The effectiveness of these nets is enhanced by the insecticide treatment, which kills or repels mosquitoes that come into contact with the netting. There are two main types of these nets:

Standard treated nets: These require re-treatment with insecticide every 6 to 12 months to remain effective.1
Long-lasting insecticide-treated nets (LLINs): These feature insecticide either coated around or incorporated directly into the fibers, allowing them to remain effective for at least three years.1

By reducing human exposure to mosquito bites, these nets have significantly lowered mortality rates in endemic regions. However, their long-term success faces challenges, including the development of insecticide resistance in mosquito populations and concerns that reduced exposure might lower acquired immunity to the disease in some populations.1