Do Mosquito Nets Prevent Malaria?
WouterDuring the late 19th century, the Anopheles mosquitoes transmitted malaria to humans. In the late 20th century, bed nets became a key malaria prevention tool. They prevent mosquitoes from biting and killing people when they sleep. They also reduce mosquito availability during foraging.
The question of whether mosquito nets prevent malaria remains controversial. Studies in different countries indicate that bed nets are effective in reducing morbidity and mortality from malaria. However, the amount of entomological and epidemiological evidence for the benefits of untreated nets is considerably less than for insecticide-treated ones.
Untreated nets were widely used in The Gambia during the mid-1990s. They significantly reduced the prevalence of malaria parasitemia, and prevented 35% of clinical disease. They were also associated with a lower prevalence of Plasmodium falciparum infection.
The World Health Organization conducted trials in five African countries. They found that insecticide effectiveness varied from 1 percent to 100 percent. They concluded that untreated nets were effective in preventing malaria, but were not completely effective in protecting humans.
High coverage of treated and untreated nets might lead to a reduction in mosquito survival because of predation and delayed host-finding. However, high population coverage is also a major factor in reducing malaria vector survival. This is because it increases the duration of host-seeking.
Insecticide-treated bed nets are the most important malaria control tools. They are used in communities where malaria transmission is high. They prevent mosquitoes from biting by blocking them from penetrating the webbing. They are also used by pregnant women to avoid malaria.
