Question 1
More than half a million people, mostly children, die from malaria each year. Many of the deaths occur in Africa, but the disease also affects Asian countries such as Indonesia, India and Pakistan.
Malaria is caused by a parasite that is spread by mosquitoes. While malaria can be treated with drugs, it is best to avoid contracting it by preventing mosquito bites.
Mosquitoes are mainly active at night, so organisations such as the World Health Organisation (WHO) seek to supply people in poorer countries with insecticide-treated bed nets (ITNs). The insecticide in the ITN repels or kills mosquitoes, protecting the person sleeping underneath. However, these nets have become less effective over time. The mosquitoes are able to stay around the net longer, increasing the chances of a bite through any small opening in the net. The nets must now be treated with new chemicals to better repel mosquitoes.
Why did the insecticide become less effective against mosquitoes?
Malaria is caused by a parasite that is spread by mosquitoes. While malaria can be treated with drugs, it is best to avoid contracting it by preventing mosquito bites.
Mosquitoes are mainly active at night, so organisations such as the World Health Organisation (WHO) seek to supply people in poorer countries with insecticide-treated bed nets (ITNs). The insecticide in the ITN repels or kills mosquitoes, protecting the person sleeping underneath. However, these nets have become less effective over time. The mosquitoes are able to stay around the net longer, increasing the chances of a bite through any small opening in the net. The nets must now be treated with new chemicals to better repel mosquitoes.
Why did the insecticide become less effective against mosquitoes?
