Insecticide treated nets (ITN) are made of a fine mesh cloth dipped in pesticide that are draped over sleeping areas. They are used to prevent the transmission of insect borne diseases, such as malaria and dengue fever. These nets are made of a nylon, cotton, or polyester fabric that allows for the free flow of air, while also keeping insects out. The cloth is treated with the pesticides deltamethrin or permethrin. Treated nets are up to 70 percent more effective in preventing malaria than nets that are not treated.
The insecticide treated nets are hung over the bed or sleeping area so that the entire sleeping surface is covered. Much of the bottom portion of the net is tucked under the mattress or bedding material. It is important to make sure that the netting does not touch the skin of the person sleeping because some insects are able to bite through the cloth. The treated nets will repel most of the flying insects away from the person sleeping under them, creating a bubble of protection around the net.
People traveling in areas that have a high incidence of malaria may want to bring along a pop-up insecticide treated net. Similar to a tent used for camping, a pop-up net is quickly assembled and can be used in many locations. The rectangular box net is used over most beds. These nets are wide, allowing for easy movement out from under the net.
Excessive exposure to sunlight can reduce the insecticide available on the nets. The insecticide treated nets will need to have the insecticide coating reapplied every six months for optimum effectiveness. Some nets will need to have the pesticide applied again after being washed six times. There are nets in development that are treated with a long lasting pesticide, and with these a reapplication of the pesticide is not necessary for up to five years.
Retreating the net is difficult to accomplish in many areas that have a high concentration of malaria cases. These areas are often rural and impoverished. Trained personnel need to be on hand with a large supply of pesticide to treat all the nets. If an untrained person retreats the nets, the pesticide may not be prepared correctly and the insect killing properties of the nets will be nullified. Some governments in malaria prone areas are teaming with non-profit organizations to distribute insecticide treated nets to people that cannot afford to buy one.