Mosquito net

A mosquito net is a type of meshed curtain that is circumferentially draped over a bed or a sleeping area, to offer the sleeper barrier protection against bites and stings from mosquitos, flies, and other pest insects, and thus against the diseases they may carry. Examples of such preventable insect-borne diseases include malaria, dengue fever, yellow fever, zika virus and various forms of encephalitis, including the West Nile virus. A mosquito net is a type of meshed curtain that is circumferentially draped over a bed or a sleeping area, to offer the sleeper barrier protection against bites and stings from mosquitos, flies, and other pest insects, and thus against the diseases they may carry. Examples of such preventable insect-borne diseases include malaria, dengue fever, yellow fever, zika virus and various forms of encephalitis, including the West Nile virus. To be effective the mesh of a mosquito net must be fine enough to exclude such insects without obscuring visibility or ventilation to unacceptable levels. It is possible to increase the effectiveness of a mosquito net greatly by pretreating it with an appropriate insecticide or insect repellent. Research has shown mosquito nets to be an extremely effective method of malaria prevention, averting approximately 663 million cases of malaria over the period 2000–2015. Mosquito netting is mainly used for the protection against the malaria transmitting vector, Anopheles gambiae. The first record of malaria-like symptoms occurred as early as 2700 BCE from China. The vector for this disease was not identified until 1880 when Sir Ronald Ross identified mosquitoes as a vector for malaria. Mosquito netting has a long history. Though use of the term dates from the mid-18th century, Indian literature from the late medieval period has references to the usage of mosquito nets in ritual Hindu worship. Poetry composed by Annamayya, the earliest known Telugu musician and poet, references domatera, which means 'mosquito net' in Telugu. Use of mosquito nets has been dated to prehistoric times. It is said that Cleopatra, the last active pharaoh of Ancient Egypt, also slept under a mosquito net. Mosquito nets were used during the malaria-plagued construction of the Suez Canal. Mosquito netting can be made from cotton, polyethylene, polyester, polypropylene, or nylon. A mesh size of 1.2 millimetres (0.047 in) stops mosquitoes, and smaller, such as 0.6 millimetres (0.024 in), stops other biting insects such as biting midges/no-see-ums. A mosquito bar is an alternate form of a mosquito net. It is constructed of a fine see-through mesh fabric mounted on and draped over a box-shaped frame. It is designed to fit over an area or item such as a sleeping bag to provide protection from insects. A mosquito bar could be used to protect oneself from mosquitoes and other insects while sleeping in jungle areas. The mesh is woven tightly enough to stop insects from entering but loosely enough to not interfere with ventilation. The frame is usually self-supporting or freestanding although it can be designed to be attached from the top to an alternative support such as tree limbs. Mosquito nets are often used where malaria or other insect-borne diseases are common, especially as a tent-like covering over a bed. For effectiveness, it is important that the netting not have holes or gaps large enough to allow insects to enter. It is also important to 'seal' the net properly because mosquitoes are able to 'squeeze' through improperly secured nets. Because an insect can bite a person through the net, the net must not rest directly on the skin. Mosquito netting can be hung over beds from the ceiling or a frame, built into tents, or installed in windows and doors. When hung over beds, rectangular nets provide more room for sleeping without the danger of netting contacting skin, at which point mosquitoes may bite through untreated netting. Some newer mosquito nets are designed to be both easy to deploy and foldable after use. Where mosquito nets are freely or cheaply distributed, local residents sometimes opportunistically use them inappropriately, for example as fishing nets. When used for fishing, mosquito nets have harmful ecological consequences because the fine mesh of a mosquito net retains almost all fish, including bycatch such as immature or small fish and fish species that are not suitable for consumption. In addition, insecticides with which the mesh has been treated, such as permethrin, may be harmful to the fish and other aquatic fauna.