Treatment and use of Insecticide-Treated Mosquito


  1. Preamble

    Sleeping under a bednet reduces the risk of man-vector contact as mosquitoes bite at night and is thus an effective preventive measure. Treating bednets with a suitable insecticide increases their effectiveness as the chemicals repel the mosquitoes and kill those, which come in contact with the treated bednet. If the bed nets are used properly and are not washed, their effectiveness lasts for more than six months. Bednets thus need to be treated twice a year for year round use. In most parts of the country, malaria is seasonal and therefore even a single treatment prior to the transmission season will provide adequate protection during the high-risk period. High coverage with the insecticide treated bednets (ITNs) in an area is thus a cost effective vector control measure besides providing individual protection.

    In many states especially in the eastern and north eastern parts of the country, which are also at high risk of malaria, bed net use is relatively high. Promotion of the use of bed nets by the community procured through commercial outlets and treatment of the community owned bednets is important so as to significantly improve the coverage of ITNs in areas with high risk of malaria. Organization of camps through public/private/NGO partnerships for the treatment of community owned bednets, is being piloted and should be extended to other districts wherever operationally feasible.

  2. Supply of bed nets under NAMP

    Limited supply of bednets for use by those in most need and with limited capacity to buy such nets from the commercial outlets is included in the strategies under NAMP. Areas for bednet distribution should be carefully selected and prioritized based on high risk factors such as high API, high proportion of Pf cases, inaccessibility of the villages or operationally difficult area for indoor residual spray. Preparatory work should be done so that the bed nets are optimally utilized, including identification and recording of the eligible families and health educational activities in the community. Involvement of local community representatives, self help groups and NGOs should be encouraged to promote transparency of operations and optimal use by the community.

  3. Criteria for the selection of villages/ subcentre areas

    The criteria suggested below are for prioritization of village/subcentres for bednet distribution. Higher priority may be accorded to areas where most of the factors given below exist.

    1. Consistently high API, high proportion of Pf cases, and/or reported deaths
    2. Inaccessible (cut off during the high transmission season), remote location
    3. Limited road and public transportation facilities and poor access to facilities for the treatment of severe and complicated cases requiring immediate medical attention
    4. Areas operationally difficult for indoor residual spray (IRS) because of difficult terrain, exophilic vectors (indoor biters but outdoor resters) and practice of frequent mud plastering of walls
    5. Socio-economically disadvantaged
    6. Children of tribal school / ashram school hostels
  4. Criteria for selection of beneficiaries

    Efforts should be made to ensure high coverage of bed net use in the area selected for distribution. As a general rule all houses should be covered, unless the household already have adequate number of bednets, suitable for treatment with insecticide (cotton and HDPE are not suitable). It must be ensured that bed nets for use by pregnant women and young children within the household are available. In a family of 5 persons, two bed nets should suffice, provided there is enough space for hanging the bed nets (including space outside the house if people sleep outside).

    • All houses should be covered
    • Pregnant women and young children should sleep under a net
    • Special high risk groups can be identified such as children in tribal school hostels
  5. Social marketing

    State/ district malaria control society should assess the paying capacity of the community and nominal charges of Rs 10 to Rs 50 may be charged. Free distribution may be made to the most needy and those below the poverty line who are unable to pay. Even nominal payment for the bednets is encouraged as it is expected to lead to a sense of ‘ownership’ and it is more likely that the bednets will used for the purpose for which these have been provided.


  6. Preparatory activities

    It is important that preparatory work is done to ensure optimal use of bednets. The following activities must be completed prior to the distribution of the bednets.


    1. Survey of the area – number of households, number of persons in each household, number of pregnant women and children under 5 years of age
    2. -number of bednets in use -knowledge, attitude and practices
    3. Identification and involvement of community representatives, self help groups, women’s organizations and NGOs
    4. Preparation of the list of beneficiaries
    5. Advocacy among the community for the regular and proper use of bed nets; for ensuring that pregnant women and young children sleep under a bed net; insecticide treatment of the bed nets and proper care of the bed nets
    6. Selection of site(s) and persons for insecticide treatment of the nets. Training of personnel and necessary items required for insecticide treatment should be arranged
  7. Insecticide treatment of the bed nets<

    Ten easy steps are enclosed.

  8. Distribution of the nets
    1. Organize camps for distribution of insecticide treated bednets
    2. Keep records of bednet distribution
    3. Make arrangements for distribution to those who were unable to attend the camp(s)
  9. Post Distribution Activities
    1. Periodic visits may be made to check bed net use
    2. Arrangements for re-impregnation of bed nets annually prior to the high transmission season
    3. Monitoring of fever cases and confirmed cases of malaria
    4. Monitoring of vector densities

Treatment and Use of Insecticide-Treated Mosquito Nets

Why use Insecticide-Treated Mosquito Nets?

  • Malaria and certain other diseases are transmitted by the bite of mosquitoes. Pregnant women, babies and young children are at the greatest risk of dying of malaria.
  • Ordinary untreated mosquito nets provide limited physical barrier between mosquito and man and protection as they may still bite through the net or get inside the net following improper use.
  • Mosquito nets treated with insecticides provide better and effective protection by keeping away mosquitoes as well as killing them. An insecticide-treated mosquito net also kills or keeps away other nuisance insects – cockroaches, bedbugs, houseflies, fleas, etc.

How to treat the net – 10 Easy Steps for Mass Treatment

  • Mass treatment is done at fixed/designated sites.
  • Insecticide treatment is recommended for synthetic nets (nylon, polyester), as treatment of cotton nets is not cost-effective and effect of insecticide is long lasting.

Step 1: Collect the necessary equipment

The necessary equipment consists of: mosquito nets, insecticide, basin, measuring container, rubber gloves, soap.

  • Make sure the net is washed/cleaned before treatment.
  • Preferably, nets should be treated outdoors in the shade. If treatment is to be carried out indoors, a room with open windows should be used.
  • Use basin, gloves that are not used for any other purpose.

Step 2: Put on protective gloves before treating nets

Step 3: Measure the correct amount of water

The amount of water needed depends on the net material. Regardless of the size and shape of net, the amount of water required for:

  • One synthetic net (nylon, polyester) – ½ litre (if the net is very large, more water may be needed).

ü If measuring container comes with insecticide, use it to measure water. Otherwise, use any measuring container, that is not used for food, drinks, medicines.

Step 4: Measure the correct amount of insecticide

  • The amount of insecticide or “dose” needed to treat a net depends on type of insecticide used. Follow instructions on the container, sachet, packet. Generally, 10-15 ml of insecticide is required to treat one net.

    Ø [BIS Number of Liquid Synthetic Pyrethroid used for treatment of Bed Nets -

    i) Deltamethrin – IS14411: 1996; ii) Cyfluthrin – IS14156: 1994].
  • Store leftover insecticide in its original container, in the dark and away from children.

Step 5: Mix the water and insecticide thoroughly by gloved hands in basin

Step 6: Treatment of nets

  • Always treat one net at a time. Put the net in the basin containing water and insecticide. Soak the net long enough to ensure that all parts of the nets are impregnated. Take out the nets and allow excess liquid to drip back. Do not wring the treated net.

Step 7: Drying the nets

  • Let the net dry flat in the shade on plastic sheets. Later, the net can be hung up to finish drying in the shade.

Step 8: Disposal of leftover mixture of water and insecticide and insecticide containers

  • Following treatment of all available nets, leftover mixture of water and insecticide, if any, may be used to treat curtains. Otherwise, dispose the liquid in the toilet or a hole away from habitation, animal shelters, drinking water sources, ponds, rivers, streams. Destroy empty insecticide containers, sachets, packets and/or bury in a hole away from habitation, animal shelters, drinking water sources, ponds, rivers, streams.

Step 9: Washing and cleaning of hands, equipments

  • Wash equipments (basin, measuring container) with lots of water while wearing protective gloves. Wash gloves (if non-disposable ones are used)] with soap and lots of water, or dispose with insecticide containers. Wash hands with soap and lots of water.

Step 10: Washing and re-treatment of nets

  • Washing removes insecticide from the net. So, wash the nets as seldom as possible and gently with soap and cold water and dry flat on plastic sheet in shade.

    ü Do not wash/rinse treated net in or near drinking water sources, ponds, lakes, rivers, streams. Dispose of water for washing/rinsing in the toilet or in a hole away from habitation, animal shelters, drinking water sources, ponds, rivers, streams

  • Nets must be re-treated again after it has been washed three times. Or, at least once a year even if it is not washed, preferably just before the rainy season. Nets may be treated twice a year in areas that have a lot of mosquitoes all year long. Remember:
  • Use the insecticide-treated net every night, all year round, even if mosquitoes are not seen/heard.
  • Preferably, everyone should sleep under a treated mosquito net. Or, at least pregnant women and children under five years must sleep under treated net.
  • Insecticides used for mosquito nets are not harmful to people, if used correctly. Direct skin contact with the insecticide on a still wet net may cause a tingling sensation on the skin. This is not harmful, even for small children.
  • After treatment, the net may smell of insecticide. This will go away in a few days and is not harmful to people who sleep under the net.