OBJECTIVE Kenya WASH Cluster Training for Emergencies Oct 2008 3.06 - Vector Control in emergencies To provide practical guidance and an overview of vector control in emergency situations It will introduce the skills required to plan and implement a vector control project in an emergency situation The importance of vector control in emergencies Effects of natural disasters Some disasters give rise to increased numbers of vectors Malaria is one of the leading causes of mortality in emergency situations Flies are involved in the transmission of diarrhoeal disease, fly control has a positive impact on health in most postdisaster situations, particularly when sanitary conditions are poor and diarrhoeal diseases are high. Other vectors may be important in specific locations, depending on the prevalence of the vector and the disease before the disaster, and the susceptibility of the population. Definitions vector : any arthropod or animal which carries and transmits infectious pathogens directly or indirectly Biological vector The pathogens in the infested host, are ingested by the vector. Mechanical vector the causative agent is transported from contaminated material on their feet or mouth parts Mosquitoes two subfamily: The anopheline subfamily including the Anopheles (malaria and filariasis.) The culicine subfamily Includes the Aedes, Culex. (Aedes yellow fever, and dengue) only the female mosquito takes blood-meals from animals and/or humans.
Mosquitoes Breeding places (Anopheles) Mosquitoes Breeding places (Culex) Mosquitoes Breeding places (Aedes) Service de Lutte Anti-Vectorielle DRASS de La Réunion Malaria Malaria remains one of the main global health problems of our time more than 1 million deaths per year, about 90% of deaths and 60% of cases occurring in Africa south of the Sahara Anopheles (some facts) Is usually a night and indoor biter (bites between sunset and sunrise) Can fly around 2 km Can breed in a foot print with clean water (if print contain water for at least 10 days) Will not breed in latrines, containers, etc Can only transmit malaria after having bitten a person affected by malaria The risk of contracting malaria is highly variable from country to country and even between areas in a country.
Malaria parasites Life cycle of the parasite 4 different parasites from which Plasmodium falciparum and P. vivax are the most common. P. falciparum malaria can be fatal. Malaria control The WHO Global Malaria Programme recommends the following three primary interventions for effective malaria control 1. diagnosis (and treatment with effective medicines) 2. distribution long-lasting insecticidal nets (LLINs), 3. indoor residual spraying (IRS) Flies The species Musca domestica (Housefly), Musca sorbens (Facefly), and Chrysomya sp. (Blowfly), are considered to be of medical importance transmit diseases by transporting pathogens between people or from faeces to food causing diarrhoeal diseases and trachoma. Fly life cycle Musca domestica breed in animal excrement in rural areas. In urban areas they breed in organic domestic waste. They land on both faeces and human food, and feed on both. Contrary to popular belief, these flies do not lay their eggs in latrines
Musca domestica (cont.) Control Measures for emergency situation responsible for carrying pathogens of infantile diarrhoea, shigellosis diarrhoea, dysentery, typhoid, and alsointestinal worm eggs. It has been proved in Pakistan and in the Gambia that fly control reduced incidence of diarrhoea by about 24 %. must be both effective and economically acceptable. Options: chemical and environmental control Environmental control chemical control measures should always complement environmental control measures in the acute phase of an emergency 1. excreta disposal, 2. solid waste management, 3. waste water disposal, 4. site drainage. Principal Control Measures applicable in emergency situation (cont) Chemical control measures 1. IRS 2. Space spraying 3. Larviciding Indoor Residual spraying
Larvicide Mosquito nets WHO Decision to carry out a vector control based on specific health problem The WHO Global Malaria Programme is calling for; purchase only LLIN distribute free or highly subsidized LLINs, achieve full LLIN coverage, promote effective use of LLINs; Important factors The effectiveness of a vector control programme will be based on the following factors: A clear understanding of basic entomology and identification of the vector A clear understanding of chemical selection, chemical use and its dangers. (WHOPES) Knowledge of application equipment. Knowledge of safety measures. Training needs 3 to 5 day training courses should be enough to cover spraying techniques. Also cover simple health education, safe use of insecticide including first aid, and equipment maintenance
Logistic needs Hand-compression sprayers Good logistical support is vital Eg for cleaning the equipment, soak pits for disposal of the polluted water, preparation of the solutions transport of personnel, equipment Backpack motorised mistblowers Personnel protection and safe use of pesticide 34 Some important notes for IRS Each level of the control programme must be well supervised. All personnel must receive a training course, for the chemical use and the manipulation of the equipment. All personnel should wear protective clothing and individual equipment. Clothes must be removed immediately after work. Avoid long exposure of the person spraying, 4 hours is a maximum and team rotation should be planned. Never spray in windy conditions. Workers must take showers after work, and immediately after accidental contact with chemicals. Each worker should leave his/her protective clothing at the base to be properly washed by skilled personnel. 35
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