Managing mozzies

Introduction Vector-borne diseases Pacific Regional Vector Borne Disease Project Introduction Have you ever been bitten by a mosquito? You may have been in bed and heard a buzzing and then silence … You may have been outside in the evening and seen them swarm. You probably felt itchy and noticed a red lump which lasted a couple of days. Unfortunately, some types of mosquitoes transmit very nasty diseases which can cause awful sickness, prevent people from working or going to school, and can even cause death. Vector-borne diseases A vector is an organism that spreads infection by passing on pathogens (a disease-causing agent) from one host to another. Mammals, birds and insects may all be vectors, but by far the most common vector is the mosquito. When the mosquitoes bite humans they inject a microscopic pathogen. When other mosquitoes bite an infected human, the pathogen is transferred to those mosquitoes where it develops in their bodies and is then passed on to other humans they bite. The most deadly vector-borne disease, malaria, kills over one million people annually, mostly African children under the age of five. Dengue fever, together with associated dengue haemorrhagic fever (DHF), is the world's fastest growing vector-borne disease. Poorly designed irrigation and water systems, inadequate housing, poor waste disposal and water storage, deforestation and loss of biodiversity may all be contributing factors to the most common vector-borne diseases. Malaria Malaria causes at least 300 million cases of acute illness and one million deaths each year in tropical and subtropical areas. It is transmitted by the Anopheles mosquito which only bites during the night. A bite by a mosquito carrying malaria leads to infection in the liver and red blood cells. This causes fever, headaches, vomiting and other flu-like symptoms about two weeks after being bitten. Malaria needs to be treated with drugs to avoid it becoming life threatening. New drugs (artemisinin-based combination therapies - ACTs) are available to treat the drug resistant forms of malaria. Prevention and control of malaria can be through limiting mosquito breeding areas of stagnant water, spraying around homes, preventing mosquito bites, and sleeping under mosquito nets treated with insecticide. Helping reduce malaria - children using bed nets on Alor, Indonesia © AusAID Dengue Dengue affects 2.5 billion people in over 100 tropical and subtropical countries, predominantly in urban and semi-urban areas. It is caused by one of four related viruses carried by the Aedes mosquito, a mosquito which bites during the day. Starting as a flu-like illness, dengue can develop into the deadly dengue haemorrhagic fever (DHF). Most cases of dengue haemorrhagic fever occur in children under the age of 15. Since there is no curative treatment, environmental management is important. George Taleo, from the Vanuatu Public Health Department initiated a program to collect old tyres to limit the breeding grounds of mosquitos carrying dengue fever. © Peter Davis/AusAID Lymphatic filariasis Lymphatic filariasis, known as elephantiasis, puts at risk more than a billion people in more than 80 countries in the tropics and subtropics. The thread-like parasitic filarial worms that cause lymphatic filariasis lodge in the lymphatic system, where they produce millions of immature microfilariae (minute larvae) that circulate in the blood. It may take many years to develop the distinctive enlarged limbs or genitalia. Pacific Regional Vector Borne Disease Project Vector-borne diseases such as malaria, dengue and lymphatic filariasis cause not only health problems, but also economic hardship for people and countries. People have costs of insecticide-treated nets, medicines, hospitalisation and travel to hospital - if they are lucky enough to be able to access these. Families also suffer the loss of income, either short term during the illness or long term if the income earner dies. Government costs include spending on maintaining health facilities and health care infrastructure, publicly managed vector control, education and research, as well as the loss of income from taxes on earnings or reduced tourism and export income. The Australian Government worked with the governments of Fiji, Solomon Islands, Vanuatu and other Pacific islands through the Pacific Regional Vector Borne Disease Project. The project aimed to: reduce the number of people becoming ill (morbidity) and dying (mortality) from vector-borne diseases prevent and control the incidence and spread of vector-borne diseases. The project fought mosquitoes on every front. It provided microscopes and trained workers in how to use them to test blood samples, so that diseases could be identified quickly for the appropriate response. Local communities undertook cleanup campaigns to dispose of sources where mosquitoes breed - discarded cans, car tyres and coconut shells, etc. Communities were educated about the types of mosquitoes and about disease prevention. The project assisted people to see they could act and help combat the effects of vector-borne diseases, rather than simply accepting illness as a part of life. Ongoing costs for insecticides and taking education and treatment to rural areas are still needed to extend the value of the project.