Malaria, still a major killer in Africa
Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. Malaria is caused by a parasite that is passed from one human to another by the bite of infected Anopheles mosquitoes. After infection, the parasites (called sporozoites) travel through the bloodstream to the liver, where they mature and release another form, the merozoites. The parasites enter the bloodstream and infect red blood cells. Malaria can also be transmitted from a mother to her unborn baby (congenitally) and by blood transfusions. Malaria can be carried by mosquitoes in temperate climates, but the parasite disappears over the winter. Every 60 seconds a child dies of Malaria. It remains one of the major disease burdens globally with over 200 million cases per year and over 650,000 deaths, predominantly in children under 5 in Africa. The estimated annual cost to the African continent is over US$ 1-billion. In the past 10 years, a concerted drive to control malaria has been put into effect in many African countries with the support of the Global Fund for Aids, TB and Malaria; the Presidents Malaria Initiative, the World Bank and several international donor funding agencies like the Bill and Melinda Gates Foundation, the EU and the Wellcome Trust. Over the past two decades there has been a global effort by scientists, health workers, governments, and private organizations to better understand Plasmodium parasites, the transmission of this disease, and to find better preventative and treatment options, with the hope of mitigating this global killer. World Malaria Day is commemorated annually on 25 April....
In spite of widespread problem of antimalarial drug resistance, use of drug remains the most effective option for malaria treatment. Chloroquine, historically the first-line drug for the treatment of malaria, is readily available and usually affordable in most African countries.
The use of insecticide-treated nets (ITN) and house spraying represent a quantum leap on the use of physical barriers and chemicals in malaria control. Mosquito nets treated with pyrethroid insecticides provide a remarkable degree of protection against malaria in Africa. Excellent results were obtained from field trials in Ghana, the Gambia, Kenya and Tanzania. It was showed that both methods reduced the prevalence of anaemia and the number of malaria-infective mosquitoes biting each night by 90%. ITN reduces child mortality and the incidence of mild and severe malaria. Implementation of ITN programmes should be encouraged and supported as widely as possible in Africa.
Today, malaria occurs mostly in tropical and subtropical countries, particularly in Africa south of the Sahara, South-East Asia, and the forest fringe zones in South America. The ecology of the disease is closely associated with the availability of water, as the larval stage of mosquitoes develops in different kinds of water bodies. The mosquito species vary considerably in their water-ecological requirements, (sun-lit or shaded, with or without aquatic vegetation, stagnant or slowly streaming, fresh or brackish) and this affects the disease ecology.
The construction of irrigation systems and reservoirs in some parts of the world can have a dramatic impact on malaria distribution and on the intensity of its transmission....