<text><span class="style10">reventing Disease (4 of 4)</span><span class="style7"></span><span class="style10">MALARIA</span><span class="style7">Every year in the tropics, more than 1 million people still die of malaria and 2 million new cases appear, despite worldwide effects to control the disease. The current situation is now more complex and difficult to solve than ever before.All efforts at controlling the disease focus on the mosquito that is the carrier of the malaria parasite. A per-son catches malaria when bitten by a female mosquito. The parasite may then stay dormant in the human liver for months or even years before causing symptoms. There are different types of malaria, some more likely than others to be fatal.Control of the mosquito population helps to control the disease. This is done by destroying breeding sites -still water such as ponds - through land drainage, treating water with chemicals to destroy mosquito larvae, and the use of insecticides to kill mosquitoes.Drugs can be used to treat infected humans, and measures - such as the use of nets, repellents and suitable clothing - can be taken to prevent the mosquito biting.Throughout the 1950s and 1960s the World Health Organization had enormous success in malaria eradication, particularly in the USA and Europe. The program also led to a 500-fold decrease in malaria in India. Unfortunately resistance of mosquitoes to the insecticide DDT then developed and in many areas in the 1970s the eradication began to falter. Some countries still have widespread malaria.Travelers to areas where malaria is prevalent must take anti-malarial tablets before setting out, during their stay, and for at least four weeks after their return. The wide variety of drugs needed to prevent malaria reflects the emergence of the malaria parasite's resistance to certain drugs. This has further hampered control of the disease. Travelers must be careful to match their drug to the exact area they are traveling to in order to ensure its effectiveness.</span></text>
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<text><span class="style10">vercrowded housing</span><span class="style7"> in the past contributed to the rapid spread of diseases such as tuberculosis, while poor sanitation was often a major factor in outbreaks of cholera and typhoid.</span></text>
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<text>ΓÇó FOOD, DIET AND DIGESTIONΓÇó THE IMMUNE SYSTEMΓÇó NON-INFECTIOUS DISEASESΓÇó INFECTIOUS DISEASESΓÇó DRUG ABUSEΓÇó POPULATION AND HUNGERΓÇó THREATS TO THE ENVIRONMENTΓÇó INDUSTRIAL SOCIETY (SOCIAL REFORMS)</text>
