In recent years, the spread of malaria seems renewed, especially in parts of sub-Saharan Africa. The global health community was once confident at their control of this disease, with many successes in ridding large areas of malaria over the previous decades; but now increasingly large numbers of people are dying from the mosquito-borne ailment. Forty percent of the world's population live in the malaria-infected areas, and it also brings around 260 million new cases.
The resurgence of malaria is occurring in several parts of the world. However, it is most acute in Africa, south of the Sahara Desert, where according to a 1993 World Health Organization (WHO) report, between 1.4 and 2.8 million people, half of their children, now die each year from the disease. This is triple the annual number of people in the same region who die of AIDS. Actual numbers of malaria deaths may be even larger because the symptoms, such as chronic fever, are often mistaken for other, unrelated illness, such as influenza or pneumonia.
In the 1950s, subtropical regions in the United States, Southern Europe and elsewhere were sprayed with DDT, which eliminated the malaria parasite where used appropriately but resulted in resistant mosquitoes where sprayed too often. No only could mosquitoes have resistance to the drugs applied on them but people also are able to build up their immune system. Take people who live in the countryside of Africa for example, 5 percent of children die of malaria, and the many who survive it go on to become adults with a high degree of natural resistance.
Health workers, discouraged by the diminishing effectiveness of malarial drugs, are seeking to promote physical barriers to infection rather than chemical ones. The concept of mosquito nets hung over beds to keep mosquitoes away is certainly not new, but recent efforts to improve them have led to some success in protecting people from malaria. In experiments in Gambia, the number of children dying from malaria has dropped 50 percent since using nets soaked in insecticide. To remain effective, the nets need to be re-soaked only twice a year, and no drugs need to be taken for prevention. The nets provide additional benefits to the families who use them in that they prevent other types of irritating insects from getting close.
Whether or not mosquito nets would be effective on a large scale remains to be seen, as conditions vary from place to place. Some users complaint it is too hot under the nets to be able to sleep. Furthermore, their cost limits the number of people who can take advantage of them.
Thus, the search for a vaccine for malaria continues. Manuel Patarroyo, a medical researcher from Colombia, stated in 1993 that he had been successful in trying a new vaccine on some 20,000 people in South America. Similar testing of the vaccine is being done in Africa, but health officials are not convinced it will be effective because the rate at which new cases of malaria develop is many times higher than that in South America. Complete the sentences below with words taken from the above passage. Please don't fill in more than one word for each blank space.
malaria: a common hot disease of hot countries, passed by the bite of certain mosquitoes.
AIDS: Acquired Immune Deficiency Syndrome; a very serious disease caused by a virus which breaks down the body's natural defense against infection.
pneumonia: a serious disease of the lungs with inflammation and difficulty in breathing
immune system: the bodily system by which special substances are produced to fight against disease-causing substances that have entered the body
vaccine: a poisonous substances used for protecting people against disease.
You should spend about 30 minutes on this task.
Some people believe that university students should gain some working experience or travel abroad to broaden their vision before going to graduate school. What are the advantages and disadvantages regarding to it and what is your opinion?