infect: to cause someone to have a disease or illness
resistant: not harmed by something
parasite: a plant or animal that lives in or on another plant or animal and gets its
food from it
prevent: to stop something from occurring
FIGHTING DISEASES 15
BEFORE YOU READ
Read these questions. Discuss your answers in a small group.
1. Have you ever been very sick? What did you do to get well? How long did it take you to get well?
2. What are some ways to prevent an illness?
3. Do you know of any insects that are helpful to humans? How do they help? Do you know of any insects that are harmful to humans? How are they harmful?
READ
This article includes information from the Centers for Disease Control and Prevention (CDC), the principal public health agency in the United States. It was founded in 1946 to help control malaria. Today, the CDC leads public health efforts to prevent and control infectious diseases.
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The Battle Against Malaria
Malaria is a serious health problem. It is a leading cause of death in many countries.
It occurs mostly in tropical and subtropical parts of the world, including parts of Africa, Asia, South America, Central America, and the Middle East. The place most intensely affected by malaria is Africa south of the Sahara Desert.
About 60% of the world’s malaria cases and 80%
of malaria deaths occur there. Even though the causes of malaria in this region are well understood, international health agencies are finding that controlling it is still an enormous and difficult task.
Because malaria is passed from mosquitoes to people and from people to mosquitoes, we can think of the disease as a cycle!. The malaria cycle begins with tiny parasites that reside in the bodies of Anopheles mosquitoes. These deadly parasites cause malaria. When a female mosquito bites a human, the mosquito draws off blood.
It also leaves malaria parasites in the human’s skin. These parasites quickly multiply inside the human and cause the individual to feel sick.
If a mosquito bites a human who is sick with malaria, parasites from the human enter the
‘cycle: a series of events that always recur in the same order
UNIT 2
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body of the mosquito. When that mosquito bites another human, it will leave parasites in the other human’s skin. In the malaria cycle, humans get parasites from mosquitoes and they also give parasites to mosquitoes.
Becoming infected with malaria is a medical emergency. The first symptoms of malaria are fever, chills, sweating, intense headache, and muscle pains. Nausea and vomiting often accompany these symptoms. Immediate medical treatment must be a priority for people who are infected. They must take medicines that will kill the parasites. If
medical treatment is started soon enough, sick individuals can be cured. If they do not, malaria can cause serious illness or even death.
Breaking the malaria cycle in Africa
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Malaria in tropical Africa could be controlled It is very difficult, however, to implement in two ways. First, it could be controlled by these plans. People in this region are poor—and killing the parasites that cause the illness. If made poorer by malaria because they may be every infected person quickly took malaria too weak to work. They cannot afford to pay medicine, most would be well in a few days. 70 for medical care or to buy bed nets. If they are Mosquitoes could not get malaria parasites from not educated, the people may be unwilling to healthy individuals, so malaria would not spread. cooperate with government efforts to help Unfortunately, many people live in far-away them. Their old beliefs about illness may villages without access to quick medical care. conflict with modern attempts to cure or Another problem is that the ability of quinine 75 prevent malaria.
(the primary medicine used against malaria) to There are other problems, too. Health kill parasites has declined over time. There ministries do not have the money to build
is hope, however, for a new drug combination, clinics or hire trained medical practitioners.
called ACT. It is being used successfully to treat They do not have the money to buy insecticide
people who have malaria. so and pay a labor force to spray regularly. And the
Malaria could also be controlled by stopping frequent rainfall would make it impossible to get
the mosquitoes. One way would be to get rid rid of pools of water where mosquitoes lay eggs.
of the pools of water where they lay their eggs. Helping African nations control malaria is Also, insecticide? could be sprayed in wet areas now a top priority of many relief organizations.
and around buildings to kill mosquitoes. Finally, ss The World Health Organization and Doctors people could be told to sleep under bed nets to Without Borders are just two of many
prevent mosquitoes from biting them at night. organizations offering help—and hope—to the Bed nets sprayed with insecticide would both people of sub-Saharan A frica.
stop and kill mosquitoes.
? insecticide: a poison that kills insects
READING COMPREHENSION
Mark each statement as 7 (True) or F (False) according to the information in Reading 1. Use your dictionary to check the meaning of new words.
sbi 1. Malaria occurs mostly in tropical and subtropical parts of the world.
ci 2. Deadly malaria parasites reside in the bodies of mosquitoes.
am 3. Intense coughing and sneezing often accompany the fever of malaria.
ses 4. Old beliefs may conflict with modern ways to cure or prevent illness.
sess 5. Getting fast medical attention after becoming ill is a priority.
vest 6. Sleeping under bed nets would lead to a decline in malaria.
Xem 7. Health ministries in poor countries often cannot afford to implement plans to control malaria.
— 8. Most people in tropical Africa have easy access to medical practitioners.
9. Educated people are not willing to cooperate with government plans to help them.
wu 10. A large labor force would be needed to spray insecticide regularly.
FIGHTING DISEASES 17
READING STRATEGY: Finding the Main Idea
The topic of an article refers to what the article is about. The mazn idea of an article goes one step further. The main idea includes the topic and also what the writer wants to say about the topic. For example,
Topic Main idea
vegetables several reasons why kids hate vegetables The main idea of an article is often clearly stated in the first paragraph, usually in the first or last sentence. It can also be stated in the second paragraph or in the last paragraph, which often summarizes the article. The main idea may be a full sentence or just a few words.
Each paragraph in an article contributes its own facts, definitions, and examples that help explain the main idea of the article. This means that each paragrah has its own main idea, which is often in the first sentence of the paragraph.
A. Reread the first paragraph of Reading 1. Find the sentence that tells you the main idea—what the writer wants to say about malaria—and circle it. Then, write the most important part of the sentence here, as the main idea.
B. Reread paragraph 2 and find the sentence that states the main idea. What is the main idea?
Circle your answer here.
a. The beginning of the malaria cycle b. Anapheles mosquitos
c. Parasites in the human’s skin
C. Reread paragraph 4 and find the sentence that states the main idea. What is the main idea?
Circle your answer here.
a. Malaria can cause death
b. Becoming infected is a medical emergency c. Sick people must take medicine
D. Reread paragraph 7 and find the sentence that states the main idea. What is the main idea?
Circle your answer here.
a. The people of the region need education about malaria b. Plans to prevent malaria are difficult to implement
c. Malaria makes people more poor because they cannot work