Preventing HIV Infection You can choose behaviors that reduce your risk of becoming infected with HIV. The only no-risk behavior with respect to HIV transmission is abstinence from sexual activity and intravenous drug use. Within a committed relationship, such as marriage, sexual fidelity between two uninfected partners presents the least risk of becoming infected with HIV. People who share needles to inject themselves with drugs are at a high risk for contracting HIV. For this reason, people who have sex with drug abusers are also at high risk. Before 1985, HIV was transmitted to some patients through transfusions of infected blood or blood products. But, such cases have been virtually eliminated by screening the blood supply for HIV antibodies and by discouraging potentially infected individuals from donating blood.

Can AIDS Be Cured? At present, there is no cure for AIDS. A steady stream of new drugs makes it possible to survive HIV infection for years. Unfortunately, HIV mutates and evolves rapidly. For this reason, the virus has evolved into many strains that are resistant to most drugs used against them. No one has developed a vaccine that offers protection for any length of time.

FIGURE 35–19 Adolescents and Young Adults Living With AIDS in the United States

d

At present, the only way to control the virus is to use a combination of expensive drugs that fight the virus in several ways. Current drugs interfere with the enzymes HIV uses to insert its RNA into a host cell, to convert RNA to DNA, and to integrate its DNA into the host's DNA. Because of these drugs, more people infected with HIV in the United States are living with HIV rather than dying from it. In many parts of Africa and Asia, however, these expensive drugs are not available.

Unfortunately, the knowledge that HIV can be treated (though not cured) has given some people the misconception that HIV infection is not serious. That idea is dead wrong.

35.4 Assessment

Review Key Concepts

1. 1. Review What happens during an allergy attack? What happens in an autoimmune disease?

   2. Apply Concepts In treating asthma, the first thing many physicians do is ask patients to list times and places they have experienced attacks. Why do you think physicians do this?

2. 1. Review What is the virus that causes AIDS? Describe how it is spread.

   2. Infer Why is it difficult for a person with HIV to fight off other infections?

ANALYZING DATA

Review Figure 35–19 and answer the following questions.

3. 1. Interpret Data What percent increase in AIDS cases occurred in 13–24-year-olds from 2002 to 2006?

   2. Draw Conclusions What are two conclusions that you could draw regarding the increasing number of adolescents and young adults living with AIDS?

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