AIDS Health Article

Definition

Acquired immune deficiency syndrome (AIDS) is an infectious disease caused by the human immunodeficiency virus (HIV). It was first recognized in the United States in 1981. AIDS is the advanced form of infection with the HIV virus, which may not cause disease for a long period after the initial exposure (latency). Infection with HIV weakens the immune system which makes infected people susceptible to infection and cancer.

Description

AIDS is considered one of the most devastating public health problems in recent history. In 1996, the Centers for Disease Control and Prevention (CDC) estimated that one million persons in the United States were HIV-positive, and 223,000 are living with AIDS. Of these patients, 44% were gay or bisexual men, 26% are heterosexual intravenous drug users, and 18% were women. In addition, approximately 1,000-2,000 children are born each year with HIV infection. In 2002, the CDC reported 42,136 new AIDS diagnoses in the United States, a 2.2% increase from the previous year. AIDS cases rose among gay and bisexual men (7.1% in 25 states that report regularly). The disease also seems to be rising among older Americans. From 1990 to 2001, the number of cases in Americans age 50 years or older rose from 16,288 to 90,153.

The World Health Organization (WHO) estimates that 40 million people worldwide were infected with AIDS/HIV as of 2001. Most of these cases are in the developing countries of Asia and Africa. In 2003, WHO cautioned that if treatment were not delivered soon to nearly 6 million people with AIDS in developing countries, there could be 45 million cases by 2010.

Risk factors

AIDS can be transmitted in several ways. The risk factors for HIV transmission vary according to category:

• Sexual contact. Persons at greatest risk are those who do not practice safe sex, are not monogamous, participate in anal intercourse, and have sex with a partner with symptoms of advanced HIV infection and/or other sexually transmitted diseases (STDs). In the United States and Europe, most cases of sexually transmitted HIV infection have resulted from homosexual contact, whereas in Africa, the disease is spread primarily through sexual intercourse among heterosexuals.
• Transmission in pregnancy. High-risk mothers include women married to bisexual men or men who have an abnormal blood condition called hemophilia and require blood transfusions, intravenous drug users, and women living in neighborhoods with a high rate of HIV infection among heterosexuals. The chances of transmitting the disease to the child are higher in women in advanced stages of the disease. Breast feeding increases the risk of transmission by 10-20% and is not recommended. The use of zidovudine (AZT) during pregnancy and delivery, however, can decrease the risk of transmission to the baby.

• Exposure to contaminated blood or blood products. With the introduction of blood product screening in the mid-1980s, the incidence of HIV transmission in blood transfusions has dropped to 1 in 100,000.
• Needle sticks among health care professionals. Present studies indicate that the risk of HIV transmission by a needle stick is about 1 in 250. This rate can be decreased if the injured worker is given AZT or triple therapy (HAART), the current standard.

HIV is not transmitted by handshakes or other casual non-sexual contact, coughing or sneezing, or by bloodsucking insects such as mosquitoes.