Lesson 5

At the end of this lesson, you should be able to

• identify three ways by which HIV is transmitted;
• dispel misconceptions about HIV transmission; and
• learn how to teach your students the topic “How HIV is Transmitted”

HIV is passed on in the sexual fluids or blood of an infected person. This usually happens by either having sexual intercourse with an infected person or by sharing needles or sharp objects that had come in contact with the blood of an infected person. People can also become infected by being born to a mother who has HIV. A very small number of people become infected by having medical treatment using infected blood transfusions.

Sex with an infected person

HIV transmission occurs most commonly during intimate sexual contact with an infected person, including genital, anal, and oral sex. The virus is present in the infected person’s semen or vaginal fluids. During sexual intercourse, the virus gains access to the bloodstream of the uninfected person by passing through openings in the mucous membrane—the protective tissue layer that lines the mouth, vagina, and rectum—and through breaks in the skin of the penis. In some parts of the world especially the United States and Canada, HIV is most commonly transmitted during sex between homosexual men, but the incidence of HIV transmission between heterosexual men and women has rapidly increased. In most other parts of the world, HIV is most commonly transmitted through heterosexual sex.

Contact with infected blood

Someone can get infected with HIV when transfused with infected blood. Also, infected blood occurs when people who use heroin or other injected drugs, share hypodermic needles or syringes contaminated with infected blood. Sharing of contaminated needles among intravenous drug users is the primary cause of HIV infection in many countries. Less frequently, HIV infection results when health professionals accidentally stick themselves with needles or other sharp objects containing HIV-infected blood or expose an open cut to contaminated blood. To combat this, government regulations have required that all donated blood and body tissues be screened for the presence of HIV before being used in medical procedures. As a result of these regulations, HIV transmission caused by contaminated blood transfusion or organ donations have reduced. However, the problem continues to concern health officials in sub-Saharan Africa. Less than half of the 46 nations in this region have blood-screening policies. By some estimates only 25 percent of blood transfusions are screened for the presence of HIV. The World Health Organisation (WHO) had hoped to establish blood safety programmes in more than 80 percent of sub-Saharan countries by 2003.

Parent-to-Child Transmission

HIV can be transmitted from an infected mother to her baby while the baby is still in the woman’s uterus or, more commonly, during childbirth. The virus can also be transmitted through the mother’s breast milk during breastfeeding. Mother-to-child transmission accounts for 90 percent of all cases of AIDS in children. Mother-to-child transmission is particularly prevalent in Africa, where the number of women infected with HIV is ten times the rate found in other regions. Studies conducted in several cities in southern Africa in 1998 indicate that up to 45 percent of pregnant women in these cities carry HIV.

Misconceptions About HIV Transmission

The routes of HIV transmission are well documented by scientists, but health officials continually grapple with the public’s unfounded fears concerning the potential for HIV transmission by other means. HIV differs from other infectious viruses in that it dies quickly if exposed to the environment. No evidence has linked HIV transmission to casual contact with an infected person, such as a handshake, hugging, or kissing, or even sharing dishes or bathroom facilities. Studies have been unable to identify HIV transmission from modes common to other infectious diseases, such as an insect bite or inhaling virus-infected droplets from an infected person’s sneeze or cough.

Resources: Four posters: Poster A showing HIV transmission through sexual contact with an infected person; Poster B showing HIV transmission through contact with infected blood; Poster C showing mother-to-child HIV transmission; and Poster D showing that HIV cannot be transmitted through hand shake, hugging or sharing dishes and bathrooms facilities.

Procedure: Using charts A, B, and C, lead pupils in interactive discussions on the three major ways of contracting HIV; viz: having sexual intercourse with an infected person; by sharing needles or sharp objects that had come in contact with the blood of an infected person; and being born to a mother who has HIV. Using chart C, dispel misconceptions about HIV transmission. Each pupil to draw a concept map of what he/she learned.  Ask pupils to share what they learned in class with family and friends.

In this lesson, we learned that HIV

• is transmitted by having sexual intercourse with an infected person; by sharing needles or sharp objects that had come in contact with the blood of an infected person; and being born to a mother who has HIV.

·        is NOT transmitted through casual contact with an infected person, such as a handshake, hugging, or kissing, or even sharing dishes or bathroom facilities. Studies have been unable to identify HIV transmission from modes common to other infectious diseases, such as an insect bite or inhaling virus-infected droplets from an infected person’s sneeze or cough.