How HIV is spread HIV INFORMATION. Community AIDS Response. HIV is transmitted through sexual intercourse

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1 How HIV is spread HIV is eneally spread in three ways - Via sexual intercourse - When HIV infected blood is passed directly into the body - From mother to child during pregnancy, childbirth and via breast feedin These are discussed in more detail below. HIV is transmitted through sexual intercourse HIV is transmitted from one person to another through the most intimate of contact- sexual intercourse. The virus is found in high quantities in the sexual fluids (semen and vaginal fluid) of people with HIV infection. In order to gain entry into the body, the virus needs to bind to specific target cells with specific receptors, called CD4 receptors e.g. macrophages, dendritic cells and T4 lymphocytes. These receptors enable the virus to successfully attach and gain entry into the body s cells. The receptor cells are plentiful in the lining of the genital tract and the ano-rectal area. Although the virus can be found in other body fluids, such as saliva, urine and sweat, the quantities of HIV in these fluids are usually too low for successful transmission. HIV infection has not been reported to have been acquired via a healthy mouth or respiratory tract. However it may be possible to transmit the virus if there are fresh sores of inflammation in the mouth. The skin does not have CD4 receptor cells on the surface, and HIV cannot enter through normal, intact (undamaged) skin. HIV is not spread via non-sexual, casual contact between people. Individuals who have not had sexual intercourse, or received or shared blood (or blood products) could not have acquired HIV infection. Children remain free from HIV infection even after intimate contact (hugging, kissing) with their infected parents, and after sharing common utensils, baths, linen etc. The presence of other sexually transmitted diseases makes the sexual transmission of HIV easier It is well established that other genital ulcers or sores, caused by syphilis, chancroid, gonorrhoea, herpes virus and other sexually transmitted diseases (STDs), assist the HIV virus in entering the body. - It appears that the virus can enter through the ulcer itself, and attach to the CD4 receptors. These are present on various inflammatory cells, in and around the ulcer.

2 - HIV can also spread, from the exposed surface of the ulcer, to the genital tract of the sexual partner. - Other STDs, such as gonorrhoea and chlamidial infection, also cause an inflammatory response in the genital tract with a migration of inflammatory cells to the infection. This also promotes the successful transmission of HIV (see also Chapter 12 on STDs and HIV). - The discharges that occur with many STDs have a very high concentration of HIV if the person with the STD is HIV positive. The effective treatment of genital ulcer disease (syphilis, chancroid, herpes) and other STDs can play an important role in the control and prevention of HIV infection. Anal or vaginal intercourse Anal sex appears to be the sexual practice carrying the highest risk for transmitting the HIV virus. The lining of the anal-rectal area is relatively easily torn during anal intercourse. This allows the virus to enter the body more easily. Vaginal sex is also an effective form of transmission. Vaginal and anal sex is safer if a condom is correctly used. It is not yet certain whether anyone has developed HIV infection through oral sex alone, however it may have some risk. Non-penetrative sex, such as sex between the thighs and masturbation, are considered safer. HIV and blood transmission Infection can also occur if HIV-infected blood gains entry into the body. For infection to occur, the blood from an HIV-infected person must bypass the barrier of the skin and enter directly into the body. This means that HIV-infected blood becomes a high risk when passed into the body in the following ways: - Through a blood transfusion - Via blood-contaminated needles, syringes, razor blades and other sharp instruments - Through intravenous drug use (sharing of needles and syringes) - It is also possible but very rare, for HIV to enter the body through an open skin wound or sore. It is important for all blood to be tested for HIV before it is regarded as safe for blood transfusion, it is also important for health care workers to be careful when using sharp instruments, taking

3 blood, putting up drips, doing invasive surgical procedures and handling blood-stained dressings, linen or instruments. Mother and child HIV transmission (MTCT) In recent years a better understanding of MTCT and the ways to prevent it has developed. Pregnancy and childbirth A pregnant mother, who is infected with HIV, can pass on the virus to her infant during pregnancy and childbirth. Research has shown that there is a 20%-40% chance that the infant will become HIV positive, there is approximately a 1 in 3 chance that her infant will be born with HIV infection. It is not yet clear why some women pass the virus on to their babies and why others do not. It appears that a woman is more likely to transmit the virus to her foetus during pregnancy if: - She becomes infected just before of during pregnancy - She has a high HIV viral load - She has symptomatic HIV disease - She has a low CD4 count This means that a symptomatic mother is more likely to pass the virus than a mother who has no symptoms of HIV disease. There are many ways to reduce the risk of MTCT during labour. These include: - The use of anti-retroviral therapy during labour - disinfection of the birth canal (vaginal cleaning) - avoiding unnecessary rupture of the membranes and episiotomy - minimising trauma of the foetus - the mode of delivery (Caesarian section) Breast feeding The issue of infant feeding in low resource and low socio-economic communities is a complex issue. There is an HIV transmission risk to the foetus from breast feeding, and there is also a potential risk to the foetus from gastro-enteritis, malnutrition and other infective condition from unsafe formula feeding. Health care workers will need to carefully inform and advise mothers. Balancing these risks and

4 choosing the most appropriate feeding method is a new challenge o health care workers and to the mothers. The most infectious phases for HIV-infected people A person is more likely to pass on the HIV virus during the following phases: - Soon after becoming infected with the HIV virus (in the first 4-8 weeks) - When there is a high HIV viral load - During the later phases of infection, when symptoms of HIV infection/aids appear This is because there are larger quantities of virus in the blood stream at these times. Remember that it is possible to transmit HIV anytime during the disease. HIV-infected people are considered the most infectious soon after acquiring the HIV infection and during the A Casual contact does not appear to spread HIV There is no good evidence that HIV is spread through normal, everyday, casual contact between individuals. - The HIV virus is not stable and does not survive for long periods outside the human body. - The virus cannot penetrate normal intact skin and does not readily enter through a healthy mouth or eye. - Also the virus is not present in high enough quantities in the saliva and urine to cause infection. - A person with a healthy genital tract is less likely to acquire HIV than a person with genital disease (such as an STD). HIV is not normally transmitted by the following means: - Airborne routes, such as coughing, sneezing, laughing, talking and kissing - Simple skin contact, such as hand-shaking, hugging and touching etc. - Food, water, or on plates, cups, spoons, toilets, baths, pools and showers etc. - Towels, bed linen, clothes, etc. - Insects, such as mosquitoes, are not known to spread HIV from one person to another. The influence of poverty and low socio-economic conditions on the spread of HIV

5 AIDS and other sexually transmitted diseases are often more common in lower socio-economic countries. Some of the reasons why low socio-economic conditions promote the spread of sexually transmitted diseases are as follows: - The relationship between men and women suffer. Women are often exploited and have a more inferior status than men. In many countries women have very little control over their sexual lives, and the ways to prevent STDs. Poverty often makes this sexual exploitation worse, and this further contributes to the spread of sexually transmitted diseases. - High unemployment promotes migrant work and family disruption. People leave their homes and therefore their loved ones, friends, familiar surroundings and local community life. In the faraway places, migrants often find themselves in lonely, unfavourable, hostile or alienating environments. There is a natural need for sex and intimacy resulting in multiple-partner sexual relationships. - Women are often forced to sell sex to earn precious money for food and basic needs, and to help raise their children. Young girls may sell sex to older men. - People in poor living conditions often do not have easy access to heath care services. Sexually transmitted diseases often go untreated and spread more easily. - Poor education and low literacy levels help to keep people ignorant in the ways and means to avoid diseases like AIDS. - People often drink too much alcohol, or smoke dagga (marijuana, zoll, ganja), or use drugs to escape from everyday hardships. This also encourages people to become loose, and to have sex with different people. - Crime and violence is also common in cities and towns, and these further stress the family and community life. - Many of the problems described above also result of the breakdown of the usual traditions, customs, beliefs and the cultural practices in the community. These - practices usually determine the accepted sexual behaviour and constraints in society. When these are broken down, it often results in multiple sexual partners and indiscriminate sexual behaviour. There are many reasons why HIV is spreading. Prevention and care measures need to take account of the socio-economic factors that promote the spread of HIV.