- Sexual transmission
- Transmission through blood
- Mother-to-child transmission
For each route of transmission there are things that an individual can do to reduce or eliminate risk. There are also interventions that have been proven to work at the community, local and national level.
Wherever there is HIV, all three routes of transmission will take place. However the number of infections resulting from each route will vary greatly between countries and population groups. The share of resources allocated to each area should reflect the nature of the local epidemic – for example, if most infections occur among men who have sex with men then this group should be a primary target for prevention efforts.
“Knowing your epidemic in a particular region or country is the first, essential step in identifying, selecting and funding the most appropriate and effective HIV prevention measures for that country or region.” – UNAIDS guidelines for HIV prevention
HIV prevention should be comprehensive, making use of all approaches known to be effective rather than just implementing one or a few select actions in isolation. Successful HIV prevention programs not only give information, but also build skills and provide access to essential commodities such as condoms or sterile injecting equipment. It should be remembered that many people don’t fit into only one “risk category”. For example, injecting drug users need access to condoms and safer sex counseling as well as support to reduce the risk of transmission through blood.
Anyone can become infected with HIV, and so promoting widespread awareness of HIV through basic HIV and AIDS education is vital for preventing all forms of HIV transmission. Specific programs can target key groups who have been particularly affected by a country’s epidemic, for example children, women, men who have sex with men, injecting drug users and sex workers. Older people are also a group who require prevention measures, as in some countries an increasing number of new infections are occurring among those aged over 50.
HIV prevention needs to reach both people who are at risk of HIV infection and those who are already infected:
- People who do not have HIV needs interventions that will enable them to protect themselves from becoming infected.
- People who are already living with HIV needs knowledge and support to protect their own health and to ensure that they don’t transmit HIV to others – known as “positive prevention”. Positive prevention has become increasingly important as improvements in treatment have led to a rise in the number of people living with HIV.
HIV counseling and testing are fundamental for HIV prevention. People living with HIV are less likely to transmit the virus to others if they know they are infected and if they have received counseling about safer behavior. For example, a pregnant woman who has HIV will not be able to benefit from interventions to protect her child unless her infection is diagnosed. Those who discover they are not infected can also benefit, by receiving counseling on how to remain uninfected.
The availability and accessibility of antiretroviral treatment is crucial; it enables people living with HIV to enjoy longer, healthier lives, and as such acts as an incentive for HIV testing. Continued contact with health care workers also provides further opportunities for prevention messages and interventions. Studies suggest that HIV-positive people may be less likely to engage in risky behavior if they are enrolled in treatment programs.
Someone can eliminate or reduce their risk of becoming infected with HIV during sex by choosing to:
- Abstain from sex or delay first sex
- Be faithful to one partner or have fewer partners
- Condomise, which means using male or female condoms consistently and correctly
There are a number of effective ways to encourage people to adopt safer sexual behavior, including media campaigns, social marketing, peer education and small group counseling. These activities should be carefully tailored to the needs and circumstances of the people they intend to help.
Comprehensive sex education for young people is an essential part of HIV prevention. This should include training in life skills such as negotiating healthy sexual relationships, as well as accurate and explicit information about how to practice safer sex. Studies have shown that this kind of comprehensive sex education is more effective at preventing sexually transmitted infections than education that focuses solely on teaching abstinence until marriage.
Numerous studies have shown that condoms, if used consistently and correctly, are highly effective at preventing HIV infection. Also there is no evidence that promoting condoms leads to increased sexual activity among young people. Therefore condoms should be made readily and consistently available to all those who need them.
There is now very strong evidence that male circumcision reduces the risk of HIV transmission from women to men by around 50%, which is enough to justify its promotion as an HIV prevention measure in some high-prevalence areas. However, studies of circumcision and HIV suggest that the procedure does not reduce the likelihood of male-to-female transmission, and the effect on male-to-male transmission is unknown.
Some sexually transmitted infections – most notably genital herpes – have been found to facilitate HIV transmission during sex. Treating these other infections may therefore contribute to HIV prevention. Trials in which HIV-negative people were given daily treatment to suppress genital herpes have found no reduction in the rate at which they become infected with HIV. Nevertheless, there is evidence to suggest that treating genital herpes in HIV positive people may reduce the risk of them transmitting HIV to their partners. Further research is ongoing.
It is usually not easy for people to sustain changes in sexual behavior. In particular, young people often have difficulty remaining abstinent and condoms are often associated with promiscuity or lack of trust. Women in male-dominated societies are frequently unable to negotiate condom use, let alone abstinence.
Gender imbalances need to be addressed to prevent HIV transmission among serodiscordant couples (where one partner is HIV positive and one is HIV negative). This group account for many new infections around the world and have become central to prevention programs for people living with HIV. In addition, many discordant couples are compelled to have unprotected sex in order to have children. Without receiving counseling and treatment the HIV negative partner may be at greater risk of becoming infected with HIV.
Some societies find it difficult to discuss sex openly, and some authorities restrict what subjects can be discussed in the classroom, or in public information campaigns, for moral or religious reasons. Particularly contentious issues include premarital sex, condom use and homosexuality, the last of which is illegal or taboo in much of the world. Marginalization of groups at high risk – such as sex workers and men who have sex with men – can be a major hindrance to HIV prevention efforts; authorities are often unwilling to allocate adequate resources to programs targeting these groups.
Safe male circumcision demands considerable medical resources and some cultures are strongly opposed to the procedure.
People who share equipment to inject recreational drugs risk becoming infected with HIV from other drug users who have HIV. Methadone maintenance and other drug treatment programs are effective ways to help people eliminate this risk by giving up injected altogether. However, there will always be some injecting drug users who are unwilling or unable to end their habit, and these people should be encouraged to minimize the risk of infection by not sharing equipment.
Needle exchange programs have been shown to reduce the number of new HIV infections without encouraging drug use. These programs distribute clean needles and safely dispose of used ones, and also offer related services such as referrals to drug treatment centers and HIV counseling and testing. Needle exchanges are a necessary part of HIV prevention in any community that contains injecting drug users.
Also important for injecting drug users are community outreach, small group counseling and other activities that encourage safer behavior and access to available prevention options.
Transfusion of infected blood or blood products is the most efficient of all ways to transmit HIV. However, the chances of this happening can be greatly reduced by screening all blood supplies for the virus, and by heat-treating blood products where possible. In addition, because screening is not quite 100% accurate, it is sensible to place some restrictions on who is eligible to donate, provided that these are justified by epidemiological evidence, and don’t unnecessarily limit supply or fuel prejudice. Reducing the number of unnecessary transfusions also helps to minimize risk.
The safety of medical procedures and other activities that involve contact with blood, such as tattooing and circumcision, can be improved by routinely sterilizing equipment. An even better option is to dispose of equipment after each use, and this is highly recommended if at all possible.
Health care workers themselves run a risk of HIV infection through contact with infected blood. The most effective way for staff to limit this risk is to practice universal precautions, which means acting as though every patient is potentially infected. Universal precautions include washing hands and using protective barriers for direct contact with blood and other body fluids.
Despite the evidence that they do not encourage drug use, some authorities still refuse to support needle exchanges and other programs to help injecting drug users. Restrictions on pharmacies selling syringes without prescriptions, and on possession of drug paraphernalia, can also hamper HIV prevention programs by making it harder for drug users to avoid sharing equipment.
Many resource-poor countries lack facilities for rigorously screening blood supplies.31 In addition a lot of countries have difficulty recruiting enough donors, and so have to resort to importing blood or paying their citizens to donate, which is not the best way to ensure safety.
In much of the world the safety of medical procedures in general is compromised by lack of resources, and this may put both patients and staff at greater risk of HIV infection.
HIV can be transmitted from a mother to her baby during pregnancy, labor and delivery, and later through breastfeeding. The first step towards reducing the number of babies infected in this way is to prevent HIV infection in women, and to prevent unwanted pregnancies.
There are a number of things that can be done to help a pregnant woman with HIV to avoid passing her infection to her child. A course of antiretroviral drugs given to her during pregnancy and labor as well as to her newborn baby can greatly reduce the chances of the child becoming infected. Although the most effective treatment involves a combination of drugs taken over a long period, even a single dose of treatment can cut the transmission rate by half.
A caesarean section is an operation to deliver a baby through its mother’s abdominal wall, which reduces the baby’s exposure to its mother’s body fluids. This procedure lowers the risk of HIV transmission, but is likely to be recommended only if the mother has a high level of HIV in her blood, and if the benefit to her baby outweighs the risk of the intervention.
Weighing risks against benefits is also critical when selecting the best feeding option. The World Health Organization advises mothers with HIV not to breastfeed whenever the use of replacements is acceptable, feasible, affordable, sustainable and safe. However, if safe water is not available then the risk of life-threatening conditions from replacement feeding may be greater than the risk from breastfeeding. An HIV positive mother should be counseled on the risks and benefits of different infant feeding options and should be helped to select the most suitable option for her situation.
In much of the world a lack of drugs and medical facilities limits what can be done to prevent mother-to-child transmission of HIV. Antiretroviral drugs are not widely available in many resource-poor countries, caesarean section is often impractical, and many women lack the resources needed to avoid breastfeeding their babies.
HIV-related stigma is another obstacle to preventing mother-to-child transmission. Some women are afraid to attend clinics that distribute antiretroviral drugs, or to feed their babies formula, in case by doing so they reveal their HIV status.
To be successful, a comprehensive HIV prevention programs needs strong political leadership. This means politicians and leaders in all sectors must speak out openly about AIDS and not shy away from difficult issues like sex, sexuality and drug use.
An effective response requires strategic planning based on good quality science and surveillance, as well as consideration of local society and culture. All sectors of the population should be actively involved in the response, including employers, religious groups, non-governmental organizations and HIV-positive people. Many of the world’s most successful HIV prevention efforts have been led by the affected communities themselves.
HIV epidemics thrive on stigma and discrimination related to people living with the virus and to marginalized groups such as sex workers. Their spread is also fueled by gender inequality, which restricts what women can do to protect themselves from infection. Protecting and promoting human rights should be an essential part of any comprehensive HIV prevention strategy. This includes legislating against the many forms of stigma and discrimination that increase vulnerability.
There is no cure for AIDS at this time. However, a variety of treatments are available that can help keep symptoms at bay and improve the quality of life of those who have already developed symptoms.
Antiretroviral therapy suppresses the replication of the HIV virus in the body. A combination of several antiretroviral agents, termed highly active antiretroviral therapy (HAART), has been highly effective in reducing the number of HIV particles in the blood stream, as measured by the viral load (how much virusis found in the blood). Preventing the virus from replicating can help the immune system recover from the HIV infection and improve T-cell counts.
HAART is not a cure for HIV, and people on HAART with suppressed levels of HIV can still transmit the virus to others through sex or sharing of needles. But HAART has been enormously effective for the past 10 years. There is good evidence that if the levels of HIV remain suppressed and the CD4 countremains high (above 200 cells/mcl), life can be significantly prolonged and improved.
However, HIV may become resistant to HAART in patients who do not take their medications on schedule every day. Genetic tests are now available to determine whether a particular HIV strain is resistant to a particular drug. This information may be useful in determining the best drug combination for each individual, and adjusting the drug regimen if it starts to fail. These tests should be performed any time a treatment strategy begins to fail, and prior to starting therapy.
When HIV becomes resistant to HAART, other drug combinations must be used to try to suppress the resistant strain of HIV. There are a variety of new drugs on the market for the treatment of drug-resistant HIV.
Treatment with HAART has complications. HAART is a collection of different medications, each with its own side effects. Some common side effects are nausea, headache, weakness, malaise (a general sick feeling), and fat accumulation on the back (“buffalo hump”) and abdomen. When used for a long time, these medications increase the risk of heart attack, perhaps by increasing the levels of fat and glucose in the blood.
Any doctor prescribing HAART should carefully watch the patient for possible side effects associated with the combination of medications the patient takes. In addition, routine blood tests measuring CD4 counts and HIV viral load (a blood test that measures how much virus is in the blood) should be taken every 3 – 6 months. The goal is to get the CD4 count as close to normal as possible, and to suppress the HIV amount of virus in the blood to an undetectable level.
Other antiviral medications are being investigated. In addition, growth factors that stimulate cell growth, such as erthythropoetin (Epogen) and filgrastim (G-CSF or Neupogen) are sometimes used to treat anemia and low white blood cell counts associated with AIDS.
Medications are also used to prevent opportunistic infections (such asPneumocystis jiroveci pneumonia) if the CD4 count is low enough. This keeps AIDS patients healthier for longer periods of time. Opportunistic infections are treated when they happen.