Mother-to-baby transmission

Mother-to-baby transmission is one of the three main methods of transmission of HIV. The virus can be transmitted from mother to baby during the pregnancy, during the birth or through breast feeding. For further general information on the disease, click here.

HIV-1 has become an important and common complication of pregnancy and there are guidelines specifically for the treatment of the disease in pregnancy. These include:

• British HIV Association guidelines (select ‘pregnancy guidelines’ in the index).
• Royal College of Obstetricians and Gynaecologists guidelines

HIV infection during pregnancy is associated with poor pregnancy outcomes. It appears that there is an increase in the risk of stillbirth, pre-term delivery and increased chance of low birthweight babies due to growth retardation in the uterus. The most serious effect of HIV however, is transmission from the mother to the baby. This can occur in the uterus, during delivery and after the baby is born (predominantly via breast milk). With routine antenatal screening, appropriate treatment, Caesarean section and exclusive artificial formula feeding (where possible) mother-to-child transmission is, in the main, preventable.

Website associated with mother-to-baby transmission

Avert is an international AIDS charity that has much information on its website about the prevention of HIV and AIDS, including a section on mother-to-baby transmission.
www.avert.org

HIV and AIDS prevention

HIV can be transmitted through sexual intercourse, from mother to baby or from contact with infected blood and its products. As such, the risk of transmission can be reduced by:

• using a condom during sex
• avoiding using drugs injected through a syringe, and avoiding sharing needles
• not allowing people with HIV or those who are considered at high risk to donate blood, sperm or organs
• preventative measures during pregnancy, childbirth and once the baby is born.

If a person is thought to be at risk of HIV, having had a high risk of exposure (such as rupture of a condom during intercourse between a known HIV carrier and an uninfected partner) emergency use of antiretroviral therapy (known as PEP, post-exposure prophylaxis) can prevent transmission. The medication is usually taken for four weeks, during which time the patient may experience significant side-effects such that they are unable to work during the prophylaxis period. The exact choice of drug requires expert guidance. Further information is available in the Department of Health guidance HIV post-exposure prophylaxis.

The British Association of Sexual Health and HIV (BASHH) has also published UK guidelines on the use of post-exposure prophylaxis for HIV following sexual exposure.

Websites associated with HIV and AIDS prevention

The Department of Health has produced the document The national strategy for sexual health and HIV implementation action plan, available on its website.
www.dh.gov.uk

The US Center for Disease Control has a website for the National Center for HIV, STD and TB prevention.
www.cdc.gov

The American Center for AIDS Prevention Studies (CAPS) has a large number of factsheets on its website available for a wide range of ‘at risk’ groups.
www.caps.ucfs.edu

Global Strategies for HIV Prevention has a mission to implement international strategies to prevent HIV infection.
www.globalstrategies.org

Avert is an international AIDS charity that has much information on its website about the prevention of HIV and AIDS.
www.avert.org

The British Association for Sexual Health and HIV (BASHH) has published guidelines on the sexual health of people with HIV. It has also published guidelines on other sexually transmitted infections.
www.bashh.org

Infection, transmission and testing

HIV can be transmitted through sexual intercourse, from mother to baby, by drug users sharing needles or using infected needles, and from blood or organs. Since 1985, all blood and tissue donations and blood products in the UK have been screened for HIV.

Symptoms experienced by a person infected with HIV vary enormously. Many people are asymptomatic (without symptoms), others will have a flu-like illness, a rash, night sweats, or rarely, a life-threatening brain infection a few weeks or months after infection. Symptoms of this nature, however, are not indicative of infection as people reporting vague symptoms commonly test negative for the virus.

Due to the implications of a positive result, various guidelines have stressed that HIV testing should be preceded by counselling, despite differences of opinion on the aims and content of such pre-test counselling. However, it can be argued that making a patient wait for a test can cause much distress. There is a growing view among health professionals that HIV testing should be "normalised" alongside other diagnostic tests and procedures. The British Medical Association Foundation for AIDS offers advice to health professionals, especially doctors and midwives, on how to provide HIV testing straightforwardly and concisely.

There are three main types of HIV test.

• HIV antibody test, which looks for the presence of the HIV virus in the blood and detects antibodies produced by the body in response to the presence of virus. However, when someone becomes infected with HIV, it can take up to three months for their immune system to produce enough antibodies to show up on an HIV test. Very rarely this takes longer (up to six months).
• P24 antibody test (usually used to screen blood, but in some places it is used to test individuals). P24 is an antigen (a protein) present on the HIV virus. This test can detect HIV infection earlier than the HIV antibody test.
• Viral load test, which is used once a person knows they have been infected with HIV, to find out the level of the virus in the blood.

In the UK, people can be tested for HIV at sexual health clinics and genito-urinary clinics. The Society of Sexual Health Advisers website has clinics listed by region.

The British Association for Sexual Health and HIV (BASHH) have published national guidelines on the sexual health of people with HIV: sexually transmitted infections. This contains information on how to support those with HIV, and on how to provide the best treatment and care. It also offers advice on how to prevent onward transmission of the HIV virus and other sexual infections.

Websites associated with HIV infection, transmission and testing

Avert is an international AIDS charity that has much information on its website about the prevention of HIV and AIDS. It has a section on transmission and testing.
www.avert.org

The Medical Foundation for AIDS and Sexual Health has a document on HIV testing on its website.
www.medfash.org.uk

The British Association for Sexual Health and HIV (BASHH) have published guidelines on the sexual health of people with HIV. It has also published guidelines on other sexually transmitted infections.
www.bashh.org

Treatment and care

Treatment of HIV and AIDS involves treatments to suppress the virus itself, treatment of the conditions that result from having the virus, and emotional and psychological support for the patient and his or her family. Treatment is most commonly provided by specialists in HIV, or at genito-urinary medicine (GUM) clinics. GPs are becoming increasingly involved in the care of HIV-positive patients.

There are two main types of medication:

• combination therapy, which uses combinations of anti-HIV, or antiretroviral drugs to suppress the virus and maintain the person’s immunity for as long as possible. This treatment is started when the person’s immune system is reaching dangerously low levels, i.e. when the CD4 count falls below 250. This treatment is complex and has to be taken for the rest of the person’s life. It can have serious side-effects
• treatment for AIDS-related illnesses, which will vary according to the condition. This treatment is unnecessary in many people who are on appropriate combination therapy.

Support is also available from:

• dieticians
• physiotherapists
• counsellors
• pharmacists
• nurse practitioners
• many voluntary organisations.

The British HIV Association (BHIVA) has produced HIV Treatment Guidelines, which it houses on its website. It has also produced Adherence Guidelines to guide healthcare professionals in helping patients comply with their treatment.

The World Health Organization, as part of its 3 by 5 initiative, has produced the document Scaling up antiretroviral therapy in resource-limited settings: Treatment guidelines for a public health approach.

NHS Quality Improvement Scotland (QIS) was set up as a special health board by the Scottish Parliament in 2003. Its role was to improve the quality of care and treatment delivered by NHS Scotland. As part of its role, NHS QIS investigated the sexual health services within Scotland and recommended how they can best support and improve the services offered around sexual health.

From their investigation, the group came up with five key clinical indicators (KCI) which would be used to monitor the improvement in sexual health care. HIV therapy uptake is one of the KCI set out for 2006.

Click here for more detail on the NHS:QIS Sexual Health Services project preliminary report (June 2006).

Websites associated with treatment and care of patients with HIV

The Medical Foundation for AIDS and Sexual Health publishes a range of documents on care and treatment of patients with HIV.
www.medfash.org.uk. Publications include the guidelines HIV in primary care.

AIDSmap is a website by NAM, an award-winning, community-based organisation, which works from the UK. It delivers reliable and accurate HIV information across the world to HIV-positive people and to the professionals who treat, support and care for them. There is a section on treatment, which covers all aspects of HIV therapy, medical tests, side-effects, opportunistic infections and drugs used in the treatment of HIV and associated illnesses.
www.aidsmap.com

Medication

There is currently no cure for HIV. Treatment involves the use of antiretroviral therapy, or ART. The purpose of ART is to limit HIV replication. ART drugs are classified into four groups, according to where they act in the replication cycle of the virus.

• NRTIs (nucleoside/nucleotide reverse transcriptase inhibitors), the first type of drug to treat HIV, became available in 1987. NRTIs inhibit the enzyme reverse transcriptase and make HIV unable to infect cells and duplicate itself.
• NNRTIs (non-nucleoside reverse transcriptase inhibitors) started to become available in 1997 and, like NRTIs, inhibit the enzyme reverse transcriptase, but in a different way as they bind to the enzyme differently.
• PIs (protease inhibitors), first approved in 1995, inhibit protease. Protease is a digestive enzyme that breaks down protein and is one of the many enzymes that HIV uses to reproduce itself. By inhibiting this enzyme, duplication of the virus is slowed, and infection of new cells is prevented. The NRTIs and NNRTIs are only effective in newly infected cells. PIs are able to slow the process of immature non-infectious virus becoming mature and infectious. They also work in cells that have been infected for a long time, by slowing down the reproduction of the virus.
• HIV has proteins on its surface called gp41 and gp120, which enable the virus to attach to and enter cells. Fusion inhibitors block these proteins and slow down the reproduction of the virus. T20, the closest of these drugs to approval binds to the protein gp41. This drug has to be administered via injection as it is a protein and would therefore be digested in the stomach if it were taken orally.

HIV frequently mutates as it replicates, allowing the virus to develop resistance very effectively to single ART drugs. Therefore three or more drugs are currently used in combination and adherence to the regimen by a patient is essential. It is possible to get resistance information of the HIV strain in an individual, which can help with the choice of ART therapy.

A combination of three or more drugs is called HAART (highly active antiretroviral therapy). ART is monitored mainly by measuring the viral load (that is the amount of virus in the blood) and also by measuring the CD4 count (a measurement of the immune system).

Once ART is started, the combination of drugs may be altered according to side-effects experienced. Most side-effects are minor but some are more serious, such as hyperlipdaemia, diabetes and lipodystrophy