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HIV stands for the human immunodeficiency virus. Viruses are extremely small, very simple organisms which can only exist and multiply by invading and taking control of a plant or animal cell (the host cell). Viruses are responsible for many different diseases. Unlike bacteria, they are not killed by antibiotics.
HIV is the human immunodeficiency virus.
Viruses may be divided into many different groups. HIV belongs to a group of viruses known as retroviruses. These viruses are unique in nature as they have a special enzyme called reverse transcriptase. This enzyme enables HIV to introduce its own genes into the nucleus of the host cell. The host cell is then instructed to produce millions of new copies of the virus each day. These are released into the bloodstream and can then infect other cells. Retroviruses usually cause long periods of silent infection before signs of disease appear.
HIV is a retrovirus.
HIV causes a chronic illness which is usually referred to as symptomatic HIV infection or HIV disease. When HIV infection has reached an advanced, serious stage it is called AIDS (acquired immune deficiency syndrome). Unfortunately, the public often uses the term AIDS incorrectly to describe the illness in anyone who is infected with HIV. Without treatment with antiretroviral drugs, AIDS is a fatal disease. HIV is the only cause of AIDS.
HIV causes a serious chronic illness.
A person who has HIV infection is said to be HIV positive, while someone without HIV infection is HIV negative.
Symptomatic HIV infection may present in many different ways. The symptoms and signs of HIV infection are usually due to secondary infections caused by a wide range of organisms. While some of these organisms are the same as those that infect HIV-negative children, other infections are due to uncommon organisms not normally seen in children who are HIV negative.
HIV infection may present with a wide range of symptoms and signs.
HIV infects, damages and finally destroys a special type of lymphocyte (white cell) called a CD4 cell. As the CD4 cells play a very important role in the functioning of the immune system, this destruction of CD4 cells damages the immune system, leading to immune deficiency.
The normal immune system protects the body against infection. By killing CD4 cells, HIV infection weakens the immune system which is then no longer able to prevent infection by many viruses, bacteria, fungi and parasites. As a result the person becomes ill.
HIV infection damages the immune system by killing CD4 cells.
Two types of HIV are recognised: HIV1 and HIV2. Most HIV infection in southern Africa is caused by HIV1 which has many subtypes (clades). The important subtype in Africa is subtype C. Subtype B is the most common subtype in the developed world.
Yes. HIV infection can be spread from one person to another.
The virus may be transmitted from one person to another by:
There is no evidence that HIV can be spread by mosquitoes, lice or bed bugs. Neither can it be spread via food or water. In Africa HIV in adolescents and adults is most commonly spread by heterosexual intercourse.
HIV in adolescents and adults is usually spread by sexual intercourse.
By the spread of HIV from a mother to her fetus or from a mother to her newly born or young infant. 95% of HIV-infected children are infected by their mother. Children may also be infected by sexual contact.
Children are usually infected with HIV by their mother.
Family and friends of an HIV-infected person do not become infected except by sexual contact. HIV is not transmitted by close social contact such as touching, holding hands, hugging and social kissing. HIV is also not spread by coughing, sneezing, swimming pools, toilet seats, sharing cooking, drinking and eating utensils or by changing a nappy. However, any bleeding, such as nose bleeds, may spread HIV.
Yes. Adults are usually infected with HIV for years before becoming ill. Most children who are infected with HIV are clinically well (asymptomatic) for the first few months. However, the illness progresses rapidly in many children and by the age of 12 months almost 80% of HIV-infected children will have symptomatic disease. In Africa, by two years of age more than 50% of HIV-infected children will die unless the correct treatment is available.
Many adults and some children with HIV infection are clinically well.
Yes. HIV is frequently transmitted by people who appear to be clinically well but are infected with HIV. This is the great danger of HIV infection as most infected people do not know that they have been infected. They are also unaware that they may transmit HIV to another person.
Over 34 million people worldwide have HIV infection. It is estimated that 5.24 million South Africans are infected with HIV. In 2010, more than 30% of all pregnant women in South Africa were HIV-positive. The province of KwaZulu-Natal had the highest prevalence. In some health districts, over 45% of pregnant women are HIV positive.
Almost a third of pregnant women in South Africa are infected with HIV.
By practising the behavioural change of ‘ABC’:
A reduction in multiple sexual partners seems to have resulted in the declining HIV prevalence in some countries such as Uganda and Zimbabwe. However, all three behavioural changes are important but difficult to implement.
Recent additions to preventing HIV transmission include:
Antiretroviral treatment reduces the likelihood of HIV transmission by 96%.
At the end of 2011, 3.3 million children under the age of 15 years were infected with HIV worldwide. At least 90% of these children live in sub-Saharan Africa. At the end of 2011 there were about 460 000 children in South Africa with HIV infection.
It is estimated that the under 5 mortality due to HIV in South Africa has dropped from 46% in 2008 to 28% in 2010. Many of these deaths could be prevented with the correct management. However, without antiretroviral treatment most people with HIV infection will eventually die of AIDS. With antiretroviral treatment HIV infection is ‘a life sentence, not a death sentence’.
Yes. Because they are still young and have immature immune systems. As a result, the progress of HIV infection to illness and death is faster in children than in adults.
Hopefully the rapid increase in new cases will slow down. Since 1990 the rate of HIV infection in women attending state antenatal care clinics in South Africa has steadily climbed from less than 2% to reach about 30% in 2009. South Africa has one of the fastest-growing HIV epidemics in the world, with one to two thousand people infected every day.
South Africa has one of the fastest-growing HIV epidemics in the world.
The epidemic of HIV infection is having a devastating impact on society in South Africa and other countries in sub-Saharan Africa. Since the start of the AIDS epidemic in South Africa, the average life expectancy had fallen from 60 to 45 years but has now increased again to 54 years in 2012.
In Africa the majority of people with HIV infection are female and most are from poor communities. This has a massive effect on the whole family and increases the risk of childhood undernutrition and death, even in HIV-negative children. The number of children who have lost one or both parents to HIV in Africa already exceeds 12 million. At the end of 2011 it was estimated that there were 2.1 million AIDS orphans in South Africa. As a result of the ever-increasing number of deaths, ill people and homeless children, HIV infection is having an enormous social and financial impact on all communities and placing a strain on the health services.
HIV infection is seriously affecting the lives of people in all communities in southern Africa.
Mother-to-child transmission of HIV (vertical transmission) may occur:
Most children with HIV are infected by mother-to-child transmission (more than 95%).
Most children with HIV are infected by mother-to-child transmission.
If antiretroviral prophylaxis or treatment is not used, the risk of HIV crossing the placenta from a mother to her fetus during pregnancy is about 5%. Although transmission may take place at any time during pregnancy, the risk is probably greatest in the last trimester (28 to 40 weeks of gestation).
A number of factors will increase the risk of HIV transmission during pregnancy:
These women have a large amount of virus (high viral load) in their blood and are, therefore, more infectious.
Other factors which increase the risk of HIV crossing the placenta are:
If antiretroviral prophylaxis or treatment is not used, the risk of HIV crossing the placenta from a mother to her fetus during labour and vaginal delivery is about 15%. As with pregnancy transmission, mothers with a high viral load have a greater risk of infecting their infant.
Other factors which increase the risk of infecting the infant during labour and vaginal delivery are:
The longer the infant is exposed to vaginal and cervical secretions during labour e.g. when there is a prolonged rupture of the membranes, the greater the risk of HIV infection.
Yes, provided it is performed before the onset of labour when the risk of HIV transmission during labour and delivery can be almost totally removed. However, the risk of post-operative bacterial infection is high in these mothers while Caesarean sections require additional staff, facilities and funds. Therefore, antiretroviral prophylaxis is the preferred method of reducing HIV transmission during labour and delivery.
This depends on the method and duration of breastfeeding:
Other factors which increase the risk of HIV transmission in the breast milk are oral candidiasis (moniliasis or thrush) in the infant and breast problems (cracked nipples, mastitis or abscess) in the mother. Mothers with a high viral load (either early or advanced HIV infection) are also at greater risk of transmitting HIV via their breast milk.
Without the use of antiretroviral drugs, the total risk after a vaginal delivery and two years of mixed breastfeeding is approximately 35% (i.e. 5% in pregnancy plus 15% at delivery plus 15% with mixed breastfeeding).
The overall risk of mother-to-child transmission is 35% if steps are not taken to reduce the risk.
Every effort must be made to keep the community, especially women of childbearing age, HIV negative. Reduction in the number of unwanted pregnancies would significantly decrease the number of HIV-infected children.
Preventing unwanted pregnancies would reduce the number of HIV-infected children.
The prevention of mother-to-child transmission (PMTCT) is usually achieved by the use of prophylactic antiretroviral drugs during pregnancy, labour and delivery, and after delivery for a minimum of 6 weeks or for the duration of breastfeeding. The aim of PMTCT is to reduce the amount of HIV in the mother’s blood and vaginal secretions and to protect the fetus and infant when exposed to HIV. This is also achieved if the mother is receiving antiretroviral treatment with three drugs for her HIV infection. PMTCT is given to protect the infant and not to treat the mother.
Pregnant women with stage 3 or 4 disease, or a CD4 count of 350 cells/μl or less, should be fast-tracked onto antiretroviral treatment with three drugs. Usually TDF (tenofovir), 3TC (lamivudine) and nevirapine are used.
In women who deliver vaginally and do not breastfeed the risk of transmission can be reduced to less that 5% with PMTCT. The size of the reduction depends on the method of PMTCT being used. In developed countries mother-to-child transmission of HIV has been dramatically reduced due to successful PMTCT programmes.
If the mother is on antiretroviral treatment, the risk of HIV transmission is about 2%.
Antiretroviral prophylaxis can reduce mother-to-child transmission of HIV.
HIV in a family is often first detected because of HIV screening during pregnancy. This provides an opportunity to manage the whole family.
A dose of nevirapine is given to the infant within 6 hours after delivery. The dose of nevirapine to the infant is 15 mg if more than 2.5 kg, 10 mg if 2 to 2.5 kg, and 2 mg/kg if less than 2 kg.
Give the nevirapine to the infant as soon as possible after delivery if the mother did not receive her dose of nevirapine or if it was given less than two hours before delivery.
In addition to the dose of nevirapine given to the infant after birth a daily dose should also be given to the infant until the age of six weeks. This should be given whether the mother breastfeeds or not. At 6 weeks the infant should be screened with a PCR test to decide whether the infant has become infected with HIV or not and to plan further management. Using nevirapine for six weeks rather than only at delivery reduces the risk of HIV infection.
Good breast care and exclusive breastfeeding are important to reduce the risk of HIV transmission.
By preventing or treating these conditions the risk of transmission can be reduced.
In contrast, antiretroviral prophylaxis or treatment makes breastfeeding much safer.
Not necessarily. There are advantages and dangers of both breastfeeding and formula feeding infants who are born to HIV-positive women. The great danger of breastfeeding, especially mixed breastfeeding, is the additional risk of HIV transmission to the infant. However, the advantages of breastfeeding are the lower risk of gastroenteritis and undernutrition, especially in poor, rural communities. The advantages of breastfeeding (especially exclusive breastfeeding), may outweigh the dangers for many HIV-positive mothers from poor communities. In contrast, it would be safer for most HIV-positive women in urban areas to formula feed their infants.
Recent studies show that the risk of HIV transmission in breast milk is low if the infant receives antiretroviral prophylaxis and very low if the mother is receiving antiretroviral treatment with three drugs.
Each HIV-positive mother should be counselled and informed of the risk and advantages so that they can make the best choice for their infant. While advice can be offered, women should not be instructed what to do. They should be encouraged to choose between exclusive breastfeeding and exclusive formula feeding. Once a woman has made her choice she should be supported in her decision by health workers. It is important that women decide on their chosen method of infant feeding before delivery. Mixed breastfeeding should be avoided if possible. Wet nursing (where the infant is breastfed by someone other than the mother) must be discouraged.
Unfortunately mothers need a lot of help and support from their family and healthcare workers to successfully breastfeed exclusively as this is not the traditional method of breastfeeding in most communities.
If HIV-positive women choose to exclusively breastfeed, they should probably stop when their infant is between four and six months old if maternal antiretroviral treatment or infant antiretroviral prophylaxis is not available. Ideally breastfeeding should be stopped over a month once formula and solid feeds are started, so that the period of mixed feeding is short. In practice it may be difficult for a mother to suddenly stop breastfeeding.
In very poor rural communities where severe childhood infections and undernutrition are common, mixed breastfeeding should be continued after the infant is six months old.
However, if the mother is on antiretroviral treatment and the infant on antiretroviral prophylaxis the benefits of mixed breast feeding beyond 6 months outweigh the risks, especially in poor communities.
It is very important that HIV-negative women and women who do not know their status are not influenced to formula feed by advice being given to HIV-positive women. Exclusive breastfeeding should be promoted among HIV-negative mothers.
It is advisable that the following criteria should be met if a mother is to exclusively formula feed:
Formula feeding is only recommended in poor communities if all the above criteria are met. If not, it would be better for women to breastfeed unless the risk of HIV transmission in breast milk is greater than the dangers of formula feeding. Women who decide to formula feed must be taught how to prepare and give formula correctly. A cup rather than a bottle should be used as cups are easier to clean.
Women should exclusively breastfeed unless the risk of HIV transmission via breast milk is greater than the dangers of formula feeding.
Most HIV-infected infants appear normal and healthy at birth. Therefore clinical examination cannot be used to determine which newborn infants are infected with HIV and which are not (i.e. only HIV exposed). HIV does not cause congenital abnormalities (birth defects). The clinical signs of HIV infection often appear between three and six months of age.
The rapid test detects whether HIV antibodies are present. Therefore it will be positive in all infants born to women who are HIV positive as the maternal HIV antibodies (IgG) crosses the placenta to the fetus. All HIV-exposed infants (both HIV-infected and non-infected infants) may have a positive screening test (rapid test) up to 18 months of age as the maternal antibodies may remain in the infant until this time.
The only reliable method of telling whether an infant under the age of 18 months has been infected with HIV is to perform a PCR (polymerase chain reaction) blood test on the infant. This detects HIV genetic material. As the window period for the PCR test is six weeks, infants should only be tested six weeks after delivery or six weeks after the last feed of breast milk. A positive PCR test before six weeks will confirm HIV infection, but a negative test cannot reliably exclude infection.
Any infant under 6 weeks with clinical signs of HIV infection should have a PCR test immediately. If negative this should be repeated at 6 weeks of age. In addition, any breast fed infant between 6 weeks and 18 months with clinical signs of HIV should also have a PCR test immediately.
Either a sample of venous blood can be taken or a few drops of capillary blood collected on filter paper (a dry blood spot) for PCR testing. Children found to be HIV infected must be referred to an HIV clinic for treatment.
PCR testing at six weeks of age is important to identify infants infected with HIV before, during or soon after birth.
The ultra-sensitive p24 antigen test can be used instead of the PCR test.
Every effort must be made to prevent assault, especially sexual assault. However, should a child be sexually assaulted (rape or sodomy), post-exposure prophylaxis must be started within 72 hours to reduce the risk of HIV infection. The sooner the treatment is started the more likely it is to be effective. HIV can also be transmitted by human bites.
Usually three drugs are used for post-exposure prophylaxis. In younger children:
In children over 40 kg TDF (Tenofovir) is used instead of AZT. All antiretroviral drugs are dosed according to the national guidelines.
Antiretroviral prophylaxis is given for 28 days. A rapid test (or PCR if the child is less than 18 months old) six weeks after the assault will indicate whether the child has become infected with HIV despite the prophylaxis. This is often repeated after a further six weeks. Usually an HIV screening test is done on the child to exclude previous infection before prophylaxis is started.
Yes, as most body fluids, especially blood, may contain HIV. Therefore, healthcare workers can become infected by HIV through needle-stick injuries or by cutting one’s finger during minor surgery. It is also possible to become infected with HIV through sores or abrasions of the skin when handling body fluids, especially blood.
By adopting standard (universal) precautions. This means that all body fluids should be regarded as potentially infectious in all patients. Precautions should always be taken to prevent exposure to HIV, especially when taking a blood sample.
All adults and children should be regarded as being potentially HIV positive. Therefore, standard precautions should be taken with all children. These precautions are especially important in children known to be HIV positive.
Standard precautions should be adopted when managing all patients.
Always use a sharps container for the disposal of lancets or needles and never resheath a needle.
If the patient is infected with HIV, the overall risk is 1 in 300. Therefore, of every 300 healthcare workers who prick or cut themselves with an instrument covered with HIV-positive blood, one person will become infected with HIV. With the correct use of antiretroviral prophylaxis this risk is reduced by 80%. The risk of infection is greatest if the child has AIDS or has recently been infected with HIV (because the child will have a high viral load). It is also higher if prophylaxis is not given correctly.
No prophylaxis is needed with blood contact with intact skin. However with non-intact skin (cuts or open sores), mucosa (eye or mouth), superficial (sharp) or deep (needle) injury prophylaxis is needed. Every effort must be made to start prophylaxis within two hours of exposure. If possible, start prophylaxis as soon as possible. Treatment is given orally for 28 days.
Usually a two drug regimen is used (TDF and 3TC). However three drugs are recommended in deep injuries:
AZT is no longer used as it often makes the healthcare worker feel nauseous and unwell. It is important to take the full course of drugs. Usually an HIV screening test is done on the healthcare worker to exclude previous infection before prophylaxis is started. An HIV screening test six weeks after exposure will indicate whether the prophylaxis has been effective or not. This is often repeated after a further six weeks.
After a needle-stick (‘sharps’) injury the following procedure should be followed:
All hospitals and clinics must keep emergency packs of prophylactic antiretrovirals for staff with accidental exposure to HIV.
A mother brings her 20-month-old son to a local clinic as he is unwell. On examination the child has clinical signs of HIV infection and the mother’s screening test for HIV is positive. She is very upset as she did not know her positive HIV status. She is clinically well.
By unprotected sexual intercourse.
No, as HIV is not transmitted during normal social contact such as touching, holding hands, hugging and social kissing. HIV is also not spread by toilet seats, shared cooking, drinking or eating utensils.
Most HIV-infected adults are not ill as HIV infection usually takes years before it causes illness in adults.
Most are infected from their mothers during pregnancy, labour or delivery, or through breast milk (vertical or mother-to-child transmission).
About 5% if antiretroviral prophylaxis is not used. This risk is increased if the mother is infected with HIV during pregnancy or has advanced (stage 4) HIV disease. Other risk factors during pregnancy include malaria and malnutrition, especially vitamin A deficiency.
Yes. During normal labour and vaginal delivery without antiretroviral prophylaxis the risk of mother-to-child transmission is about 15%. The overall risk of transmission during pregnancy, labour and delivery is, therefore, about 20%.
Parents bring their three-year-old daughter to a general practitioner for a second opinion. The child has been diagnosed with HIV infection at the local hospital. The parents have very little knowledge about HIV infection and AIDS.
It is estimated that 5.24 million South Africans are infected with HIV. Almost a third of pregnant women in South Africa are infected with HIV.
About 460 000 at the end of 2011. HIV infection is one of the major causes of death in both children and adults in most developing countries.
Not only does HIV infection cause illness and death of children but also loss of parents. This may result in many homeless and orphaned children. Everyone in society is affected by the HIV epidemic.
By damaging the body’s immune system and making one more susceptible to a wide range of other infections.
Because children have an immature immune system, the illness caused by HIV progresses more rapidly.
If a mother does not breastfeed at all, a PCR test on the infant at six weeks of age will indicate whether the infant is infected or not. If the mother breastfeeds, the test should be done and if negative it should be repeated again six weeks after she stops breastfeeding.
An HIV antibody screening test (rapid test) can reliably exclude HIV infection in children only at or beyond 18 months of age.
The superintendent and his staff of a small hospital plan to start a programme of antiretroviral prophylaxis in the maternity service. They are looking at various options and have asked for guidelines.
AZT (zidovudine) and nevirapine (dual therapy).
The mother is given 300 mg AZT orally twice daily from 14 weeks and then 300 mg orally every three hours during labour. In addition a single oral dose of 200 mg nevirapine is given to the mother at the onset of labour
The infant is given a daily dose of nevirapine starting soon after birth and then continuing for six weeks until a PCR test is done. At this stage further management is planned.
Therapy with TDF and 3TC daily for 28 days.
Lopinavir/ritonavir daily should be added to the TDF and 3TC daily for 28 days.
An HIV-positive pregnant woman is being counselled at an antenatal clinic. She asks the midwife whether she should plan to breastfeed her infant. This mother lives in a rural community with poor facilities. She has come to town to deliver her infant and wants to return home as soon as possible after the birth.
You should give her the necessary information so that she can make the best choice for herself and her infant. Do not simply push her into doing what you think is best.
Yes, as HIV is present in breast milk. With mixed breastfeeding (breast milk plus other liquids or solids) for two years there is a 15% chance of the HIV in her breast milk infecting her infant. The risk is much less with exclusive breastfeeding for six months followed by rapid weaning off breast milk.
Probably not if she remained in town for the first few years. However, she plans to return to a rural area where formula milk may not be available, affordable or safe. It may also not be acceptable to her family and community. The result may be malnutrition and gastroenteritis in her infant.
Mastitis or breast abscess. These can be avoided with good breastfeeding practices. Therefore it is important to teach this mother how to breastfeed correctly.
Probably to exclusively breastfeed for six months unless she is able to safely formula feed at her rural home. Antiretroviral treatment for the mother or prophylaxis for the infant will greatly reduce the risk of HIV transmission.