Mother-to-Child Transmission of HIV / AIDS: A Potential Threat to Child Survival
It is amazing, and humbling, to realize that in the late 1970s the human immuno-deficiency virus (HIV) was spreading silently- unrecognized and unnoticed around the world. In the summer of S981, when AIDS was first recognized by the Centre for Disease Control (CDC) in the United States among five homosexual men in Los Angeles. Presently, HIV/ATDS is the greatest health crisis ever faced by the mankind. Already this pandemic has killed about 30 million people. More than 40 million are living with virus. An additional 14,000 are added everyday to this pool. Each year 3 million are dying of HIV/'AIDS. Three decades into the epidemic there still no "vaccine" or no "cure" for AIDS. On the basis of available information, it is believed that HIV is an old virus, of unknown geographical origin affecting millions of people worldwide.
Globally, about half of all adults living with HIV are women and 2,5 million children around the world living with the virus-, mostly in the African countries. More than 4 million children have been infected since the virus first appeared. Of the 5 million people who became infected with the virus in 2003, 700,000 were children. Infants and children are affected by HIV/AIDS in multiple ways. Children can be infected with HIV through-mother-to-child transmission (MTCT), infected blood, contaminated medical equipment or sexual abuse. Mother-to-child transmission also called vertical transmission or perinatal transmission is the most direct way of infecting children. Mother can transmit virus to their children in three ways: during pregnancy, during childbirth, and after childbirth through breastfeeding. Mother-to-child transmission through pregnancy, labour, delivery, or after birth through breastfeeding is responsible for over 90 percent of HIV infections in infants and children under the age of 15.
More than one-third of mothers having HSV in their blood transmits virus to their newborns. It is estimated that approximately one in five babies born to HIV-positive mother become infected during delivery and one in seven during breasfeeding. Worldwide, one in ten of those who become infected with HFV are children. About four out of every ten HIV-positive children die before they are one year old. Those who survived especially in resource-poor setting face severe illness and near certain early death. The risk of infection is thought to be 5-10 percent during pregnancy; 10-20 percent during childbirth, and 10-20 percent during breastfeeding. Disease in children who acquire HIV infection from their mothers is more rapid in developing countries than the developed ones, provably because children in developing countries are exposed to early and multiple infections, have high rats of malnutrition and micronutrient deficiency, and Sack access to adequate health services.
According to UNAIDS, the disproportionately high MTCT rates of 25-45 percent in the developing countries in contrast to less than 5 percent in the developed countries are due to maternal ill health, poor delivery practices, high percentage of HIV infected women of childbearing age, and HIV infection acquired during pregnancy and while breastfeeding. Since the beginning of the epidemic, it is estimated that more than 4 million children under 15 years of age died of AIDS and over 90 percent of them were from Africa.
MTCT of HIV During Pregnancy:
In most infected women HIV usually doesn't cross the healthy placenta from mother to foetus. But when the placenta breakdown due to infections that affect the placenta or her HIV infection is new or in advanced stage or the mother is undernourished, virus passes through placenta from mother to foetus.
MTCT of HIV during childbirth: During me delivery of an HIV-positive mother extra care is needed. The risk of mother-to-child transmission during childbirth alone is estimated at 10-20 percent. The chance of transmission is greatest if the foetus is exposed to HP/ infected blood and/or fluids. The newborns that acquire HIV during labour and delivery do so by sucking, imbibing or aspirating maternal blood or cervical secretions that contain HIV. Other way of getting infection through the mixing of foetal and maternal blood as the placenta separates. For this reason providers should avoid episiotomy or amniotomies or other procedures that increase the newborn's exposure to the mother's blood. The risk of mother-to-child transmission increases by 2 percent during each hour after membranes have ruptured. So it is safe to perform cassarean section before and/or the rapture of the membranes in order to reduce the mother-to-child transmission.
MTCT of HIV during breastfeeding: HIV present in breast milk, a source of infection for the newborn and infants. Between 10-20 percent infants born to HIV positive mothers become infected through breastfeeding. However, various studies during the recent years suggest that the risk of HIV transmission during breastfeeding depends on several factors that include infant age, pattern of and duration of brestfeeding, breast health, maternal viral load, and onset of infection and infant oral lesion. Partial breastfeeding in the early months, longer duration of breastfeeding and heavy viral load increase the chance of infection of infants and children. The risk is greater if the mother becomes infected while she is breastfeeding. So, it is better to avoid breastfeeding the child born to HIV-positive mother. In some cases, where less availability breast milk substitute, bad hygienic condition, the newborn can be given absolute breastfeeding in the first month only.
Risk factors for Mother-to-child transmission: The overall risk of mother-to-child transmission is associated with factors related to the virus, the mother and the infant. Maternal RNA viral load is plasma has been strongiy associated with this risk. If a mother is infected with HIV but maintain good health nutritionally and in other aspects, the risk of transmitting the virus is reduced. Malnutrition, vitamin A deficiency, smoking, substance abuse and presence of other infections like STDs/RTIs are all associated with higher rates of mother-to-child transmission of HIV.
Viral load m the blood, clinical stage of the HIV infection also influences the chances of transmitting the virus to the foetus or newborn. Moreso, factors related to labour and childbirth such as pre-mature birth, placenatal disruption, duration of membrane rupture and mode of delivery (whether birth vaginal or caesarean) affect the viral transmission from mother to newborn in greater extent. Though prevalence of HIV/AIDS in Bangladesh is still low, increasingly high prevalence in the neighbouring countries recent years alarms me danger bell. In many of the Sub Saharan countries more than one-fifth of all pregnant women are living with HIV. Over 2.5 million children were at risk for HIV infection through mother-to-child transmission in 2001.
Magnitude of The Problem:
HIV/AIDS is a global issue and MTCT is major public health problem. Tragically, more than one-forth of babies born to mothers infected with HIV turnout themselves to be infected. WHO and UNAIDS estimate that at the end of 2001, 40 million people around the world were living with HIV, half of all adults living with HIV are women and 2.5 million are children. Though AIDS was first reported in Thailand in 1984 in Asia by the end of 2001, more than 6 million persons were living with HIV/AIDS in the South-east Asia region of WHO, of which, more than 5 million are living in India. Globally India has the second highest estimated number of HIV-infected people of any single country- next only to South Africa.
In 2003, an estimated 700,000 children were newly infected with HIV, about 90 percent of these infections occurred in Sub-Saharan Africa. In the same year less than 1000 children were estimated to have become infected with HIV in North America and Western Europe and less than 100 in Australia and New Zealand. UNAIDS estimates that as ofend-2001, 1300 adult and 310 children were living with HIV/AIDS in Bangladesh. The country like USA, the rate of MTCT is less than 2 per cent, whereas country like Sub-Saharan Africa (SSA) this rate as high as 35 percent, where every fifth pregnant women living with HIV virus 800,000 children
Prevention of MTCT:
Perinatal HIV is a child survival issue. More number of mother getting infection as the time passes and snaking the future generation more vulnerable. In 2001, the united Nations General assembly Special Session on HIV/AIDS set the goal of reducing the proportion of infants infected with HIV by 20 percent by 2005 and by 50 percent by 2010.
To reach these goals integrated and comprehensive programmes to be undertaken to prevent HIV infection among infants and young children. Such programmes include:
Primary prevention HIV infection among women and their partners by promoting safe sex before and during pregnancy and during breastfeeding;
Prevention of unwanted pregnancy providing effective and accessible family planning Services;
Using antiretroviral drugs to the women known, to be HIV-infected immediately before and during delivery and to the baby immediately afterbirth;
Making delivery safer, such as preventing prolonged labour and avoiding unnecessary handling;
Considering safe alternative to breastfeeding if possible, stopping as early as is safe;
Transfusing screened-HIV free blood to women and children when necessary.
United Nations General Assembly (2001) stated that "By 2005, reduce the proportion of infants infected with HIV by 20 percent, and by 50 per cent by 2010, by: ensuring that 80 percent of pregnant women accessing antenatal care have information, counseling and other HIV prevention services available to them increasing the availability of and by providing access for HTV-infected women and babies to effective treatment to reduce mother-to-child transmission of HIV as well as through effective interventions for HIV-infected women, including voluntary and confidential counselling and testing, access to treatment, especially anti-retroviral therapy and, where appropriate, breast milk substitutes and the provision of a continuum of care" (United Nations General Assembly, 2001).
Voluntary counseling and testing (VCT): Studies from Africa have shown that counseling and testing is a cost-effective intervention for reducing HIV-related risk-behaviour, particularly when it serves at-risk couple. Experience from Thailand in the early years of me epidemic confirms the value of VCT in contributing to the HIV transmission there as well. In response to global epidemic of HIV, especially in MTCT crisis, VCT is increasingly being found to be an integral part of access to comprehensive, essential quality health care.
For women who are identified before or during pregnancy as being HIV-positive, test-related counseling can help them plan for their future and the future of their families. For HIV-negative women, counseling can re-enforce the importance of safe sexual behaviour and provide other information and support to help them to remain uninfected. VCT services are also an essential prerequisite to identify women who may benefit for certain MTCT prevention interventions.
Antirefrevirai prophylaxis: The risk of MTCT can be reduced by using anti-retroviral drags are now available, Antiretroviral prophylaxis is offered to all HIV-infected women, usually m the form of short course of Zidovudine or a single dose of nevirapine for both the mother and the infant.
The HIVNET 012 two-dose regimen reduces intrapurtum and early postpartum transmission of HIV by nearly 50 percent though it does not prevent later transmission through breastfeeding. Pregnant woman is identified as HIV-positive by VCT and provided with Zidovudine/ Azidothymidine (ZDV/AZT), MTCT can be reduced to a greater extent.
Provider perspective: The provider who assist HIV-positive women during childbirth should also take extra precautions to appropriately disinfect and process all instruments used during childbirth and to clean and disinfect all surface potentially exposed to blood and body fluids of the infected mother.
Conclusion: Prevention of MTCT, the vertical transmission of HIV, recently has drawn the attention of international Development partners within the broader goals of HIV/AIDS prevention and improving overall child health and survival.
Each country is continuing to makes its efforts to combat this unprecedented challenge to human society by implementing national strategic plans with the involvement of all sectors concerned and non-government organisations.
Though Bangladesh is a HIV/AIDS low prevalence country, but faces tremendous challenges due to the prevalence of high risk behaviour of its population, more people in reproductive age- and geographically adjacent to the most HIV/AIDS affected areas of Indian Hill State and Northern Myanmar.
In Asian countries with generous and technical financial resources mother-to-child transmission could be reduced to a minimum level as that of many developed countries like United States. Australia and Europe.
Dr. Md. Abdur Rahman
The author is a Professor and Head, Department of Reproductive and Child Health, National Institute of Preventive and Social Medicine (MPSOM).
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