Ethical, Economic & Social Issues
AIDS results from the specific damage HIV inflicts on the immune system, and is the collection of illnesses suffered as a consequence. These symptoms may not develop until long after infection, and a sufferer might not know they have the virus, but can still transmit it to others. In my view, governments should attempt more vigorous screening, preventing thousands from unknowingly transmitting HIV through intercourse and pregnancy. This is undoubtedly one of the most prominent ways in which HIV is spread.
However, HIV test results are never 100% accurate and can incur prejudice. When applying for insurance, people are asked if they have had an HIV test or counselling. Although life-insurance companies are now under pressure to replace such questions by asking only if they have had a positive test, this offers no reassurance to those with the possibility of a positive result. In some areas, being known as an HIV sufferer is too great a risk.
Under-developed countries have the highest HIV rates but insufficient money for adequate medical resources to implement preventative methods. Only 8% of HIV positive women have access to treatment, counselling and testing.
Due to social or political circumstances the mother may not be educated about the virus or how to prevent infection. This has a huge impact on whether or not her baby receives adequate help to prevent transmission.
The disease has a marked impact on particular countries. In some areas of Sub-Saharan Africa, its prevalence is so high that it has reduced life expectancy by 20 years and more than 1 in 3 people have HIV.
Benefits and risks of anti-viral drugs
In the drug trial described above, toxic effects of zidovudine included lower haemoglobin at birth in the babies. However, after 12 weeks this abnormality had subsided, and the haemoglobin levels of the infants in each group were similar (.). Although encouraging, there may be alternative treatments which are much simpler and in fact cheaper………………
Nutrition
The book “Clinical Nutrition” describes research in Tanzania on the effects of nutrition on maternal-infant HIV transmission. A multivitamin supplement reduced low birth weight and foetal deaths by 40% and caused an increase in T-helper cells. Micronutrient deficiency has been associated with accelerated progression of HIV in several studies. For example, vitamin A deficiency causes increased mortality, greater risk of transmission of HIV via pregnancy, growth problems in HIV-positive children and a greater viral load in breast milk and the genital tract. I would consider micronutrient supplements one of the most promising treatments in the developing world, where deficiency is common and can be prevented with little cost.
Caesarean section
A caesarean section delivers the baby through an incision in the mother’s lower abdominal wall and uterus. In HIV-positive mothers it is done to protect the baby from direct contact with her bodily fluids, which contain the HIV virus.
This quote, as recent as November 2005, was supported by a 2003 study including 149 women, and considered valid enough to be published in PloS medicine. Although the source strongly recommends caesarean delivery, this advice is currently being reconsidered, see the quote below from a WHO report. Women taking specific drug combinations during pregnancy are told that caesarean section is not a significant method in preventing mother to baby HIV transmission. It’s rarely advised unless the mother is ill with the virus, or has a detectable viral load. I believe having a caesarean presents an unnecessary risk for the mother. An anaesthetic is used, the woman is more prone to bleeding following delivery and their babies have an increased risk of breathing difficulties.
In contrast, in patients with multi drug-resistant HIV, a specific drug with poor penetration into the genital tract may be advised and the HIV virus here may remain comparatively active. Mothers who need to have this drug treatment require a caesarean section to avoid active viral DNA coming into contact with the baby.
Bottle-feeding
The World Health Organisation recommends avoidance of all breastfeeding when replacement feeding is affordable, feasible, acceptable, sustainable, and safe. HIV-infected T-helper cells are within breast milk and may otherwise be passed on to the baby.
Many HIV-infected women live in conditions that prevent them from having safe access to breast milk substitutes. These women are advised to give exclusive breastfeeding followed by early breastfeeding termination. If the child is fortunate, HIV will not be transmitted and the breast milk provides other antibodies to protect against unrelated infections, which could offset the increased risk of mortality from HIV. In my opinion, agencies should invest money in providing such substitutes. Anything else they are putting money into is surely not as valuable as having more than 85% of people currently in affected areas alive in 20 years time.
Future developments: RNA interference:
mRNA carries instructions encoded in our DNA to ribosomes. RNA interference (RNAi) disrupts this process. With HIV it could prevent viral DNA from generating proteins. Alternatively it may alter the receptors of T-helper cells, preventing the membrane from fusing with that of an HIV molecule. However, HIV has a high mutation rate and changes rapidly to different strains of the virus. The RNAi is specific to the target cell and must therefore be regenerated in this instance. Other obstacles in development are delivery of RNA molecules into cells and the chance of side effects. This is discussed in a medical research article in the magazine ‘Wellcome Science’. The article is based on peer-reviewed results that have gone through all the stages of ensuring they are valid, addresses the complications with research progression, and does not present a one-sided or biased viewpoint. If everyone in the world had access to treatment, HIV would be an entirely different prospect. The biology is well understood, but currently only helps around 10% of HIV-positive pregnant women. I wrote this report with the aim of motivating people to see the potential and to change the fact that a child’s risk of getting HIV is currently dependent on its parents’ nationality and circumstances.
Bibliography
Piwoz EG, Ross JS. J Nutr. 2005 May; 135(5):1113-9.
Welcome Science - October 2005 edition
Clinical Nutrition – Edited by Michael J. Gibney, Marinos Elia, Olle Ljungqvist and Julie Dowsett
AIDS AND SOUTH AFRICA The Social Expression of a Pandemic. Edited by Kyle D. Kauffman and David L. Lindauer
Strategic approaches to prevention of HIV infection in infants: report of WHO meeting March 2002
Word Count = 2083
Appendix – Biology of HIV
The HIV virus is transmitted in blood, semen, vaginal fluid and breast milk. Infection may occur following sex, sharing needles and, up to 1985, from receiving a blood transfusion. HIV-infected mothers can also pass the virus to their babies during the perinatal period or in breastfeeding.
The virus has entered the body. How does it become incorporated with the DNA of the sufferer?
- Viral gp120, a surface glycoprotein on HIV encounters a T-helper cell, which has a CD4 glycoprotein molecule on its surface.
- The membranes of the HIV particle and T-helper cell fuse, releasing the contents of the HIV particle.
- The capsid, a core shell surrounding structures within the virus, dissolves, releasing viral RNA and reverse transcriptase.
- Reverse transcriptase turns RNA into DNA, which enters the host nucleus and combines with its DNA.
- Viral DNA is transcribed to from mRNA, which leaves the cell and is translated to form viral proteins.
- The immune system is weakened: T-helper cells, used as hosts then destroyed by HIV, are essential to the immunological response. When stimulated by a particular antigen, they release peptides that signal between cells and promote B- and T-cell activation. Without T-helper cells, the body becomes vulnerable to infection.
- HIV overwhelms the immune system and infections that a healthy person could manage become life threatening.
Commentary
1. Biological methods and processes used.
The problem of HIV transmission from mother to child is described in some detail and clearly identified (4). There is an excellent description of the methods used to solve this (4) together with a really good discussion of why they are appropriate and effective. Relevant data, charts and evidence for the effectiveness of anti-viral treatment is given (4). There is also a look into the future using RNAi but together with a critical opinion on the effectiveness of this due to the adverse social and economic conditions in some parts of the world. The detail on the biology of HIV is useful for the discussion but not really essential.
(12 marks)
2. Applications and implications of the biology encountered
Notice that this part is to with applied biology and in this case, ethical, social and economic implications are described in detail with supporting evidence and data (4). Side effects and implications of the treatments are discussed (3) although there could perhaps be more on this. There is also a good discussion of alternative methods such as Caesarean section, nutrition and bottle feeding. (4)
(11 marks)
3. Evaluation of source material
There is a good range of sources (4), both web based and non web based and quotes are acknowledged throughout the report (4). There is good evaluation of 4 of the sources although perhaps a little more evidence could have been given to support this. For example, ‘The article is based on peer-reviewed results that have gone through all the stages of ensuring they are valid, addresses the complications with research progression, and does not present a one-sided or biased viewpoint’ – this is excellent but some evidence would have been good. (3)
(11 marks)
4. Communicate clearly, concisely and logically
The report is very well set out and presented; spelling, punctuation and grammar are fine, there are some excellent ‘visuals’ and the technical language is very good (2).
(4 marks)
Overall mark – 38 marks out of 40 (an excellent piece of work)
