HIV

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HIV (standing for Human immunodeficiency virus) is the retrovirus (virus that usesRNA rather than DNA as its genetic material), that leads to the condition known of as AIDs (Acquired Immune Deficiency syndrome).

Contents

How HIV works

The virus works by attaching itself to receptors on the surface of white blood cells, including lymphocytes, in particular CD4+T4 cells [1] , (an important part of the body’s immune system). By attaching to this receptor the virus gains the ability it access the inside of the cells. As well as the RNA genetic material thevirus will also include the protein reverse transcriptase. This is used to reverse engineer the DNA strand that is complementary to the cells RNA. This DNA then integrates into the white blood cells own DNA, using a protein called intergrase, also present in the virus capsid. The cell now starts to produce progeny viruses. These viruses then multiply till they burst out the cell and move on to affect other cells. This effectively destroys their host cells, and those weakens theimmune system (due to the cells important role in the immune system) [2][3].

Spread of HIV

HIV is avirus and such can be passed from one person to another. This is done through the exchange of bodily fluid; e.g. through unprotected sex, from mother to fetus, or sharing a needle.

Symptoms

Initially HIV is likely to cause fever like symptoms 3-4 weeks after infection. This will soon subside however as the sufferersimmune system manages to control the virus, although it is never truly irradiated. This then leads ion to a stage called the latent period. During this time patients will often experience no symptoms, which is often why people don’t know they have contracted HIV till a while latter. This latent stage can last up to several years. Some people may then progress to have AIDs, but this occurs at different rates in different people and may never even happen in some (these people are given the term nonprogressors). A sufferer is classed as having AIDs when he/she has 1 or more opportunistic infection and 200 or less CD4+T4 cells per ml cubed of blood. The sufferers immune system however will be impaired so even if they don’t have symptoms directly from HIV, they are more susceptible to other infections, which will intern have their own symptoms [4] .

Treatment

Currently there is no cure, but treatment methods exist to increase quality of life and potential life span. This tends to be a combination of antiretroviral drugs, known as antiretroviral therapy. This hiders the viruses ability to replicate, slowing down the speed and reducing viral count. Over time the drugs can stop having an effect and new combinations need to be formed. This treatment isn’t overly pleasant and can often have undesirable side-effects such as; diarrhoea, fever, weakness or the deposition of fat at lower back forming what is known as ’buffalo hump’.

References

  1. Dr Richard Hunt (2009), HUMAN IMMUNODEFICIENCY VIRUS AND AIDS THE COURSE OF THE DISEASE [online]. Available at: http://pathmicro.med.sc.edu/lecture/HIV3.htm [Assessed date: 23/11/14]
  2. Ali A. Al-Jabri (2003), How does HIV-1 infect a susceptible human cell? [online]. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3174721/ [Assesed date: 16/11/2014]
  3. John Pickrell (2006), Introduction: HIV/AIDS [online]. Available at: http://www.newscientist.com/article/dn9948-instant-expert-hiv-and-aids.html#.VGjuR_msVrY [Assessed date: 16/11/14]
  4. Pubmed (2013), HIV/AIDS [online]. Available at: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001620/ [Assessed date: 16/11/2014]
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