Infectious Diseases Assignment Hiv

Infectious Diseases Assignment 2: HIV

1.2 The Characteristics of HIV

The HIV virus is a retrovirus, with a viral centre which is which is bullet-shaped and is made from protein. Inside the centre are three enzymes required for HIV copying called 'reverse transcriptase, integrase and protease' (1). Also held within the centre is HIV's genetic material, which consists of two identical strands of RNA. This is why HIV is called a retrovirus. The virus is surrounded with a coat of fatty material known as the viral envelope. Projecting from this are about 72 little spikes, which are important in joining onto exact host cells, called T Helper cells. HIV, like all viruses, can only copy inside human cells. The process normally begins when a virus particle bumps into a cell that carries on its surface a special protein called CD4 (1). HIV gets into the patients DNA and becomes part of the patient's genetic material. When you give a patient a particular antiretroviral (ARV) (the drugs for HIV patients) then the virus can often develop resistance to the drug. That means the drug can no longer kill the virus as the virus changes. So 3 ARVs are usually given at once, as then the virus needs to develop 3 changes at once to become resistant and that is very hard to happen.

2.3 Why Eradication of HIV is a Priority

Eradication of HIV is a priority because there are many economic, social and medical problems that it causes;

Inadequate health care (2): Many people learn about HIV prevention from their health care provider. But for those who lack insurance, money to pay for health care and drugs, or who live too far from a clinic, it may be difficult to get information about HIV prevention, or to obtain adequate care if they become ill.

Poverty (2): The poor are more vulnerable to HIV/AIDS because they are less likely to be educated about prevention. If they cannot afford adequate food, they may become malnourished, making them more vulnerable to infection. They are also less likely to be able to afford medical care and drugs if they do become infected.

Discrimination (2): People who face discrimination - whether on the basis of their gender, ethnicity, race or other factors - often find it difficult to obtain jobs that will keep them out of poverty. They may be less likely to go to school or complete school, and may have less access to health care, it less likely that they will know how to protect them from HIV infection.

Women's inequality (2): In many countries, girls and women have less social status than boys and men. They may be denied the right to go to school or complete their education. They may have little or no choice over who they marry, and may be forced into having sex against their will. When women are not able to control their own bodies or resist pressure to have sex, they are more vulnerable to HIV infection.

3.2 The Primary and Secondary Immune Response

Primary immune response is the body's first line of defence. It involves in general only the macrophages of the lymph system which will consume any foreign material and cells which they discover in the body tissues. Secondary immune response or Induced immune response doesn't activate for several days, when infections are prolonged or widespread enough that the macrophage/complement system cannot purge them itself. It involves the induction of T-cell and B-cell mediated defence, wherein antibody mediated cell clearing or induced apoptosis occurs, isolating invader cells or killing infected cells respectively. The reason why a secondary response has a greater intensity and produces more antibodies is that there are pre-formed; specially designed memory cells that recognize the pathogen, and are ready just start functioning. In the primary response, your body first has to go through a demanding process of finding lymphocytes that can bind to the antigen. This can take a little bit of time, but once such lymphocytes have been found, they multiply, and they can hopefully help eliminate the pathogen. A few of these specific lymphocytes differentiate into memory cells, which circulate in the body for a long time, and are ready to act whenever the pathogen returns - this time the body knows just what to do - and they can do it faster and more efficiently.

3.1 Immunity, Immunisation and How Vaccines Work

Immunity to any disease is based on current and historical information. Viruses and some bacteria are naturally different to one another and mutations will mean that there will be a population of them that will be able to take the place of the others which have been stopped by immunity. Sometimes this happens quickly, and others it happens slowly. These "new" strains then become the dominant