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the immunity system

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Name Elaheh Mokhtari Issue HIV Word count 1,870 Target audience University students interested in HIV prevention . HIV and AIDS Many young people in Britain think that AIDS has gone away. Although there are treatment drugs for the disease but there is no cure yet. AIDS first surfaced in Africa in 1977-78. There are two types of HIV virus. HIV1 and HIV2. HIV1 is more common than HIV2. There are around 30.8 million adults and 2.5 million children infected with HIV. Around 11% of infections are babies, who acquire the virus from their mother during her pregnancy, Delivering or breast milk. 10% are due to drug infections, 5-10% is from sex between men and 5-10% is from health care setting. Around 2/3 of new infections are due to sex between men and women. The immunity system The immune system has a very important role in all vertebrates' bodies. The immune system's job is to protect the body from infections. It does that by finding out which cell belongs to the body and which does not. The immunity system does this by looking for antigens. Antigens are little marks that we can count them as being little uniforms for cells. All the cells in our body have the same uniform whereas they all have different uniforms from our body cells. We can not point to one part of our body and say that is the immune system. ...read more.


The CD4 protein is a part of a helper T cell (Th1 and Th2). Thus HIV targets especially T-cell with special CD4 which is a specific receptor for HIV. However other cells can become infected by the HIV virus. During the first stages of infection a number of T-cells will be killed by the virus. Here the symptoms of an infection which is infecting the immune system such as fever, headache, and tender lymph nodes and generally feeling unwell will display. However the speed of infection stabilises once the antibodies have formed by B-cells. The HIV virus has not been destroyed but all the symptoms will disappear for months to even several years. Here the virus has been stabilised and it will continue to grow even at a much slower rate. The person who is infected by HIV becomes very weak. When a microbe enters the bloodstream the immune system sends T-cells to fight the microbe but as the T-cells are infected, they are weaker than normal T-cells so they can be killed very easily from a microbe attack or they start to divide to make more T-cells. So more infected T- cell will be produced. As time passes the amount of virus in the body will increase until it reaches a certain level. The number of T-cells will decrease. This makes the immune system totally useless. Table 1 shows the diseases that usually define the beginning of AIDS. ...read more.


One third of all babies who have been given birth by an untreated pregnant woman infected with HIV will infected. However if an infected pregnant woman takes drug AZT during her pregnancy she can significantly reduce the chances that her baby becomes infected. The pregnant woman also needs to deliver her baby by caesarean section (an operation to deliver a baby through its mothers abdominal wall) to reduce the chances of baby being infected to a rate of 1 percent. NIAID (National Institute of Allergy and Infections Diseases) in Uganda found a very effective and safe drug which is more affordable. The drug is called antiretroviral drug nevirapine/ NVP. A HIV infected woman needs to take a single oral dose of NVP and her baby within 3 days of birth needs to take one to reduce the transmission rate of HIV to half percent compared with AZT. Transmission through blood HIV is also transmitted by sharing equipment during intravenous drug abuse and by blood products. Sharing needles, syringes, drugs and other drug equipments can put drug users at a high risk of becoming infected with HIV even if syringes and needles are sterile. HIV can also be transmitted by blood products. Blood screening is now carried out in all developed countries before any blood has been used in surgeries. Blood screening reduces the risk of HIV being transmitted through blood to less than 1 in 500000 pin. HIV can be transmitted by tattooing, skin piercing and cutting. Health care workers (lab technicians, cleaners) are also at risk for becoming infected with HIV during clinical or surgical procedures. ...read more.

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