Wednesday, February 9, 2011

How Is Aids Caused

AIDS (Acquired Immunodeficiency Syndrome) is a disease caused by a virus called HIV (Human Immunodeficiency Virus). HIV is transmitted through the exchange of infected bodily fluids such as blood, semen, vaginal fluids or breast milk. Once an individual is infected with HIV, his immune system may be compromised such that he develops AIDS, a serious life-threatening condition. At one time, an HIV/AIDS infection was akin to a death sentence. Due to advances in medicine, there are now pharmaceuticals that counteract the HIV virus, AIDS, as well as secondary conditions. These medicines can extend the lives of those infected with HIV/AIDS, but they cannot cure the body of the HIV virus completely.


History


Scientists believe that the HIV virus originated in nonhuman primates in Sub-Saharan Africa and that it was first passed to humans in the early part of the 20th century. However, it was not until the late 1970s and early 1980s that AIDS first came to the attention of medical and public health professionals.


Symptoms


The most severe symptoms of HIV occur right before or in conjunction with the actual onset of AIDS. These symptoms include persistent fatigue, soaking night sweats, shaking chills or fever higher than 100 degrees Fahrenheit for several weeks, dry cough or shortness of breath, persistent white spots or unusual lesions in the oral cavity, chronic diarrhea, headaches, blurred or distorted vision and weight loss.


The actual onset of AIDS occurs when these symptoms, plus one of the following, are found in the infected individual:


1. The development of an opportunistic infection such as Pneumocystis carinii pneumonia (PCP), Kaposi's sarcoma, cervical cancer or lymphoma


2. A CD4 lymphocyte count of 200 or less (a normal count ranges from 800 to 1,200).


In children, HIV infection is related to adverse motor development, delayed mental development, stunted growth and difficulty maintaining or gaining weight.








Mechanisms


HIV is a retrovirus that works by destroying healthy white blood cells known as T cells or CD4 lymphocytes. As a retrovirus, HIV stores its genetic information as RNA rather than DNA. The HIV virus enters a healthy human cell where it releases its RNA. An HIV virus enzyme, transcriptase, then makes a DNA copy of the HIV RNA, infecting the healthy cell with HIV DNA. It is by infecting and destroying white blood cells that the HIV virus spreads through the body. As these white blood cells are destroyed, it becomes harder for the body to fight off infection, thus leading to the onset of AIDS.


Treatments


When HIV and AIDS first surfaced in the early 1980s, there were no effective treatments for the diseases. In 1989, doctors began treating HIV infection with antiretroviral drugs. These drugs stop the growth and replication of the HIV virus. While there is still no complete cure for HIV and AIDS, antiretroviral drugs have proven to be effective in increasing the lifespan and quality of life for those infected.


Conclusion


AIDS is caused by the advanced progression of the HIV virus along with the onset of a secondary infection. Although its symptoms can be alleviated or suppressed, there is no cure currently available.

Tags: blood cells, onset AIDS, white blood, white blood cells, actual onset