DRUG DISCOVERY:
HIV/AIDS
The Human Immunodeficiency Virus, more commonly known as HIV, is a virus that attacks the body's immune system. Spread through contact with blood, breast milk, and other bodily fluids, HIV enters the bloodstream and attacks the cells, specifically the CD4 cells, or T-Helper cells. Once infected with HIV, the individual carries it for life. HIV is considered a retrovirus due to the fact that it infects cells by placing copies of its own RNA into the CD4 cells.
AIDS, or Acquired Immunodeficiency Syndrome, is the final stage of an HIV infection. When someone's CD4 cell count falls below 200 cells per cubic millimeter of blood (200 cells/mm3) or if they develop one or more infections/cancers while being infected with HIV, then they are considered to have AIDS. Someone with AIDS has a severely weak immune system and may require extensive medical care. Presently, no cure for an HIV infection or AIDS exists.
What is HIV/AIDS?
How did HIV/AIDS Originate? How is it Transmitted?
HIV originated from the Simian Immunodeficiency Virus, which is a virus that attacks the immune system of chimpanzees. Scientists believe that it was transmitted from the chimpanzee to humans due to an open-wound contact with the blood of the chimpanzee. From then on, "a roaring sex trade, rapid population growth, and unsterilized needles used in health clinics" caused the virus to instantly spread along Kinshasa and to other regions in Africa (2.4).
The virus enters a person's body through contact with bodily fluids. More commonly, HIV is transmitted from person to person by unprotected sexual intercourse and by sharing unsterilized needles and syringes. However, the virus can also transfer from mother to child during pregnancy, birth, and breastfeeding. The chance of transmitting HIV may be reduced by taking antiretroviral treatment, but this may not always be the case. Although HIV positive people may have an undetectable viral load, they still run the risk of transmitting the virus. For this not to happen, an HIV-positive person and their partner must exercise caution to reduce the possibility of transmission.
Once the HIV virus enters the bloodstream through contact with blood, it attaches to the CD4 (T-helper) cells and inserts its RNA past the cell membrane and into the cytoplasm. The single-stranded RNA is then interpreted into DNA, which is then recognized as the cell's own. As a result of this, the cell creates more copies of HIV, worsening the infection.
The reason why HIV targets the CD4 cells is because they are a vital part of our immune system. Though they do not fight infections directly, the cell activates and warns the cytotoxic T-cells and B cells about the invasion. It is then up to the cytotocxic T-cells and B cells to attack the invading bacteria or virus.
As HIV targets these cells, they alter their purpose. Instead of fighting against invasions, the CD4 cells actively create copies of the harmful virus, leaving the immune system vulnerable to many bacteria-causing diseases or viruses.
How does HIV Attack the Body?
What are the Symptoms and Signs of an HIV Infection?
The first stage of an HIV infection is called Acute HIV Infection. Within the first few weeks of HIV invading the body, people usually experience an illness similar to the flu. This is the body's normal reaction to a foreign invasion, so one might not think that they have been infected, and just believe it to be a common flu. This stage is also characterized by a large amount of HIV in the body, as well as being more contagious.
The next stage is Clinical Latency, often called Chronic HIV Infection. In this stage, the virus is still multiplying; however, it is going at a slower rate and at very low levels. Many still do not experience many symptoms during this time. If antiretroviral medication is taken at this time, this stage can extend for several decades, allowing one to live a normal lifestyle. People are still able to transmit HIV in this stage, but for those taking ART, they have a lower transmission rate. As the phase draws near to its end, a person experiences an increase in their viral load of HIV and their CD4 cell count starts to lower. In result, they start having different symptoms and move to the third stage of the infection.
AIDS, or Acquired Immunodeficiency Syndrome, is the last stage of an HIV infection. It is the most severe stage, as it weakens the body's immune system and leaves it susceptible to many opportunistic illnesses. Without treatment, people usually survive for three years. Symptoms of AIDS are chills, weight loss, fever, swollen lymph glands, and weakness. The CD4 cell drops below 200 cells/mm and people in this stage have a higher chance of transmitting the disease.