Overview
HIV, which stands for human immunodeficiency virus, is the cause of acquired immunodeficiency syndrome. The virus is transmitted through contaminated bodily fluids and it attacks the immune system. As the immune system gets weaker, patients develop AIDS, which is ultimately fatal.
Transmission
HIV is transmitted through contaminated body fluids, according to Avert.org. People can become infected with HIV by having sexual intercourse with an infected person or by sharing needles or syringes with a person who is HIV-positive. Infected mothers can also pass the virus along to her baby during labor, pregnancy or during breastfeeding. HIV can also be transmitted by receiving contaminated blood products, but this is rare because blood donations are screened for the virus.
CD4 T Cells
HIV infects a type of cell called CD4 positive T cells, according to AIDSInfo. T cells are a type of white blood cell and are essential for the body’s ability to fight off infections. Some T cells have a protein called CD4 on it. In order to enter a cell, HIV binds to CD4 as well as other proteins on the surface of the T cell. It then is able to enter the cell and hijack the cell’s machinery, which allows HIV to replicate.
Symptoms
The early symptoms of an HIV infection typically occur a few weeks after the virus has been transmitted. Patients with an acute HIV infection often develop flu-like symptoms that can include a fever, diarrhea and swollen lymph nodes, according to MedlinePlus, a medical information resource established by the U.S. National Library. After the initial symptoms have passed, most patients don’t have symptoms for many years. However, as the immune system weakens, patients become prone to other infections, including some infections that typically only affect patients with weakened immune systems. This diseases, termed opportunistic infections, include rare kinds of pneumonia, brain infections and fungal infections. Late-stagee HIV infections can also cause a prolonged fever, swollen lymph nodes, diarrhea and the appearance of discolored blotches on the skin.
Testing
The main test that is used to screen patients for an HIV infection measures a kind of immune protein called an antibody, according to MedlinePlus. Antibodies to HIV are produced when a patient is infected with the virus. It typically takes six weeks for the body to produce antibodies to HIV, so the test can only give a positive test after at least six weeks have passed since the initial infection. If a person has a positive antibody test for HIV, it is usually repeated. If the second test is also positive, a more accurate test, which detects proteins that the virus makes, is used. Patients who are positive on this test as well, have been infected with HIV.
Treatment
HIV is a retrovirus, which means that its genetic material has to be converted from RNA into DNA for it to replicate. Many different HIV medications target the mechanism by which this process occurs. Patients who are HIV-positive typically receive Highly Active Anti-Retroviral Therapy, which is commonly abbreviated HAART. HAART usually involves a combination of different medications that block points of the virus’s life cycle in an attempt to slow its reproduction. Although HAART cannot cure an HIV infection, it can slow the disease’s progression.
About this Author
Adam Cloe has been published in various scientific journals. He is an M.D./Ph.D. student at the University of Chicago. He has a Bachelor of Arts in biochemistry from Boston University, where he won an award for excellence in undergraduate science writing.
