| More Signs* |
| Written by Kimberly Dayton | |
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According to the Center for Disease Control, more than a million people in the United States are HIV-positive, and 21% of them don't know it. The most effective way to find out if you're infected is to get an HIV test. The virus causes few symptoms until very late in the progression of the disease, when it has spread so far throughout the body and done so much damage to the immune system that the body has deteriorated into full-blown AIDS. At this point, most HIV-infected people have about a year left to live, and they may have been spreading the virus to their sexual partners for over a decade. HIV attacks and destroys white blood cells that ward off infections. It also hijacks the reproductive system of immune cells, by inserting itself into their cellular structure so that when the infected cells reproduce themselves, they also reproduce HIV. Finally, HIV targets the core of the immune system, the master cells that don't fight off germs themselves, but are dedicated solely to the production of new white blood cells when the old white blood cells get too old either to reproduce or to disinfect the body. The first victims of this insidious virus are the immune cells in the lymph nodes and the intestinal lining, which reproduce more quickly than immune cells in most other areas of the body. The cells under attack quickly begin to fight back. In an otherwise healthy host, they are quite effective in preventing HIV from spreading out of the area around the intestine. Then the initial symptoms die off. Because the immune cells are partially successful in warding off HIV, the first symptoms of the infection are hard to distinguish from those of other, less lethal viruses. Indeed, initial HIV infection resembles the flu. Not every newly infected person becomes symptomatic, and the symptoms that do occur are hard to distinguish from flu symptoms. They include fevers, headaches, a sore throat, perhaps a rash, and swollen lymph glands. Even in healthy people, however, the HIV doesn't disappear. It remains in the body, and continues to destroy white blood cells, albeit at a much slower rate than before. The cells targeted by HIV, known as CD4 lymphocytes, are hard for the virus to find and relatively difficult to kill off. For this reason, the disease can take up to eight or nine years to kill you. But kill you it will, because CD4 lymphocytes are the killer app of the immune system. They do most of the heavy lifting in the body's constant war against disease, engulfing and digesting foreign invaders like bacteria, fungi, and viruses. During the long latent phase of HIV infection, some symptoms of a weakened immune system come back periodically and can gradually increase in intensity. The lymph nodes keep swelling. Digestion is difficult, because the body is losing its ability to keep intestinal bacteria in check, so HIV patients may have chronic diarrhea, frequent coughs and fevers, or weight loss. Even in this period of latency, HIV-positive people are more susceptible than the non-infected population to two types of cancer: Kaposi’s sarcoma and Non-Hodgkin's Lymphoma. The former condition shows up as tongue and mouth sores that appear pink, purple or red in people with light skin, and brown or black in dark-skinned people. The sores are caused by tumors in the walls of blood vessels. Kaposi's Sarcoma can also cause tumors in the blood vessels lining the lungs and the digestive tract. However, antiretrovirals appear to decrease the risk of this particular type of cancer, possibly by slowing down the spread of HIV in the body. The latter type of cancer, non-Hodgkin's lymphoma, affects white blood cells in the skin, the digestive system, the bone marrow, and the lymph nodes. The most common symptom is swollen lymph nodes. This type of cancer also occurs in the general population, but it is more common among HIV infected patients. A decade after the initial infection, HIV-positive people who haven't been taking anti-retrovirals begin to suffer more severe symptoms. Their immune systems have grown too weak to fight off most infections. The symptoms are not caused only by HIV, but also by opportunistic infections -- diseases that people with healthy immune systems can fight off, but HIV-positive people can no longer resist. An example of such an infection would be PCP, a rare form of pneumonia. The symptoms of PCP and other opportunistic infections can include distorted or blurred vision, dry coughs, constant diarrhea, high fevers and chills that last for weeks, headaches, weight loss, distorted or blurred vision, and chronic tongue or mouth sores. Late stage HIV does cause symptoms of its own, such as chronic fatigue, night sweats, and swollen lymph nodes, but they often overlap with those of opportunistic infection. In about 10-20% of HIV victims in Western countries, HIV can infect brain cells during late-stage HIV and cause dementia. Signs of advanced HIV infection -- in other words, the tangible measures of changes in the body that tell a doctor that HIV has spread quickly throughout the body-- include a positive HIV-antibody test, and a CD4 lymphocyte count of less than 200 CD4 cells in a microliter (millionth of a liter) of blood. In healthy people, the ratio is between 800 and 1200 cells per microliter. Although HIV causes AIDS, HIV infection and AIDS are not the same thing. Since the development about 15 years ago of anti-retroviral drugs, which can slow down the spread of HIV and postpone the day of reckoning when HIV overwhelms the immune system, the CDC has developed a specific definition of AIDS (Acquired Immune Deficiency Syndrome) that distinguishes it from mere HIV infection. People have AIDS when they meet two out of three criteria -- they test positive for HIV antibodies, their CD4 count is 200 or less, and/or they have an opportunistic infection such as CDC. These criteria are used to distinguish the majority of HIV positive people, whose infection is still under control, from those in which the immune system has deteriorated beyond repair. Even with anti-retrovirals, HIV infection will eventually develop into AIDS, which is fatal. Most people who've been diagnosed with AIDS will die within a year. However, in the years since 1996 when the first anti-retrovirals became available, HIV-infected people have been able to prolong their healthy lives by anywhere from four to twelve years, depending on how strong their immune systems were before they became infected and how well they've taken care of themselves after the infection. *http://www.cdc.gov/hiv/resources/factsheets, http://www.hivla.org/factsheets/index.html, http://www.webmd.com/hiv-aids/default.htm, http://aidsinfo.nih.gov/, http://en.wikipedia.org/wiki/HIV/AIDS/, http://www.avert.org/aids.htm, http://www.mayoclinic.com/health/hiv-aids/ds00005 |
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