Disease of the 20th century
- 4
- 0
- Опубликовано: 2018-06-14
AIDS is an acronym for Acquired Immune Deficiency Syndrome and is thought to be caused primarily by a virus that invades white blood cells (lymphocytes) and certain other body cells including the brain.
Although treatments for both AIDS and HIV exist to slow the virus' progression in a human patient, there is no known cure. The rate of clinical disease progression varies widely between individuals and has been shown to be affected by many factors such as host susceptibility.
AIDS is thought to have originated in sub-Saharan Africa during the twentieth century and is now a global epidemic.
In 1983 and 1984, French and U.S. researchers independently identified the virus believed to cause AIDS as an unusual type of slow-acting retrovirus now called « human immunodeficiency virus » or HIV. Like other viruses, HIV is basically a tiny package of genes. But being a retrovirus, it has the rare capacity to copy and insert its genes right into a human DNA.
Once inside a human host cell, the retrovirus using its own capacities begins to copy its genetic code into a DNA molecule which is then incorporated into the host's DNA. The virus becomes an integral part of the person's body. But the viral DNA may sit hidden and inactive within human cells for years, until some trigger stimulates it to replicate.
Thus HIV may not produce illness until its genes are «turned on» five, ten, fifteen or perhaps more years after the initial infection.
During the latent period, HIV carriers who harbour the virus without any sign of illness can unknowingly infect others. On average, the dormant virus seems to be triggered into action three to six years after first invading human cells. When switched on, viral replication may speed along, producing new viruses that destroy fresh lymphocytes. As viral replication spreads, the lymphocyte destruction virtually sabotages the entire immune system.
In essence, HIV viruses do not kill people, they merely render the immune system defenceless against other infections, e.g. yeast invasions, toxoplasmosis
Although treatments for both AIDS and HIV exist to slow the virus' progression in a human patient, there is no known cure. The rate of clinical disease progression varies widely between individuals and has been shown to be affected by many factors such as host susceptibility.
AIDS is thought to have originated in sub-Saharan Africa during the twentieth century and is now a global epidemic.
In 1983 and 1984, French and U.S. researchers independently identified the virus believed to cause AIDS as an unusual type of slow-acting retrovirus now called « human immunodeficiency virus » or HIV. Like other viruses, HIV is basically a tiny package of genes. But being a retrovirus, it has the rare capacity to copy and insert its genes right into a human DNA.
Once inside a human host cell, the retrovirus using its own capacities begins to copy its genetic code into a DNA molecule which is then incorporated into the host's DNA. The virus becomes an integral part of the person's body. But the viral DNA may sit hidden and inactive within human cells for years, until some trigger stimulates it to replicate.
Thus HIV may not produce illness until its genes are «turned on» five, ten, fifteen or perhaps more years after the initial infection.
During the latent period, HIV carriers who harbour the virus without any sign of illness can unknowingly infect others. On average, the dormant virus seems to be triggered into action three to six years after first invading human cells. When switched on, viral replication may speed along, producing new viruses that destroy fresh lymphocytes. As viral replication spreads, the lymphocyte destruction virtually sabotages the entire immune system.
In essence, HIV viruses do not kill people, they merely render the immune system defenceless against other infections, e.g. yeast invasions, toxoplasmosis
Комментариев нет
оставить комментарий могут только авторизованные пользователи
| без названия | Все работы автора | Следующая работа |
