AIDS

        AIDS is an insidious and up to the present moment incu­rable but less contagious disease than measles or hepatitis B.AIDS is thought to be caused primarily by a virus that invades white blood cells (lymphocytes) and certain other body cells, including the brain. 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 НГѴmay 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, cytome­galovirus, massive herpes infections, special forms of pneu­monia that kill in half of all AIDS patients.

       That is AIDS. There are several types of AIDS. No one has been cured up to the present moment.

QUESTIONS:

1.  Is AIDS curable?

2.  Is AIDS very contagious disease in comparison with other viruses?

3.  Who and when identified the virus?

4.  What is HIV?

5.  What rare capacity for viruses has HIV?

6.  Does НIV kill the carrier instantly?

7.  Can HIV kill human body itself?

VOCABULARY:

insidious — коварный

incurable — неизлечимый

contagious — заразный

measles — корь

hepatitis В — гепатит Б

to cause — причинять, быть причиной

to invade — зд. вторгаться

white blood cells — белые кровяные тельца

lymphocytes — лимфоциты (белые кровяные тельца)

researcher — исследователи

to identify — идентифицировать; зд. выделить

retrovirus — ретровирус

HIV — ВИЧ

gene — ген

DNA — ДНК

trigger — «пусковой механизм»

to replicate — реплицироваться, размножаться

the initial infection — первоначальное инфицирование

latent period — латентный (скрытый) период

to harbour — зд. иметь, носить

dormant — спящий

to spread (past spread, p.p. spread) — распространять(ся)

merely — просто

to render — делать, превращать

yeast — зд.грибок

toxoplasmosis — токсоплазмоз

cytomegalovirus — цитомегаловирус, ЦМВ

massive herpes infections — тяжелая форма герпеса

AIDS patient — зд. больной СПИДом