文档介绍:AIDS
1. Concept
Acquired immune deficiency([di'fiʃənsi]) syndrome(['sindrəum])(获得性免疫缺陷综合症) or acquired immunodeficiency([i'mju:nəudi'fiʃənsi]) syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV)(人类免疫不全病毒).
It is transmitted through direct contact of a mucous membrane(['mju:kəs] ['membrein]粘膜) or the bloodstream (血液流动) with a bodily fluid containing HIV, such as blood, semen, vaginal fluid, preseminal fluid, and breast milk.
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ic research indicates that HIV originated in west-central Africa during the late eenth or early twentieth century. AIDS was first recognized by the . Centers for Disease Control and Prevention in 1981 and its cause, HIV, identified in the early 1980s. AIDS is now a pandemic.
a)Sexual transmission
The majority of HIV infections are acquired through unprotected sexual relations between partners, one of whom has HIV. The primary mode of HIV infection worldwide is through sexual contact between members of the opposite sex.
b)Exposure to blood-borne pathogens(['pæθədʒən] 病原体)