什麼是人類免疫不全病毒

全名作human immunodeficiency virus

與愛滋病相關的反轉錄病毒。HIV病毒攻擊並逐漸破壞免疫系統，導致受體不能抗禦感染。它不會通過偶然的接觸傳播，而主要通過血液和血製品（例如共用皮下注射的針頭或者偶然被感染過的針頭刺中）、精液和婦女的陰道分泌液或者乳汁來傳播。懷孕的婦女可以通過胎盤將病毒傳給胎兒。病毒首先在接近感染部位的淋巴結中繁殖起來。通常約十年後，病毒擴散到全身，這時就會出現症狀，標誌着愛滋病的開始。多種藥物合成的「雞尾酒」可以推遲症狀的發生，但是劑量不足會導致抗藥性。像其他的病毒一樣，HIV病毒也需要一個主體細胞來繁殖。它攻擊輔助T細胞並感染其他的細胞。一次快速的突變率可以幫助它既擊垮免疫系統又對抗藥物治療。還沒有疫苗或治癒的方法。在性方面不要濫交，使用安全套或其他的手段來避免通過性來傳播疾病，還要避免共用針頭，在有些地區採取這些措施後已經降低了感染率。

HIV

Retrovirus associated with AIDS. HIV attacks and gradually destroys the immune system, leaving the host unprotected against infection. It cannot be spread through casual contact, but instead is contracted mainly through exposure to blood and blood products (e.g., by sharing hypodermic needles or by accidental needle sticks), semen and female genital secretions, or breast milk. A pregnant woman can pass the virus to her fetus across the placenta. The virus first multiplies in lymph nodes near the site of infection. Once it spreads through the body, usually about 10 years later, symptoms appear, marking the onset of AIDS. Multi-drug “cocktails” can delay onset, but missing doses can lead to drug resistance. Like other viruses, HIV needs a host cell to multiply. It attacks helper T cells and can infect other cells. A rapid mutation rate helps it foil both the immune system and treatment attempts. No vaccine or cure exists. Abstinence from sex, use of condoms or other means to prevent sexual transmittal of the disease, and avoidance of needle sharing have reduced infection rates in some areas.