艾滋病的未解之謎

艾滋病，即獲得性免疫缺陷綜合症(又譯：後天性免疫缺陷症候羣)，英語縮寫AIDS(Acquired Immune Deficiency Syndrome)的音譯。接下來小編爲大家整理艾滋病的未解之謎，希望對你有幫助哦!

In the 20years since the first cases of AIDS were detected， scientists say they have learned more about this viral1) disease than any other.

Yet Peter Piot， who directs the United Nations AIDS program， and Stefano Vella of Rome， president of the International AIDS Society， and other experts say reviewing unanswered questions could prove useful as a measure of progress for AIDS and other diseases.

Among the important broader scientific questions that remain：

Why does AIDS predispose infected persons to certain types of cancer and infections?

A long-standing belief is that cancer cells constantly develop and are held in check by a healthy immune2) system. But AIDS has challenged that belief. People with AIDS are much more prone3) to certain cancers like non-Hodgkins lymphomas and Kaposi's sarcoma4)， but not to breast， colon and lung， the most common cancers in the United States. This pattern suggests that an impaired immune system， at least the type that occurs in AIDS， does not allow common cancers to develop.

What route does HIV take after it enters the body to destroy the immune system?

When HIV is transmitted sexually， the virus must cross a tissue barrier to enter the body. How that happens is still unclear. The virus might invade directly or be carried by a series of different kinds of cells.

Eventually HIV travels through lymph5) vessels6) to lymph nodes and the rest of the lymph system. But what is not known is how the virus proceeds to destroy the body's CD-4cells that are needed to combat invading infectious agents.

How does HIV subvert the immune7) sys-tem?

Although HIV kills the immune cells sent to kill the virus， there is widespread variation in the rate at which HIV infected people become ill with AIDS. So scientists ask：Can the elements of the immune system responsible for that variability be identified?If so， can they be used to stop progression to AIDS in infected individuals and possibly prevent infection in the first place?

What is the most effective anti-HIV therapy?

In theory， early treatment should offer the best chance of preserving immune function. But the new drugs do not completely eliminate HIV from the body so the medicines， which can have dangerous side effects， will have to be taken for a lifetime and perhaps changed to combat resistance. The new policy is expected to recommend that treatment be deferred until there are signs the immune system is weakening.

Is a vaccine8) possible?

There is little question that an effective vaccine is crucial to controlling the epidemic9)。 Yet only one has reached the stage of full testing， and there is wide controversy over the degree of protection it will provide. HIV strains that are transmitted in various areas of the world differ genetically. It is not known whether a vaccine derived from one type of HIV will confer protection against other types.

In the absence of a vaccine， how can HIV be stopped?

Without more incisive10)， focused behavioral research， prevention messages alone will not stop the global epidemic.

科學家說， 在第一批艾滋病例被發現以後的20年裏， 他們對這種病毒性疾病的瞭解， 已超過其他任何一種病毒性疾病。

但是， 聯合國艾滋病規劃署的負責人彼得·皮奧和國際艾滋病學會會長羅馬的斯特凡諾·韋拉及其他一些專家都認爲， 全面考察那些未決問題， 可能對艾滋病和其他疾病治療的進展是一項有益的舉措。

這些較廣泛的重要科學問題包括：

爲什麼艾滋病使患者容易感染某些癌症和傳染病?

一種傳統的說法是， 癌細胞在人體內不斷繁殖， 但受到健康免疫系統的控制。艾滋病的情況卻不是這樣。艾滋病人很容易患非何傑金氏淋巴瘤和卡波西氏肉瘤， 但不易患在美國最常見的乳腺癌、結腸癌和肺癌等。這說明， 受損的免疫系統(至少是艾滋病患者的免疫系統)， 可以抑制普通癌細胞的發展。

艾滋病病毒侵入人體後通過什麼途徑摧毀免疫系統?當艾滋病病毒通過性接觸傳播時， 病毒必須穿過組織屏障進入人體。這個過程目前尚不清楚。病毒可能直接侵入， 或許由一系列不同種類的細胞帶入。最終， 艾滋病病毒穿過淋巴管到淋巴結和淋巴系統的其他部分。但病毒是如何摧毀人體內負責打擊入侵傳染體的CD-4細胞的， 目前還無法確定。

艾滋病病毒是怎樣破壞免疫系統的?

艾滋病病毒能殺死對付自己的免疫細胞， 但艾滋病病毒攜帶者患艾滋病的快慢卻大不相同。因此科學家提出問題：免疫系統中那些使人患艾滋病時間出現差異的因素能否被識別出來?如果能， 它們能否用於制止艾滋病患者病情的惡化， 甚至在最初就可能防止人們感染艾滋病病毒?

最有效的艾滋病療法是什麼?

從理論上來說， 儘早治療可以提供維護免疫功能的最佳時機。但是新藥物無法徹底清除體內的艾滋病病毒， 因此患者不得不終身服用這些具有危險副作用的藥物， 而且還可能在產生抗藥性時改服別的藥物。因此新的方法可能建議在免疫系統出現衰退跡象時纔開始治療。

可能研製出疫苗嗎?

毫無疑問， 一種有效的疫苗是控制這種瘟疫的關鍵。但是目前只有一種疫苗進入了全面檢驗的階段， 而對其會有多大的保護功能， 卻有着很大的爭議。世界各地流行的艾滋病在遺傳類型上各不相同， 目前還不清楚， 從某種艾滋病病毒獲得的疫苗能否防止其他類型的艾滋病。

如果沒有疫苗， 能否阻止艾滋病病毒的傳播?

如果沒有深入集中的行爲研究， 僅靠宣傳是無法阻止這種全球性瘟疫的。