AIDS (acquired immunodeficiency syndrome) is caused by the human immunodeficiency virus (HIV). This kills or impairs cells of the immune system and progressively destroys the body's ability to fight infections and certain cancers. HIV is most commonly spread by sexual contact with an infected partner. Another important means of spreading HIV is contact with infected blood from contaminated needles, 注射器, 或者其他吸毒用具.

The term AIDS applies to the most advanced stages of an HIV infection. The current definition of AIDS includes all HIV-infected people who have fewer than 200 CD4+ T cells (healthy adults usually have CD4+ T-cell counts of around 800 or more.)另外, the definition includes HIV-infected people who have been diagnosed with one or more clinical conditions (including opportunistic infections and certain cancers) that affect people with advanced HIV disease.

根据疾控中心, an estimated 1 million adults and adolescents are living with 艾滋病毒/艾滋病 in the United States. The AIDS epidemic still rages out of control in many areas of the world.

艾滋病毒/艾滋病是如何传播的?

性接触

HIV is spread most commonly by sexual contact with an infected partner. 病毒通过阴道内膜进入人体, 阴户, 阴茎, 直肠, 或者在性行为时的嘴巴.

血液污染

艾滋病毒也可能通过接触受感染的血液传播. However, due to the screening of blood for evidence of HIV infection in the U.S., the risk of acquiring HIV from blood transfusions is extremely low.

针

艾滋病病毒通常通过共用针头传播, 注射器, or drug use equipment with someone who is infected with the virus. 从患者到医护人员的传播, or vice-versa through accidental sticks with contaminated needles or other medical instruments, 是罕见的.

母婴

HIV also can be spread to babies born to, or breastfed by, mothers infected with the virus.

艾滋病毒/艾滋病不能通过以下途径传播:

• 唾液

• 汗水

• 眼泪

• Casual contact, such as sharing food utensils, towels, and bedding

• 游泳池

• 电话

• 马桶座圈

• 咬人的昆虫(如蚊子)

Some people may develop a flu-like illness within a month after exposure to the HIV virus. 但 many people do not develop any symptoms at all when they first become infected. 除了, 出现的症状, 通常会在一周到一个月内消失, 经常被误认为是另一种病毒感染. 这些可能包括:

• 发热

• 头疼

• 不适

• 淋巴结肿大

Persistent or severe symptoms may not surface for 10 years or more after HIV first enters the body in adults, 或2年内出生时感染艾滋病毒的儿童. This "asymptomatic" period of the infection is highly variable from person to person. 但, 在无症状期, HIV is actively infecting and killing cells of the immune system. Its most obvious effect is a decline in the blood levels of CD4+ T cells (also called T4 cells)—a key immune system infection fighter. The virus initially disables or destroys these cells without causing symptoms.

As the immune system deteriorates, complications begin to surface. The following are the most common complications, or symptoms, of AIDS. 然而，每个人可能经历不同的症状. 症状可能包括:

• 淋巴结肿大超过3个月

• 精力不足

• 减肥

• 经常发烧和出汗

• 持续或频繁的酵母菌感染(口腔或阴道)

• 持续的皮疹或片状皮肤

• Pelvic inflammatory disease that does not respond to treatment

• 短期记忆丧失

• One or more infections (opportunistic infections) related to having a weakened immune system. 这些疾病包括肺结核和某些类型的肺炎.

Some people develop frequent and severe herpes infections that cause mouth, 生殖器, 或者肛门溃疡, 或者是一种叫做带状疱疹的疼痛神经疾病. 孩子们可能发育迟缓或无法茁壮成长.

在感染艾滋病毒的过程中, most people experience a gradual decline in the number of CD4+ T cells. Though some individuals may have abrupt and dramatic drops in their counts.

The symptoms of an HIV infection may resemble other medical conditions. 请务必咨询您的医疗保健提供者以获得诊断. Rapid diagnostic tests are available and early diagnosis is important.

如何诊断艾滋病毒/艾滋病?

早期艾滋病毒感染通常没有任何症状, and must be detected by testing a person's blood for the presence of antibodies—disease-fighting proteins—against HIV. These HIV antibodies generally do not reach levels high enough to detect by standard blood tests until 1 to 3 months following infection, 可能需要长达6个月的时间. People exposed to HIV should be tested for HIV infection as soon as they think they may have been exposed to HIV.

When a person is highly likely to be infected with HIV and yet antibody tests are negative, 一种检测血液中是否存在艾滋病毒的方法被使用. 晚些时候再做一次抗体测试, 这时更有可能产生艾滋病毒抗体, 经常被推荐.

As with many other conditions, early detection offers more choices for treatment. 今天, there are medical treatments that not only can slow down the rate at which HIV weakens the immune system, but also may keep HIV in check so that the individual has a chance to live a normal life span. 不幸的是，目前还没有治愈HIV感染的方法. Talk with your healthcare provider for more information regarding various drug therapies for the treatment of 艾滋病毒/艾滋病.

艾滋病毒仍在世界范围内蔓延. 研究 continues to provide more insight to possible vaccine strategies, but no cure is available.