科技研究已经给人们提供了许多有关人类免疫缺陷性病毒(HIV)和获得性免疫缺陷综合症(AIDS)医疗、科学、公共健康方面有价值的信息。HIV传播的方式也已经被确定。不幸的是，没有科学依据的虚假信息和结论仍然在网络、大众传媒之间广泛传播。因此，美国疾病控制预防中心发表此事实报告，以纠正那些对HIV错误的认识。

1：HIV是怎么传播的

HIV是通过与HIV感染者性接触，共用针头、皮下注射器（主要是吸毒），输血（在那些血液要经过HIV抗体初筛的国家已经很少见），母亲是HIV感染者的新生儿可能会在未出生或者分娩、哺乳时感染HIV病毒。

在医疗机构里，有工作人员因被含HIV病毒的针扎伤而被感染，也有因身体开口的地方或者黏膜（如眼睛和鼻子内部）沾了感染了HIV的血液而被感染的，可是这样的例子并不常发生。在美国至今只有一例是病人被医护人员所感染的案例——一位携带有HIV的牙医传染了他的6个病人。随后深入的调查涉及到了22000多个病人和63个感染了HIV的内，外科医生和牙医，从那以后美国再也没有出现过像这样的事件了。

有的人害怕HIV会通过其他渠道传播，可是没有任何的科学依据能证明他们的担心不是多余的。如果HIV能通过其他方式传播，如空气，水或者昆虫，那么所报道了的艾滋病病历的情况就应该跟我们所观察到的有所不同。如果蚊子能传播HIV，那么现在已经应该有很多幼儿和儿童被诊断为艾滋病了。

州或者本地卫生部门都会在美国疾病控制预防中心辅助，监督和实验室支持下，对所有上报的怀疑HIV可能通过新的或者不明确途径传播的病历做全面的调查研究。甚至有一个国家防疫句部门曾专门去检测过，也没有发现HIV的其他传播方式。
接下来的文章将详细解释一些对HIV传播普遍的错误认识。
2：HIV在外界环境

科学家和医学权威一致认为HIV在外界环境中无法正常存活，这一观念彻底否定了HIV在外界环境传播的可能性。只有在血液，精液，阴道分泌物，乳液，唾液和泪液中才找得到HIV病毒，而且它的病毒载量在这些体液中差别很大。为了得到有关HIV存活率的资料，实验室使用了人工培养单位数量多的HIV病毒的。尽管这些人工培养出来的病毒在精确的控制和实验室有限条件下存活了十几天甚至几周，可是CDC研究显示尽管是载量高，90%-99%的HIV病毒在几个小时内也会很快死亡。既然实验室研究用的HIV病毒的载量比在血液或者其他体液中的载量高很多，随着感染了HIV的人类血液或者其他体液自身死亡，这便降低了理论上在外界感染上HIV的机率！

那些对实验室结论的不准确的解释更多的是引起了人们不必要的恐慌。

实验室的结论不应该运用在估计个人感染危险系数上面，因为，第一，在人体内和其他地方都找不到像实验室用的载量高的病毒，第二，至今还没有报告有人因为接触了外界表面而感染HIV的。第三，和其他许多能在适宜条件下复制的细菌或真菌不一样，HIV病毒离开了寄主便无法复制。因此，HIV病毒不可能离开了寄主仍然传播并保持感染力。
家庭

虽然HIV能在家庭成员中传播，可是这种感染的几率是非常的小，都是因为皮肤或者黏膜跟被感染了的血液发生了接触。在之前发表的前言中已经讲解过，为了避免这种感染的发生，在任何情况下，包括家庭中，都应该防止直接接触那些感染了HIV、有感染上HIV的危险，或者情况不明确的人的血液。比如说：

   1：接触血液或者其他带有血（肉眼能看见）的体液，如尿，粪，呕吐物时应该戴上手套。

   2：无论是护理人员还是病人，都应该将暴露在外的伤口和裂缝用绷带贴好。

   3：接触血液或者其他体液之后，都应该迅速清洗手或身体其他部分。被血液弄污的表面也应该仔细清洗。

   4：像共用剃须刀和牙刷这种增加血液接触的行为应该避免。

   5：根据医疗部门建议，只有在治疗需要时使用针或者其他利器。（不要自己用手将针盖套到针头上或者将针头从注射器上面取下来。废弃的针头要丢在不会被刺穿的箱子里）

工作和其他场所

目前还没有报道称在像饮食服务这些行业中,HIV会在同事,顾客或者消费者中通过接触传播.(参照"HIV在外界环境中的存活情况")饮食服务行业中有感染HIV的工作人员是不需要被辞职的,除非他们感染了其他疾病(如痢疾和甲肝).CDC建议所有在饮食服务行业工作的人们都要严格要求自己的个人卫生和食品卫生.

CDC在1985年发布了所有个人服务人员(如美发、理发师,美容师，按摩治疗师）必须遵守的注意事项，虽然目前还没有证明HIV能在服务人员和顾客之间相互感染。用来穿刺皮肤的器具（如纹身、针刺疗法和穿耳朵用的针）只能使用一次并且丢弃或者彻底清洁消毒。不是用来穿刺皮肤的器具，如剃须刀，只能给一位顾客使用并且丢弃，或者在每次使用之后彻底清洁消毒。个人服务人员可以采用专门为医疗机构推荐的清洁程序。

虽然乙肝能通过纹身和穿孔传染,但是CDC目前还没有听说过一例由此染上HIV的病例.文件上记载唯一的一例是通过针灸染上的.身体穿孔(包括穿耳洞)在美国还相对于比较新,引起的并发症也比纹身多.穿的孔通常需要几个星期,甚至几个月才能完全愈合,即使在愈合后，穿孔部位的组织仍然有可能被磨伤或者发炎。因此，如果未愈合或被磨损的组织接触了一个HIV携带者的血液或者其他能传染HIV的体液，在理论上这是有感染上HIV的可能的。另外，如果使用的器具被血污染了又没有消毒杀菌，也有可能传染HIV。

接吻

随意的“干吻”或吻礼都没有传染HIV的可能，考虑到有可能会接触到血液，CDC建议避免跟一个HIV携带者舌吻或湿吻。不过由接吻感染上HIV的几率非常的小，至今为止，CDC只调查到一例是因为在湿吻时接触到了血液而感染上HIV的。

咬

曾经有一个州卫生部对一个涉及到由咬人引起的血液感染HIV的案例作出了调查。CDC在1997年公布了调查结果。曾经在医学文献中还记载有其他由咬伤而引起HIV感染的例子，在这些案例中都报告有大面积的组织撕损创伤和出血。咬并不是传染HIV通常的方式，而实际上，在许多咬伤事件中都没有引起HIV传染。

唾液，泪液和汗液

在AIDS病人的唾液和泪液中都能找到少量的HIV病毒。不过，我们有必要知道在有的体液中能找到HIV病毒并不意味着HIV能通过这种体液传染。HIV携带者的汗液中没有HIV病毒。唾液，泪液和汗液接触也不会引起HIV传染。

昆虫

从HIV流行开始，一直都有对HIV会通过吸血类昆虫叮咬而传播的担忧。不过，CDC和其他地方的研究人员调查研究显示HIV是不会通过昆虫传染的——甚至在那些AIDS病人密集并且有很多像蚊子这样的昆虫的地方。尽管已经作出了很多努力去调查，由于没有这种案例的发生，所以不能证明HIV能通过昆虫传播。

对昆虫叮咬习惯的观察研究结果发现，当昆虫叮咬物体时，它不会将先前叮咬的人或动物的血液注到下一个被叮咬的人，而是注射自己的唾液，起润滑和防止血液凝固，以便吸血。像黄热病和痢疾这样的病就是由蚊子的唾液传播的。不过HIV在昆虫体内只能存活很短一段时间。不像那些通过蚊虫传播的生物，HIV是不会在昆虫体内自我复制（无法存活）。因此，就算HIV病毒进如了蚊子或者其他吸血昆虫的体内，这种昆虫是不会被感染的，更不会将HIV传染给下一个被它叮咬的人。在昆虫的粪便中也找不到HIV病毒。

没有理由去担心HIV会通过蚊子这类昆虫嘴部残留的血传染。这里有两个理由证明为什么不会——首先，HIV携带者的血液中的病毒量不会一直停留在高浓度；第二，昆虫嘴部表面不会保留大量血液。另外，研究昆虫的科学家认为吸血昆虫在吸完血之后不会立即飞到另外一个人身上吸血，而是到一个地方休息，消化刚吸了的血。

安全套的效用

安全套一直被归为医疗器械，并由FDA（美国食品与药物管理局）规范管理。在美国的安全套生产商在安全套包装前都会对每只乳胶型安全套作测试，检查是否有包括小孔在内的任何缺陷。在性交时（包括阴交，肛交和口交）正确并坚持使用乳胶型或聚氨酯型安全套能在很大程度上减少被感染或传染性病和HIV的危险。

目前市面上有不同种类和牌子的安全套出售。然而只有乳胶型和聚氨酯型安全套能提供一个对HIV有效的机械屏障。在实验室中发现，偶尔会有HIV病毒能够穿过天然的薄膜（“皮”或羔羊皮）安全套。这些安全套之所以不被推荐作为预防性病的安全措施（有记载说它们能够有效地避孕）是因为它们有的带有天然的细孔。当男方不能使用安全套时，女方应该考虑使用女用安全帽。

为了让安全套的保护作用发挥到最大，必须对其坚持（每次）并正确使用。几次对安全套正确并坚持的使用做的研究清楚说明了在美国，乳胶型安全套的破损率不超过2%。在另外一个调查中发现，就算安全套破损了，超过一半的这种情况都发生在射精前。

调查显示，在那些只把安全套作为避孕措施的夫妇中，其避孕效果达98%。同样的，许多在性活跃人群中进行的研究也表明正确地使用乳胶型安全套能在很大程度上抵御包括HIV在内的各种性传播疾病。

若想了解更多有关安全套的知识，请看CDC发布的“安全套与性传播疾病”。

CDC的反应

CDC承诺向科研单位和公众提供有关HIV/AIDS准确并客观的信息。为了帮助防止HIV进一步传播和减少由错误信息引起的恐惧和偏见，提供最新最准确的与HIV/AIDS相关的信息是至为重要的。

本文出自ＣＤＣ官方网站　　翻译：轻微

另附全文:

HIV and Its Transmission

Research has revealed a great deal of valuable medical, scientific, and public health information about the human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). The ways in which HIV can be transmitted have been clearly identified. Unfortunately, false information or statements that are not supported by scientific findings continue to be shared widely through the Internet or popular press. Therefore, the Centers for Disease Control and Prevention (CDC) has prepared this fact sheet to correct a few misperceptions about HIV.

How HIV is Transmitted

HIV is spread by sexual contact with an infected person, by sharing needles and/or syringes (primarily for drug injection) with someone who is infected, or, less commonly (and now very rarely in countries where blood is screened for HIV antibodies), through transfusions of infected blood or blood clotting factors. Babies born to HIV-infected women may become infected before or during birth or through breast-feeding after birth.

In the health care setting, workers have been infected with HIV after being stuck with needles containing HIV-infected blood or, less frequently, after infected blood gets into a worker抯 open cut or a mucous membrane (for example, the eyes or inside of the nose). There has been only one instance of patients being infected by a health care worker in the United States; this involved HIV transmission from one infected dentist to six patients. Investigations have been completed involving more than 22,000 patients of 63 HIV-infected physicians, surgeons, and dentists, and no other cases of this type of transmission have been identified in the United States.

Some people fear that HIV might be transmitted in other ways; however, no scientific evidence to support any of these fears has been found. If HIV were being transmitted through other routes (such as through air, water, or insects), the pattern of reported AIDS cases would be much different from what has been observed. For example, if mosquitoes could transmit HIV infection, many more young children and preadolescents would have been diagnosed with AIDS.

All reported cases suggesting new or potentially unknown routes of transmission are thoroughly investigated by state and local health departments with the assistance, guidance, and laboratory support from CDC. No additional routes of transmission have been recorded, despite a national sentinel system designed to detect just such an occurrence.

The following paragraphs specifically address some of the common misperceptions about HIV transmission.

HIV in the Environment

Scientists and medical authorities agree that HIV does not survive well in the environment, making the possibility of environmental transmission remote. HIV is found in varying concentrations or amounts in blood, semen, vaginal fluid, breast milk, saliva, and tears. (See page 3, Saliva, Tears, and Sweat.) To obtain data on the survival of HIV, laboratory studies have required the use of artificially high concentrations of laboratory-grown virus. Although these unnatural concentrations of HIV can be kept alive for days or even weeks under precisely controlled and limited laboratory conditions, CDC studies have shown that drying of even these high concentrations of HIV reduces the amount of infectious virus by 90 to 99 percent within several hours. Since the HIV concentrations used in laboratory studies are much higher than those actually found in blood or other specimens, drying of HIV-infected human blood or other body fluids reduces the theoretical risk of environmental transmission to that which has been observed--essentially zero. Incorrect interpretation of conclusions drawn from laboratory studies have unnecessarily alarmed some people.

Results from laboratory studies should not be used to assess specific personal risk of infection because (1) the amount of virus studied is not found in human specimens or elsewhere in nature, and (2) no one has been identified as infected with HIV due to contact with an environmental surface. Additionally, HIV is unable to reproduce outside its living host (unlike many bacteria or fungi, which may do so under suitable conditions), except under laboratory conditions, therefore, it does not spread or maintain infectiousness outside its host.

Households

Although HIV has been transmitted between family members in a household setting, this type of transmission is very rare. These transmissions are believed to have resulted from contact between skin or mucous membranes and infected blood. To prevent even such rare occurrences, precautions, as described in previously published guidelines, should be taken in all settings "including the home" to prevent exposures to the blood of persons who are HIV infected, at risk for HIV infection, or whose infection and risk status are unknown. For example,

• Gloves should be worn during contact with blood or other body fluids that could possibly contain visible blood, such as urine, feces, or vomit.
  
• Cuts, sores, or breaks on both the care giver抯 and patient抯 exposed skin should be covered with bandages.
  
• Hands and other parts of the body should be washed immediately after contact with blood or other body fluids, and surfaces soiled with blood should be disinfected appropriately.
  
• Practices that increase the likelihood of blood contact, such as sharing of razors and toothbrushes, should be avoided.
  
• Needles and other sharp instruments should be used only when medically necessary and handled according to recommendations for health-care settings. (Do not put caps back on needles by hand or remove needles from syringes. Dispose of needles in puncture-proof containers

Businesses and Other Settings

There is no known risk of HIV transmission to co-workers, clients, or consumers from contact in industries such as food-service establishments (see information on survival of HIV in the environment). Food-service workers known to be infected with HIV need not be restricted from work unless they have other infections or illnesses (such as diarrhea or hepatitis A) for which any food-service worker, regardless of HIV infection status, should be restricted. CDC recommends that all food-service workers follow recommended standards and practices of good personal hygiene and food sanitation.

In 1985, CDC issued routine precautions that all personal-service workers (such as hairdressers, barbers, cosmetologists, and massage therapists) should follow, even though there is no evidence of transmission from a personal-service worker to a client or vice versa. Instruments that are intended to penetrate the skin (such as tattooing and acupuncture needles, ear piercing devices) should be used once and disposed of or thoroughly cleaned and sterilized. Instruments not intended to penetrate the skin but which may become contaminated with blood (for example, razors) should be used for only one client and disposed of or thoroughly cleaned and disinfected after each use. Personal-service workers can use the same cleaning procedures that are recommended for health care institutions.

CDC knows of no instances of HIV transmission through tattooing or body piercing, although hepatitis B virus has been transmitted during some of these practices. One case of HIV transmission from acupuncture has been documented. Body piercing (other than ear piercing) is relatively new in the United States, and the medical complications for body piercing appear to be greater than for tattoos. Healing of piercings generally will take weeks, and sometimes even months, and the pierced tissue could conceivably be abraded (torn or cut) or inflamed even after healing. Therefore, a theoretical HIV transmission risk does exist if the unhealed or abraded tissues come into contact with an infected person抯 blood or other infectious body fluid. Additionally, HIV could be transmitted if instruments contaminated with blood are not sterilized or disinfected between clients.

Kissing

Casual contact through closed-mouth or "social" kissing is not a risk for transmission of HIV. Because of the potential for contact with blood during "French" or open-mouth kissing, CDC recommends against engaging in this activity with a person known to be infected. However, the risk of acquiring HIV during open-mouth kissing is believed to be very low. CDC has investigated only one case of HIV infection that may be attributed to contact with blood during open-mouth kissing.

Biting

In 1997, CDC published findings from a state health department investigation of an incident that suggested blood-to-blood transmission of HIV by a human bite. There have been other reports in the medical literature in which HIV appeared to have been transmitted by a bite. Severe trauma with extensive tissue tearing and damage and presence of blood were reported in each of these instances. Biting is not a common way of transmitting HIV. In fact, there are numerous reports of bites that did not result in HIV infection.

Saliva, Tears, and Sweat

HIV has been found in saliva and tears in very low quantities from some AIDS patients. It is important to understand that finding a small amount of HIV in a body fluid does not necessarily mean that HIV can be transmitted by that body fluid. HIV has not been recovered from the sweat of HIV-infected persons. Contact with saliva, tears, or sweat has never been shown to result in transmission of HIV.

Insects

From the onset of the HIV epidemic, there has been concern about transmission of the virus by biting and bloodsucking insects. However, studies conducted by researchers at CDC and elsewhere have shown no evidence of HIV transmission through insects--even in areas where there are many cases of AIDS and large populations of insects such as mosquitoes. Lack of such outbreaks, despite intense efforts to detect them, supports the conclusion that HIV is not transmitted by insects.

The results of experiments and observations of insect biting behavior indicate that when an insect bites a person, it does not inject its own or a previously bitten person抯 or animal抯 blood into the next person bitten. Rather, it injects saliva, which acts as a lubricant or anticoagulant so the insect can feed efficiently. Such diseases as yellow fever and malaria are transmitted through the saliva of specific species of mosquitoes. However, HIV lives for only a short time inside an insect and, unlike organisms that are transmitted via insect bites, HIV does not reproduce (and does not survive) in insects. Thus, even if the virus enters a mosquito or another sucking or biting insect, the insect does not become infected and cannot transmit HIV to the next human it feeds on or bites. HIV is not found in insect feces.

There is also no reason to fear that a biting or bloodsucking insect, such as a mosquito, could transmit HIV from one person to another through HIV-infected blood left on its mouth parts. Two factors serve to explain why this is so--first, infected people do not have constant, high levels of HIV in their bloodstreams and, second, insect mouth parts do not retain large amounts of blood on their surfaces. Further, scientists who study insects have determined that biting insects normally do not travel from one person to the next immediately after ingesting blood. Rather, they fly to a resting place to digest this blood meal.

Effectiveness of Condoms

Condoms are classified as medical devices and are regulated by the Food and Drug Administration (FDA). Condom manufacturers in the United States test each latex condom for defects, including holes, before it is packaged. The proper and consistent use of latex or polyurethane (a type of plastic) condoms when engaging in sexual intercourse--vaginal, anal, or oral--can greatly reduce a person抯 risk of acquiring or transmitting sexually transmitted diseases, including HIV infection.

There are many different types and brands of condoms available--however, only latex or polyurethane condoms provide a highly effective mechanical barrier to HIV. In laboratories, viruses occasionally have been shown to pass through natural membrane ("skin" or lambskin) condoms, which may contain natural pores and are therefore not recommended for disease prevention (they are documented to be effective for contraception). Women may wish to consider using the female condom when a male condom cannot be used.

For condoms to provide maximum protection, they must be used consistently (every time) and correctly. Several studies of correct and consistent condom use clearly show that latex condom breakage rates in this country are less than 2 percent. Even when condoms do break, one study showed that more than half of such breaks occurred prior to ejaculation.

When condoms are used reliably, they have been shown to prevent pregnancy up to 98 percent of the time among couples using them as their only method of contraception. Similarly, numerous studies among sexually active people have demonstrated that a properly used latex condom provides a high degree of protection against a variety of sexually transmitted diseases, including HIV infection.

For more detailed information about condoms, see the CDC publication "Male Latex Condoms and Sexually Transmitted Diseases."

CDC抯 Response

CDC is committed to providing the scientific community and the public with accurate and objective information about HIV infection and AIDS. It is vital that clear information on HIV infection and AIDS be readily available to help prevent further transmission of the virus and to allay fears and prejudices caused by misinformation. For a complete description of CDC抯 HIV/AIDS prevention programs, see "CDC's Role in HIV and AIDS Prevention."

For more information...

CDC-INF
1-800-CDC-INFO (232-4636)
TTY: 1-888-232-6348
In English, en Espa?/font>ol
24 Hours/Day

CDC National Prevention Information Network:
P.O. Box 6003
Rockville, Maryland 20849-6003
1-800-458-5231

Internet Resources:
NCHSTP: http://www.cdc.gov/nchstp/od/nchstp.html
DHAP: http://www.cdc.gov/hiv
NPIN: http://www.cdcnpin.org