艾滋病感染者能活多久
2009-02-19 10:14:00
艾滋病感染者一般能活多长？
　　一个健康人从感染上艾滋病毒（HIV）到死亡，一般分为三个阶段，第一阶段称为HIV急性感染期，感染后，少部分感染者会出现类似流行性感冒的症状，如发热、咽喉炎、皮疹、淋巴结肿大等，在2—3个星期内，这些症状会自然消失。

　　接着，感染者进入第二个阶段，这一阶段被称为无症状期，约占从感染到死亡整个过程的80％时间，这时的病人被叫作HIV携带者，表面上大多数感染者是健康的，与正常人没有区别，只是其体内的免疫系统正在与　病毒进行着无形的斗争。

　　HIV每天都摧毁大量的免疫细胞，而骨髓则通过加速生成新的细胞来加以补偿，但是，新细胞的补充速度总是赶不上细胞损失的速度。在正常人体内，每立方毫米血液中约有800至1000个免疫细胞，而感染者体内，每立方毫米血液的免疫细胞则以每年50—70个的速度逐渐下降，当免疫细胞减少到在一立方毫米血液中只有200个左右时，下降速度就会加快。感染者的无症状期持续的时间可长可短，少则为2年，多的可达20年，其长短与感染途径密切相关，一般情况下，经血感染者（主要为非法采血与共用注射器）为4—5年，性交感染一般为11—13年，如果一个感染者的无症状期能达到13年，就可以被称为长期生存者了。

　　当感染者体内的免疫细胞已无法与HIV抗衡时，就标志着进入HIV感染的最后阶段，称有症状期，这时，感染者被叫作艾滋病（AIDS）患者，他们非常容易受到其他疾病的感染，一些平时根本不会对人的生命产生威胁的普通传染病如肺炎等，一旦进入AIDS的肌体就会无法控制，人一般在6至24月内死亡。

　　广州市传染病院传染一科蔡卫平医师说，AIDS病人，会出现各种迸发症，如连片皮肤疱疹、脑膜炎、癌症、肺结核、肝炎等，一个一百多斤的男性体重可以下降到七十多斤，眼睛深陷，毛发脱落，肌肉萎缩，呼吸困难，皮肤奇痒难耐，甚至出现痴呆症，失去记忆，临死前如同一个包着皮的骷髅。

　　一次不安全性行为感染HIV的可能性是多大？

　　是不是一次不安全的性行为就会染上HIV？为什么同性恋者容易得AIDS？

　　西方从八十年代后期开始对性接触传播规律进行调查，研究表明，男性传染给男性的危险度最高，其后依次为男传女、女传男、女传女，而在不同的性行为中，肛交具有最大的传染危险，然后是无保护的阴道交、口交、手淫。

　　资料显示，男传男的危险机率是1／10至1／1600，即如果一个健康男性与一名受感染的男性进行十次无保护的肛交，就会有一次感染上HIV，而最乐观的统计是1600次才有一次，这也是男同性恋者容易感染HIV的原因。其它的危险机率是这样的，男性传染给女性1／200—1／2000，女性传染给男性1／700—1／3000，女性传染给女性至今尚未有可靠的统计数据。据估计，在泰国，女性通过性交将HIV传染给男性的可能性为每一百次性接触平均有3—6人受到传染。

　　无论是发达国家还是发展中国家，性交都是HIV传播的主要途径，但其他方式传播病毒的可能性却更大。据各种估计，母亲将病毒传播给婴儿的概率是13％—48％，如果在医疗过程中意外地被带HIV的血液的针头刺破皮肤，感染病毒的可能性只是二百五十分之一，或0·3％，但输入带HIV的血液，其传染率是90％—100％。

　　另一项调查表明，HIV的传染由于感染者所处的感染期不同而大不相同。一般情况下，疾病初期的传染性最高，传染机率是1／10—1／20，因为此时感染者体内病毒含量最高，第二个传染高峰期为无症状期即将结束、临床期即将到来的一段，传染率为1／100—1／200，无症状期的传染机率为1／1000。

　　一项对男同性恋的调查结果显示，在一次无保护的肛交中，如果性伙伴正处在传染力最强的早期阶段，接受方被感染的可能性是10％—30％，在感染的中期阶段，接受方被感染的可能性只是0·01—0·1％，但到了感染后期，传染可能性又回升至0·1—1％。

　　蚊叮虫咬会不会传染艾滋病？

　　蚊子吸血时并不将自己的或刚吸来的血注入被叮咬者，而只是注入唾液作为润滑剂以便吸血。而且HIV—1在蚊子体内也不能复制而存活很短时间，因而，即使病毒进入蚊虫体内也不能感染蚊子或传播给他人。

　　还有一些其它原因可以进一步说明不必担心蚊子传播艾滋病病毒。第一，感染者血液中并非总有高水平的病毒量；第二，蚊虫口表面一般只有极少量的血，研究发现，蚊子嘴上的残血量仅有0·0004毫升，按此计算，要蚊子必须有目的地连续叮咬艾滋病感染者2800次，残血量中才能携带足够量的艾滋病毒然后传染给另一个健康的人，而实际上，研究昆虫的科学家们发现，蚊虫在吸血后通常不会马上去叮咬下一个，而是需要很长的一段时间去消化吸到的血液。

　　研究表明，与其他流行病毒如肝炎、肺炎、虐疾等相比，HIV—1是一种极其脆弱的病毒，它在人体外的存活时间不会超过三四个小时，热水、肥皂、酒精、漂白剂都是HIV—1的克星，病毒也无法在体内酸性的肠胃环境中生存，因此，专家们指出，那些害怕HIV—1通过蚊叮虫咬或公共游泳池传播的担心无疑都是多余的。

　一旦皮肤被划破并有接触病毒的危险，最简单有效的方法是，把伤口表面的血液挤出来，然后用消毒剂清洗，如果没有消毒剂，有肥皂或大量的清水冲洗也可降低被感染的可能性。

　　另一些研究还表明，人的唾液中含有微量病毒，如果口腔或嘴唇的粘膜没有破损，病毒是无法通过唾液传染的。不过，法国的研究表明，法式的长时间深吻可能会损伤口腔或嘴唇粘膜而导致HIV—1通过伤口进入人体。

　　艾滋病最有效的治疗方法是什么？

　　HIV—1虽然无法根治，但在医疗方面已取得了很多的进展，医学研究人员已成功地延长了HIV携带者以及AIDS患者的生命。第一种被证实可阻止HIV—1在患者身体内复制的药是叠氮胸苷（又叫AZT），当AZT八十年代末在西方发达国家问世时，患者一年的费用约为1万美元，到1997年降至2738美元，泰国和几个其他的发展中国家经过谈判，使每年每个患者的费用降至657美元。

　　但是，AZT只能使每个患者平均延长约六个月的健康生活。1994年，一种更为有效的、使用三种抗逆转录酶病毒药物的治疗方法被发明，因为它是一种联合疗法，所以又叫鸡尾酒疗法（或HAART疗法）。

　　新的抗病毒联合疗法在欧美已经明显地降低了AIDS的迸发症和死亡率。该疗法由于同时作用于HIV—1的逆转录酶和蛋白酶，因此强有力地抑制体内HIV—1的复制。在感染早期应用鸡尾酒疗法，使得CD4细胞计数维持正常，CD4／CD8细胞（均为免疫细胞）比值增高，淋巴结结构保持完整，明显地降低了血和组织中的病毒量。欧洲、部分亚洲国家和美国的许多急性和慢性感染者已经应用了这些抗病毒药物。

　　鸡尾酒疗法同样可以用于预防医源性HIV感染。美国对260名医护人员的调查显示，如果医护人员在工作过程中一旦被带病毒血液的利器刺伤皮肤，只要能在2小时之内服药，被感染的危险为零。如果在4小时内服药，危险度就可能增加20％，超过48小时，被感染的可能性达100％。

　　鸡尾酒疗法是目前为止被认为最有效的控制HIV—1复制的治疗方法。可是，该疗法副作用很明显，　而且非常昂贵，一年约需要10万人民币。

　　AZT可以防止母亲把HIV—1传染给孩子，今年11月7—9日，中国卫生部艾滋病预防与控制中心副主任曹韵贞教授在广州开办预防HIV—1母婴传播预防治疗学习班。其中最令人兴奋的消息是，使用AZT和新的NVP（维乐命）对HIV—1感染孕妇及其婴儿进行预防性治疗，能使母婴传播率由15～40％下降到8￣10％，这一方案在欧美国家得到广泛应用。特别是维乐命，每次用药只需4美金。

　　研究表明，婴儿在母亲子宫内被感染的机率只是5％，而85％会在出生过程中由于母亲阴道内存在的病毒而被感染，另一个被感染的途径是母乳，母乳喂养可增加25％—35％的危险性。目前，在西方，阻断母婴传播的有效方法是在分娩前或分娩期间准确地使用药物，采用剖腹产、停止母乳喂养。云南省昆明第三人民医院在曹韵贞教授指导下，目前在中国是首家采用药物实施阻断母婴传播的医院，今年已先后为3名感染了HIV—1的孕妇实施母婴阻断，3名婴儿至目前还在追踪检查中。AIDS can活多久
2009-02-19 10:14:00
AIDS is generally live much longer?
From a healthy person infected with HIV (HIV) to death, will generally be divided into three phases called acute HIV infection, after infection, a small number of infected persons will appear flu-like symptoms such as fever, pharyngitis, rash, swollen lymph nodes and so on, in 2-3 weeks, these symptoms will disappear naturally.

Then, infected persons have entered the second stage, this stage is known as asymptomatic period from infection to death about the whole process 80% of the time, when the patients were known HIV carriers, the surface, the majority of infected persons are healthy, with no distinction between normal, but the body's immune system is working with the viruses of the invisible struggle.

HIV every day, destroying a large number of immune cells, and bone marrow by accelerating the generation of new cells to be compensated, but the added speed of the new cells are always behind the rate of cell loss. In normal human body, each about the blood mm3 800-1000 immune cells, and infected the body, each mm3 of blood immune cells are an annual rate of 50-70 months decreased gradually reduced when the immune cells in one mm3 of blood, only about 200 when the rate of decline will accelerate. Asymptomatic infected persons sustained period of time can be shorter or longer periods, at least for 2 years, many of the up to 20 years, the duration of infection is closely related to, under normal circumstances, blood infection (mainly for the illegal blood collection and sharing of syringes ) for 4-5 years, sexual intercourse is generally 11-13 years of infection, if an asymptomatic infected persons can be reached 13 years, it will be known as a long-term survivors.

When infected with the body's immune cells and HIV have been unable to contend with when entering marks the final stage of HIV infection, have symptoms that period, then called AIDS-infected persons (AIDS) patients, they are very susceptible to other diseases infections, some normal person would not have threatened the lives of the ordinary, such as infectious diseases such as pneumonia, once entering the body of AIDS will not be able to control, generally in the 6-24 months of death.

Canton City hospital for infectious diseases transmitted one physician said Cai Weiping Branch, AIDS patients, there will be a variety of display cases, lace skin such as herpes, meningitis, cancer, tuberculosis, hepatitis and so on, a hundred men多斤weight could be reduced to seven ten多斤, eyes down, hair loss, muscle atrophy, dyspnea, skin奇痒intolerable, or even dementia, loss of memory, dying like a skeleton wrapped in skin.

Unsafe sex a possibility of HIV infection are the odds?

Are not an unsafe sex will be infected with HIV? Why are homosexuals easily AIDS?

West from the late eighties the start of sexual contact to investigate the dissemination of the law, studies have shown that male to male transmission of the highest risk, followed by Chuan-man woman, female male, female Chuan women, and in different sex anal infection have the greatest risk, are then unprotected vaginal delivery, oral sex, masturbation.

Statistics show that the risk of male-male odds are 1 / 10 to 1 / 1600, that is, if a healthy male with a male infected for ten times unprotected anal sex, there will be an infected with HIV, while the most optimistic statistics are only the first 1600 meeting, which is easy to male homosexuals causes of HIV infection. The risk of other probability is that the male to female transmission 1/200-1/2000 female to male transmission 1/700-1/3000, women have not yet been transmitted to women have reliable statistical data. It is estimated that in Thailand, female HIV transmission through sexual intercourse will be given the possibility of men for every one hundred times the average have 3-6 sexual contact was infected person.

Both developed and developing countries, sexual intercourse is the main means of HIV transmission, but other means likely to transmit the virus are greater. According to various estimates, the mother will be the spread of the virus to her baby is 13% probability of -48%, if the medical process with HIV accidental needle prick blood skin, the possibility of infection is only 1/250, or 0.3%, but the importation of blood with HIV, its transmission rate is 90% -100%.

Another survey showed that, HIV-infected persons because of the spread of the infection which varies widely. Under normal circumstances, the early infectious diseases the highest probability of transmission are 1/10-1/20, because virus-infected persons at this time was the highest, and the second peak period of transmission is coming to an end for the asymptomatic period, the upcoming clinical phase paragraph, the transmission rate of 1/100-1/200, asymptomatic phase of infection probability of 1 / 1000.

One pairs of male homosexuality in the survey, in an unprotected anal intercourse, if sexual partners are in the early stages of the most highly infectious, Recipient of the possibility of being infected are 10% -30% in infected the medium term, the recipient was infected with the possibility of only 0.01 -0 1%, but the late stage of infection, the possibility of infection rose again to 0.1 -1%.

Bites grave-sweepers will be transmitted AIDS?

Blood-sucking mosquitoes does not own or just smoke to the blood was injected into the bite of those, but only into the saliva as a lubricant in order to vampire. And HIV-1 in the mosquitoes can not reproduce and survive a very short time, thus, even if the virus enters the body can not be infected mosquito mosquitoes or disseminate to others.

There are also other reasons may not have to worry about further mosquito-borne HIV. First, the blood of infected persons do not always have a high level of viral load; Secondly, the surface of mosquito population in general only a very small amount of blood, the study found that the residual amount of blood the mosquito lips only 0.0004 milliliters, this calculation to mosquito bites must have a destination for AIDS 2800 meeting, the residual amount of blood can be enough to carry the amount of HIV then spread to another person's health, and in fact, research scientists have found insects, blood-sucking mosquitoes in the post - usually do not immediately go the next bite, but required a long time to digest the blood of breath.