如果乙型肝炎被性传播，我的合作伙伴怎么没有感染？

StephenW

If Hepatitis B Is Sexually Transmitted, How Come My Partner Isn’t Infected?                                        February 1, 2017 hepbtalk                                                               
                                        Image courtesy of David Castillo Dominici at FreeDigitalPhotos.net.By Christine Kukka
I thought hepatitis B was sexually transmitted? I just tested positive, but my partner tested negative, we’ve been together for years, what gives?
This question is a common one. Hepatitis B is indeed easily transmitted sexually, so why do some people — who were not vaccinated — never get hepatitis B from their sexual partners?
It comes down to variables, such as the type of sexual activity you engage in, the viral load (HBV DNA) of the infected partner, and who is on the receiving end of infectious body fluids, especially blood that contains the most virus and semen.
Having one partner infected, and other not, can add more stress to an already traumatic hepatitis B diagnosis. “It was very confusing and made me question how was it possible I was the only one infected,” said a woman who tested positive while her husband tested negative.  “I thought it was possibly a mistake, maybe I was a biological anomaly, which of course I was not.”
Let’s look at the factors that affect who gets infected and who doesn’t when two people have sex.
Viral load: Semen, vaginal fluids and blood all contain the hepatitis B virus (HBV), and the higher the viral load, the more infectious one’s blood and body fluids are. However, having an undetectable viral load doesn’t mean you won’t infected someone during unsafe sex. Even if a man has an undetectable viral load, studies show his semen still contains some HBV and can spread infection, though the risk is lower.
So the rule here is if a man tests positive for the hepatitis B surface antigen (HBsAg), he must consider himself infectious.
The role of gender: In heterosexual relationships, uninfected women are at higher risk of getting infected by a male partner infected with hepatitis B, than the reverse. Women are on the receiving end of semen, which greatly increases their risk of becoming infected unless a condom is used.
Image courtesy of renjith krishnan at FreeDigitalPhotos.net.When a woman is infected with hepatitis B, an uninfected man is at risk through direct contact with her vaginal secretions, but that contact is lower-risk than a woman’s direct exposure to infectious semen during intercourse.
However, an infected woman who is menstruating is more likely to spread hepatitis B because blood can contain higher levels of HBV than vaginal secretions. That is why gloves and dental dams are recommended to provide a barrier against exposure.
The type of sexual activity: Certain sexual activities are far more efficient at spreading hepatitis B than others. Oral sex appears to have a lower rate of hepatitis B transmission than vaginal sex. Anal sex carries a very high risk of transmission because of tears in the skin that can occur during penetration improves transmission of HBV.
Fingering carries a lesser risk, unless the infected woman is menstruating or a person has bruises or cuts on their hands that allow entry to hepatitis B in semen or vaginal fluids, then gloves are recommended.
The “uninfected” partner could already have been infected and cleared hepatitis B: When a person is first diagnosed with hepatitis B, doctors often test his or her partner for only the hepatitis B surface antigen (HBsAg), which indicates a current hepatitis B infection. If they are negative for HBsAg, they are immediately vaccinated.
If the partner isn’t also tested for the hepatitis B surface antibody (anti-HBs or HBsAb), then no one knows if  the individual was infected years ago (or earlier in the relationship) with hepatitis B and cleared the acute infection.
Hepatitis B is not called the “silent” infection for nothing — many people who get hepatitis B never have any symptoms and never realize they were infected. As a result, a wife, husband, partner or lover who tested negative for HBsAg, may actually have been infected in the past and cleared the infection and now has protective hepatitis B surface antibodies to forever safeguard them from infection. If they’re immediately vaccinated and retested after the three-dose vaccination, they will test positive for surface antibodies, without ever knowing that their antibodies resulted from a past infection, not immunization.
Bottom line, if one of you have been diagnosed and the other is not infected, it is unusual but not uncommon. Get tested and immediately vaccinated if the uninfected partner tests negative for the hepatitis B surface antibody.
Take a quiz to find out how much you know about hepatitis B transmission: click here.

       
                hepatitis Bimmunizationsafe sexsexual transmissionsexually transmitted infectionSTIvaccinewhen one partner has hepatitis B and the other does not

StephenW

如果乙型肝炎被性传播，我的合作伙伴怎么没有感染？
2017年2月1日hepbtalk

由克里斯汀·库卡

我以为乙型肝炎是性传播的？我刚刚测试了积极的，但我的伴侣测试了负面，我们已经在一起多年，给了什么？

这个问题是一个常见的问题。乙型肝炎确实容易传播，所以为什么有些人 - 谁没有接种疫苗 - 从他们的性伴侣不会得到乙型肝炎？

它归结为变量，例如您所从事的性活动的类型，受感染的合作伙伴的病毒载量（HBV DNA）以及传染性体液的接收端，特别是含有最多病毒和精液的血液。

有一个受感染的人，另外一个没有，可以增加一个已经创伤性乙型肝炎诊断的压力。一位女性在丈夫测试为阴性时，测试呈阳性的女性说：“这很令人困惑，让我质疑我是唯一感染的人。” “我以为这可能是一个错误，也许我是一个生物异常，当然我不是。”

我们来看看影响谁被感染的因素，两个人没有性行为的因素。

病毒载量：精液，阴道液和血液均含有乙型肝炎病毒（HBV），病毒载量越高，血液和体液感染越多。然而，具有不可检测的病毒载量并不意味着您不会在不安全的性行为中感染某人。即使一个人的病毒载量不可检测，研究显示他的精液仍然含有一些HBV，并且可以扩散感染，尽管风险较低。

所以这里的规则是，如果一名男子对乙型肝炎表面抗原（HBsAg）检测阳性，他必须考虑自己感染。

性别的作用：在异性恋关系中，未感染妇女感染乙型肝炎的男性伴侣感染风险较高。妇女正处于精液的接收端，除非使用避孕套，否则会大大增加其感染的风险。
图片由renjith krishnan在FreeDigitalPhotos.net提供。
图片由renjith krishnan在FreeDigitalPhotos.net提供。

当一名女性感染乙型肝炎时，一名未感染人员与其阴道分泌物直接接触，处于危险之中，但这种接触风险低于妇女在性交期间直接感染传染性精液。

然而，月经期感染的女性更有可能传播乙型肝炎，因为血液中含有比阴道分泌物更高的HBV水平。这就是为什么建议使用手套和牙科水坝来防止暴露。

性活动的类型：某些性行为比其他性传播乙肝更有效率。与阴道性别相比，口交性似乎具有较低的乙型肝炎传播率。肛交性传播的风险很高，因为在渗透期间可能发生的皮肤撕裂改善了HBV的传播。

手指风险较小，除非受感染的妇女月经不便，或者手上有瘀伤或切口，使精液或阴道液进入乙型肝炎，否则建议使用手套。

“未感染”的伴侣可能已经被感染并清除了乙型肝炎：当一个人首先被诊断患有乙型肝炎时，医生经常检查其合作伙伴只有乙型肝炎表面抗原（HBsAg），这表明目前的乙型肝炎感染。如果HBsAg阴性，则立即接种疫苗。

如果合作伙伴还没有测试乙型肝炎表面抗体（抗HBs或HBsAb），那么没有人知道个体是否在乙型肝炎前几年（或更早的关系）感染，并清除了急性感染。

乙型肝炎没有被称为“沉默”感染 - 许多乙肝患者从来没有任何症状，从未意识到他们被感染。结果，对HBsAg阴性的妻子，丈夫，伴侣或情人可能实际上已经感染过，并清除了感染，现在有乙型肝炎表面抗体可以永久保护他们免受感染。如果在三次接种疫苗后立即接种疫苗并重新测试，他们将测试表面抗体阳性，而不知道其抗体是由过去的感染导致的，而不是免疫的。

底线，如果你们中的一个被诊断出来，另一个没有感染，那是不常见的，但并不罕见。如果未感染的合作伙伴对乙型肝炎表面抗体阴性，则进行测试并立即接种疫苗。

进行测验，了解您对乙型肝炎传播的了解程度：点击此处。

乙型肝炎免疫安全性交性传播性传播感染一名伴侣患有乙型肝炎，另一名不服用乙型肝炎