乙型肝炎是世界上最常见的肝脏感染。它是由乙型肝炎病毒 (HBV) 引起的，该病毒会攻击和伤害肝脏。它通过血液、无保护性行为、共用或重复使用的针头传播，在怀孕或分娩期间由受感染的母亲传染给新生婴儿。大多数感染的成年人能够毫无问题地消除乙型肝炎病毒。然而，一些成年人和大多数受感染的婴儿和儿童无法消除这种病毒，并将发展为慢性（终生）感染。
全世界 20 亿人（3 人中就有 1 人）已感染乙型肝炎；2.57 亿人为慢性感染（这意味着他们无法消除这种病毒）。据估计，每年有 70 万人死于乙型肝炎及其并发症。
急性感染的症状可能包括食欲减退、关节和肌肉疼痛、低烧和可能胃痛。虽然大多数人不会体验到症状，但症状会在感染后的 60-150 天出现，平均为 3 个月。有些人可能出现更严重的症状，如恶心、呕吐、黄疸（眼睛和皮肤发黄），或者胃胀，这些可能导致他们去看卫生保健提供者。
仅需简单的验血即可辨别一个人的血液中是否存在乙型肝炎病毒。如果您已被诊断为急性乙型肝炎，医生需要在 6 个月后再次测试您的血液，以确定您是已康复，还是发展为慢性乙型肝炎感染。在您的卫生保健提供者确认您的验血表明您的血液中不再存有乙型肝炎病毒之前，保护其他人避免感染可能性是十分重要的。让您的性伴侣和家庭成员（或与您密切接触的家属）接受乙型肝炎测试也是十分重要的。如果他们尚未受感染，而且尚未接受乙型肝炎疫苗接种，那么他们就应该开始注射乙型肝炎疫苗系列。
- 90% 受感染的新生儿和婴儿会发展为慢性乙型肝炎感染
- 高达 50% 受感染的儿童（1-5 岁）会发展为慢性乙型肝炎感染
- 5%-10% 受感染的成年人会发展为慢性乙型肝炎感染（即，90% 会恢复）
受感染的孕妇可以在分娩期间将病毒传给新生儿。因此，由于新生儿在出生时患慢性感染的风险很高，世界卫生组织 (WHO) 和美国疾病控制和预防中心 (CDC) 建议，所有婴儿在出生后 12-24 小时内接受首剂乙型肝炎疫苗接种。如果您已怀孕并且您知道自己受感染，则您可以确保您的宝宝在分娩后的 12-24 小时内接受首剂乙型肝炎疫苗接种！
凭着所有令人振奋的新研究，有很大希望在不久的将来找到慢性乙型肝炎的治愈方法。访问我们的 Drug Watch（药品观察 获取研发中的其他有前景药物的清单。
有几种抗病毒药物可以减缓或阻止乙型肝炎病毒的复制，从而减少肝脏炎症和损伤。这些抗病毒药物为丸剂，每天服用一次，疗程至少 1 年，通常更久。目前有 6 种经美国 FDA 批准的抗病毒药物，但是只有 3 种“一线”抗病毒药物获得推荐：替诺福韦酯（Viread/TDF）、替诺福韦艾拉酚胺（Vemlidy/TAF）和恩替卡韦（Baraclude）。推荐使用一线抗病毒药物，因为它们更安全、最有效。对一线抗病毒治疗无应答或无法获取一线抗病毒治疗的患者可使用其他选择：替比夫定（Tyzeka，Sebivo）、阿德福韦酯（Hepsera）和拉米夫定（Epivir-HBV，Zeffix，Heptodin）。
尽管 FDA 已经批准这些用于慢性乙型肝炎的抗病毒药物，但它们不能提供彻底治愈。然而，它们可以大大减少发展肝损伤和肝癌的风险。抗病毒药物不能随意停止和开始，这就是在开始治疗慢性乙型肝炎之前需要由知识渊博的医生进行彻底评估是如此重要的缘由。
还有免疫调节药可以增强免疫系统，以帮助控制乙型肝炎病毒。它们在 6 个月至 1 年的时间里以注射方式给药。最常见的处方药物包括干扰素 alfa-2b (Intron A) 和聚乙二醇干扰素 (Pegasys)。
如需获取经 FDA 批准的药物和其他处于研发中的有前景药物的完整清单，请访问我们的 Drug Watch（药品观察。
What is hepatitis B?
Hepatitis B is the world's most common liver infection. It is caused by the hepatitis B virus (HBV), which attacks and injures the liver. It is transmitted through blood, unprotected sex, shared or re-used needles, and from an infected mother to her newborn baby during pregnancy or delivery. Most infected adults are able to get rid of the hepatitis B virus without any problems. However, some adults and most infected babies and children are unable to get rid of the virus and will develop chronic (life-long) infection.
The good news is that there is a safe vaccine to prevent a hepatitis B infection and new treatments for those already infected with hepatitis B.
How many people are affected by hepatitis B?
Worldwide, 2 billion people (1 out of 3 people) have been infected with hepatitis B; and 257 million people are chronically infected (which means they are unable to get rid of the virus). An estimated 700,000 people die each year from hepatitis B and its complications.
Why is hepatitis B more common in some parts of the world?
Hepatitis B can infect any person of any age or ethnicity, but people from parts of the world where hepatitis B is common, such as Asia, parts of Africa and South America, Eastern Europe, and the Middle East, are at much higher risk for getting infected. Hepatitis B is also common among Americans who were born (or whose parents were born) in these regions.
Hepatitis B is more common in certain regions of the world because there are so many more people already infected with hepatitis B in these regions. Although hepatitis B is not an "Asian disease" or an “African disease,” it affects hundreds of millions of people from these regions – so there are more people who can pass the hepatitis B virus on to others. This increases the risk that you could get infected. Since there is a smaller number of Westerners who are infected, this group has a lower risk of infection.
In regions where hepatitis B is common, people are usually infected as newborns - from a mother who unknowingly passes the virus to her baby during delivery. Young children are also at risk if they live in close daily contact with an infected family member. Babies and children are more likely to develop a chronic hepatitis B infection because their young immune systems have trouble getting rid of the virus.
If you, or your family, is from an area of the map that is darker blue, you might be at greater risk for hepatitis B infection and should talk to a doctor about getting tested.
Why should I be concerned about hepatitis B?
Chronic hepatitis B can lead to serious liver disease such as cirrhosis or liver cancer. It's important to get tested because early diagnosis can lead to early treatment which can save your life. Also, people who are infected can spread the virus to others. Since most people don't know they are infected, they are unknowingly spreading it to many other people. If people are not tested, hepatitis B can pass through several generations in one family and throughout the community.
One common myth is that hepatitis B can be "inherited" since several generations in one family may be infected. But hepatitis B is NOT a genetic disease -- hepatitis B is caused by a virus, which is often transmitted among family members due to mother-to-child transmission or accidental household exposure to blood. Families can break the cycle of hepatitis B infection by getting tested, vaccinated and treated.
Why is hepatitis B so dangerous?
Hepatitis B is dangerous because it is a “silent infection” that can infect people without them knowing it. Most people who are infected with hepatitis B are unaware of their infection and can unknowingly pass the virus to others through their blood and infected bodily fluids. For those who become chronically infected, there is an increased risk of developing liver failure, cirrhosis and/or liver cancer later in life. The virus can quietly and continuously attack the liver over many years without being detected.
What is acute hepatitis B?
An acute hepatitis B infection may last up to six months (with or without symptoms) and infected persons are able to pass the virus to others during this time.
Symptoms of an acute infection may include loss of appetite, joint and muscle pain, low-grade fever, and possible stomach pain. Although most people do not experience symptoms, they can appear 60-150 days after infection, with the average being 3 months. Some people may experience more severe symptoms such as nausea, vomiting, jaundice (yellowing of the eyes and skin), or a bloated stomach that may cause them to see a health care provider.
A simple blood test can tell a person if the hepatitis B virus is in their blood. If you have been diagnosed with acute hepatitis B, the doctor will need to test your blood again in 6 months to figure out if you have recovered, or if you have developed a chronic hepatitis B infection. Until your health care provider confirms that your blood test shows that there is no more hepatitis B virus in your blood, it is important to protect others from a possible infection. It is also important to have your sexual partner(s) and family members (or those you live in close household contact with) tested for hepatitis B. If they have not been infected – and have not received the hepatitis B vaccine – then they should start the hepatitis B vaccine series.
People who have acute hepatitis B are not prescribed specific hepatitis B treatment – there is no treatment that will get rid of an acute hepatitis B infection, and most people infected as adults recover on their own. Sometimes, a person with severe symptoms may be hospitalized for general support. Rest and managing symptoms are the primary goals of this medical care. A rare, life-threatening condition called “fulminant hepatitis” can occur with a new acute infection and requires immediate, urgent medical attention since a person can go into sudden liver failure.
Simple tips for taking care of your liver during an acute hepatitis B infection are to avoid alcohol, stop or limit smoking, eat healthy foods, avoid greasy or fatty foods, and talk to your health care provider about any medications you are taking (prescriptions, over-the-counter medications, vitamins or herbal supplements) to make sure they are safe for your liver. This is a good time to ask any other questions you may have. The use of vitamins and liver health supplements will likely not assist your recovery and may actually cause more harm than good to the liver.
Be sure to follow-up with your health care provider for any additional blood tests that are needed to confirm your recovery from an acute infection.
What is chronic hepatitis B?
People who test positive for the hepatitis B virus for more than six months (after their first blood test result) are diagnosed as having a chronic infection. This means their immune system was not able to get rid of the hepatitis B virus and it still remains in their blood and liver. There are effective ways to treat and manage a chronic infection, but there is no cure. If you are chronically infected, the virus will likely remain in your blood for the rest of your life.
People who have chronic hepatitis B can unknowingly pass the virus on to others. Chronic hepatitis B can also lead to serious liver diseases, such as cirrhosis or liver cancer. Not every person who is chronically infected will develop serious liver disease. However, they have a greater chance than someone who is not infected.
The risk of developing a chronic hepatitis B infection is related to the age at which one first becomes infected with the hepatitis B virus:
- 90% of infected newborns and babies will develop a chronic hepatitis B infection
- Up to 50% of infected children (1-5 years) will develop a chronic hepatitis B infection
- 5-10% of infected adults will develop a chronic hepatitis B infection (that is, 90% will recover)
Learning that you have a chronic hepatitis B infection can be very upsetting. Because most people do not have symptoms and can be diagnosed decades after their initial exposure to the hepatitis B virus, it can be a shock and a surprise to be diagnosed with a chronic hepatitis B infection. The good news is that most people with chronic hepatitis B should expect to live a long and healthy life.
Infected pregnant women can pass the virus to their newborns during childbirth. Therefore, since the risk of newborns becoming chronically infected at birth is high, both the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) recommend that all infants receive the first dose of the hepatitis B vaccine within 12-24 hours after birth. If you are pregnant and you know that you are infected, you can make sure that your baby gets the first dose of the hepatitis B vaccine within 12-24 hours after delivery!
While there is no cure for chronic hepatitis B infection, there are effective drug therapies that can control the hepatitis B virus and stop it from damaging the liver. There are also promising new drugs in the research phase that could provide a cure in the very near future. Although the risk of developing a serious liver disease or liver cancer is higher for those living with chronic hepatitis B than those who are not infected, there are still many simple things a person can do to help reduce their risk.
- Schedule regular visits every six months (or at least every year) with a liver specialist or a health care provider who is knowledgeable about hepatitis B so they can monitor the health of your liver.
- Talk to your health care provider about whether treatment for your chronic hepatitis B infection would be helpful in preventing serious liver disease or liver cancer.
- Make sure that your health care provider screens you for liver cancer during your regular visits since early detection equals more treatment options and a longer life.
- Avoid or limit alcohol and smoking since both cause a lot of stress to your liver.
- Eat a healthy diet with lots of vegetables since fried, greasy foods are hard on your liver.
What does it mean to be a “chronic carrier”?
When someone has a chronic hepatitis B infection, their doctor may refer to them as being a “chronic carrier.” Being a “chronic carrier” means that you have a chronic hepatitis B infection, can pass the virus on to others, and you should be managed by a doctor for your infection.
Is there a cure for hepatitis B?
Most adults will recover from an acute infection on their own without the need for medication. For adults, children and infants who develop a chronic hepatitis B infection, there is currently no cure. But the good news is there are treatments that can help slow the progression of liver disease in chronically infected persons by slowing down the virus. If there is less hepatitis B virus being produced, then there is less damage being done to the liver.
With all of the new exciting research, there is great hope that a cure will be found for chronic hepatitis B in the near future. Visit our Drug Watch for a list of other promising drugs in development.
What options are there to treat my hepatitis B?
For an acute infection, there is generally no treatment other than rest and supportive measures to manage any symptoms.
For chronic hepatitis B, there are several treatments available. It is important to understand that not everyone with chronic hepatitis B needs treatment. Your doctor will help you decide if you need medication or if you can wait and monitor your condition.
There are several antiviral medications that slow down or stop the hepatitis B virus from replicating, which reduces the inflammation and damage to the liver. These antivirals are taken as a pill once a day for at least 1 year, usually longer. There are 6 U.S. FDA approved antivirals, but only three “first-line” antivirals are recommended: tenofovir disoproxil (Viread/TDF), tenofovir alafenamide (Vemlidy/TAF) and entecavir (Baraclude). First-line antivirals are recommended because they are safer and most effective. For people who do not respond to, or have access to, the first-line antiviral treatments, other options are available: telbivudine (Tyzeka, Sebivo), adefovir dipivoxil (Hepsera), and lamivudine (Epivir-HBV, Zeffix, Heptodin).
Although the FDA has approved these antivirals for chronic hepatitis B, they do not provide a complete cure. They can, however, greatly decrease the risk of developing liver damage and liver cancer. Antivirals are not meant to be stopped and started, which is why a thorough evaluation by a knowledgeable doctor is so important before beginning treatment for chronic hepatitis B.
There are also immunomodulator drugs that boost the immune system to help control the hepatitis B virus. They are given as injections over 6 months to 1 year. The most commonly prescribed include interferon alfa-2b (Intron A) and pegylated interferon (Pegasys).
You and your doctor will need to discuss the treatment options before deciding which one, if any, is best for you. For many people, these medications will decrease or stop the hepatitis B virus. This results in patients feeling better within a few months because liver damage from the virus is slowed down, or even reversed in some cases, when taken long-term.
For a complete list of FDA approved drugs and other promising drugs in development for hepatitis B, visit our Drug Watch.