什麼是 B 型肝炎？
B 型肝炎是世界上最常見的肝臟感染。是由會攻擊和傷害肝臟的 B 型肝炎病毒引起的。經由血液、沒有保護的性行為、共用或重複使用的針頭傳染，以及在懷孕或分娩期間由受感染的母親傳染給新生兒。大多數受感染的成年人都能毫無困難地擺脫 B 型肝炎病毒。然而，某些成年人和大多數受感染的嬰兒和兒童卻無法擺脫這種病毒，因而演變為慢性（終生）感染。
好消息是有安全的疫苗可以預防 B 型肝炎感染，並且也有針對已感染人士的新治療方法。
有多少人受 B 型肝炎影響？
全世界有 20 億人（每 3 人中就有 1 人）感染 B 型肝炎；2.57 億人為慢性感染（也就是說他們無法擺脫這種病毒）。據估計，每年有 70 萬人死於 B 型肝炎及其併發症。
為什麼 B 型肝炎在世界的某些地區比較常見？
B 型肝炎可以感染任何年齡或種族的任何人，但是來自世界上 B 型肝炎較為常見的地區（如亞洲、非洲和南美洲部分地區、東歐以及中東）的人，受感染的風險要高得多。B 型肝炎在出生（或其父母出生）於這些地區的美國人中也很常見。
B 型肝炎在世界上某些地區較為常見，是因為在這些地區已經有更多的人感染了 B 型肝炎。雖然 B 型肝炎並非「亞洲病」或「非洲病」，但卻影響著來自這些地區的數億人——因此，會有更多的人將 B 型肝炎病毒傳給他人。這增加了您受感染的風險。因為比較少西方人受感染，所以這個群體的感染風險較低。
在 B 型肝炎常見的地區，人們通常在新生兒時期就受到感染——在分娩過程中由母親在不知情的情況下將病毒傳給嬰兒。在生活上與受感染的家庭成員日常接觸密切的幼兒也面臨風險。嬰兒和兒童比較容易演變為慢性 B 型肝炎感染，因為他們未成熟的免疫系統難以擺脫這種病毒。
如果您或您的家人來自地圖上的深藍色區域，您感染 B 型肝炎的風險可能更大，應該和醫生談談接受檢查的事宜。
我為什麼應該關心 B 型肝炎？
慢性 B 型肝炎可以導致嚴重的肝病，如肝硬化或肝癌。接受檢查十分重要，因為早期診斷可以早期治療，進而挽救您的生命。另外，感染者可能將病毒傳給他人。大多數人根本不知道自己受感染，所以他們會在不知情的情況下傳給許多其他人。如果人們不接受檢查，B 型肝炎可能傳給一個家庭好幾代人及整個社區。
一個常見誤解是 B 型肝炎會「遺傳」，因為一個家庭中幾代人都可能感染。但 B 型肝炎並不是遺傳疾病—— B 型肝炎是由病毒引起的，通常因母嬰傳染或者不小心接觸血液而在家人之間傳染。家人之間可以透過接受檢查、接種疫苗和治療，不受 B 型肝炎感染。
B 型肝炎很危險，因為這是一種「無聲的感染」，可以讓人在不知情之下受到感染。大多數 B 型肝炎感染者根本不知道自己被感染，會在不知情的情況下經由血液和體液將病毒傳給他人。那些慢性感染者日後有更高的風險會演變為肝功能衰竭、肝硬化和/或肝癌。這種病毒可以悄無聲息、持續不斷地長年攻擊肝臟而不被察覺。
什麼是急性 B 型肝炎？
急性 B 型肝炎感染可能持續達 6 個月（不論是否有症狀），感染者在這段期間會將病毒傳給他人。
急性感染的症狀可能包括食慾減退、關節和肌肉疼痛、低燒及可能出現胃痛。雖然大多數人都不沒有任何症狀，但症狀可能會在感染後的 60-150 天，平均3 個月後出現。有些人可能出現更嚴重的症狀，如噁心、嘔吐、黃疸（眼睛和皮膚發黃）或者胃脹，這些可能導致他們去就醫。
只需要簡單驗血即可辨別一個人的血液中是否有 B 型肝炎病毒。如果您已被診斷為急性 B 型肝炎，醫生需要在 6 個月後再次為您驗血，以確定您是否已經痊癒，還是已經演變為慢性 B 型肝炎。在醫護人員替您驗血確認您的血液中不再有 B 型肝炎病毒之前，保護其他人避免被感染是十分重要的。讓您的性伴侶和家人（或與您密切接觸的家屬）接受 B 型肝炎檢查也是十分重要的。如果他們尚未受感染，而且尚未接受 B 型肝炎疫苗接種，那麼他們就應該開始接種 B 型肝炎系列疫苗。
急性 B 型肝炎患者沒有特定的治療方法——目前沒有任何治療方法可以完全擺脫急性 B 型肝炎，大多數在成年期受到感染的人都能自行痊癒。有時候，症狀嚴重者可能要住院接受治療。休息和控制症狀是治療的主要目標。新的急性感染會伴隨一種叫做「猛暴型肝炎」的罕見致命疾病，需要立即進行緊急治療，因為患者可能會突然肝衰竭。
在感染急性 B 型肝炎期間照顧肝臟的簡單方法就是要避免飲酒、戒菸、食用健康食物、避免油膩或高脂肪的食物，以及告知醫護人員您正在服用的所有藥物（處方藥、非處方藥、維他命或草藥補充劑），以確保他們對您的肝臟無害。這時如果您有任何疑問要儘量提出來。使用維他命和肝臟健康補充劑可能沒法助您痊癒，實際上對肝臟的影響可能弊大於利。
什麼是慢性 B 型肝炎？
B 型肝炎病毒檢驗結果呈陽性超過 6 個月（初次驗血結果以後）就會被診斷為患慢性感染。這表示他們的免疫系統無法擺脫 B 型肝炎病毒，而且這種病毒仍然存在於他們的血液和肝臟中。目前已經有有效的方法可以治療和控制慢性感染，但是沒有辦法治癒。如果您是慢性感染者，病毒很可能在您的一生中都留在您的血液裡。
慢性 B 型肝炎患者會在不知情的情況下將病毒傳給他人。慢性 B 型肝炎也可以導致嚴重的肝病，如肝硬化或肝癌。但並非每個慢性感染者都會演變為嚴重的肝病。然而，他們的可能性比未感染者更大。
演變為慢性 B 型肝炎感染的風險與首次感染 B 型肝炎病毒的年齡有關：
- 90% 受感染的新生兒和嬰兒會演變為慢性 B 型肝炎感染
- 高達 50% 受感染的兒童（1-5 歲）會演變為慢性 B 型肝炎感染
- 5%-10% 受感染的成年人會演變為慢性 B 型肝炎感染（即 90% 會痊癒）
獲悉自己患有慢性 B 型肝炎感染會非常令人沮喪。因為大多數人沒有症狀，他們在最初接觸 B 型肝炎病毒後數十年被診斷出來，所以會令人感到震驚和意外。好消息是，大多數慢性 B 型肝炎患者會活得健康長壽。
受感染的孕婦會在分娩期間將病毒傳給新生兒。新生兒在出生時慢性感染的風險很高，世界衛生組織（世衛組織）和美國疾病控制和預防中心 (CDC) 建議，所有嬰兒在出生後 12-24 小時內接受首劑 B 型肝炎疫苗接種。如果您已懷孕並且您知道自己受感染，您應該確保您的寶寶在分娩後的 12-24 小時內接受首劑 B 型肝炎疫苗接種！
儘管慢性 B 型肝炎感染沒有治癒的方法，但有藥物可以控制 B 型肝炎病毒，並可阻止他們繼續損害肝臟。也有處於實驗階段的新藥，可以在不久的將來提供治癒方法。儘管慢性 B 型肝炎患者演變為嚴重肝病或肝癌的風險較高，但還有許多簡單的事情可以幫助他們降低風險。
- 安排每 6 個月（或至少每年）一次定期到肝臟專科醫生或精通 B 型肝炎治療的醫護人員處就診，以便他們能監測您的肝臟健康。
- 與您的醫護人員討論您的慢性 B 型肝炎感染治療是否有助於預防嚴重的肝病或肝癌。
當某人有慢性 B 型肝炎感染時，他們的醫生可能會稱他們為「慢性帶原者」。身為「慢性帶原者」表示您有慢性 B 型肝炎感染，可以將病毒傳給他人，應該由醫生來幫您控制感染。
大多數成年人無需藥物治療，急性感染即可自行痊癒。對於演變為慢性 B 型肝炎感染的成年人、兒童和嬰兒，目前還沒有治癒的方法。但好消息是，有一些治療方法可以減緩病毒擴散的速度，進而減緩慢性感染者肝病的進展。如果產生的 B 型肝炎病毒較少，那麼對肝臟的損傷就比較小。
隨著令人振奮的新研究，相信找到慢性 B 型肝炎的治癒方法指日可待。請參閱我們的 Drug Watch，瞭解目前正在研發中的其他具有潛力的藥物。
慢性 B 型肝炎有幾種治療方法。重要的是要瞭解，並非每個慢性 B 型肝炎患者都需要治療。您的醫生會幫助您決定是要進行藥物治療，還是可以靜待觀察您的病情。
有幾種抗病毒藥物可以減緩或阻止 B 型肝炎病毒的複製，進而減少肝臟發炎和造成的損害。這些抗病毒藥丸每天服用一次，至少需要服用 1 年，通常更久。目前有六種經美國食品和藥物管理局 (FDA) 批准的抗病毒藥物，但是只有三種「一線」抗病毒藥物獲得推薦：惠立妥（tenofovir disoproxil，商品名 Viread/TDF）、韋立得（tenofovir alafenamide，商品名 Vemlidy/TAF）和貝樂克（entecavir，商品名 Baraclude）。推薦使用一線抗病毒藥物，因為他們更安全也最有效。對一線抗病毒治療無反應或無法獲取一線抗病毒治療的患者可以使用其他選擇：喜必福（telbivudine，商品名 Tyzeka、Sebivo）、干適能（adefovir dipivoxil，商品名 Hepsera）和干安能（lamivudine，商品名 Epivir-HBV、Zeffix、Heptodin）。
儘管 FDA 已經批准這些用於慢性 B 型肝炎的抗病毒藥物，但他們無法徹底治癒這種病。不過他們可以大幅降低肝臟損傷和肝癌的風險。抗病毒藥物不能隨意停止和開始服用，這就是為什麽在開始治療慢性 B 型肝炎之前，需要由專業醫生進行徹底評估的原因。
也有免疫調節藥物可以增強免疫系統，以助於控制 B 型肝炎病毒。他們在 6 個月到 1 年的時間裡以注射方式給藥。最常見的處方藥物包括干擾素 alfa-2b (Intron A) 和聚 B 二醇干擾素 (Pegasys)。
您和您的醫生需要討論哪種治療選擇最適合您。對許多人來說，這些藥物會減少或阻止 B 型肝炎病毒。患者在幾個月以內會有所改善，這是因為病毒對肝臟的損傷減緩，或者在某些情況下，甚至在長期服用後出現逆轉。
請參閱我們的 Drug Watch，取得 FDA 批准的藥物和目前正在研發中的其他具有潛力的藥物的完整名單。
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.