Cúm là gì?
Hepatitis B is an infection caused by the hepatitis B virus (HBV). It can affect both adults and children, causing acute liver inflammation.
Once acute infection has resolved, it is estimated that up to 10% of those infected in adulthood, and up to 90% of those infected in infancy, will go on to develop chronic infection.
Chronic hepatitis B (CHB) can lead to cirrhosis (scarring of the liver) and liver failure and/or hepatocellular carcinoma (liver cancer). Liver cancer is the second leading cause of cancer deaths globally. There is no cure for CHB, although there are some antiviral medications that can reduce potential liver damage.
Cần để ý những gì
The incubation period for hepatitis B ranges from 45 to 180 days. The infectious period starts from several weeks before the onset of symptoms (if present), and usually lasts approximately 4 to 5 months. Those who develop CHB usually remain infectious for life.
Initial hepatitis B infection is often asymptomatic, meaning a person may be unaware that they are carrying the infection. In those who develop signs of acute hepatitis B infection, symptoms may include:
- loss of appetite
- nausea and vomiting
- abdominal pain
- sốt
- pain in the joints
- jaundice (yellowing of the skin and eyes).
HBV infection is confirmed via Một blood test (serology), which may also be used to determine whether infections are newly acquired or chronic.
Bệnh lây truyền qua đường nào
Bệnh viêm gan B là transmitted through broken or penetrated ski, hoặc when a person’s mucosal surface (nose, eyes or mouth) is exposed ĐẾN blood, semen hoặc khác body fluids of an infected person. Transmission can occur:
- from an infected mother to baby during delivery
- during sexual contact
- with exposure to contaminated sharp objects (e.g. during tattoos or piercings, or injecting drugs)
- through sharing a toothbrush or razor
- through contact with contaminated surfaces.
HBV can survive on surfaces for at least 7 days Và remains capable of causing infection during this time.
Dịch tễ học
Humans are the only known host for HBV. Around 296 million people globally are living with CHB.
In Australia, it is estimated that there are over 200,000 people living with diagnosed CHB, representing around three quarters of the total number of cases (with one quarter remaining undiagnosed). Over 90% of new CHB cases in Australia are contracted overseas.
Aboriginal and Torres Strait Islander peoples, people who inject drugs, men who have sex with men (MSM), and those born in areas endemic with HBV carry the highest burden of disease in Australia.
Phòng ngừa
The spread of hepatitis B can be reduced by:
- promoting and practicing safe sex
- not sharing injecting, piercing or tattooing equipment
- maintaining infection control measures in healthcare settings
- washing your hands thoroughly with soap and water after any contact with blood, body fluids, or contaminated surfaces
- ensuring appropriate antenatal care, including HBsAg screening
- vaccination.
Vaccination
Vaccination provides high levels of protection against HBV infection. In Australia, vaccination is available through either monovalent or combination vaccines.
Hepatitis B vaccination is funded via the Chương trình Tiêm chủng Quốc gia (NIP); a single dose vì neonates at birth and a 3-dose course given at 6 weeks, 4 months and 6 months of age. Additional doses and/or boosters are recommended for certain groups (e.g. preterm babies, people with renal failure and those with ức chế miễn dịch.).
The birth dose of hepatitis B vaccine is recommended to prevent transmission of HBV during childbirth. Due to the long incubation period and high rates of asymptomatic infection, administration is recommended regardless of a mother’s infection status.
Table 1: Hepatitis B vaccine brands and schedules available in Australia
| Vaccine brand and antigen | Tuổi | Dose, hepatitis B antigen content and route | Recommended schedule* |
| Monovalent vaccines | |||
| Engerix-B (paediatric formulation) hepatitis B | < 20 years | 0.5 mL (10 µg) TÔI | 3 doses, minimum 1 month between doses 1 & 2, minimum 4–6 months between doses 1 & 3* |
| H-B-Vax II (paediatric formulation) hepatitis B | < 20 years | 0.5 mL (5 µg) TÔI | |
| Engerix-B (adult formulation) hepatitis B | ≥ 20 years^ | 1.0 mL (20 µg) TÔI | 3 doses, minimum 1 month between doses 1 & 2, minimum 4–6 months between doses 1 & 3* |
| H-B-Vax II (adult formulation) hepatitis B | ≥ 20 years^ | 1.0 mL (10 µg) TÔI | 3 doses, minimum 1 month between doses 1 & 2, minimum 4–6 months between doses 1 & 3 |
| H-B-Vax II (dialysis formulation) hepatitis B | ≥ 20 years | 1.0 mL (40 µg) TÔI | 3 doses, minimum 1 month between doses 1 & 2, minimum 6 months between doses 1 & 3 |
| Combination vaccines | |||
| Infanrix hexa OR Vaxelis DTPa, polio, hepatitis B, Hib | ≥ 6 tuần | 0.5 mL (10 µg) TÔI | 3 doses, minimum 1 month between dose 1 & 2, minimum 2 months between dose 2 & 3# |
| Twinrix Junior (360/10) viêm gan A và B | 1– <16 years | 0.5 mL (10 µg) TÔI | 3 doses, minimum 1 month between doses 1 & 2 minimum 6 months between doses 1 & 3 |
| Twinrix (720/20) viêm gan A và B | 1– <16 years | 1.0 mL (20 µg) TÔI | 2 doses, minimum 6 months apartΩ |
| ≥ 16 years | 3 doses, minimum 1 month between doses 1 & 2, minimum 6 months between doses 1 & 3* |
* Refer to Australian Immunisation Handbook for advice on accelerated schedules for those at imminent risk of exposure to hepatitis B.
^ Adolescents aged 11–15 years can receive a 2-dose schedule of Engerix-B adult formulation or HB-Vax II adult formulation, given 6 months apart as an alternate schedule.
# Infants vaccinated overseas who received a dose at birth, 1–2 months and > 6 months are considered fully vaccinated (birth dose is considered as a valid dose 1, no need to complete a 4th dose).
Ω Do not use this schedule if individual is at imminent risk of hepatitis B exposure (e.g. close contact).
shaded boxes indicate NIP-scheduled vaccines.
Interchangeability of brands
TÔInfanrix hexa Và Vaxelis Có thể be used interchangeably to complete a vaccine course.
Switching brands between Engerix B and H-B-Vax II to complete a vaccine course is not recommended due to the different processes utilised to manufacture these vaccines. If the brand required to complete an already commenced course in unavailable, adults are recommended to receive 2 doses of the corresponding paediatric vaccine simultaneously (ensuring they are injected 2.5 cm apart when using the same limb). Refer to Updated ATAGI clinical advice regarding alternatives during supply shortage of the adult formulations of hepatitis B vaccines để biết thêm thông tin.
Phản ứng phụ
Tác dụng phụ thường gặp following vaccination include cáu gắt, drowsiness, injection site pain, redness and swelling, and low-grade fever, nausea and general aches and pains.
Hepatitis B serology
Performing serology following hepatitis B vaccination is not routinely recommended, however may be indicated in some circumstances such as for:
- those at risk of severe complications of hepatitis B (e.g. people who have HIV , people with pre-existing liver disease)
- sexual partners or household contacts of people living with hepatitis B
- those with impaired renal function
- infants born to mothers who are chronically infected with HBV.
TÔIt is important to note that serology may be less reliable when conducted more than 4 to 8 weeks post the last dose of vaccination. This is because circulating anti-HBs levels decline over time even when immune memory remains, meaning results are not a reliable indicator of immunity. The exception to this is in infants born to mothers chronically infected with hepatitis B; serology should be performed 3-12 months after completion of the infant schedule (and no younger than 9 months of age) to avoid detecting maternal antibodies and HBIG (hepatitis B immunoglobulin) given at birth.
Table 2: Interpretation of hepatitis B serology and actions required
| Result | Outcome | Action required |
| anti-HBs ≥ 10 m IU/mL | immune | no further action required |
| anti-HBs < 10 m IU/mL | non-immune | 1. administer single age-appropriate dose of vaccine (4quần què dose) 2. check anti-HBs 4 weeks later - if anti-HBs ≥ 10 m IU/mL, no further action required - if anti-HBs < 10 m IU/mL, investigate possibility of HBV infection by ordering HBsAg and Anti-HBc blood test - if no infection, follow MVEC's pathway for hepatitis B non-responders (detailed below in the section: Recommendations for specific populations) |
Further guidance can be found at The Australian Immunisation Handbook: Hepatitis B; Laboratory diagnosis.
Recommendations for specific populations
Infants born to mothers known to be HBV positive
Infants born to mothers known to have chronic hepatitis B must receive:
- a birth dose of monovalent hepatitis B vaccine
- hepatitis B immunoglobulin (HBIG).
These are recommended, and ideally administered on the day of birth (preferably within 12 hours), at the same time, in separate thighs. HBIG needs to be administered within 48 hours after birth (efficacy is significantly reduced if administration is delayed > 48 hours after birth) and the vaccine up to 7 days after birth. The routine scheduled 3 dose course of hepatitis B vaccine should also be completed at 6 weeks, 4 months and 6 months (as per the NIP).
If these precautions are followed it is safe for the infant to be breastfed.
The infant should have serology performed 3 to 12 months post the 6-month dose of hepatitis B vaccine (and no earlier than 9 months of age).
Refer to the Immunisation Handbook: Hepatitis B, recommendations for other groups for detailed guidance.
People with impaired renal function
People with impaired renal function (defined as chronic kidney disease 4-5, GFR < 30ml/min +/- requiring dialysis) are at increased risk of hepatitis B infection. This is complicated by this patient cohort having a diminished immune response to hepatitis B vaccination. Whilst the cause of this suboptimal response is not completely understood, it has been established that the earlier a patient is vaccinated in the disease progression, the better the response and more long-term protection they will have.
MVEC recommends using the combination hepatitis A and B vaccine, Twinrix (720/20) in this patient group (see Table 3). There is evidence to suggest that using this vaccine can enhance seroconversion. It also has the added benefit of providing hepatitis A protection. If immune response to hepatitis B remains sub-optimal following the vaccination recommendations in Table 3, please refer to the below information on hepatitis B non-responders in this section.
Table 3: Recommended vaccine schedule for those with renal impairment using combined hepatitis A and B vaccine (Twinrix (720/20))
WordPress Tables PluginTuổi lúc chẩn đoán bệnh Twinrix (720/20)* Serology required < 12 months 2 doses, 6 months apart
(commence vaccine course at ≥ 12 months)- at diagnosis
- 1 month after 2thứ dose of Twinrix (720/20) (month 7)
- every 12 months thereafter≥ 12 tháng if baseline anti-HBs titre ≥ 10 m IU/mL at diagnosis:
2 doses, 6 months apart- at diagnosis
- 1 month after 2thứ dose of Twinrix (720/20) (month 7)
- every 12 months thereafterif baseline anti-HBs titre < 10 m IU/mL at diagnosis:
3 doses, 1 week between doses 1 & 2, 5 months between doses 2 & 3- at diagnosis
- 1 month after 2thứ dose of Twinrix (720/20) (month 2)
- 1 month after 3thứ dose of Twinrix (720/20) (month 7)
- every 12 months thereafter* Twinrix (720/20) is a combination hepatitis A and B vaccine. It contains 720 ELISA units of hepatitis A virus and 20mcg of hepatitis B surface antigen protein. Each dose is 1.0 mL given intramuscularly.
Hepatitis B non-responders
A non-responder to hepatitis B vaccination is any person with a documented age-appropriate vaccine history, who has an anti-HBs level of <10 m lU/mL 4 to 8 weeks following the final vaccine dose.
Recommendations for how to promote seroconversion in this population vary with different studies. MVEC recommends the following immunisation pathway for hepatitis B non-responders: MVEC pathway for hepatitis B non-responders ≥ 12-months of age (December 2024).
Persistent non-responders should be informed of their immune status and advised to minimise the risk of exposure.
Hepatitis B immunoglobulin (HBIG) may be given to non-immune persons within 72 hours of exposure to prevent infection. Refer to The Australian Immunisation Handbook: Table: Post-exposure prophylaxis for non-immune people exposed to a source that is positive for hepatitis B surface antigen or has an unknown status để biết thêm thông tin.
Tài liệu
-
- Australian Immunisation Handbook: Hepatitis B
- Better Health Channel: Hepatitis B
- b Positive: A Guide for Primary Care Providers
- MVEC pathway for hepatitis B non-responders ≥ 12-months of age (December 2024)
- MVEC: Người nhận ghép tạng rắn
- MVEC: Tiêm chủng cho trẻ sinh non
- MVEC: Breastfeeding and vaccines
- Hướng dẫn thực hành lâm sàng của RCH: Chấn thương do kim đâm
- Tùng J, Carlisle E, Smieja M, Kim PT, Lee CH. Một thử nghiệm lâm sàng ngẫu nhiên về chủng ngừa kết hợp viêm gan A và B so với viêm gan B đơn độc để bảo vệ huyết thanh viêm gan B ở bệnh nhân chạy thận nhân tạo. Am J Thận Dis. 2010;56(4):713-9.
- Playford EG, Hogan PG, Bansal AS, Harrison K, Drummond D, Looke DF, Whitby M. Vắc xin viêm gan B tái tổ hợp trong da dành cho nhân viên y tế không đáp ứng với vắc xin tiêm bắp. Kiểm soát nhiễm trùng và Dịch tễ bệnh viện 2002 Tháng 2;23(2):87-90
Các tác giả: Nigel Crawford (Giám đốc, SAEFVIC, Viện Nghiên cứu Trẻ em Murdoch) và Rachael McGuire (Y tá Nghiên cứu SAEFVIC, Viện Nghiên cứu Trẻ em Murdoch)
Đượcxem xét bởi: Rachael McGuire (Education Nurse Coordinator, Melbourne Vaccine Education Centre), Katie Butler (Education Nurse Coordinator, Melbourne Vaccine Education Centre), Nigel Crawford (Director, SAEFVIC and MVEC, Murdoch Children’s Research Institute) and Laura Voss (SAEFVIC Research Nurse, Murdoch Children’s Research Institute)
Ngày: December 2024
Tài liệu trong phần này được cập nhật khi có thông tin mới và có vắc-xin. Nhân viên của Trung Tâm Giáo Dục Vắc-xin Melbourne (MVEC) thường xuyên xem xét độ chính xác của các tài liệu.
Quý vị không nên coi thông tin tại trang mạng này là lời khuyên y tế chuyên nghiệp, cụ thể cho sức khỏe của riêng mình hoặc sức khỏe riêng của gia đình quý vị. Đối với những mối lo ngại về y tế, bao gồm các quyết định về chủng ngừa, thuốc men và các phương pháp điều trị khác, quý vị phải luôn hỏi ý kiến chuyên gia y tế.