Breakwell Lucy, Tevi-Benissan Carol, Childs Lana, Mihigo Richard, Tohme Rania
Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.
World Health Organization Regional Office for Africa, Brazzaville, Republic of Congo.
Pan Afr Med J. 2017 Jun 22;27(Suppl 3):17. doi: 10.11604/pamj.supp.2017.27.3.11981. eCollection 2017.
The World Health Organization (WHO) African Region has approximately 100 million people with chronic hepatitis B virus (HBV) infection. This review describes the status of hepatitis B control in the Region. We present hepatitis B vaccine (HepB) coverage data and from available data in the published literature, the impact of HepB vaccination on hepatitis B surface antigen (HBsAg) prevalence, a marker of chronic infection, among children, HBsAg prevalence in pregnant women, and risk of perinatal transmission. Lastly, we describe challenges with HepB birth dose (HepB-BD) introduction reported in the Region, and propose strategies to increase coverage. In 2015, regional three dose HepB coverage was 76%, and 16(34%) of 47 countries reported ≥ 90% coverage. Overall, 11 countries introduced HepB-BD; only nine provide universal HepB-BD, and of these, five reported ≥ 80% coverage. From non-nationally representative serosurveys among children, HBsAg prevalence was lower among children born after HepB introduction compared to those born before HepB introduction. However, some studies still found HBsAg prevalence to be above 2%. From limited surveys among pregnant women, the median HBsAg prevalence varied by country, ranging from 1.9% (Madagascar) to 16.1% (Niger); hepatitis B e antigen (HBeAg) prevalence among HBsAg-positive women ranged from 3.3% (Zimbabwe) to 28.5% (Nigeria). Studies in three countries indicated that the risk of perinatal HBV transmission was associated with HBeAg expression or high HBV DNA viral load. Major challenges for timely HepB-BD administration were poor knowledge of or lack of national HepB-BD vaccination guidelines, high prevalence of home births, and unreliable vaccine supply. Overall, substantial progress has been made in the region. However, countries need to improve HepB3 coverage and some countries might need to consider introducing the HepB-BD to help achieve the regional hepatitis B control goal of < 2% HBsAg prevalence among children < 5 years old by 2020. To facilitate HepB-BD introduction and improve timely coverage, strategies are needed to reach both facility-based and home births. Strong political commitment, clear policy recommendations and staff training on HepB-BD administration are also required. Furthermore, high quality nationally representative serosurveys among children are needed to inform decision makers about progress towards the regional control goal.
世界卫生组织(WHO)非洲区域约有1亿人感染慢性乙型肝炎病毒(HBV)。本综述描述了该区域乙型肝炎防控状况。我们呈现了乙型肝炎疫苗(HepB)接种覆盖率数据,并根据已发表文献中的现有数据,阐述了HepB疫苗接种对儿童慢性感染标志物乙型肝炎表面抗原(HBsAg)流行率的影响、孕妇中的HBsAg流行率以及围产期传播风险。最后,我们描述了该区域报告的引入HepB首剂疫苗(HepB-BD)所面临的挑战,并提出提高接种覆盖率的策略。2015年,区域三剂HepB接种覆盖率为76%,47个国家中有16个(34%)报告覆盖率≥90%。总体而言,11个国家引入了HepB-BD;只有9个国家提供普遍的HepB-BD,其中5个国家报告覆盖率≥80%。在针对儿童的非全国代表性血清学调查中,引入HepB后出生的儿童中HBsAg流行率低于引入HepB前出生的儿童。然而,一些研究仍发现HBsAg流行率高于2%。在针对孕妇的有限调查中,HBsAg流行率中位数因国家而异,从1.9%(马达加斯加)到16.1%(尼日尔)不等;HBsAg阳性女性中的乙型肝炎e抗原(HBeAg)流行率从3.3%(津巴布韦)到28.5%(尼日利亚)不等。三个国家的研究表明,围产期HBV传播风险与HBeAg表达或高HBV DNA病毒载量有关。及时接种HepB-BD的主要挑战包括对国家HepB-BD疫苗接种指南了解不足或缺乏相关指南、在家分娩比例高以及疫苗供应不可靠。总体而言,该区域已取得显著进展。然而,各国需要提高HepB3接种覆盖率,一些国家可能需要考虑引入HepB-BD,以帮助实现到2020年5岁以下儿童中HBsAg流行率<2%的区域乙型肝炎防控目标。为便于引入HepB-BD并提高及时接种覆盖率,需要采取策略覆盖医疗机构分娩和在家分娩。还需要坚定的政治承诺、明确的政策建议以及关于HepB-BD接种的工作人员培训。此外,需要在儿童中开展高质量的全国代表性血清学调查,以便为决策者提供有关区域防控目标进展情况的信息。