An overview of hepatitis B prevalence, prevention, and management in the Pacific Islands and Territories

Abstract

There are over 500-750 000 deaths per year because of hepatitis B virus (HBV)-related cirrhosis and liver cancer worldwide and the World Health Organization Western Pacific Region has some of the highest endemic levels of HBV in the world, particularly within China, South East Asia and Pacific Island Countries and Territories (PICT). The PICT have unique ethnic diversity and a very high prevalence of smoking and metabolic syndrome, both important risk factors for liver fibrosis and liver cancer. However, in contrast to many Asian countries, there is little published data on HBV prevalence and related liver disease burden in PICT. In this review, the available published literature and World Health Organization data for HBV prevalence and related liver disease and liver cancer burden in PICT is outlined, and unmet needs for improving HBV prevention and control in the region are highlighted.

Accelerating the elimination of viral hepatitis: a Lancet Gastroenterology & Hepatology Commission

“…The prevalence of HBV in the Pacific Island Countries and Territories ranges from 3% to 23% 329,330 (supplemental figure 8), and vertical HBV transmission of HBV persists despite timely birthdose vaccination, with 3-5% of infants born to HBsAg-positive mothers becoming HBsAg positive after vaccination 331 . This is attributed to high viral loads at time of delivery, lack of access to additional prevention strategies such as HBIg and nucleoside analogue therapy, and incomplete delivery of timely full vaccination schedule in some settings 329 . Data on HCV in this region are scarce (supplemental figure 8), but prevalence estimates are generally low (<0.5%) 329, .…”

“…This is attributed to high viral loads at time of delivery, lack of access to additional prevention strategies such as HBIg and nucleoside analogue therapy, and incomplete delivery of timely full vaccination schedule in some settings 329 . Data on HCV in this region are scarce (supplemental figure 8), but prevalence estimates are generally low (<0.5%) 329, . The prevalence of liver cirrhosis and liver cancer in this region is poorly characterised 329,353,354 , but 2016 estimates from the Global Burden of Disease Study show that mortality from viral hepatitis (predominantly HBV) exceeds that from malaria, HIV and TB combined for all of the Pacific Island Countries and Territories except Vanuatu and Solomon Islands 329 .…”

“…Data on HCV in this region are scarce (supplemental figure 8), but prevalence estimates are generally low (<0.5%) 329, . The prevalence of liver cirrhosis and liver cancer in this region is poorly characterised 329,353,354 , but 2016 estimates from the Global Burden of Disease Study show that mortality from viral hepatitis (predominantly HBV) exceeds that from malaria, HIV and TB combined for all of the Pacific Island Countries and Territories except Vanuatu and Solomon Islands 329 . Additionally, obesity and type 2 diabetes are highly prevalent in the region and are important cofactors for non-alcoholic fatty liver disease, cirrhosis progression and liver cancer 355,356 .…”

“…Furthermore, catch-up vaccination programs for adults are inadequate 331 , and birth-dose vaccination delivery varies significantly across the region 382, [394][395][396][397][398] . Many factors contribute to low vaccine uptake, including geographical isolation, limited access to antenatal screening, births outside health care facilities, inadequate vaccine supplies and cold chain systems, lack of Gavi funding for the monovalent vaccine, lack of skilled medical staff, and higher obstetric complication rates, the latter because health workers often withhold birth-dose vaccine when the infant is unwell, despite guidelines 329,[399][400][401][402] . Neither HBIg nor antiviral therapy in the third trimester are routinely provided in most Pacific Island Countries and Territories due to prohibitive cost and limited supply 329 .…”

Factors associated with HBV Virological Breakthrough

“…Clinicians' consistent use of international HBV treatment guidelines [14,30] is the most likely reason for the similarity of demographic characteristics between this sub-study sample and across previous HBV treatment-based studies. Most participants migrated from HBV-endemic countries [31,32], in particular, Western Pacific countries such as Tonga, and also China [28,29].…”