Global burden, trends and inequalities of hepatitis B among women of childbearing age, 1990–2021

Abstract

Background

Women of childbearing age (WCBA) are a key group for hepatitis B virus (HBV) infection elimination and maternal health. We aimed to investigate global patterns, trends and inequalities in the burden of HBV among WCBA based on the Global Burden of Disease 2021 database.

Methods

We extracted data on the prevalence of chronic HBV infection and HBV-related mortality among WCBA in 204 countries and territories from 1990 to 2021. The estimated annual percentage change (EAPC) was calculated to quantify the temporal trends in age-standardized prevalence (ASPR) and mortality rate (ASMR). Inequalities across countries in chronic HBV infection and HBV-related deaths were measured using the concentration index.

Results

In 2021, the global ASPR per 100,000 population of chronic HBV infection among WCBA was 3664, corresponding to 71.4 million infected people. From 1990 to 2021, the global ASPR declined annually by 1.2%, while prevalence rates remained relatively high in Central and Western Africa. HBV-related ASMR declined worldwide (EAPC = −1.49%, 95% CI: −1.55, −1.42), whereas upward trends were observed in the United Kingdom (EAPC = 1.79, 95% CI: 1.41, 2.18) and Poland (EAPC = 1.29, 95% CI: 0.89, 1.69). Both the number of chronic HBV infection cases and HBV-related deaths in low socio-demographic index (SDI) region showed an increasing trend. SDI-related inequality in chronic HBV infection increased from 1990 to 2021, except in high-income countries, Latin America and the Caribbean.

Conclusions

The global prevalence of chronic HBV infection among WCBA declined over time, but low SDI countries remained a region of concern. Furthermore, the concentration of HBV disease burden among disadvantaged populations requires targeted interventions.

KEY MESSAGES

• We identified a negative correlation between SDI and HBV-related mortality among WCBA, with more pronounced declines observed in low SDI regions.

• Both chronic HBV infections and HBV-related deaths among WCBA in low SDI regions showed an upward trend, with growing inequality noted.

• λ Results reveal the urgent need for targeted interventions in low SDI regions to achieve the World Health Organization’s goal of eliminating viral hepatitis by 2030.

1. Introduction

Hepatitis B virus (HBV) is a hepatotropic DNA virus that can lead to severe liver complications [1]. HBV infection remains a significant public health concern, leading to approximately 555,000 deaths worldwide each year [2]. It is estimated that the global HBsAg seroprevalence in 2019 is 3.8%, with approximately 296 million individuals living with chronic HBV infection [3]. The typical course of chronic HBV is a slow progression to cirrhosis and hepatocellular carcinoma, which accounts for the majority burden of HBV infection [1]. Over the past three decades, the global prevalence of chronic HBV and mortality associated with HBV have declined following the introduction of the hepatitis B vaccine. However, many countries are experiencing an increase in HBV-related deaths as a result of population growth and ageing [2].

Women of childbearing age (WCBA) represent a key population for HBV prevention and control, driven not only by the fact that HBV infection can impair their reproductive health and quality of life [4,5], but also by the presence of gender disparities in HBV-related health literacy and access to HBV screening and treatment [6]. To reduce the global burden of HBV, interrupting mother-to-child transmission (MTCT) is essential. The health impacts of MTCT on infants include a high risk of chronic HBV infection and potential progression to liver cirrhosis or hepatocellular carcinoma in adulthood [7,8]. The implementation of antiviral treatment for pregnant women with high HBV DNA levels, combined with timely infant immunization, serves as a clinical management priority for HBV-infected pregnant women, as well as an effective strategy to reduce the risk of mother-to-child hepatitis B transmission [9]. The state of women of childbearing age (WCBA) who are infected with HBV and require antiviral therapy remains poorly characterized. HBV MTCT incidence varies across regions, with the Western Pacific Region bearing the heaviest burden [10]. A cross-sectional study in China shown that the prevalence of HBV among pregnant women was 2.5%, emphasizing the significance of hepatitis B public education and strengthened postnatal follow-up for MTCT prevention [11]. Currently, early diagnosis of HBV and the provision of adequate antiviral treatment are still far from achieving the goal of eliminating HBV by 2030. A meta-analysis in 2021 indicated that although there are many HBV treatment guidelines, there were only approximately 19% of people with HBV infection globally were eligible for antiviral treatment [12]. The global number of HBV-related deaths is projected to increase by 39% if no measures are implemented to improve HBV management [1].

Progress towards achieving HBV elimination goals has varied widely across different countries and regions of the world. Globally, the prevalence of HBV is inversely related to income levels, with higher endemicity observed in low-income regions [13]. Substantial disparities in mortality burden associated with chronic HBV infection persist, with notably higher rates in many sub-Saharan African nations and several Asian countries [2]. The unequal advancements in disability-adjusted life years among global regions also highlight the disparities in access to treatment and care for viral hepatitis [14]. WCBA represent a key population in the prevention and control of HBV, as they playing an important role in preventing MTCT of the virus. A comprehensive understanding of HBV trends and disparities among WCBA is essential for achieving global hepatitis elimination targets.

Understanding the current global burden and epidemic trends of HBV among WCBA, along with enhancing public awareness for disease prevention measures, is essential for effective HBV management. However, research on the disease burden and prevalence of HBV among WCBA on a global scale remains limited. Based on the latest Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2021 in 204 countries and territories, our study aims to evaluate geographical variations, regional trends and inequalities in chronic HBV prevalence and HBV-related mortality among WCBA.

2. Methods

2.1. Data sources

In this study, WCBA is defined as the female population aged 15 to 49 years [15]. Data on the prevalence of chronic HBV infection and HBV-related mortality among WCBA were derived from GBD 2021. GBD 2021 was sourced from vital registration systems, censuses, verbal autopsies, household surveys, disease-specific registries or health service contact data across 204 countries and territories [16]. The 95% uncertainty intervals (UI) for these indicators were defined as the 2.5th and 97.5th percentiles of their respective posterior distributions. The socio-demographic index (SDI) is a composite metric that includes per capita income, years of education and fertility rates, was used to assess the level of social and economic development across countries. Specifically, we extracted data on the annual number of cases and prevalence rates of chronic HBV infection, as well as the number of deaths and mortality rates due to HBV-related diseases among women aged 15–49 years from 1990 to 2021. We retrieved data for these four indicators at the global level, as well as at the regional level (21 GBD regions and 7 super GBD regions determined by geographic contiguity and 5 SDI regions classified by SDI values), and at the country/territory level. The analytical processes and reproducible statistical codes for HBV infection estimation are publicly accessible on the GBD 2021 Data Resources website (http://ghdx.healthdata.org/gbd-2021).

2.2. Statistical analysis

We conducted a secondary analysis of GBD 2021. We calculated age-standardized prevalence rates (ASPR) for chronic HBV infection and age-standardized mortality rates (ASMR) for HBV-related diseases per 100,000 people of WCBA aged 15–49 years, according to the formula:

$$\frac{{\sum }_{i=1}^N{\alpha }_i{T}_i}{\sum _{i=1}^N{T}_i}$$

where, α_i represents the age-specific rate for the ith age group, while T_i indicates the count of individuals in the same age group according to the GBD 2021 standard population. N denotes the total number of age groups. The 95% confidence interval (CI) was calculated using the ‘ageadjust. Direct’ function from the ‘epitools’ package in R software.

We calculated the estimated annual percentage change (EAPC) in ASPR and ASMR to evaluate the secular trends from 1990 to 2021. The following linear regression model was employed: y = α + βx + ε, where y was the logarithmic indicators and x was the calendar year. α refers to the intercept and ε signifies the error term. EAPC was calculated as (exp(β) −1) × 100 and the 95% CI of EAPC was also calculated using this equation by substituting β with its corresponding 95% CI. An increasing trend in the age-standardized rate was considered when the 95% CI of the corresponding EAPC estimation was greater than 0, a decreasing trend when the 95% CI was less than 0 and a stable trend was considered when the 95% CI included 0.

A locally weighted scatterplot smoothing (LOESS) regression was conducted to define the expected relationship between ASPR for chronic HBV infection, ASMR for HBV-related disease and SDI among WCBA. LOESS is a nonparametric regression method that smooths data and captures nonlinear relationships via weighted local polynomial fitting. The health inequality concentration index was calculated by fitting a concentration curve, which plots the cumulative relative distributions of the population ranked by SDI on the x-axis against the cumulative proportion of cases or deaths on the y-axis. The 45 degrees diagonal line, extending from the bottom left corner to the top right, known as the line of equality, indicates that the burden of HBV infection is equally distributed across the population. The concentration index is a measure of inequality that compares disease distribution across socio-economic groups, defined as twice the area between the concentration curve and the line of equality. Ranging from −1 to 1, values closer to 0 indicate greater equality. When the concentration curve lies below the line of equality, it suggests that HBV infection is more prevalent among the advantaged population. Conversely, if the curve is situated above the line of equality, HBV infection is concentrated among the disadvantaged.

3. Results

3.1. Prevalence of chronic HBV infection among women of childbearing age

Globally, an estimated 71.4 (95% UI: 64.4–79.2) million women of childbearing age were living with chronic hepatitis B virus infection in 2021 (Table S1). The global age-standardized chronic HBV prevalence per 100,000 among WCBA decreased from 5344 in 1990 to 3664 in 2021, with an EAPC of −1.21 (95% CI: 1.02, 1.37) (Table 1). The decline in prevalence was slowest in low-SDI regions, with an EAPC of −0.65 (95% CI: −0.75, −0.55) (Table S2). At the GBD region level, the age-standardized chronic HBV prevalence among WCBA decreased across all GBD regions from 1990 to 2021, and the large decrease in age-standardized prevalence appeared in Central Europe (EAPC=-2.18%, 95% CI: −2.40, −1.95). The highest age-standardized prevalence in 2021 was in Central Sub-Saharan Africa (12.6%), followed by Western Sub-Saharan Africa (9.2%) (Figure 1A). The lowest prevalence in 2021 was 0.3% in Southern Latin America. Country-level variation in age-standardized prevalence of chronic HBV among WCBA in 2021 is shown in Figure 2A and C. Some countries in Sub-Saharan Africa had high prevalence in 2021, among which Democratic Republic of the Congo, Zimbabwe, Niger, Somalia and Central African Republic had the top five age-standardized prevalence (Figure S1). From 1990 to 2021, only Denmark showed a slight increase in chronic HBV prevalence among WCBA (EAPC: 0.24, 95% CI: 0.17, 0.32), despite its low HBV prevalence (ASPR: 0.18%) in 2021 (Figure S2).

Table 1.

Prevalence of chronic HBV infection and HBV-related mortality among women of child-bearing age in 1990 and 2021, and their estimated annual percentage changes from 1990 to 2021.

	Chronic HBV infection			HBV-related mortality
	ASPR per 100,000, 1990	ASPR per 100,000, 2021	EAPC, 1990–2021	ASMR per 100,000, 1990	ASMR per 100,000, 2021	EAPC, 1990–2021
Global	5344 (5343 to 5345)	3664 (3663 to 3664)	−1.21 (−1.30 to −1.12)	3.16 (3.13 to 3.19)	1.81 (1.79 to 1.83)	−1.49 (−1.55 to −1.42)
GBD regions
Central Asia	3800 (3791 to 3810)	3192 (3185 to 3199)	−0.47 (−0.64 to −0.30)	3.25 (2.95 to 3.57)	1.97 (1.79 to 2.15)	−1.83 (−2.11 to −1.54)
Central Europe	1891 (1886 to 1896)	902 (898 to 905)	−2.18 (−2.40 to −1.95)	1.79 (1.64 to 1.94)	1.06 (0.95 to 1.19)	−2.29 (−2.56 to −2.02)
Eastern Europe	2581 (2576 to 2585)	1646 (1642 to 1649)	−1.20 (−1.50 to −0.90)	0.52 (0.46 to 0.58)	1.22 (1.14 to 1.32)	2.84 (1.81 to 3.87)
Australasia	2229 (2217 to 2242)	1340 (1332 to 1348)	−1.56 (−1.77 to −1.35)	0.45 (0.28 to 0.67)	0.43 (0.30 to 0.61)	0.16 (0.01 to 0.31)
High-income Asia Pacific	2804 (2800 to 2809)	1553 (1549 to 1557)	−2.09 (−2.19 to −1.99)	1.62 (1.51 to 1.75)	0.57 (0.51 to 0.65)	−3.32 (−3.42 to −3.21)
High-income North America	601 (600 to 603)	380 (379 to 381)	−1.28 (−1.49 to −1.07)	0.28 (0.25 to 0.32)	0.33 (0.3 to 0.37)	0.73 (0.60 to 0.87)
Southern Latin America	402 (399 to 406)	313 (310 to 315)	−0.58 (−0.70 to −0.46)	0.87 (0.71 to 1.07)	0.30 (0.23 to 0.4)	−2.75 (−3.17 to −2.33)
Western Europe	1072 (1070 to 1074)	632 (630 to 634)	−1.58 (−1.73 to −1.43)	0.50 (0.46 to 0.55)	0.23 (0.2 to 0.26)	−2.76 (−2.89 to −2.63)
Andean Latin America	1345 (1338 to 1353)	1042 (1037 to 1047)	−0.82 (−0.88 to −0.77)	1.54 (1.26 to 1.86)	0.63 (0.51 to 0.76)	−3.33 (−3.56 to −3.10)
Caribbean	1121 (1114 to 1128)	862 (857 to 868)	−0.71 (−0.82 to −0.61)	0.98 (0.77 to 1.24)	0.67 (0.53 to 0.84)	−1.43 (−1.64 to −1.21)
Central Latin America	2746 (2740 to 2751)	1452 (1449 to 1454)	−1.98 (−2.20 to −1.77)	0.54 (0.46 to 0.63)	0.26 (0.22 to 0.30)	−2.69 (−2.95 to −2.43)
Tropical Latin America	2005 (2000 to 2009)	1112 (1109 to 1114)	−1.82 (−2.09 to −1.55)	1.07 (0.96 to 1.19)	0.42 (0.37 to 0.47)	−3.18 (−3.31 to −3.05)
North Africa and Middle East	3993 (3989 to 3998)	2199 (2197 to 2201)	−1.79 (−1.94 to −1.64)	3.41 (3.26 to 3.56)	1.31 (1.25 to 1.37)	−3.09 (−3.13 to −3.04)
South Asia	3588 (3585 to 3590)	2859 (2857 to 2860)	−0.64 (−0.68 to −0.60)	3.42 (3.34 to 3.5)	2.53 (2.48 to 2.58)	−0.84 (−1.00 to −0.67)
East Asia	9908 (9905 to 9912)	5264 (5261 to 5266)	−2.04 (−2.17 to −1.90)	4.88 (4.79 to 4.96)	1.23 (1.19 to 1.27)	−4.83 (−4.99 to −4.68)
Oceania	11186 (11131 to 11240)	7777 (7746 to 7807)	−1.06 (−1.22 to −0.91)	2.42 (1.61 to 3.51)	1.41 (1.02 to 1.90)	−1.93 (−2.08 to −1.79)
Southeast Asia	6419 (6414 to 6423)	4188 (4185 to 4191)	−1.32 (−1.46 to −1.17)	4.59 (4.46 to 4.73)	2.38 (2.31 to 2.45)	−2.18 (−2.27 to −2.09)
Central Sub-Saharan Africa	14999 (14977 to 15022)	12628 (12616 to 12641)	−0.54 (−0.64 to −0.43)	5.37 (4.9 to 5.88)	3.56 (3.33 to 3.8)	−1.23 (−1.35 to −1.12)
Eastern Sub-Saharan Africa	7465 (7457 to 7474)	5515 (5511 to 5520)	−0.89 (−1.01 to −0.77)	6.34 (6.06 to 6.64)	3.98 (3.84 to 4.12)	−1.77 (−1.89 to −1.65)
Southern Sub-Saharan Africa	5511 (5497 to 5524)	3607 (3599 to 3615)	−1.26 (−1.38 to −1.14)	3.67 (3.3 to 4.07)	2.55 (2.34 to 2.79)	−0.57 (−1.29 to 0.15)
Western Sub-Saharan Africa	12134 (12123 to 12145)	9207 (9201 to 9213)	−0.79 (−0.87 to −0.7)	8.25 (7.93 to 8.57)	4.35 (4.22 to 4.49)	−2.15 (−2.24 to −2.06)

Note: 95% confidence intervals are included in parentheses. HBV, hepatitis B virus. EAPC, estimated annual percentage change; ASPR: age-standardized prevalence rate; ASMR: age-standardized mortality rate.

Figure 1.

Estimated age-standardized prevalence of chronic HBV infection (A) and age-standardized HBV-related mortality (B) among women of child-bearing age across GBD regions, 1990–2021.

Figure 2.

Geographical distribution of the age-standardized prevalence (A) of chronic HBV infection and age-standardized HBV-related mortality (B) among women of child-bearing age in 2021, and their temporal trends (C, D) from 1990 to 2021.

3.2. HBV-related mortality among women of childbearing age

HBV-related deaths among WCBA decreased from 36,384 in 1990 to 35,024 in 2021 worldwide (Table S1). There was a significant decline in the age-standardized HBV-related mortality rate over the study period (EAPC: −1.49%, 95% CI: −1.55, −1.42) (Table 1). At the GBD region level, most HBV-related death occurred in South Asia, East Asia and South-East Asia. From 1990 to 2021, HBV-related ASMR significantly decreased in East Asia (EAPC: −4.83, 95% CI: −4.99, −4.68), Southeast Asia (EAPC: −2.18, 95% CI: −2.27, −2.09) and South Asia (EAPC: −0.84, 95% CI: −1.00, −0.67) (Figure 1B). Notably, Eastern Europe (EAPC: 2.84, 95% CI: 1.81, 3.87), High-income North America (EAPC: 0.73, 95% CI: 0.60, 0.87) and Australasia (EAPC: 0.16, 95% CI: 0.01, 0.31) all had a significant increase in mortality (Table 1 and S3). At the country or territory level, some countries in Sub-Saharan Africa had high HBV-related mortality rates in 2021, among which Guinea-Bissau, Somalia, Guinea, Chad and Central African Republic had the top five ASMR (Figure 2B). Russian Federation, Ukraine, Lesotho, United Kingdom, Zimbabwe and Poland had the most rapid increase in HBV-related mortality rate, with EAPCs of 3.56 (95% CI: 2.45, 4.69), 2.32 (95% CI: 1.16, 3.49), 1.87 (95% CI: 1.15, 2.59), 1.79 (95% CI: 1.41, 2.18), 1.78 (95% CI: 0.89, 2.68) and 1.29 (95% CI: 0.89, 1.69) respectively (Figure 2D and Table S4).

3.3. Age-related burden of HBV infection among women of childbearing age

We further analyzed HBV burden among WCBA in seven age groups in different SDI regions (Figure 3). Globally, chronic HBV cases among WCBA were most prevalent in the 15–19 age group in 1990, shifting to 30–34 in 2021. Notably, chronic HBV cases exhibited a significant upward trend in low SDI regions during the study period, with the 40–44 age group experiencing the highest increase of 129.19%. While the 15-19-year-old age group in low SDI regions had the highest number of chronic HBV cases in 1990, it was gradually overtaken by 20–24 age group between 2019 and 2021. On a global scale, HBV-related deaths among WCBA were most common in 45–49 age group from 1990 to 2021. HBV-related deaths in all age groups in low SDI regions showed a significant increasing trend, with the 20–24 age group seeing the largest increase (67.75%). HBV-related death burden in low SDI regions was lowest in the 15–19 age group and exhibited a steady increase with age, peaking in the 45–49 age group. Similar trend is also observed in the low-middle, high-middle and high SDI regions.

Figure 3.

Trends in the age-specific distribution of chronic HBV infection cases and HBV-related deaths among women of childbearing age in different SDI regions.

3.4. Distributive inequality in HBV infection among women of childbearing age

Figure 4 illustrates that the age-standardized HBV prevalence exhibited a bell-shaped relationship with the socio-demographic Index (SDI). HBV-related ASMR was negatively correlated with SDI, showing steeper slopes when the SDI was below 0.5. Significant SDI-related inequalities in chronic HBV infection and HBV-related deaths across countries were noted in 1990 and 2021 (Figure 5). In most super GBD regions, the relative gradient of inequality (measured by the concentration index) lies above the line of equality, indicating that the burden of chronic HBV infection was disproportionately concentrated among poorer countries. These inequalities were greater in 2021 compared to 1990, except in high-income regions, Latin America and the Caribbean. We observed a significant reduction in SDI-related inequalities in HBV-related deaths over time in Central Europe, Eastern Europe and Central Asia. The poorest quintile of countries within this region accounted for 44.4% of the HBV-related mortality burden in 1990 and decreased to 25.9% in 2021. Additionally, the wealthiest quintile of countries (such as Switzerland, Germany, Denmark, Norway) in high-income regions accounted for 17.5% of HBV-related deaths in 1990, increasing to 26.7% in 2021.

Figure 4.

The relationship between age-standardized prevalence rate for chronic HBV infection (A) and age-standardized HBV-related mortality rate (B) and sociodemographic index among women of child-bearing age.

Figure 5.

SDI-related health inequality concentration curves showing geographical inequality in chronic HBV infection (A) and HBV-related deaths (B) among women of child-bearing age in different regions, 1990 and 2021.

4. Discussion

Our secondary analysis of the GBD 2021 data described the global burden and trends of hepatitis B among WCBA from 1990 to 2021. The results showed that the global prevalence of chronic HBV infection and HBV-related mortality among WCBA had declined over the past three decades. However, the number of chronic HBV infection cases and HBV-related deaths in low sociodemographic index regions showed an upward trend, and significant increases in HBV-related mortality had been observed in the United States, the United Kingdom and Poland. We also quantified cross-country inequalities in HBV infection across the SDI gradient in different regions, and our findings may contribute to the identification of countries or territories requiring targeted interventions and to develop tailored strategies to reduce the burden of HBV infection globally.

The decline in global prevalence among WCBA can be attributed to several factors, including the extensive implementation of hepatitis B vaccination programs worldwide, improved screening measures for pregnant women that have facilitated early detection and management of HBV and the use of antiviral treatments to reduce viral load in HBV-positive patients [2,17,18]. For example, to further lower HBV MTCT rates, China launched a program for triple elimination of MTCT of HIV, syphilis and HBV in 2011. It provides complementary HBsAg screening to all pregnant women and free HBIG to neonates of HBsAg-positive mothers [19]. Despite a significant decrease in the global prevalence of chronic HBV infection among WCBA from 1990 to 2021, prevalence rates remain higher in Central and Western Africa, with prevalence rates often exceeding 10% in some countries. In line with our findings, a systematic review of the worldwide prevalence of HBV infection indicated high rates in the majority of countries within West and Central Africa [20]. One major reason is the limited access to vaccination, screening and antiviral treatments [21,22]. In most African countries, hepatitis B virus immunization programs were not implemented until the early twenty-first century [23]. With only 17% of newborns receiving a timely dose of the hepatitis B birth dose vaccine in the WHO African region in 2021, this region marked the lowest vaccination coverage among all WHO regions [24]. Administering antiviral treatment during pregnancy has been confirmed to be both effective and safe in decreasing HBV replication and risk of MTCT [25]. Nevertheless, HBV screening and treatment programs are largely absent in Africa and the prevention of MTCT of HBV remains a neglected public health challenge across the continent [22]. To control MTCT of hepatitis B, it is necessary to strengthen the screening and treatment programs for hepatitis B among WCBA in Africa. In addition, timely initiation of antenatal care, promotion of delivery in healthcare facilities and enhancing awareness regarding HBV prevention are also crucial elements contributing to effective prevention strategies [26].

Notably, Denmark was the sole country where the ASPR of chronic HBV among WCBA did not decline between 1990 and 2021. This phenomenon may be related to the following reasons. Denmark was one of the countries with low HBV prevalence among WCBA globally in 2021. Its low baseline prevalence leaves limited room for further reduction. In addition, previous research indicated that the majority of people living with chronic hepatitis B in Denmark are immigrants from highly endemic countries infected through vertical transmission [27], and pregnant undocumented immigrants have a lower chance of undergoing hepatitis B virus testing [28]. This underscores that even in low-prevalence countries with robust healthcare systems, targeted interventions for immigrant populations remain critical to sustaining progress against HBV.

Based on the GBD 2021 data, we found that absolute HBV-related deaths among WCBA tended to increase in low SDI regions, with the number of deaths in the 20–24 age group experiencing the highest increase of 67.75% from 1990 to 2021. The growing burden of HBV-related deaths among WCBA in low SDI settings underscores the disproportionate impact of HBV in different socio-demographic settings. In contrast, age-standardized mortality rates among WCBA due to HBV-related diseases exhibited a decline in low SDI regions (EAPC=-1.71%, 95% CI −1.86%, −1.56%). The reduction in HBV-related mortality rates indicates progress in HBV interventions, but the persistent rise in the absolute number of deaths suggests that these efforts may not be sufficient to counterbalance the impacts of population expansion and ageing [2]. A simulation study indicated that without enhancing current interventions, ongoing transmission and inadequate treatment access will result in a cumulative 17 million HBV-related deaths from 2015 to 2030 [29]. Therefore, scaling up HBV prevention and treatment interventions, including expanding birth-dose vaccination, especially in Sub-Saharan Africa and integrating HBV screening and treatment into antenatal care, is needed to achieve the World Health Organization’s goal of eliminating viral hepatitis as a public health issue by 2030. During the study period, the upward trend in HBV-related deaths among WCBA aged 20–24 years in low SDI region emphasizes the need for ongoing endeavours to control and prevent HBV infections among adolescents and young adults. The primary reasons for the increase in HBV-related deaths among women aged 20–24 years may include unprotected sex and insufficient routine screening and timely intervention during antenatal care, which elevate the risk of HBV infection and its related complications [30,31]. Another possible explanation is that younger women in this age group may have stigma and limited knowledge regarding HBV infection, which can delay diagnosis and treatment and impact their quality of life [5]. All these factors collectively widen the gaps in HBV care and treatment.

It is noteworthy that in some developed countries with low age-standardized HBV prevalence among WCBA, including the United States, the United Kingdom and Poland, HBV-related mortality rates have increased from 1990 to 2021. A hypothesis supported by prior research holds that migration from high HBV-prevalence regions may contribute to the observed increase in HBV-related mortality in high-income countries. A study utilizing data from the National Center for Health Statistics in the United States indicated that individuals of Asian or Pacific Islander descent are at a greater risk of HBV-related death [32]. A modelling study in the United States found HBV infections concentrated among immigrants, emphasizing the need for culturally appropriate screening and care-linkage programs to meet WHO’s elimination targets [33]. A study conducted in the United Kingdom revealed that women living in Britain who identify as Black African, non-British White, or of Pakistani ethnicity have a higher rate of HBV infection compared to the average in England [34]. Another cohort study in the United Kingdom suggested that Asians and Black Africans had a higher likelihood of being diagnosed with hepatocellular carcinoma than White British individuals, and that those with higher socioeconomic deprivation were more often diagnosed through emergency routes [35]. Due to language barriers, insufficient disease knowledge and awareness, immigrants from high-prevalence countries often receive a lower level of preventive health services and prenatal care [36,37]. Given the plausible role of immigrants from endemic regions in the rising trend of HBV-related mortality, focused strategies for migrant populations in these countries are needed, including culturally adapted health literacy initiatives, community-based screening services and prenatal care support.

We found that inequalities in chronic HBV infection increased in most GBD regions from 1990 to 2021. The geographic inequalities in HBV infection that we observed align with previous research findings. A study based on GBD 2019 indicated that the Quality-of-Care Index for cirrhosis and other chronic liver diseases showed a strong correlation with SDI, with lower socioeconomic countries exhibiting a higher age-standardized prevalence of these diseases in 2019 [38]. A review indicated that the lowest-income countries bear the heaviest burden of cirrhosis, primarily resulting from cirrhosis linked to hepatitis B infection [39]. Another study indicated that while the overall burden of liver cancer is declining, considerable variations in the quality of healthcare for liver cancer control exist across different countries [40]. This inequality in HBV infection can be attributed to limited medical access, substance abuse, increased comorbidities and the financial burden of treatments in countries with lower socioeconomic status [38,41]. This trend underscores the gaps in prevention and treatment services in different SDI settings, as well as the urgent need for targeted interventions to address the disproportionate impact of HBV on countries with lower SDI levels. Additionally, the study results show that, among high-income regions, the proportion of HBV-related deaths in the wealthiest countries has increased. One potential cause is that these developed economies often attract many immigrants from HBV-endemic regions. Without effective intervention, HBV infections may progress to severe conditions like cirrhosis and liver cancer among migrant populations, which in turn raises the mortality rate in host countries [42].

Our study had several limitations. First, the GBD data were generated using estimation corrections from multiple models, and varying sources of original data might impose biases on our estimates [43]. These GBD estimates rely on modelling assumptions, and their accuracy may vary depending on the quality of data sources. Second, there are significant geographical differences in the diagnosis rates of HBV, which may lead to an underestimation of the true burden of the disease. For example, a nationwide study conducted in the USA among individuals with private health insurance indicates that only 19% of chronic hepatitis B cases were diagnosed [44]. Another study reveals that less than 1% of individuals infected with HBV are diagnosed in sub-Saharan Africa [11]. HBV prevalence is likely to be underestimated in regions with inadequate screening infrastructure. This emphasizes the necessity for improved screening and diagnostic measures for HBV among WCBA, especially in regions with high prevalence and limited screening capacity, to better address the challenges posed by HBV.

5. Conclusions

HBV infection among WCBA represents a global public health challenge. Despite a downward trend in the prevalence of chronic HBV infection and HBV-related mortality among WCBA from 1990 to 2021, regional disparities persist. The number of chronic HBV infections and HBV-related deaths among WCBA demonstrated an upward trend in low SDI regions during the study period, with the age group of 20–24 years experiencing the largest increase in HBV-related deaths. To effectively prevent HBV infection among WCBA, primary and secondary prevention measures, as well as healthcare strategies, should be optimized in accordance with age and regional differences.

Funding Statement

This study was supported by the Natural Science Foundation of Shandong Province in China (ZR2023QH319) and the National Natural Science Foundation of China (82304200).

Ethical approval and consent to participate

The institutional review board of School of Public Health in Shandong University in Shandong Province, China, determined that the study did not need approval because it used publicly available data.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data supporting the findings of this study are available upon reasonable request from the corresponding author.