Hepatitis B in Ghana: a systematic review & meta-analysis of prevalence studies (1995-2015)

Viral Hepatitis A, B, C, D and E cause significant morbidity and mortality affecting more people worldwide than even HIV [1]. Nearly 2 billion people across the world are estimated to be infected with Hepatitis B Virus (HBV) with nearly a quarter of this having chronic infection [2, 3]. Each year, over half a million HBV-related deaths are recorded across the globe [4].

Epidemiological studies have often demonstrated varying levels of endemicity of HBV worldwide, with highly endemic areas present in Sub-Saharan Africa (SSA) and East Asia, where between 5 and 10 % of the adult population are deemed to be chronically infected [5]. In Western Europe and North America, Less than 1 % of the population is chronically infected. The lifetime risk of infection from HBV in many African and Asian countries, the Amazon Basin and parts of the Middle East is estimated to be more than 60 % [6]. Accurate determination of the burden of HBV in Africa is difficult owing to poor record keeping and under-reporting, but estimates put that about 70–95 % of the adult population show evidence of past exposure to HBV infection and the HBsAg seroprevalence rate has been put around 6–20 % [6, 7].

Chronic HBV increases individuals’ risk of progressive liver disease and hepatocellular carcinoma (HCC). In the natural history of HBV infection, it is estimated that 10 to 33 % of those who develop persistent infection would end up with chronic hepatitis of which 20 to 50 % may develop liver cirrhosis [8]. HCC is a highly aggressive cancer with limited treatment options, often lacking in many resource-poor settings such as Africa [9]. SSA has one of the highest HBV-related liver cancer rates in the world [10]. HBV-related liver cancer also remains the most common cancer among males and the third most common cancer among females in the African region [11, 12]. Of significant importance is that, the average age of HCC development in Africa is considerably younger than in other more advanced regions (mean age 33 years compared to 60 years in Western Europe) meaning HBV-related HCC affects patients in their most productive and reproductive years [9]. HBV therefore represents a critical threat to health as well as other developmental and economic parameters on the African continent.

In Ghana, HBV is considered to be of significant public health importance and a disease that requires greater attention [13, 14]. Ghana has been grouped as part of the areas of the world where the prevalence of chronic HBV infection is high (≥8 %) [9, 15]. Sweitzer et al. for instance in estimating the global burden of hepatitis B in 2013, put the prevalence of chronic hepatitis B virus infection in Ghana at 12.92 % [3]. However, this was derived from an analysis of only 12 studies. Some experts have also put the prevalence rate of HBV in Ghana to be around 10–15 % [16, 17]. A scoping of the literature identified no other thoroughly conducted reviews specifically summarizing data on prevalence of HBV in Ghana. This observation points out that although there may have been significant research into understanding the burden of HBV in Ghana, the evidence available remains fragmented. To overcome this perceived gap in evidence compilation, we conducted a systematic review to thoroughly summarize the available information towards answering the key question; what has been the prevalence of HBV in Ghana over the last two decades (1995–2015)?

Hepatitis B virus (HBV) infection is a major problem of public health in the world particularly in developing countries. Our review identified the prevalence of HBV in Ghana as detected by HBsAg seropositivity to be high at 12.3 %. Our result is comparable to the prevalence rate reported by Sweitzer et al‘s. review [3] albeit larger number of studies involved in our study. The results achieved is also in alignment with the categorization of Ghana as a high HBV endemic country (prevalence ≥8 %) [8, 15]. The prevalence rate achieved significantly exceeds the reported global prevalence rate of 3.61 % as well as the rate of 8 · 83 % for the WHO Africa region [3]. In countries like the US, HBV prevalence rate has been estimated to be around <0.27 % [59]. In Iran and Kosovo current estimates put HBV prevalence at 2.14 and 4.2 % respectively [60, 61]. Such comparative information further highlight the enormity of the HBV burden in Ghana.

Our study also raises serious concerns regarding the safety of blood supply in Ghana as nearly 1 in 9 blood donors may be infected with HBV with even higher proportions in replacement blood donors. Ghana has a national blood policy which requires the screening of all donated blood for HIV 1 and 2, HBV, Hepatitis C and Syphilis [62]. Our findings however highlight the need for stricter adherence to such policies as the risk of receiving contaminated blood, which in this is HBV remains high. Additionally, HBV infection among pregnant women also remains high (≈1 in 8) and which justifies the establishment of a national HBV screening program for all pregnant women in antenatal clinics throughout Ghana. Additionally, a national policy to vaccinate all pregnant women who test negative for HBV should be adopted so as to reduce the risk of mother to child transmission within the population [45].

A number of factors may account for the observed high HBV prevalence in Ghana. This includes lack of adequate information and understanding among Ghanaians of the transmission dynamics of the virus. For instance, in an assessment of 200 barbershops within the Kumasi metropolis, only 7 % knew the route of transmission of HBV [63]. Akumiah and Sarfo further point out that, the barber community in Ghana paid more attention to the decoration (e.g., availability of television, air conditioning, sound system etc.) other than the risk factors associated with their profession in the transmission of diseases such as HBV [64]. Although, the 3 main transmission routes of HBV in Ghana are transfusion of infected blood, unprotected sex and mother to child transmission, and most Ghanaians with chronic hepatitis B were infected at birth or in childhood, HBV has often been framed as a sexually transmitted infection in many communities and even among health workers [13]. Stigmatization arising from such misconceptions has many times prevented patients from finding their way to proper care and subsequently reducing their infectivity rates.

There are three (3) key components to controlling hepatitis B. These include treating infected persons, interrupting the spread of the infection transmission and reducing the mortality associated with advanced hepatic disease and HCC [65]. A vaccine against hepatitis B has been available since 1982. The vaccine is safe and 95 % effective in preventing infection and the development of chronic disease and HCC due hepatitis B [5]. For instance, in Senegal, vaccinations have reduced infection rates among children from 18.7 to 2.2 %, whereas in Gambia, it has led to a reduction in infection rate from 10 % to less than 1 % [66]. Ghana introduced Hepatitis B vaccination of babies as part of the Expanded Programme of Immunization (EPI) in 2002 [13]. Babies from 6 weeks onwards receive the pentavalent vaccine (diphtheria, polio, tetanus, hepatitis B, influenza type B). The coverage of EPI is good in all regions of the country and among the highest in Sub-Saharan Africa [67]. The introduction of the HBV vaccine in 2002 may have by inference contributed to the lowering of prevalence rates as studies published in the post vaccine introduction periods 2003–2015 recorded lower HBV prevalence rates than the pre-vaccine introduction period (1995–2002).

On the other hand, although, Ghana’s National Health Insurance Scheme (NHIS) introduced in 2003, aims to improve access to health services by eliminating financial barriers (particularly out-of pocket payments), hepatitis B screening and vaccination in Ghana outside EPI are still not covered under the scheme. Screenings are only covered and prescribed at hospitals for patients suspected to be reactive to hepatitis B and/or C. Hepatitis B immunoglobulin G and hepatitis B monovalent vaccine for babies born to hepatitis B reactive mothers are also not covered by the NHIS [68]. These may have all hampered effective control of the disease over the last couple of years.

Epidemiological studies have demonstrated that rapid urbanization, overpopulated cities and poor socioeconomic conditions such as lack of access to clean water and sanitation are implicated in the burden of HBV [69]. The World Bank notes that over the last 2 decades, there has been a steady increase in the proportion of Ghanaians with access to portable water with current rates exceeding 88 % [70]. Nevertheless, less than 15 % of Ghanaians have access to proper sanitation [71]. Martinson et al. [48], has demonstrated that the improvement of socioeconomic conditions may lead to a decreasing exposure to viral hepatitis such as HBV in Ghana. Hence, the apparent reported lower prevalence rate within the period 2003–2015, may have been due to the combined effect of vaccine introduction and improvement in some socioeconomic conditions. Better socioeconomic improvement and vaccination coverage in urban areas compared to rural areas may underline the difference in HBV prevalence rates difference between these two settings. However, it is unclear the extent to which factors such as vaccination and socioeconomic conditions have played in the slight regional variations in HBV prevalence across the country.

Although, there exist significant gaps in the evidence documenting the burden of HBV on individuals, the healthcare system and the country as whole, the cost associated with HBV in Ghana can be enormous because of the high morbidity and mortality associated with end-stage liver disease, cirrhosis and HCC. Blankson et al., identified that over 2 in 5 cirrhotic patients in Ghana had chronic HBV [8]. The cost of oral treatment for HBV in Ghana is about GHC 300-400 (USD100-150) a month or same weekly to take an injection for 48 weeks as a way of managing the condition [72]. This cost is enormous and one that majority of Ghanaians cannot afford. Even if this was to be publicly funded, the impact on health expenditure would be significant. Moreover, as identified from the studies, the most prevalent population was 16–39 years covering some of the most productive age groups. Thus the economic impact of HBV in Ghana through loss of life and absenteeism from work cannot be underestimated.

Addressing Ghana’s high HBV prevalence should remain a key national priority and one that needs strategic public health interventions. In 2014, the World Health Assembly adopted the second WHO resolution on viral hepatitis (WHA67.6), providing guidance to governments on how to prioritize actions to tackle all forms of viral hepatitis in a coordinated manner [73]. Subsequently, the recently released WHO guidelines on the management of chronic hepatitis B highlights the importance of adopting a simplified public health approach to controlling the virus [74]. The key highlights of this guideline includes developing publicly-funded screening and treatment programmes and providing universal access to hepatitis B prevention, care and treatment. Scaling up this programme in Ghana will have two main benefits. Firstly, it will expand access to the general population. And secondly, it will strengthen the diagnostic services and laboratory infrastructure to support care. In line with this, Hepatitis B vaccination should be covered by the NHIS, preferably for every citizen. If this is not achievable owing to resource limitations, it should be made available at least to all family members/close contacts of persons with hepatitis B in efforts to reduce horizontal transmission of the disease.

Effectively tackling HBV burden calls for a stronger political will and a wider social involvement. The aim will be to solidify the inclusion of HBV prevention in the overall national health agenda and salvage the needed resources to execute the necessary interventions. Lemoine et al. makes interesting reference to lessons learnt from the HIV/AIDS epidemic and advocates that the same energy and mobilization must be applied to fighting viral hepatitis such as HBV [1]. Within the HIV/AIDS domain, pressure from patient advocacy groups and civil societies for instance “pushed” policy makers and drug manufacturers to lower the cost of ARTs to the current level of around USD100 per person per year from about $10,000 per patient per year in the early 2000s [1]. This has subsequently had tremendous impact on the number of individuals receiving ART. Also integrating viral hepatitis programmes into the existing national health programmes around Tuberculosis (TB) or HIV may allow shared synergies in terms of the programme’s success and limit its cost [1, 65].

This study raises a number of key issues regarding HBV research in Ghana. Firstly, while there seems to be a positive trend of increased research in this area characterized by 60 % of papers being published in the last 5 years, there are widespread regional variations in the level of research. About 75 % of studies were conducted in two regions (Ashanti & Greater Accra) and in four regions it was not possible to derive aggregate data due to limited number of studies. Moreover, studies were concentrated in adult populations giving little information about HBV prevalence in children which is a better predictor of the level of maternofaetal transmission [48]. Likewise most studies provided no information regarding the relationship between prevalence and socio-demographic characteristics such as religion, income, and type of occupation all of which are recognized predictors of HBV prevalence [75]. Further research in these areas would be needed to fully understand the dynamics of HBV burden in Ghana.

In conclusion, there is a high burden of chronic HBV infection among Ghanaians. This is a preventable disease and indeed one that can be eradicated by vaccination. Addressing the challenges of HBV infection in Ghana will require multi-level approaches that includes population-wide educational interventions and a strengthening of the Ghanaian health system. There is urgent need for the government of Ghana and its international partners to prioritize HBV control as done successfully for conditions such as HIV, Malaria and TB. This is necessary to prevent a potential future explosion of HBV in Ghana.