Background
Hepatitis C virus (HCV) infection is now considered to be of significant global health importance affecting all countries and requires the needed attention [
1]. About 2.8 % of the world’s population representing almost 180 million individuals are estimated to be infected with HCV; as much as 80 % of this number suffer chronic infection—almost five times the number for HIV [
2]. Although, recent estimates point to a declining burden mainly due to reduced prevalence among children, it is widely accepted that more needs to be done to control the disease [
3].
Chronic HCV infection has been strongly implicated in the development of hepatocellular carcinoma (HCC). About 10–20 % of chronic HCV sufferers develop liver cirrhosis within 20–30 years of onset of infection, 1–5 % of these are likely to progress into liver cancer [
4,
5]. Each year, more than 350,000 deaths from HCV-related liver diseases are recorded across the globe with majority of these deaths arising from liver cirrhosis and HCC [
6]. Over 25 % of the global cases of liver cirrhosis and HCC are attributable to chronic HCV infection, with rates higher in endemic regions [
7].
There are variations in the burden of HCV across the globe as depicted by prevalence rates of 1.5 %, 2.3 % and 3.2 % for the World Health Organization (WHO)’s Americas, Europe and Africa regions, respectively [
1]. Madhava et al. [
8] estimated the HCV prevalence in 2002 in Sub-Saharan Africa to be 3.0 % with a prevalence rate of 2.4 % for the West African region where Ghana is located. Recent estimate by Rao et al. [
9] presents a slightly lower prevalence of 2.65 % for the Sub-Saharan Africa region.
However, there are concerns that prevalence rates reported for Sub-Saharan Africa may be substantially underestimated owing to factors such as the limited availability of HCV representative surveys in the region [
10]. Aside the regional variations in HCV prevalence, even within countries, the patterns of HCV epidemiology vary greatly. In the United States for instance, highest HCV prevalence is recorded among persons 30-49 years, although in countries like Italy and China, persons >50 years account for most infections [
11].
It is important to highlight that there are some real challenges in documenting an accurate burden of HCV to ascertain true incidence and prevalence in any country. Such challenges include for instance, the unavailability of assays with ability to distinguish acute and chronic infections as majority of acute HCV infections often present no symptoms [
12].
Globally, where the impact of HCV has been thoroughly studied, the implications on national health systems has been found to be enormous [
13]. Razavi et al. [
14] estimated the lifetime cost of a person infected with HCV in 2011 in US to be at $64,490, although, this could rise to $205,760 ($154,890–$486,890) when medical inflation is applied. Myer et al. [
15] also estimated an amount of $64,694 as the lifetime cost for Canadian with HCV infection in 2013 which could rise to as high as $327,608 if liver transplantation becomes necessary.
Viral hepatitis including HCV, are considered to be significant contributors to morbidity and mortality in Ghana and deserve greater attention [
16]. However, extensive aggregate data on prevalence of HCV in Ghana are currently lacking [
17]. Lavanchy [
1] reported a national HCV prevalence rate of 1.7 % for Ghana in 2010 based on WHO’s data. A systematic review focusing on HCV seroprevalence in Africa by Riou et al. [
18] also reported an HCV prevalence rate for Ghana within the range 0.2–9.4 %. Aside the very wide range presented by this study, the estimate was also based on only ten studies and was restricted to adult populations. To the best of our knowledge, no other thoroughly conducted systematic review and meta-analysis on the prevalence of chronic HCV infection in Ghana has been published. This observation further highlight the lack of thorough compilation of the evidence regarding the prevalence of HCV in Ghana.
To inform evidence-based policymaking, public health research and programming prioritization in Ghana, accurate prevalence estimates based on thorough and up-to-date evidence complication is essentially needed. In this paper, we aimed at estimating the prevalence of chronic HCV infection in Ghana based on studies published over the last two decades (1995–2015). This was a contribution to our large study documenting the burden of common viral hepatitis in Ghana.
Discussion
In this review, we present a high prevalence (3.0 %) of chronic HCV infection in Ghana. This prevalence rate is significantly higher than the national prevalence of 1.7 % reported previously by Lavanchy [
1]. The observation of higher prevalence rate in this study may be in alignment with the observation by Layden et al. [
10] that HCV prevalence rates for sub-Saharan Africa have generally been underestimated in the past. Even that, the prevalence rate reported may still be modest considering that a significant proportion of studies included in this review involved low risk populations such as blood donors who are often biased towards a healthier population [
56]. Additionally, as highlighted in the sensitivity analysis, the anti-HCV prevalence was most impacted by two studies all conducted in blood donors [
37,
38]. In developed countries like Australia and the US, prevalence of chronic HCV infection has been estimated to be less than 2 % [
7]. This may highlight that the level of chronic HCV infection in Ghana may be considerably high.
The high prevalence of chronic HCV infection together with previously reported high prevalence of other viral hepatitis in Ghana [
57], points to a growing concern regarding the safety of blood products in the country. Although, Ghana has a national blood policy which requires that all donated blood are screened for blood-borne infections including HIV 1 and 2, Hepatitis B (HBV), HCV and Syphilis [
58], a greater emphasis and stricter monitoring to ensure high levels of adherence to this policy will be needed to minimise the risk of supplying contaminated blood to patients.
The prevalence of chronic HCV infection among pregnant women was estimated as 4.6 % which is high when reference is made to other regions like the United States and Europe where prevalence of chronic HCV among this group has been estimated to be around 1–2.5 % [
59]. Our result therefore highlight the importance of vertical transmission in the overall spread of HCV infection in Ghana. Studies have demonstrated that chronic HCV infection during pregnancy poses significant risks to mother and child and may further exacerbate the risks of preterm delivery, low birth weight, congenital malformations, glucose intolerance during pregnancy and overall perinatal mortality [
60,
61]. The high HCV prevalence among pregnant women draws attention to the need for the adoption of a national program that includes HCV screening for all or most-at-risk pregnant women in Ghana. Although, a vaccine to prevent HCV infection is currently non-existent, treatment with preparations such as interferon for women with high HCV viral load will lead to reduction in HCV infection levels for the women and also minimise the risks of vertical transmission of the disease in future pregnancies [
59].
Several factors may contribute to the observed high levels of chronic HCV infection in Ghana. Studies have reported low levels of awareness and knowledge among Ghanaians about the transmission pathways of the disease. For instance, Mutocheluh and Kwarteng [
62], reported that among 200 barbers in Kumasi none (0 %) of the barbers could describe the common HCV transmission pathways and only 7 % were aware that sharing razor blade or hair trimmer could be a means of transmitting viral pathogens like HCV and HBV. Similar trends of low awareness has been reported for pregnant women [
63]. Additionally, while the transmission dynamics of HCV remains varied and include unprotected sex, mother-to-child transmission and transfusion of infected blood, in many Ghanaian communities, there has been an over-emphasis on HCV and related viral hepatitis as sexually transmitted infections (STIs) [
13]. Such perceptions have often led to HCV-positive individuals been stigmatized and at times discouraged such patients seeking proper care to minimise their chances of spreading the disease.
Controlling HCV will require three (3) key strategies which include offering treatment for infected individuals, implementing measures to halt the transmission of the disease and reducing mortality arising from unmanaged complications such as HCC [
7]. Antiviral medications have shown great potency in curing HCV infections (approximately 90 % of infections) but access to these medicines remain poor in many developing countries including Ghana [
64]. To ensure that such therapies are available to majority of chronic HCV sufferers in Ghana, they must be provided freely under the country’s National Health Insurance Scheme (NHIS). This must be one of the key focus or priority for the government considering that wider availability of highly effective new generation direct-acting antiviral medications to treat HCV infections would not only reduce the occurrence of complications such as HCC but will also lead to decline in prevalence of the disease arising from altered infectivity state of treated individuals.
Unfortunately, unlike HBV, a vaccine for HCV is currently unavailable and therefore interruption of infection transmission through risk reduction would rely mainly on education to improve knowledge and awareness of the transmission dynamics of the disease. While routine screening of the general population may not be recommended as it’s deemed to be not cost effective, screening of high-risk groups such as injection drug users (IDUs) and persons with high-risk sexual behaviours should be expanded nationwide and provided possibly freely to increase patronage. This should be backed with other innovative strategies such as provision of comprehensive harm-reduction services to injection drug users including sterile injecting equipment [
64]. Additionally, attention needs to be paid to conditions in the prisons as the risk of HCV infection remains high in these settings. Agyei et al. [
38], reported that as much as 35.2 % of prisoners reported ever injecting drugs and of these 11.5 % were HIV-positive. Public health interventions should aim at addressing the specific needs of such populations as they may pose additional transmission risk once released into the community [
37,
38].
Horizontal transmission of HCV has been recognized to be linked to factors such as age, socioeconomic/living conditions as well as other risky behaviours such as sharing towels, dental cleaning materials and chewing gum [
45]. Martinson et al. [
45], for instance, has demonstrated that general improvements in socio-economic conditions may lead to a decreased exposure to viral hepatitis including hepatitis B and HCV among Ghanaians. Over the last few decades, there have been significant improvement in the living conditions of Ghanaians. For instance, the percentage of Ghanaians with improved access to water increased from 56.0 % in 1990 to 86.0 % in 2012 [
65]. The proportion of Ghanaians classified as poor has also decreased by more than 50 % from 52.6 % in 1991 to 21.4 % in 2012 [
66]. Although, studies conducted after 2005 generally reported lower HCV prevalence than those conducted before, in the context of limited data it is difficult to assess the extent to which general improvements in socioeconomic conditions have contributed to reductions in the HCV burden across the country and for different regions. The high prevalence of HCV in Greater Accra may be due to the region’s national status of harbouring the capital city. This has often resulted in a high influx of both young and old into its commercial areas from all corners of the country and internationally for business, tourism or to seek greener pastures, an atmosphere which provides a conducive environment for the promotion of anti-social behaviours such as drug abuse and prostitution; patterns which may facilitate HCV transmission [
67].
Although, limited studies have been conducted to evaluate the impact of chronic HCV infection on Ghana’s health system and economy in general, the impact arising from the high prevalence of the disease may be enormous owing to significant mortality and costs associated with complications such as HCC and liver cirrhosis. The contribution of HCV to liver cirrhosis was demonstrated in a study by Blankson et al. [
37], which identified that chronic HCV infection was implicated in 1 in 14 liver cirrhosis cases. Treatment for chronic HCV is deemed to be expensive. A standard 12-week treatment with one of the newer drugs Sovaldi® (Sofosbuvir) cost around US $ 84,000 which breaks down to $1000 for each pill taken daily [
68]. This is certainly a cost that most HCV Ghanaians cannot afford neither could it be absorbed by any sustainable public funding. While generic versions of such medications cost significantly less, there remains major availability issues. The high prevalence of HCV infection in HIV patients is also likely to increase mortality in such groups. While majority of studies did not document the most prevalent age groups, high HCV burden is likely to impact on economic growth as productivity among affected persons are likely to be affected and their general wellbeing diminished. Thus, high HCV burden can have significant impact on Ghana’s economy and as such a strong economic argument for government commitment and intervention in tackling the disease should be made.
Reducing the overall burden of chronic HCV infection in Ghana will require new measures and strategies and the recognition of the disease as one of the key country’s priority areas. Recently, the World Health Organization (WHO) introduced updated guidelines as a framework for countries to plan the expansion of clinical services to persons suffering chronic HCV infection [
69]. The guideline highlights nine (9) key areas such as screening of high-risk, groups, mitigating liver damage through measures such as alcohol assessment and treatment with appropriate regimen such as interferon [
69]. The government of Ghana would need to pay closer attention to implementing the recommendations set out in this guideline if the battle against HCV is to be won. Tackling the burden of chronic HCV infection in Ghana would also require stronger commitments from government and all other interest groups with the objective of ensuring that measures to control HCV are fully incorporated in national policies. The role of civil societies and pressure groups in driving such changes have been widely recognized and their involvement in for instance, the fight against the HIV/AIDS epidemic has been referenced as a remarkable achievement including successfully pushing for the reduction in the cost of ARTs. The successes and experience from HIV/AIDS epidemic should guide future strategies against viral hepatitis such as HCV [
70].
Strengths and limitations
The screening method employed can significantly impact on the HCV prevalence rate [
71]. Since our review covered a two decade period, the studies adopted different screening techniques there are likely vary in terms of sensitivity and specificity which could partly account for the difference in prevalence rates across studies published in different years. As indicated by Fox [
72], it can be extremely difficult to differentiate acute from chronic HCV infection especially in patients who have not previously undergone anti-HCV testing and it is possible that the prevalence rate reported in some studies may not be representative of only chronic infections. While this review highlights a growing evidence in this area of research as depicted by almost half (48 %) of studies were recently published (within last 5 years), there are significant regional variations. Nearly two-thirds (75 %) of studies as well as around 90 % of total population size involved were from two regions (Ashanti and Greater Accra), although these two regions represented just a little over 35 % of the country’s population in 2010 [
73]. Also it was not possible to deduce aggregate HCV prevalence estimates for seven regions and no data was retrieved from the upper west region. A wider epidemiological study conducted around the same time may help to provide a more accurate prevalence estimate as well as minimize the wide heterogeneity as observed in the studies reviewed. Additionally, most studies involved adult participants with only one study specifically conducted in children [
45]. Likewise, most studies reported no information on HCV prevalence in relation to demographic (e.g. age and sex) and socio-economic (e.g. education) as well as risk profiles (e.g. blood transfusion, multiple injection drug use, HIV status) which are all known predictors of HCV status [
74]. It will be important for future research to look into the epidemiology of HCV in the underrepresented regions as well as targeted high-risk groups to provide greater insight into the HCV burden in Ghana. In spite of the above limitations, this review presents a more rigorous estimate of chronic HCV infection in Ghana that should inform health planning, policy decisions and the design of public health strategies by the ministry of Health and the Ghana Health service towards controlling the disease.