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Is screening baby boomers for HCV enough?
A call to screen for hepatitis C virus in persons from countries of high endemicity
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"we commend the CDC for updating their guidelines for HCV screening. However, there are likely to be at-risk foreign-born persons who originate from HCV high prevalence countries that may still be missed with the current guidelines"
"Despite the differences in geographical distribution of HCV prevalence worldwide, there are currently no recommendations in the USA or Europe to screen persons who originate from countries with high HCV prevalence. According to data from the 2010 USA census, there are approximately 1 74 000 individuals from Egypt currently residing in the USA [12]. Recent data from a viral hepatitis community outreach program in New York City, found that 15% of persons born in Egypt residing in the USA are positive for HCV
Worldwide, there is a substantial preventable burden of HCV because of iatrogenic transmission......the reuse of glass syringes during the parenteral therapy campaigns to control endemic schistosomiasis is widely held to be responsible for a very large number of iatrogenic transmissions
we commend the CDC for updating their guidelines for HCV screening. However, there are likely to be at-risk foreign-born persons who originate from HCV high prevalence countries that may still be missed with the current guidelines. To help identify additional cases of HCV, we recommend screening for HCV in persons born in Egypt and Cameroon immediately and investigation of the testing of persons from other countries with high HCV prevalence regions in the future. Of course, we need more research and epidemiological data regarding HCV prevalence worldwide, and to look at HCV among immigrants, in Europe and the USA. With the progress of HCV therapy with oral DAAs, screening will be even more important with the possibility of HCV eradication. With the hope of improving access to therapy, a -test and treat- strategy may become cost-effective and relevant in the future."
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Editorial
Is screening baby boomers for HCV enough? A call to screen for hepatitis C virus in persons from countries of high endemicity
Liver Intl Oct 2014
Tarik Asselah1, Ponni V Perumalswami2 and
Douglas Dieterich2
1 Centre de Recherche sur l'Inflammation (CRI), INSERM
UMR 1149, Universite Paris Diderot and Service
d'Hepatologie, AP-HP H^opital Beaujon, Clichy, Paris, France
2 Mount Sinai School of Medicine, NewYork, USA
Hepatitis C virus (HCV) has a current global prevalence rate of approximately 2-3%, representing approximately 130-180 million infected individuals [1, 2]. Persons chronically infected with HCV are at risk of chronic hepatitis and of developing serious hepatic complications such as cirrhosis, hepatocellular carcinoma (HCC), or liver failure.
Several data suggest that the prevalence of HCV is higher in countries located in Asia (2.1%, 83 millions) and Africa (3.2%, 28 millions), while a lower prevalence is found in North America, Europe and Australia [1, 2]. (Fig. 1). The highest prevalence of HCV, 15%, is found in Egypt, while the lowest reported prevalences are <1.0% in both the UK and Scandinavia. However, only limited country-specific estimates of HCV prevalence are available to guide decision making.
In the USA and Europe, HCV is the leading cause of cirrhosis and hepatocellular carcinoma, and the major cause of end-stage liver disease leading to liver transplantation. Data from death certificates show that HCV-related deaths now outpace deaths because of HIV in the USA and many European countries [3, 4].
Despite progress in antiviral treatment with direct-acting antivirals [5], screening and access to treatment has been low. A recent report commissioned by the Institute of Medicine (IOM) of the National Academies estimates that up to 75% of HCV-infected persons have not been diagnosed [6].
Several HCV management guidelines have been provided [7-9] (Table 1). Prior risk-factor based HCV screening guidelines have demonstrated limited effectiveness, identifying only approximately 25% of chronically infected individuals in the USA. In an effort to identify more cases of HCV-infected persons, the CDC recently updated their screening guidelines to include one-time testing for all adults born during the period of 1945-1965 [9]. Several studies suggest that HCV screening and treating among the 1945-1965 birth cohort at a prevalence of approximately 3% would be cost-effective [10, 11].
Despite the differences in geographical distribution of HCV prevalence worldwide, there are currently no recommendations in the USA or Europe to screen persons who originate from countries with high HCV prevalence. According to data from the 2010 USA census, there are approximately 1 74 000 individuals from Egypt currently residing in the USA [12]. Recent data from a viral hepatitis community outreach program in New York City, found that 15% of persons born in Egypt residing in the USA are positive for HCV [13]. Infected persons from the HONE programme included 30% of persons who did not admit to traditional risk factors for HCV or fall within the birth cohort screening criteria. These patients would have been missed by current screening guidelines. While the HONE study was conducted in one city, it may suggest a broader problem regarding HCV infection in Egyptians in the USA. In France, at Beaujon Hospital, approximately 20% of patients admitted for chronic HCV, are infected with genotype 4 [14]. Of these HCV genotype four infected persons, approximately one-third were born in Egypt [15]. The majority of these patients grew up in Egypt and came to France when they were adults. The IOM report recently made a recommendation to consider screening persons from Egypt for HCV. Data from both the HONE programme and France support immediate screening of persons for HCV in those originating from Egypt and an appeal for additional data regarding prevalence of HCV infection in persons originating from other HCV high prevalence countries.
Worldwide, there is a substantial preventable burden of HCV because of iatrogenic transmission. Transfusion-associated HCV infection is a major worldwide risk before HCV testing became available in 1989. The risk of acquiring HCV via blood transfusion has been virtually eliminated in countries that have implemented routine HCV testing of donors. However, some countries have not prioritized blood transfusion safety and/or lack the resources to implement donor screening, and in these countries blood transfusion remains an important source of infection. There is a high prevalence of transfusions, reuse of needles and syringes, needle-stick injuries among healthcare workers, and unnecessary medication injections [16]. It has been estimated that approximately two million HCV infections are acquired annually from contaminated healthcare injections, and may account for up to 40% of all HCV infections worldwide [17]. In addition to unsafe injection practices, poor or nonexistent infection control in health and dental care facilities may be a source of HCV transmission in some countries. In Egypt, where the prevalence of HCV is the highest in the world, the reuse of glass syringes during the parenteral therapy campaigns to control endemic schistosomiasis is widely held to be responsible for a very large number of iatrogenic transmissions [18]. To be fair, there may have been other concurrent iatrogenic exposures at the time [19]. More recent evidence in Egypt supports continuing iatrogenic exposures which contribute to ongoing HCV transmission [19, 20].
Chronic hepatitis B (HBV), unlike HCV, has high vertical transmission rates. Persons born abroad with HBV infection are almost universally infected during birth, thus the population prevalence of HBV in a specific country is a close proxy indicator for the prevalence among individuals who were born in that specific country but who now reside in the USA. Therefore, the CDC and other guidelines have recommended screening for HBV in persons originating from countries with HBsAg prevalence higher than 2% [21, 22]. Unlike HBV, immigration to the USA reduces the probability of HCV exposure given that the primary route of transmission of HCV in high prevalence countries is iatrogenic. Therefore, specific country prevalence estimates of HCV are likely to overestimate the prevalence of individuals born in that country but now residing in the USA. It is unclear what the best threshold for HCV Ab country prevalence will be necessary to include for identifying additional cases of HCV that would otherwise be missed with current screening practices. We would recommend additional data studies by the CDC and other groups to help determine the country-specific HCV Ab prevalence to use in developing additional guidelines.
There is realistic hope for an oral regimen against HCV in the near future, as several direct-acting antivirals with different mechanisms of action are in advanced drug development [5]. For instance, for HCV genotype 4, results of treatment with DAAs are presented in Fig. 2. Some of these drugs or drug combinations have pan-genotypic activity. This rapid progress strongly suggests that IFN-free short duration DAA combinations will make HCV the first chronic viral infection to be eradicated worldwide. The ideal goal will be the eradication of HCV worldwide, and we will have to take into account the significant epidemiological differences changes worldwide.
Finally, we commend the CDC for updating their guidelines for HCV screening. However, there are likely to be at-risk foreign-born persons who originate from HCV high prevalence countries that may still be missed with the current guidelines. To help identify additional cases of HCV, we recommend screening for HCV in persons born in Egypt and Cameroon immediately and investigation of the testing of persons from other countries with high HCV prevalence regions in the future. Of course, we need more research and epidemiological data regarding HCV prevalence worldwide, and to look at HCV among immigrants, in Europe and the USA. With the progress of HCV therapy with oral DAAs, screening will be even more important with the possibility of HCV eradication. With the hope of improving access to therapy, a -test and treat- strategy may become cost-effective and relevant in the future.
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