INFECTIOUS DISEASE CQ\CTION

Inuit living in and Greenland Inuit migrated to have similar high prevalence of markers of viral hepatitis

1 2 3 4 Karsten Fleischer Rex ' *, Henrik B. Krarup , Peter Laurberg and Stig Andersen5

1 Department of internal medicine, Queen lngrids Hospital, , Greenland; 2Arctic Health Research Centre, Aalborg University Hospital, Aalborg, Denmark; 3Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark; 4Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark; 5 Department of Geriatric Medicine, Aalborg University Hospital, Aalborg, Denmark

Introduction contacted for a short telephone interview. We excluded More than 400 million persons are chronically infected individuals who were unable to give informed consent for with hepatitis B virus (HBV). One of the highest rates of medical reasons, had moved out of the study area or had HBV infection is found among the indigenous popula­ passed away (3). tions of the Arctic (1). The occurrence of HBV exposure In Greenland, we invited a random sample of 25% of was 55% in West Greenland and 88% in East Greenland men and women aged 50-69 years in Nuuk in West in a population-based study of men and women aged Greenland, and all men and women in that age range 50-69 years with a participation rate of 95%, and chronic in , Tiniteqilaaq, Sermiligaaq, Kuummiut and HBV infection was found in 3% of the population in West in East Greenland (3) to join the study. Greenland and 29% of the population in East Greenland Participants answered an interview-based question­ using advanced methods (2). naire and underwent a physical examination that included Citizens of Greenland have Danish citizenship, and height without shoes, weight in indoor clothing, detection Denmark hosts a group of Greenlanders (3). Migration of scleral signs of icterus, spider naevi and recording of may be related to disease. Though there are a number of any major disabilities. Blood samples were drawn and reports of hepatitis among Inuit in the Arctic (1), studies tested for HBsAg, anti-HBs, anti-HBc, HBeAg, anti-HBe, of hepatitis in migrated Inuit are lacking. Also studies HBV-DNA, HBV genotypes, anti-HOV, HOV-RNA, of hepatitis D virus (HOV) and hepatitis C virus (HCV) anti-HCV, HCV-Elisa test, HCV-RNA, aspartate amino­ infections are lacking in Greenland Inuit who have mig­ transferase, y-glutamyl transferase, bilirubin and albumin rated. We thus investigated hepatitis B, D and C virus as detailed in (3). infection among Greenland Inuit living in Denmark and in Greenland in order to compare the frequency Results of serological markers of infection between Inuit in Participation rates were 52% (n = 136) in Denmark and Greenland and those in Denmark for estimation of the 95% (n =441) in Greenland. Half of the participants association with migration. in Denmark had lived more than half of their lives in Denmark. Methods Figure 1 shows the frequency of serological signs of Names and addresses of persons born in Greenland and exposure to hepatitis B, D and C among Greenlanders in living in the study areas were obtained from the National East Greenland, West Greenland and Denmark. Civil Registration System in which details of every person Among Greenlanders living in Denmark, 54.5% had living in Denmark, the Faeroe Islands and Greenland is been exposed to HBV This was similar to the 53% among recorded. Greenlanders living in West Greenland (p = 0.76) while In Denmark, we included all individuals who had at different from participants from East Greenland (p < least 1 parent born in Greenland, were 40- 69 years of age, 0.001). Migration did not influence the occurrence of and lived in the selected areas in either Arhus or Aalborg. markers of HBV infection as shown in Table I; this A letter of invitation was sent and each responder was includes participants living in Nuuk compared to those

Citation: Int J Circumpdar Health 2013, 72: 22447 - http://dx.doi. org/10.34021ijch.v72i0.22447 715 Infectious Disease

100% 100%

80% 80%

~ i:i D Never 60% :I"' 60% :I"' D Never :I.. []Previous :I D Previous Q. 40% &'" 40% :i::"' • Present :i:: • Present 20% 20%

0% 0%

100%

80% u E 60% D Never :I.. D Previous & 40% • Present :i:: 20%

00/o

Fig. 1. Columns show the occurrence of hepatitis B (upper panel), hepatitis D (middle panel) and hepatitis C Oower panel) among Greenlanders living in East Greenland, West Greenland and Denmark (3). coming from Nuuk. Overall, HBsAg was positive m parents born in Greenland (p = 0.007) and with IV drug 4.4% of Greenlanders in Denmark (n = 6). These were use (p = 0.03), though only 2.2% had been IV drug users all anti-HBe positive and had low viral load. at some point in their life. Serological signs of HBV infection among Green­ As can be read from Fig. 1, we found serological signs landers in Denmark were associated with having both of HOV exposure among participants in Denmark/ Greenland in 0.7/1.1% (n = 1/5) and HCV exposure in 1. 5/0.0% (n = 2/0). Table I Frequencies of markers of HBV infection among Greenlanders living in Nuuk and in Greenlanders who migrated Liver biochemistry was elevated in the 6 Greenlanders from Nuuk to Denmark who had been exposed to HOV Physical examination revealed no adverse health effects of HBV infection (3). Migrated to Denmark Discussion Yes No The population of 56,000 in Greenland is scattered along the coast of the biggest island in the world, N % N % pa and the majority live in small towns and settlements. This makes it complicated to conduct satisfactory East Greenland origin sampling of people to describe the occurrence of disease HBsAg + 0 0.0 82 29.0 in different areas of Greenland. Our investigation in 5 100 201 71.0 Denmark included Greenlanders from all over Greenland Ant1-HBs + 3 60.0 158 79.0 and may reflect the pattern of hepatitis in the different 2 40.0 42 21.0 areas of Greenland (3). Antr-H Be-tot + 4 80.0 144 71.6 Migration is associated with a number of health issues. 20.0 57 28.4 However, previous studies indicating differences in dis­ West Greenland origrnb ease frequencies (e.g. cancer) with migration (4) were HBsAg + 0 0.0 4 2.7 0.48 based on registries that have inherited limitations. 18 100 144 97.3 Diagnostic thresholds and capacities differ between Ant1-HBs + 8 44.4 53 37.6 0.57 Greenland and Denmark and this may influence the 10 55.6 88 62.4 detection of disease. In addition, geographic association Antr-H Be-tot + 9 50.0 69 47.9 0.87 can be complicated as some move to Denmark for 9 50.0 75 52.1 diagnostic work-ups and treatments that are not available aChi-squared test. in Greenland. These limitations may be overcome by bFrom the capital Nuuk. population-based surveys.

716 Citatim : Int J Circumpolar Health 201 3, 72: 22447 - http://dx.doi.org/10.34021ijch.v72i0.22447 Infectious Disease

Our population-based comparative epidemiological of HBV exposure confirmed in Greenlanders in both investigation of frequencies of serological markers of Greenland and Denmark a call for attention as all our hepatitis B, D and C virus infection showed no difference Greenland participants with evidence of HOV exposure between Greenlanders living in Greenland and those who had elevated liver biochemistry even though HOV-RNA have migrated to Denmark (3). With regard to HBV could not be detected. infection, this accounted both for the classification of all participants as presently, previously and never before References exposed to HBV (3) and for the direct comparisons of the frequencies of HBsAg, anti-HBs and anti-HBc among 1. McMahon BJ. Viral hepatitis in the Arctic. Int J Circumpolar participants living in or coming from Nuuk (Table I). Health. 2004;635(Suppl 2):41-8. 2. Krarup HB, Andersen S, Madsen PH, Okkels H, Hvingel BH, We found 6 anti-HOV positive individuals out of Laurberg P Benign course of long-standing hepatitis B virus 342 HBV exposed Greenlanders in Greenland and 1 out infection among Greenland 1nuit? Scand J Gastroenterol. of 136 in Denmark. This does not suggest high rates of 2008;43:334-43. HOV in Greenland in general. None of the participants 3. Rex K, Krarup HB, Laurberg P, Andersen S. Population based in Greenland had markers of hepatitis C and only 1% of comparative epidemiological survey of hepatitis B, D and C Greenlanders in Denmark had anti-HCV. This is similar among Inuit migrated to Denmark and in high endemic Greenland. Scand J Gastroenterol. 2012;47(6):692-701. to reports of a low frequency of HCV in other Arctic 4. Boysen T, Friborg J, Andersen A, Poulsen GN, Wohlfahrt J, areas (1). Melbye M. The Inuit cancer pattern - the influence of In conclusion, the occurrence of hepatitis virus infec­ migration. Int J Cancer. 2008;122:2568- 72. tion and the influence on health and liver biochemistry did not change with migration of people from a high *Karsten Fleischer Rex endemic to a low endemic area. Still, the high rates Email: [email protected]

Citation: Int J Circumpdar Health 2013, 72: 22447 - http://dx.doi. org/10.34021ijch.v72i0.22447 717