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Background: Since the 1970s, Greenland has presented the highest reported incidence rates of the sexually transmitted infections (STIs) gonorrhoea and chlamydia in the Arctic regions. Objective: This study aims to describe sex- and age-specific incidence rates of gonorrhoea and chlamydia from 1990 to 2012 in Greenland, and to evaluate if changes in case definitions, diagnostic procedures and implementation of STI interventions during the period coincide with rate changes. Design: Gonorrhoea and chlamydia cases were identified from the national STI surveillance. For 1990–2008, STI cases were identified from weekly notified aggregated data. For 2009–2012, cases were identified in person-identifiable national registers. We used log-linear Poisson regression to calculate incidence rates (IRs) and incidence rate ratios (IRRs) with 95% confidence intervals (95% CI). Analyses were stratified according to sex, age and calendar period. Results: Gonorrhoea and chlamydia incidence rates have increased since 1995 to reach 2,555 per 100,000 person-years (PY) for gonorrhoea and 6,403 per 100,000 PY for chlamydia in 2012. From 2006 to 2012, the incidence rates among young adults aged 15–19 years were 8,187 and 22,515 per 100,000 PY for gonorrhoea and chlamydia, respectively. Changes in surveillance reporting did not seem to influence the incidence rates for either disease, whereas a change in diagnostic test coincided with an increased incidence of chlamydia. Conclusion: Overall, the incidence of chlamydia in Greenland increased during the study period, whereas the incidence of gonorrhoea decreased until 1995 but increased thereafter. Young adults aged 15–24 years were at highest risk of infection. The increase in incidence rates was independent of changes in case definitions, whereas an observed increase in chlamydia incidence in 2005 coincided with a change in diagnostic test. None of the STI interventions launched after 1995 seemed to coincide with decreasing national incidence rates. [ABSTRACT FROM AUTHOR]

Objective In spite of the high incidence of cervical cancer in Greenland, no assessment has been made of the impact of organized cervical screening, introduced in 1998, in relation to occurrence of high-grade cervical lesions. The objectives of the present study were to estimate coverage of the screening program and to examine possible changes in cervical intraepithelial neoplasia (CIN3) incidence in Greenland during 1997–2011 according to calendar period and age. Methods Using nationwide registries, we calculated age-standardized incidence rates for all women born and living in Greenland. To investigate whether possible variation in the incidence of CIN3 were related to differences in screening coverage, we further estimated relative risks of CIN3 within two years of screening among women who participated in the screening program using log-linear binomial regression. Results Coverage of the screening program was low during 1997–2011 with the highest level of 54% observed in 2011. Peaks in CIN3 incidence of around 300 per 100,000 person-years were observed in 1999 and between 2009 and 2011, while the incidence was lower of approximately 100 per 100,000 person-years between 2000 and 2008. During 2009–2011, the highest incidence was found among women aged 25–34 years. Similar patterns of CIN3 risk according to calendar period and age groups were observed among screened women. Conclusions The great variations in CIN3 incidence and low screening coverage observed during 1997–2011 suggest that improvements in the Greenlandic screening program are warranted. [ABSTRACT FROM AUTHOR]

Greenland remains a highly endemic area for hepatitis B virus (HBV) infection. This is in sharp contrast to other modern societies, such as Denmark. To address this discrepancy, we investigated the natural history of HBV infection in Greenland by estimating the age-specific incidence of HBV infection, the proportion of chronic carriers, and the rates of hepatitis B surface antigen seroclearance. In total, 8,879 Greenlanders (16% of the population) from population-based surveys conducted in 1987 and 1998 were followed through March 2010. Data on HBV status were supplemented by HBV test results from all available HBV registries in Greenland to determine changes in HBV status over time. Incidence rates of HBV infection and hepatitis B surface antigen seroclearance were estimated after taking into account interval censoring. The incidence of HBV infection in 5–14-year-old subjects was less than 1 per 100 person-years and peaked at 5 per 100 person-years in persons 15–24 years of age. Overall, 17.5% of persons infected in adulthood were estimated to become chronic carriers. HBV is primarily transmitted in adolescence and adulthood in Greenland. In contrast to what is observed in most other populations, HBV-infected adults in Greenland have a high risk of progressing to chronic HBV carriage. This phenomenon might explain how the high rate of infection is maintained in Greenland. [ABSTRACT FROM PUBLISHER]

Objectives. To evaluate the effectiveness of the hepatitis B virus (HBV) vaccination program in Greenland, which targets children born to mothers who are positive for HBV surface antigen (HBsAg), we determined vaccination coverage, levels of postvaccination antibodies, and frequency of breakthrough infections in at-risk children. Methods. We conducted a population-based retrospective cohort study with data from nationwide registries. We identified all children born to HBsAg-positive mothers from 1992 to 2007 and collected data on their HBV vaccination status. In 2008 to 2010, we tested the children for HBV core antibody, HBsAg, and anti-HBsAg antibody (HBsAb). Results. Of 4050 pregnant women, 3.2% were HBsAg positive. Of 207 children born to these women, 20% received no vaccinations, and only 58% received at least 3 vaccinations. At follow-up, HBsAb levels in vaccinated children were much lower than expected, and 8 (6%) of 140 at-risk children had breakthrough infections, with 4 chronically infected (persistently HBsAg positive). Conclusions. The prevention program targeting children at risk for HBV in Greenland is ineffective. HBV vaccination should be included in the universal childhood vaccination program, and postvaccination HBsAb levels should be monitored. [ABSTRACT FROM AUTHOR]

Background In Greenland, the prevalence of hepatitis B surface antigen carriers, reflecting chronic hepatitis B virus (HBV) infection, is 5%–10%. However, the incidence of cirrhosis and hepatocellular carcinoma in this population has been reported to be low. We investigated this discrepancy in a large population-based cohort study. Methods In total, 8879 Greenlanders (16% of the population) were recruited for population-based surveys performed from May 5 to July 7, 1987, and from November 1 to November 21, 1998, with follow-up until March 31, 2010. HBV status was based on serological testing, supplemented by data from all available HBV registries in Greenland to determine changes in HBV status over time. Information on morbidity and mortality was obtained from the Patient Discharge Registry, the Cancer Registry, and the Central Registration System. Sex, age, ethnicity, and period-adjusted incidence rate ratios (IRRs) were estimated using Poisson regression. World standardized rates were derived from these and World Health Organization data. Results The 650 chronically HBV-infected persons had higher rates of hepatocellular carcinoma (adjusted IRR = 8.70; 95% CI = 2.06 to 36.7), liver disease (adjusted IRR = 5.73, 95% CI = 3.52 to 9.34), and all-cause mortality (adjusted IRR = 1.47; 95% CI = 1.21 to 1.79) than the 5160 HBV-negative persons. However, the world standardized incidence rates of hepatocellular carcinoma (38.5 cancers per 100 000 person-years) and cirrhosis (24 cases per 100 000 person-years) among chronically HBV-infected persons were low compared with results from population-based studies from countries with low, intermediate, and high rates of endemic HBV infection. Conclusion The relatively low incidence of hepatocellular carcinoma and other HBV-related morbidity among chronic HBV-infected persons in Greenland suggest a more benign course of HBV among the Greenlandic Inuit than in populations in other parts of the world. [ABSTRACT FROM PUBLISHER]

Objectives. We sought to determine precise estimates of infant mortality rates and to describe overall trends in infant mortality in Greenland and Denmark from 1973 to 1997. Methods. We analyzed data from population-based registries of all live-born infants in Greenland and Denmark to calculate infant mortality rates from 1973 to 1997. Results. Between the periods of 1973-1977 and 1993-1997, neonatal mortality rates in Greenland declined from 20.9 per 1000 live-born infants to 15.7, and postneonatal mortality rates declined from 20.9 per 1000 to 5.9. Infant mortality rates were significantly higher in Greenland than in Denmark, and the excess mortality was uniformly distributed over all birthweight percentiles. In Greenland, the risk of infant death was significantly lower if the mother was born outside Greenland. Conclusions. Postneonatal mortality rates in Greenland have decreased significantly during the past 25 years, but little progress has been made in decreasing neonatal mortality rates. Disparities exist among children with different maternal origins. (Am J Public Health. 2004;94:452-457) [ABSTRACT FROM AUTHOR]

To assess coverage rates of standard childhood vaccinations in Greenland, a geographically isolated and sparsely populated area, and to determine risk factors for low coverage, we performed a register-based cohort study among 596 children from 1993 to 1998 in Sisimiut, Greenland. For vaccines given before the age of 2 years (pertussis 1–3, DT-IPV 1–3, and MMR 1) coverage rates in general were impressively high being on or above levels of Western countries. A risk factor for low coverage was migration. The Greenlandic vaccination model with free vaccinations administered by health workers who systematically call in children at scheduled times seems highly efficient and could be a model for other similar countries. [Copyright &y& Elsevier]

Background Human immune responses to latent Mycobacterium tuberculosis ( Mtb ) infection (LTBI) may enable individuals to control Mtb infection and halt progression to tuberculosis (TB), a hypothesis applied in several novel TB vaccines. We aimed to evaluate whether immune responses to selected LTBI antigens were associated with subsequent reduced risk of progression to TB. Methods We conducted a population-based cohort study in East Greenland (2012–2014) including individuals aged 5–31 years. A personal identifier allowed follow-up in national registers including the TB notification register. Mtb infection was defined by a positive Quantiferon test. Immune responses to LTBI antigens were assessed by whole blood antigen stimulation and interferon gamma measurement. Results Among 978 participants, 67 previously had TB. LTBI antigen (Rv1284, Rv2659, Rv2660c) immune response prevalence was 18%, 50%, 2% among Mtb -infected and 7%, 40%, 4% among non-infected (Quantiferon negative) participants. Among 911 participants without prior notified TB, 31 were notified with TB during study follow-up. Immune responses to LTBI antigens were not associated with reduced risk of subsequent TB; Rv1284 HR 0.92 (95%CI 0.28–3.04), Rv2659 HR 1.05 (95%CI 0.51–2.13), Rv2660c HR 3.06 (95%CI 0.70–13.37). Conclusion In this large population-based study, human immune responses to selected LTBI antigens were not found to be strongly associated with reduced risk of subsequent TB. [ABSTRACT FROM AUTHOR]

Objective To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection. Methods Between 2005 and 2007, 1797 Greenlandic schoolchildren in five different areas were tested for MTI with an interferon gamma release assay (IGRA) and a tuberculin skin test (TST). Parents or guardians were surveyed using a standardized self-administered questionnaire to obtain data on crowding in the household, parents' educational level and the child's health status. Demographic data for each child - i.e. parents' place of birth, number of siblings, distance between siblings (next younger and next older), birth order and mother's age when the child was born - were also extracted from a public registry. Logistic regression was used to check for associations between these variables and MTI, and all results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). Children were considered to have MTI if they tested positive on both the IGRA assay and the TST. Findings The overall prevalence of MTI was 8.5% (152/1797). MTI was diagnosed in 26.7% of the children with a known TB contact, as opposed to 6.4% of the children without such contact. Overall, the MTI rate was higher among Inuit children (OR: 4.22; 95% CI: 1.55--11.5) and among children born less than one year after the birth of the next older sibling (OR: 2.48; 95% CI: 1.33--4.63). Self-reported TB contact modified the profile to include household crowding and low mother's education. Children who had an older MTI-positive sibling were much more likely to test positive for MTI themselves (OR: 14.2; 95% CI: 5.75--35.0) than children without an infected older sibling. Conclusion Ethnicity, sibling relations, number of household residents and maternal level of education are factors associated with the risk of TB infection among children in Greenland. The strong household clustering of MTI suggests that family sources of exposure are important. [ABSTRACT FROM AUTHOR]

Background: In Greenland, the prevalence of hepatitis B surface antigen carriers, reflecting chronic hepatitis B virus (HBV) infection, is 5%-10%. However, the incidence of cirrhosis and hepatocellular carcinoma in this population has been reported to be low. We investigated this discrepancy in a large population-based cohort study., Methods: In total, 8879 Greenlanders (16% of the population) were recruited for population-based surveys performed from May 5 to July 7, 1987, and from November 1 to November 21, 1998, with follow-up until March 31, 2010. HBV status was based on serological testing, supplemented by data from all available HBV registries in Greenland to determine changes in HBV status over time. Information on morbidity and mortality was obtained from the Patient Discharge Registry, the Cancer Registry, and the Central Registration System. Sex, age, ethnicity, and period-adjusted incidence rate ratios (IRRs) were estimated using Poisson regression. World standardized rates were derived from these and World Health Organization data., Results: The 650 chronically HBV-infected persons had higher rates of hepatocellular carcinoma (adjusted IRR = 8.70; 95% CI = 2.06 to 36.7), liver disease (adjusted IRR = 5.73, 95% CI = 3.52 to 9.34), and all-cause mortality (adjusted IRR = 1.47; 95% CI = 1.21 to 1.79) than the 5160 HBV-negative persons. However, the world standardized incidence rates of hepatocellular carcinoma (38.5 cancers per 100 000 person-years) and cirrhosis (24 cases per 100 000 person-years) among chronically HBV-infected persons were low compared with results from population-based studies from countries with low, intermediate, and high rates of endemic HBV infection., Conclusion: The relatively low incidence of hepatocellular carcinoma and other HBV-related morbidity among chronic HBV-infected persons in Greenland suggest a more benign course of HBV among the Greenlandic Inuit than in populations in other parts of the world.

Vitamin D deficiency has been associated with increased risk of tuberculosis (TB). Changes from a traditional to a Westernised diet among Greenlanders have resulted in reduced serum vitamin D, leading to considerations of whether preventive vitamin D supplementation should be introduced. The association between vitamin D status and TB was examined to assess the feasibility of vitamin D supplementation in Greenland. This was examined in a case-control study involving seventy-two matched pairs of TB patients (cases) and controls aged 8-74 years. Cases were diagnosed with TB during 2004-6 based on clinical findings in combination with either (1) positive Mycobacterium tuberculosis culture, (2) characteristic X-ray abnormalities together with a positive tuberculin skin test or a positive interferon-γ release assay or (3) characteristic histology. Controls were individually matched on age ( ± 5 years), sex and district. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured and OR of TB were the outcome. Compared with individuals with 25(OH)D concentrations between 75 and 140 nmol/l, individuals with concentrations < 75 nmol/l (OR 6.5; 95% CI 1.8, 23.5) or > 140 nmol/l (OR 6.5; 95% CI 1.9, 22.2) had higher risks of active TB (P = 0.003; adjustment for alcohol and ethnicity). Supplementing individuals with low vitamin D to normalise serum 25(OH)D concentrations was estimated to result in a 29% reduction in the number of TB cases. The study indicated that vitamin D supplementation may be beneficial to individuals with insufficient vitamin D concentrations but may increase the risk of TB among individuals with normal or high concentrations.

The Inuit cancer pattern is characterized by high frequencies of Epstein-Barr Virus (EBV)-associated carcinomas of the nasopharynx and salivary glands. The reasons are unknown, but genetic and environmental factors are believed to be involved. Using data from the well-defined Inuit population in Greenland we investigated whether migration to Denmark influenced their risk of cancer. Greenland is part of the Danish Kingdom, and population-based registries cover both countries. Using rates for Denmark as reference, sex-specific standardized incidence ratios (SIR) were calculated for Inuit who never lived in Denmark and for those who at least once were registered with a Danish address. During 1973-2003, we observed 3,567 cancers in a cohort of 77,888 persons. Of these, 862 among 26,214 Inuit ever living in Denmark, and 2,705 among 51,674 nonmigrating Inuit. High SIRs for cancers of the nasopharynx [31.7 (CI 22.0-45.5)] and salivary glands [3.1 (CI 1.4-6.9)] observed among Inuit migrating to Denmark were comparable to those observed among Inuit never living in Denmark. Significant higher risk of cancer of the bladder, breast, prostate gland, skin, brain and stomach was observed among Inuit following migration to Denmark. The SIR was not generally influenced by duration of stay. The high risk of carcinoma of the nasopharynx and salivary glands observed in Inuit populations is maintained after migration to a low incidence area. This indicates that genetic factors or environmental factors acting early in life are etiologically important for these cancers., ((c) 2008 Wiley-Liss, Inc.)

Undifferentiated nasopharyngeal carcinoma is a result of environmental factors, in particular EBV infection, affecting genetically susceptible individuals. The familial risk of nasopharyngeal carcinoma is among the highest of any malignancy. Whether this susceptibility is restricted to nasopharyngeal carcinoma is unknown as information on the risk of other cancers in relatives is limited. We did a population-based study of the cancer incidence in nasopharyngeal carcinoma families in Greenland, a nasopharyngeal carcinoma-endemic area. Using population-based registers, a cohort of all persons born in Greenland was followed from 1973 to 2002. In this cohort, 134 individuals developed nasopharyngeal carcinoma and their relatives were identified through registers and interviews. Subsequently, the occurrence of cancer was determined by linkage to the population-based cancer register and the risk of cancer in nasopharyngeal carcinoma relatives and nonrelatives compared by relative risks. Among 766 first-degree relatives, the relative risk of nasopharyngeal carcinoma following the family index case was 8.0 [95% confidence interval (95% CI), 4.1-14.0]. Sex and age of the relative or the index case had no modifying effect on the familial risk of nasopharyngeal carcinoma. The relative risks of carcinoma of the salivary glands, 8.4 (95% CI, 2.7-19.5), and uterine cervix, 2.2 (95% CI, 1.1-3.9), were also significantly increased. In families with multiple cases of nasopharyngeal carcinoma, the risk of other cancers than nasopharyngeal carcinoma was further increased. These results indicate that the increased risk of cancer in nasopharyngeal carcinoma families is not restricted to nasopharyngeal carcinoma, but extends to the virally associated cancers of the salivary glands and cervical uteri.

Respiratory morbidity in Inuit children is high. However, little is know regarding lung function measures in this population. The forced expiratory volumes in one second (FEV(1)) and forced vital capacity (FVC) in 888 Greenlandic Inuits (N=888) and Danes (N=477) aged 6-18 years were compared. Furthermore, associations between level of lung function and atopy and lifestyle factors were estimated in Greenlanders. The effect of height on FEV(1) and FVC was significantly different in Greenlanders and Danes, this difference in lung function increased with increasing height, and could not be explained by differences in age weight and BMI. Thus, Greenlanders taller than 130 cm had up to 300-400 ml higher FEV(1) and FVC compared with Danes of the same height. Among Greenlanders, those living in settlements had the highest levels of both FEV(1) and FVC. Greenlanders had elevated levels of FEV(1) and FVC compared with Danes. The Inuit having a shorter limb length in relation to trunk height may account for these differences. However, our finding that Greenlanders living in settlements had the highest lung function level also suggests a possible role of factors in the traditional Greenlandic lifestyle.

Context: It has been suggested that BCG vaccination may protect against development of allergic diseases, particularly when given just after birth. BCG vaccination was given routinely to all infants in Greenland until 1990, when it was withdrawn from the vaccination program. Whether this resulted in an increased prevalence of atopy in children born after the stop of BCG vaccination is unknown., Objective: To determine whether BCG vaccination and age at BCG vaccination are associated with development of atopy., Design, Setting, and Participants: Cross-sectional study among schoolchildren aged 8 to 16 years in 4 towns on the northwest coast of Greenland. Participants had a blood sample drawn and information on BCG vaccination was obtained during 2 periods, November 1998 and November 2001. A total of 1686 children (79% of available children) participated, 1575 of whom had complete information on vaccination status. Atopy was defined as a positive test result in an assay that tests for IgE specific against the most common inhalant allergens in serum., Main Outcome Measures: Odds ratio (OR) of atopy in BCG-vaccinated compared with unvaccinated children and OR according to age at vaccination., Results: The risk of atopy was the same in BCG-vaccinated compared with unvaccinated children after adjustment for confounders (OR, 1.03; 95% confidence interval, 0.72-1.48). The risk of atopy in BCG-vaccinated children was not associated with age at vaccination (P =.17)., Conclusions: BCG vaccination administered to infants is not associated with reduced risk of development of atopy.