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Anders Koch

Publications and source records attributed to Anders Koch.

18 recordsLinked to original sources

Cancer susceptibility in nasopharyngeal carcinoma families--a population-based cohort study.

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.

Cohort Studies↗

Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

Adult↗

Lung function in Greenlandic and Danish children and adolescents.

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.

Adolescent↗

Seroprevalence and risk factors for Helicobacter pylori infection in Greenlanders.

BACKGROUND: In contrast to most populations worldwide, the incidence of gastric cancer increases among Inuit in Greenland. Contributing factors to this increase are unknown, but Helicobacter pylori may be involved. However, little is known regarding the epidemiology of H. pylori in Arctic communities. With the aim of determining age-specific prevalence, risk factors, and association with clinical conditions of H. pylori infection, we carried out a population-based study of H. pylori in Sisimiut, the second biggest town of Greenland. MATERIALS AND METHODS: A population-based sample of 685 persons had serum drawn that was analyzed for H. pylori IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Risk factors analyses were carried out using multivariate logistic regression models. RESULTS: The seroprevalence was lowest among children aged 0-4 years (6%), but increased rapidly thereafter. In persons aged 15-87 years the seroprevalence had stabilized around 58%. Total number of children in household, number of older, but not younger, siblings and narrow age gap to closest older sibling were associated with H. pylori seropositivity. In contrast, number of adults in household and socioeconomic status did not influence serostatus. CONCLUSIONS: The age-specific prevalence pattern in Greenland is intermediate between that of developing and developed countries. The risk factor pattern indicates crowding and older siblings in particular to be key elements in risk of infection.

Adolescent↗

Human metapneumovirus and respiratory syncytial virus in hospitalized danish children with acute respiratory tract infection.

The newly discovered human metapneumovirus (hMPV) has been shown to be associated with respiratory illness. We determined the frequencies and clinical features of hMPV and respiratory syncytial virus (RSV) infections in 374 Danish children with 383 episodes of acute respiratory tract infection (ARTI). Study material comprised routine nasopharyngeal aspirates obtained during 2 winter seasons (November-May) 1999-2000 and 2001-2002 from children hospitalized at the Departments of Paediatrics, Hvidovre Hospital and Amager Hospital, Denmark. hMPV was detected in 11 (2.9%) and RSV in 190 (49.6%) ARTI episodes by real-time reverse transcription-polymerase chain reaction using primers targeting the hMPV N gene and the RSV L gene. Two children were co-infected with hMPV and RSV. They were excluded from statistical analysis. Hospitalization for ARTI caused by hMPV was restricted to very young children 1-6 months of age. Asthmatic bronchitis was diagnosed in 66.7% of hMPV and 10.6% of RSV-infected children (p < 0.001). Overall symptoms and clinical findings were similar among hMPV and RSV positive episodes, but more RSV-infected children required respiratory support. hMPV is present in young Danish children hospitalized with ARTI although less frequent than RSV and with a tendency to a milder clinical course.

Acute Disease↗

Intussusception in early childhood: a cohort study of 1.7 million children.

OBJECTIVE: To describe incidence and temporal trends of intussusceptions in Danish children during 1980 to 2001. METHODS: A population-based cohort study was conducted of 1.67 million children who were younger than 5 years during 1980 to 2001 and were followed up for 6.66 million person-years. The Danish National Patient Registry was used to identify cases of intussusception in the cohort. Age-specific incidence rates were main outcome measure. RESULTS: A total of 1814 cases of intussusception among children who were younger than 5 years were reported from 1980 to 2001. The incidence rate remained fairly constant during 1980 to 1990 but decreased by 55% (95% confidence interval: 43%-65%) from 1990 to 2001. The reduction was most pronounced among children aged 3 to 5 months. CONCLUSIONS: The incidence of intussusception among Danish children declined significantly during the 1990s, particularly among infants 3 to 5 months of age.

Age Distribution↗

A population-based registry study of infant mortality in the Arctic: Greenland and Denmark, 1973-1997.

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.

Arctic Regions↗

The Greenlandic research database: a population-based research resource.

Information on past exposures is often warranted in health studies in Greenland, as living conditions have changed markedly in this century. To provide a longitudinal population-based research tool with such information the Department of Epidemiology Research at Statens Serum Institut has established 'The Greenlandic Research Database', a comprehensive population-based database comprising data from Greenland from national registers, population-based longitudinal and cross-sectional studies and human biological samples from 1979 to the present day.

Adult↗

Cancer in Greenlandic Inuit 1973-1997.

OBJECTIVES: During the second half of the 20th century living conditions of the Inuit populations in the Arctic have undergone major transitions. The objective was to investigate how the cancer pattern was affected by these changes, using data from the Danish Cancer Registry and the Civil Registration System. RESULTS: In the period 1973-1997 total cancer incidence increased by 4% per 5 years for men and 6% per 5 years for women. The incidence of lung, stomach, breast and colon cancer increased in both sexes, whereas the incidence of cervical cancer decreased. CONCLUSIONS: Thus, the overall cancer incidence among Greenlandic Inuit is increasing as a result of increases in several cancers that are common in Western populations. In contrast to global trends, a significant increase in the incidence of stomach cancer in both sexes was observed.

Female↗

Infection control in day-care centres in Greenland.

OBJECTIVES: The aim of this study was to determine hygienic habits and precautions taken with main focus on hand hygiene, cleaning and laundry in day-care centres in Greenland. METHODS: In the period 2000-2002 we investigated 33 day-care centres in towns along the west coast of Greenland using a questionnaire. The majority of the day-care centres (18/33) were found in the biggest towns in Greenland Nuuk and Sisimiut. RESULTS: The institutions covered 34% of children attending day-care centres in Greenland. Although most caregivers and children would wash their hands before meals and after changing diaper/toilet, not all did so. One third of caretakers did not wash hands after wiping a child's nose. Paper towels were only available as recommended in 25% of day-care centres. Linen was washed weekly or more often per month, but at lower temperatures than recommended. Most floors were washed daily. CONCLUSIONS: The day-care centres in general did not follow hygienic recommendations sufficiently, and the hygienic behaviours resembled more those of home. For public institutions this is not sufficient to prevent cross-contamination, as the risk of spread of microorganisms is high in institutions with many contacts. Caregivers are the most important role models in teaching the child good hygienic habits such as hand hygiene. Hygienic education of caregivers and early hygienic training of children, preferably already in nursery, is therefore important and should be strengthened.

Child↗

Cancer in Greenlandic Inuit 1973-1997: a cohort study.

The increasing westernization of the Arctic countries may influence the very particular cancer profile of these populations. Our objective was to investigate the development in cancer incidence from 1973 to 1997 in a large and well-defined Inuit population in Greenland. Greenland is part of the Danish Kingdom, and population statistics covering both countries are available from the same registry resource. Data from the Danish Civil Registration System and from the Danish Cancer Registry were used to calculate age-standardized cancer incidence rates for the periods 1973-1987 and 1988-1997 for persons born in Greenland. Using rates for Denmark, sex-specific standardized incidence ratios (SIRs) for 1988-1997 were calculated. Furthermore, age- and sex-specific incidence rates in the 2 periods were calculated for selected cancers. Total cancer incidence increased from 248.5 to 277.9 per 100,000 person-years in men and from 269.4 to 302.2 per 100,000 person-years in women. The incidence of lung, stomach, breast and colon cancer increased, whereas the incidence of cervical cancer decreased. Compared to the Caucasian population in Denmark, high SIRs were found for cancers of the nasopharynx, salivary gland, esophagus, stomach and cervix and low SIRs for testis, bladder, prostate, breast and hematologic cancers. Overall cancer incidence among Greenlandic Inuit is increasing as a result of increases in several cancers that are common in Western populations. A significant increase in the incidence of stomach cancer in both sexes, which contrasts global trends for this cancer, warrants further investigation.

Cohort Studies↗

Risk factors for acute respiratory tract infections in young Greenlandic children.

Acute respiratory infections cause considerable morbidity among Inuit children, but there is very little information on the risk factors for these infections in this population. To identify such factors, the authors performed a prospective community-based study of acute respiratory infections in an open cohort of 288 children aged 0-2 years in the town of Sisimiut, Greenland. Between July 1996 and August 1998, children were monitored weekly, and episodes of upper and lower respiratory tract infections were registered. Risk factor analyses were carried out using a multivariate Poisson regression model adjusted for age. Risk factors for upper respiratory tract infections included attending a child-care center (relative risk = 1.7 compared with home care) and sharing a bedroom with adults (relative risk = 2.5 for one adult and 3.1 for two adults). Risk factors for lower respiratory tract infections included being a boy (relative risk = 1.5), attending a child-care center (relative risk = 3.3), exposure to passive smoking (relative risk = 2.1), and sharing a bedroom with children aged 0-5 years (relative risk = 2.0 for two other children). Breastfeeding tended to be protective for lower respiratory tract infections. The population-attributable risk of lower respiratory tract infections associated with passive smoking and child-care centers was 47% and 48%, respectively. The incidence of acute respiratory infections among Inuit children may be reduced substantially through public health measures.

Acute Disease↗

A population-based register study of vaccine coverage among children in Greenland.

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.

Child↗

BCG vaccination and risk of atopy.

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.

Adolescent↗

[Acute respiratory tract infections and mannose-binding lectin insufficiency in small children].

INTRODUCTION: According to hospital-based studies, increased susceptibility to certain infections is associated with genotypes that cause low serum levels of the protein mannose-binding lectin (MBL). However, the contribution of MBL insufficiency to the incidence of common childhood infections on a population basis is unknown. To investigate the effect of MBL insufficiency on the risk of acute respiratory infections (ARI) in unselected children, we performed a prospective population-based study of ARI in young children in Sisimiut, Greenland. MATERIAL AND METHODS: An open cohort of children aged 0-2 years was formed in 1996, and followed up with weekly morbidity surveillance visits for a two-year period. Episodes of ARI were diagnosed on medical history and clinical examinations. MBL genotypes were determined from blood samples according to the presence of structural alleles and promoter alleles. RESULTS: Altogether 294 children participated and 44 refused. Blood samples were taken from 252 participants. A 2.1-fold (95% confidence interval 1.4-3.1) increased risk of ARI was found in MBL-insufficient children compared with MBL-sufficient children (p < 0.001). The risk association was largely restricted to the period 6 to 17 months of age, whereas less or no effect could be shown in younger and older children. DISCUSSION: These population-based data suggest that genetic factors such as MBL insufficiency play an important role in host defence, particularly during the vulnerable period of infancy between 6 and 17 months of age, when the adaptive immune system is immature.

Acute Disease↗

Frequency of atopy in the Arctic in 1987 and 1998.

Few studies have measured the frequency of atopy with objective measures, and most of these studies have been done in industrialised countries. We analysed serum samples from 859 15-80-year-old Greenlanders who had participated in population-based screening campaigns in 1987 and in 1998. We defined atopy as a positive result in an assay that tests for specific IgE against the eight most common inhalant allergens in one pool (grass, birch, mugwort, dog, cat, horse, Cladosporum herbarum, house dust mite). The frequency of atopy doubled between 1987 (39 [10%] of 392) and 1998 (87 [19%] of 467; risk ratio 1.88 [95% CI 1.31-2.68]). This increase was largest in 15-19-year olds, but also occurred in older people, suggesting that the risk factors responsible for the increase in atopy do not operate only in childhood.

Adolescent↗

Population-based study of acute respiratory infections in children, Greenland.

Acute respiratory infections (ARI) are frequent in Inuit children, in terms of incidence and severity. A cohort of 294 children <2 years of age was formed in Sisimiut, a community on the west coast of Greenland, and followed from 1996 to 1998. Data on ARI were collected during weekly visits at home and child-care centers; visits to the community health center were also recorded. The cohort had respiratory symptoms on 41.6% and fever on 4.9% of surveyed days. The incidence of upper and lower respiratory tract infections was 1.6 episodes and 0.9 episodes per 100 days at risk, respectively. Up to 65% of the episodes of ARI caused activity restriction; 40% led to contact with the health center. Compared with studies from other parts of the world, the incidence of ARI appears to be high in Inuit children.

Acute Disease↗