A nationwide registry-based observational study of thyroid disease incidence in the Faroe Islands.

OBJECTIVE: The occurrence of thyroid disease varies among populations. While the iodine nutrition level of the Faroese seems to have been decreasing over the past decades, there is no systematic evaluation of the thyroid disease pattern in the Faroe Islands. Such knowledge of thyroid disease occurrence in the North Atlantic region may support healthcare planning and prevention. To investigate incidence rates, including subtypes of thyroid diseases, and demographic characteristics of thyroid disease patients in the Faroe Islands, to improve understanding of the patterns and trends of these disorders. DESIGN AND METHOD: A registry-based observational study was conducted over 10 years, encompassing all adult Faroese individuals. PATIENTS AND MEASUREMENTS: Health records from general practitioners and hospitals were used to identify incident cases of thyroid diseases. Validation was performed using multiple data sources. The incidence rates were standardised using population data from the middle of the study period 2006-2018. RESULTS: Among the 1152 individuals diagnosed with thyroid disease, the standardised incidence rates per 100,000 person-years were 55 for hyperthyroidism and 112 for hypothyroidism, and around four times higher in women than in men. Hashimoto's thyroiditis was the dominant cause of hypothyroidism, while Graves' disease was the leading cause of hyperthyroidism. The incidence of hypothyroidism increases with age. A decreasing trend was observed over time for both hypothyroidism and hyperthyroidism. CONCLUSION: Considering the decrease in iodine nutrition levels over the past decades, we were surprised by the high incidence of autoimmune thyroid disease. The findings highlight the need for continuous monitoring of thyroid disease occurrence in coastal areas of the North Atlantic Ocean.

Risk of malignancy in a high-incidence population-based cohort of Faroese patients with inflammatory bowel disease from 1960 to 2020 - a Faroese IBD cohort study.

BACKGROUND: The association between inflammatory bowel disease (IBD) and malignancy remains disputed despite many observational studies. The Faroese population exhibits the highest occurrence of IBD in the world. This study aimed to investigate the cancer risk in Faroese IBD patients in a nationwide IBD cohort. METHODS: This study included all IBD patients diagnosed in the Faroe Islands between 1960 and 2020. Clinical demographics and cancer diagnoses were retrieved from patient files and the Faroese cancer registry. Cancer risk in IBD patients was calculated as standardized incidence ratios (SIRs) based on the Faroese background population's age- and sex-specific cancer incidence rates, retrievable from NORDCAN. RESULTS: The cohort consisted of 699 patients with a total follow-up time of 9,629 person-years. Overall, the risk of cancer was not statistically significantly increased compared to the background population. Patients diagnosed with cancer at age 50-59 years had higher overall cancer risk (SIR 1.8; 95% CI, 1.02-2.99) as did UC patients diagnosed with IBD at 50-59 (SIR 2.1; 95% CI, 1.10-3.54). Absolute numbers were small and no estimates for site-specific cancers reached statistical significance, though lung, breast, and cancer of the female reproductive organs were elevated among IBD and UC patients, and colorectal cancer in CD patients. CONCLUSIONS: This nationwide study found no statistically significantly increased risk of cancer among Faroese patients with CD or UC, except from age 50 to 59 years. While the incidence of IBD is significantly higher in the Faroe Islands than in other countries, risk estimates of cancers are comparable.

Cancer survival in the Faroe Islands over the last 50 years compared to the other Nordic countries.

As sustained development in cancer treatment protocols have led to improved survival in most areas of the world, surveillance is needed to ensure that small populations follow suit. Our study reports age-standardized relative cancer survival in the Faroe Islands compared to the other Nordic countries. We present 1- and 5-year survival estimates and corresponding 95% confidence intervals for the Faroe Islands and compare them with estimates for the Nordic countries. The data for this article has been obtained through the NORDCAN collaboration (2019 data). Age-standardized relative survival was estimated using shared R codes on individual-level data within each country. Ten-year calendar inclusion periods were used in addition to the usual 5-year calendar periods to include cancer sites with few cases, which is especially beneficial to the smaller populations. The primary findings were that 1- and 5-year survival were consistently lower in the Faroes for the summary group all sites but non-melanoma skin cancer for both women and men. Further, 5-year survival was lower for women with ovarian cancer and men with lung cancer than in other Nordic countries. Previously, breast cancer survival was low in the Faroes but has improved to a comparable level over the last few years. Colorectal cancer survival was relatively high for both sexes. The reported estimates in this article call for further research to investigate the cancers with lower survival and should call for actions to improve the survival of Faroese cancer patients.

Factors influencing the immune response over 15 months after SARS-CoV-2 infection: A longitudinal population-wide study in the Faroe Islands.

BACKGROUND: The durability of SARS-CoV-2 antibody response and the resulting immunity to COVID-19 is unclear. OBJECTIVES: To investigate long-term humoral immunity to SARS-CoV-2. METHODS: In this nationwide, longitudinal study, we determined antibody response in 411 patients aged 0-93 years from two waves of infections (March to December 2020) contributing 1063 blood samples. Each individual had blood drawn on 4-5 occasions 1-15 months after disease onset. We measured total anti-SARS-CoV-2 receptor-binding domain (RBD) antibody using a qualitative RBD sandwich ELISA, IgM, IgG and IgA levels using an quantitative in-house ELISA-based assay  and neutralizing antibodies (NAbs) using an in-house ELISA-based pseudoneutralizing assay. IgG subclasses were analyzed in a subset of samples by ELISA-based assay. We used nonlinear models to study the durability of SARS-CoV-2 antibody responses and its influence over time. RESULTS: After 15 months, 94% still had detectable circulating antibodies, mainly the IgG isotype, and 92% had detectable NAbs. The distribution of IgG antibodies varied significantly over time, characterized by a biphasic pattern with an initial decline followed by a plateau after approximately 7 months. However, the NAbs remained relatively stable throughout the period. The strength of the antibody response was influenced by smoking and hospitalization, with lower IgG levels in smokers and higher levels in hospitalized individuals. Antibody stability over time was mainly associated with male sex and older age with higher initial levels but more marked decrease. CONCLUSIONS: The humoral immune response to SARS-CoV-2 infection varies depending on behavioral factors and disease severity, and antibody stability over 15 months was associated with sex and age.

Birthweight and gestational age in the Faroe Islands: A comparison between birthweight and gestational age in the Faroe Islands and other Nordic countries.

INTRODUCTION: This study aimed to examine Faroese infants' birthweight and gestational age in 2010-2019 and compare these findings with other Nordic countries. Risk factors for high birthweight among Faroese infants were also investigated in this study. MATERIAL AND METHODS: All singleton liveborn infants registered in the Faroese Birth Registry in 2010-2019 were included in the study (n = 6121). A comparison was made with data on birthweight and gestational age from Denmark, Iceland, Norway, and Sweden. RESULTS: The mean birthweight increased significantly from 3652 g (95% confidence interval [CI]: 3505-3699 g) in 2010 to 3745 g (95% CI: 3700-3790 g) in 2019, a mean increase in birthweight of 93 g (95% CI: 28-158 g) (p < 0.05). The birthweight increased 186 g (95% CI: 179-193 g) for each gestational week and 11 g (95% CI: 7-15 g) for each year. Changes in gestational age explained 31% of the change in birthweight. The proportion of infants weighing 4500 g or more increased significantly from 6.1% in 2010 to 9.6% in 2019 (p < 0.05). The risk of giving birth to an infant weighing 4000 g or more was consistently associated with previously giving birth (OR 1.98 (95% CI: 1.71-2.30)) and gestational age (OR 1.28 (95% CI: 1.23-1.33) per week increase in gestational age). Infants born in gestational weeks 40 and 42 in 2019 had a higher birthweight z-score than infants born in gestational weeks 40 and 42 in 2010. Compared to other Nordic countries, Faroese infants' mean birthweight was high, the Faroe Islands had a higher number of infants born with a weight of 4000 g or more and a higher proportion of infants born in gestational week 41 or later (31.5%). CONCLUSIONS: Our results showed that the mean birthweight and the proportion of infants with high birthweight significantly increased during 2010-2019 in the Faroe Islands. The mean birthweight, the proportion of infants with high birthweight and the gestational age at birth for Faroese infants was higher than all other Nordic countries. The reasons for this require further investigation.

Low Seroprevalence among Undetected COVID-19 Cases, Faroe Islands, November 2020.

We conducted a second nationwide severe acute respiratory syndrome coronavirus 2 seroprevalence study in the Faroe Islands during November 2020. We found crude seroprevalence was 0.3% and prevalence was 0.4% after adjusting for test sensitivity and specificity. This low seroprevalence supports the prevention strategies used in the Faroe Islands.

Polygenic risk of Alzheimer's disease in the Faroe Islands.

BACKGROUND AND PURPOSE: The Faroe Islands are a geographically isolated population in the North Atlantic with a similar prevalence of Alzheimer's disease (AD) and all-cause dementia as other European populations. However, the genetic risk underlying AD and other dementia susceptibility has yet to be elucidated. METHODS: Forty-nine single-nucleotide polymorphisms (SNPs) were genotyped in 174 patients with AD and other dementias and 159 healthy controls. Single variant and polygenic risk score (PRS) associations, with/without APOE variability, were assessed by logistic regression. Performance was examined using receiver operating characteristic area under the curve (ROC AUC) analysis. RESULTS: APOErs429358 was associated with AD in the Faroese cohort after correction for multiple testing (odds ratio [OR] 6.32, 95% confidence interval [CI] 3.98-10.05, p = 6.31e-15 ), with suggestive evidence for three other variants: NECTIN2 rs41289512 (OR 2.05, 95% CI 1.20-3.51, p = 0.01), HLA-DRB1 rs6931277 (OR 0.67, 95% CI 0.48-0.94, p = 0.02) and APOE rs7412 [ε2] (OR 0.28, 95% CI 0.11-0.73, p = 0.01). PRSs were associated with AD with or without the inclusion of APOE (PRS+APOE OR = 4.5, 95% CI 2.90-5.85, p = 4.56e-15 , and PRS-APOE OR = 1.53, 95% CI 1.21-1.98, p = 6.82e-4 ). AD ROC AUC analyses demonstrated a PRS+APOE AUC = 80.3% and PRS-APOE AUC = 63.4%. However, PRS+APOE was also significantly associated with all-cause dementia (OR = 3.39, 95% CI 2.51-4.71, p = 2.50e-14 ) with an AUC = 76.9%, that is, all-cause dementia showed similar results albeit less significant. DISCUSSION: In the Faroe Islands, SNP analyses highlighted APOE and immunogenomic variability in AD and dementia risk. PRS+APOE , based on 25 SNPs/loci, had excellent sensitivity and specificity for AD with an AUC of 80.3%. High PRSs were also associated with an earlier onset of late-onset AD.

Iodine nutrition among the adult population of the Faroe Islands: a population-based study.

The WHO recommends monitoring iodine status in all populations with median urinary iodine concentration (UIC) below 100 µg/l suggesting iodine deficiency. There are no data on the iodine intake among the population of the Faroe Islands. This study aimed to provide data on iodine nutrition in a representative sample of the general adult population from the Faroe Islands. We conducted a population-based cross-sectional survey in 2011-2012 and measured iodine in urine from 491 participants (294/197 men/women) using the ceri/arsen method after alkaline ashing. Participants include about 100 subjects in each of four adult decades and included participants from both the capital city and villages. The median UIC was low within the recommended range 101 µg/l (range 21-1870 µg/l). No samples were in the range suggesting severe iodine deficiency, but half of the samples were in the range of just adequate or mildly insufficient iodine intake with UIC markedly lower in women than in men (86 v. 115 µg/l; P < 0·001). Intake of fish and whale meals affected the UIC. In conclusion, nearly half of the population had an iodine excretion in the range of borderline or mild iodine deficiency. The lowest iodine nutrition level among Faroese women is a concern as it may extend to pregnancy with increased demands on iodine nutrition. In addition, we found that large variations and the intermittently excessive iodine intakes warrant follow-up on thyroid function in the population of the Faroe Islands.

Cancer in the Faroe Islands from 1960-2019 - incidence, mortality, and comparisons with the other Nordic countries.

Purpose: In this paper, we present age-standardized cancer incidence and mortality rates in the Faroe Islands. We also compare with the Nordic rates and show incidence rate ratios (IRR) and mortality rate ratios (MRR).Materials and methods: The Faroese cancer registry (FCR) was established in 1994, with incidence available from 1960 and mortality from 1983. The FCR is a part of the NORDCAN collaboration, where the different Nordic countries all report anonymized cancer data by standardized methods, ensuring comparability. Validation efforts revealed that 13% of cases had not been reported to the FCR from 2006 to 2019, emphasizing the need for continued validation efforts of cancer registries. After validation, we submitted the updated cancer cases to NORDCAN and now present this data, taken directly from the NORDCAN website (2019 data).Results: We found that the incidence of the summary group all cancers in the Faroe Islands increased from 1960 to 2019, while cancer mortality decreased from 1983 to 2019. Comparisons with Nordic rates showed significantly lower IRRs for cancer in all cancers, bladder and urinary tract, and skin cancer for both sexes, while IRR was lower for breast cancer in women and prostate cancer in men. Contrary, IRR was higher for rectum and kidney cancer in women and esophagus and testicular cancer in men. There was an increased MRR for cancer in female organs, bladder and urinary tract, and kidney cancer in women, and esophagus and pancreas cancer in men. In contrast, malignant hematopoietic diseases and melanoma in women had a lower MRR.Conclusions: Cancer incidence in the Faroe Islands was lower than in the other Nordic countries. Of particular interest, the incidence of testicular cancer saw a steep increase during the last 20 years, and an investigation into possible causes for this is needed.

FarGen - participants in the genetic research infrastructure of the Faroe Islands.

Background: The demographic history of the Faroe Islands makes this isolated population - founded in the 9th century - interesting for genetic research. The goal of the FarGen project was to recruit individuals to the FarGen infrastructure to promote research into the genetic features of the Faroese people, and to develop a reference panel of population-specific variants. We aimed to recruit 1500 individuals. Participation was voluntary; participants had to donate a blood sample for whole-genome sequencing, and had to answer a questionnaire regarding sociodemographics, health, motivation and attitude towards participation in genetic research. Methods: A total of 1541 participants voluntarily joined the project, donated a blood sample and returned the questionnaire. Results: Answers from the questionnaire show that participants are, in general, European, have children, have a relatively high level of education, rate their health to be good, are willing to participate in future health-related research, and were motivated to sign up primarily to participate in research to help others and local research competency building. Conclusions: Overall, the initial cohort of the FarGen infrastructure comprises 3% of the Faroese population, and represents the general population well based on the collected sociodemographic data. However, there is an excess of women, and some geographic sub-regions and age groups are slightly underrepresented. We find the recruitment method with voluntary sign-up appropriate, and knowledge acquired through the first phase will aid the next phase of the project, with the aim of expanding the FarGen cohort with additional individuals, bio-specimens and body measurements in order to perform multifactorial analyses.

The Faroese Septuagenarians cohort: A comparison of well-being before and during the COVID-19 pandemic among older home-dwelling Faroese.

AIMS: Despite success in avoiding morbidity and mortality in the oldest members of the population during the COVID-19 pandemic, the crisis may have affected the well-being of older adults, for example due to social distancing measures. The aim of this study was to examine the well-being of older Faroese by conducting a direct comparison of well-being indicators on the same group of elderly people before and during the COVID-19 pandemic. METHODS: Data were collected from 227 home-dwelling adults aged 82-86 years from the Faroese Septuagenarians cohort. The pre-COVID-19 period was from December 2017 to January 2019, and the COVID-19 period was from 8 June to 15 July 2020. Three aspects of well-being were assessed: loneliness, self-rated health and quality of life (WHOQOL-BREF). RESULTS: During the COVID-19 pandemic, there were significant increases in loneliness (21.8% vs. 6.8%; p<0.001) and in worse self-rated health compared to the previous year (37.2% vs. 19.0%; p<0.001). In terms of quality of life, the domains of overall quality of life (74.33±14.96 vs. 71.88±15.21; p=0.04) and physical health (73.81±17.11 vs. 71.66±17.37; p=0.03) deteriorated. On the other hand, the domains of social relationships (78.87±16.52 vs. 85.81±13.35; p<0.001), environment (82.49±10.78 vs. 87.06±7.88; p<0.001) and psychological health (77.07±11.52 vs. 80.53±10.89; p<0.001) improved during the pandemic. CONCLUSIONS: Our findings suggest that attention should be directed to loneliness and physical well-being amongst home-dwelling old adults, despite the elderly showed resilience and improved psychological health, social relations and environment domains in a quality of life assessment during the COVID-19 pandemic.

Long COVID in the Faroe Islands: A Longitudinal Study Among Nonhospitalized Patients.

BACKGROUND: Little is known about long-term recovery from coronavirus disease 2019 (COVID-19) disease, especially in nonhospitalized individuals. In this longitudinal study we present symptoms registered during the acute phase as well as long COVID (ie, long-lasting COVID-19 symptoms) in patients from the Faroe Islands. METHODS: All consecutive patients with confirmed reverse transcription-polymerase chain reaction testing from April to June 2020 were invited to participate in this study for the assessment of long COVID. Demographic and clinical characteristics and self-reported acute and persistent symptoms were assessed using a standardized detailed questionnaire administered at enrollment and at repeated phone interviews in the period 22 April to 16 August. RESULTS: Of the 180 participants (96.3% of the 187 eligible COVID-19 patients), 53.1% reported persistence of at least 1 symptom after a mean of 125 days after symptoms onset, 33.0% reported 1 or 2 symptoms, and 20.1% reported 3 or more symptoms. At the last follow-up, 46.9% were asymptomatic compared with 4.4% during the acute phase. The most prevalent persistent symptoms were fatigue, loss of smell and taste, and arthralgias. CONCLUSIONS: Our results show that it might take months for symptoms to resolve, even among nonhospitalized persons with mild illness course in the acute phase. Continued monitoring for long COVID is needed.

Seroprevalence of SARS-CoV-2-Specific Antibodies among Quarantined Close Contacts of COVID-19 Patients, Faroe Islands, 2020.

Close contacts of coronavirus disease (COVID-19) patients are at high risk for severe acute respiratory syndrome 2 (SARS-CoV-2) infection. We assessed the seroprevalence of SARS-CoV-2-specific antibodies among quarantined close contacts of COVID-19 patients in the Faroe Islands. We invited quarantined close contacts of COVID-19 index patients identified during March 3-April 22, 2020, to participate in this study; 584 (81%) contacts consented and underwent serologic testing. Among the 584 participants, 32 (5.5%) were seropositive for total antibody against SARS-CoV-2. Household and young or elderly contacts had higher risk for seropositivity than other contacts. We found a secondary attack rate of 19.2%. Seroprevalence among close contacts was almost 10-fold higher than among the general population of the Faroe Islands. Regularly testing household close contacts of COVID-19 patients might help track the transmission of SARS-CoV-2.

Epidemiology and Clinical Course of First Wave Coronavirus Disease Cases, Faroe Islands.

The Faroe Islands was one of the first countries in the Western Hemisphere to eliminate coronavirus disease (COVID-19). During the first epidemic wave in the country, 187 cases were reported between March 3 and April 22, 2020. Large-scale testing and thorough contact tracing were implemented early on, along with lockdown measures. Transmission chains were mapped through patient history and knowledge of contact with prior cases. The most common reported COVID-19 symptoms were fever, headache, and cough, but 11.2% of cases were asymptomatic. Among 187 cases, 8 patients were admitted to hospitals but none were admitted to intensive care units and no deaths occurred. Superspreading was evident during the epidemic because most secondary cases were attributed to just 3 infectors. Even with the high incidence rate in early March, the Faroe Islands successfully eliminated the first wave of COVID-19 through the early use of contact tracing, quarantine, social distancing, and large-scale testing.

Incidence, gender influence, and neuropsychological predictors of all cause dementia in the Faroe Islands-the Faroese Septuagenarian cohort.

BACKGROUND: Using the Faroese Septuagenarian cohort, we aimed to describe the incidence of dementia and assess the validity of neurocognitive tests to predict subsequent dementia diagnosis. METHODS: In this population-based cohort, 713 Faroese septuagenarians aged 70-74 years without dementia, underwent clinical and neuropsychological examinations. After 10-years of follow-up, information was collected on all participants referred for cognitive evaluations and diagnosed with dementia. Incidence rates were calculated and presented with 95% confidence intervals (CIs), assuming a Poisson distribution. We then performed discriminant analysis to determine the best set of neuropsychological tests to identify those who would develop dementia. RESULTS: Over the 10-years, 65 participants (9.1%) were diagnosed with dementia, with a 10-year incidence rate of 1063 cases per 100,000 person years (95% CI 825, 1343). Women had a greater incidence than men (incidence rate ratio (IRR) = 1.58; 95% CI 0.93, 2.71). After stepwise selection, gender and six neuropsychological measures were selected to discriminate between those who would and would not develop dementia. Overall, the model was able to correctly identify 82% of those who would not develop dementia (specificity) and 71% of those who would (sensitivity). CONCLUSIONS: These results indicate that among a greater number of tests covering a broad range of cognitive abilities, tests reflecting verbal and visual learning and recall, visuospatial function, attention, and encoding into and retrieval from long-term memory may be helpful in identifying patients in the pre-symptomatic phase of dementia. Thus, helping care-givers identify patients at a higher risk of developing dementia and adjusting management of care accordingly.

Seroprevalence of SARS-CoV-2-Specific Antibodies, Faroe Islands.

We conducted a nationwide study of the prevalence of severe acute respiratory syndrome coronavirus 2 infection in the Faroe Islands. Of 1,075 randomly selected participants, 6 (0.6%) tested seropositive for antibodies to the virus. Adjustment for test sensitivity and specificity yielded a 0.7% prevalence. Our findings will help us evaluate our public health response.

Blood Harmane (1-Methyl-9H-Pyrido[3,4-b]indole) and Mercury in Essential Tremor: A Population-Based, Environmental Epidemiology Study in the Faroe Islands.

BACKGROUND: Essential tremor (ET) is among the most prevalent neurological diseases. Its environmental determinants are poorly understood. Harmane (1-methyl-9H-pyrido[3, 4-b]indole), a dietary tremor-producing neurotoxin, has been linked to ET in a few studies in New York and Madrid. Mercury, also a tremor-producing neurotoxin, has not been studied in ET. The Faroe Islands have been the focus of epidemiological investigations of numerous neurological disorders. OBJECTIVE: In this population-based, case-control study, we directly measured blood harmane concentrations (HA) and blood mercury concentrations (Hg) in ET cases and controls. METHODS: In total, 1,328 Faroese adults were screened; 26 ET cases were identified whose (HA) and (Hg) were compared to 197 controls. RESULTS: Although there were no statistically significant differences between diagnostic groups, median (HA) was 2.7× higher in definite ET (4.13 g-10/mL) and 1.5× higher in probable ET (2.28 g-10/mL) than controls (1.53 g-10/mL). Small sample size was a limitation. For definite ET versus controls, p = 0.126. (Hg) were similar between groups. CONCLUSIONS: We demonstrated marginally elevated (HA) in definite and probable ET. These data are similar to those previously published and possibly extend etiological links between this neurotoxin and ET to a third locale. The study did not support a link between mercury and ET.

Increased risk of sudden death in untreated primary carnitine deficiency.

Primary carnitine deficiency (PCD) affects fatty acid oxidation and is associated with cardiomyopathy and cardiac arrhythmia, but the risk of sudden death in PCD is unknown. The Faroe Islands have a high prevalence of PCD, 1:300. This study systematically investigated a possible association between untreated PCD and sudden death in young Faroese subjects. We investigated all medico-legal cases of sudden death between 1979 and 2012 among subjects below the age of 45. Stored biomaterial was examined with molecular genetic analysis to reveal PCD. We compared the prevalence of PCD among sudden death cases with that of the background population (0.23%) to calculate the odds ratio (OR) for sudden death with PCD. Biomaterial was available and genetically analyzed from 53 of 65 sudden death cases (82%) in the Faroe Islands. Six (one male and five females) of the 53 cases were homozygous for the PCD related c.95A>G mutation-a prevalence of 11.3% (95% CI 5%-23%) and an OR of 54.3 (95% CI 21-138, P < .0001) for the association between sudden death and untreated PCD. Only 11 of the 53 sudden death cases were women-of whom five were homozygous for the c.95A>G mutation (45.5%) yielding an OR of 348.8 (95% CI 94-1287, P < .0001) for the association between sudden death and untreated PCD in females. This study showed a strong association between sudden death and untreated PCD, especially in females.

Host age predicts parasite occurrence, richness, and nested infracommunities in a pilot whale-helminth network.

Ecological data on marine mammal parasites represent an excellent opportunity to expand our understanding of host-parasite systems. In this study, we used a dataset of intestinal helminth parasites on 167 long-finned pilot whales Globicephala melas (Traill, 1809) from seven localities in the Faroe Islands to evaluate the extent to which the host's age and sex influence the occurrence, richness, and nested pattern of helminth parasites and the importance of individual hosts to the helminth community. We found positive effects of age on both the occurrence and richness of helminths. Older host individuals showed an ordered accumulation of parasites, as evidenced by the nested pattern in their composition. Males had a higher occurrence of parasites than females, but the richness of helminths did not differ between sexes. Our findings suggest that differences in host-parasite interactions in long-finned pilot whales result mainly from age-structured variations in biological and behavioral characteristics.

Prevalence of Essential Tremor in the Faroe Islands: A Population-Based Study.

BACKGROUND: No studies of the prevalence of one of the most common movement disorders, essential tremor (ET), have been undertaken in the Faroe Islands. Given the potential for founder effects in the Islands, and the highly genetic nature of ET, the Faroe Islands provide a particularly interesting setting in which to study the prevalence of ET. OBJECTIVE: To estimate the prevalence of ET and study its characteristics. METHODS: We used a 2-phase, population-based design, screening 1,328 randomly selected Faroese individuals aged ≥40 years. A subsample of 282 individuals who had returned the spirals and questionnaire was selected to participate in an in-person clinical evaluation. Tremor was systematically quantified by a senior movement disorder neurologist with particular specialization in tremor using a reliable and valid clinical rating scale followed by the application of rigorous diagnostic criteria used by tremor investigators internationally. RESULTS: The overall crude prevalence was 2.9%. The age-adjusted prevalence was 3.1%. There was an age-associated rise in prevalence; by age ≥70, prevalence reached 4.8%. Twenty six of 27 (96.2%) were previously undiagnosed. CONCLUSIONS: This is the first population-based study of the prevalence of ET in the Faroe Islands. The estimated prevalence was similar to studies using the same or comparable methodologies.