COVID-19 and local community resilience in the Westfjords of Iceland

Remote Arctic communities have often been depicted as being particularly vulnerable to the challenges of disasters, with their location and lack of infrastructure exacerbating risk. This study explores the characteristics of local resilience in the Arctic using the case study of the communities of the north-western Westfjords. A total of 42 semi-structured interviews were carried out with various community members, seeking to uncover the features of inbuilt resilience that contribute to successes and vulnerabilities. These were transcribed, coded, and categorised in relation to an integrated framework for assessing community resilience in disaster management, which groups topics via the themes of environmental, social, governance, economic, and infrastructure. All themes played a role in the success of local coping strategies, with easy access to the natural environment central to physical and mental well-being. Despite this, vulnerabilities of the community were evident, including insufficient local healthcare workers during a severe COVID-19 outbreak in a care home, the absence of a local quarantine hotel, and insufficient information in foreign languages for non-natives of Iceland. The general trend of following rules and expert advice was demonstrative of strong social capital, with locals trusting those in charge, nationally and locally, to manage the pandemic.

Trends of perceived disruption in healthcare services during the pandemic: findings from the COVID-19 National Resilience Cohort in Iceland

BACKGROUND

Coronavirus disease 2019 (COVID-19) caused major disruptions in healthcare services worldwide. Yet, little is known about the association between perceived disruption in healthcare services and socio-demographic factors, pre-existing health conditions as well as concurrent physical and psychological symptoms.

METHODS

Leveraging data from the Icelandic COVID-19 National Resilience Cohort, we performed a repeated measure analysis among 15 754 participants who responded to the question on perceived disruption in healthcare services from December 2020 to July 2021, to explore its association with socio-demographic factors, health indicators and conditions. Furthermore, we performed a longitudinal analysis among 7848 participants with two repeated measures to explore the association between timing and duration of perceived disruption in healthcare services and changes in depression, anxiety, sleep quality and somatic symptoms.

RESULTS

The prevalence of perceived disruption in healthcare services slightly decreased over time (P < 0.01). Perceived disruption in healthcare services was more prevalent among individuals with pre-existing health conditions, i.e. history of psychiatric disorders (prevalence ratio = 1.59, 95% confidence interval 1.48-1.72) and chronic somatic conditions [1.40 (1.30-1.52)]. However, no increase in the prevalence of perceived disruption in healthcare services was observed among individuals diagnosed with COVID-19 [0.99 (0.84-1.18)]. Moreover, we found that emerging perceived disruption in healthcare services was associated with an increase in symptoms of mental illness during the pandemic (βs 0.06-0.68).

CONCLUSIONS

A disruption in healthcare services during the COVID-19 pandemic was reported by vulnerable groups, while the Icelandic healthcare system managed to maintain accessible services to individuals with COVID-19.

[Prevalence and Trends in Prepregnancy Overweight and Obesity in Northern Iceland 2004-2022]

INTRODUCTION

Prepregnancy overweight and obesity is an increasing public health issue worldwide, including Iceland, and has been associated with higher risk of adverse maternal and birth outcomes. The aim of this study was to investigate trends in prepregnancy weight amongst women in North Iceland from 2004 to 2022, and the prevalence of overweight and obesity in this population.

MATERIAL AND METHODS

This retrospective cross-sectional study included all women who gave birth at Akureyri Hospital in North Iceland between 2004 and 2022 (N = 7410). Information on age, parity, height, and prepregnancy weight was obtained from an electronic labour audit database. Body mass index (BMI) was calculated from self-reported height and weight, and the median BMI and proportions in each of the six BMI categories were calculated for four time periods.

RESULTS

Median BMI increased significantly from 24.5 kg/m2 in 2004-2008 to 26.2 kg/m2 in 2019-2022. On average, BMI increased by 0.15 kg/m2 with each passing year (p<0.001). The prevalence of normal weight decreased from 53% to 40% and the entire BMI distribution shifted towards a higher BMI. The proportion of women in obesity class I (BMI 30.0 - 34.9) increased from 12.8% to 17.3%, the proportion of women in obesity class II (BMI 35.0 - 39.9) doubled (3.7% to 8.1%) and tripled in obesity class III (BMI ≥ 40.0; 1.6% to 4.8%).

CONCLUSION

Prepregnancy weight of women in Northern Iceland has gradually increased over the last 19 years and 30% of pregnant women are now classified as obese. Further studies on the subsequent effects on maternal and birth outcomes are needed, with a focus on strategies to decrease adverse effects and reverse this trend.

[Anaesthesia for Emergent Caesarean Section: A Population-based Study on Icelandic and Migrant Women during 2007-2018]

INTRODUCTION

General anaesthesia for emergent caesarean section, though uncommon, is vital in expediting deliveries. Studies indicate higher complication risks among pregnant migrant women. This research investigates if migrant women in Iceland are more likely to undergo general anaesthesia for emergent caesarean section compared to their Icelandic counterparts.

MATERIALS AND METHODS

This population-based cohort study analysed 4,415 emergency caesarean sections in Iceland between 2007 and 2018, sourced from the National Birth Registry. Participants were categorized by citizenship, with migrants further stratified by their country's Human Development Index (HDI). NCSP-IS and ICD-10 codes indexed diseases, interventions, and complications. The impact of variables was assessed through multiple logistic regression analysis.

RESULTS

Migrant women received general anaesthesia in 16.1% of cases, slightly surpassing Icelandic women's 14.6%. Adjusting for risk factors showed no increased risk for migrant women. However, they had a higher likelihood of urgent caesarean sections (OR 1.45, 95% CI 1.08-1.94, p=0.015), a known risk factor for general anaesthesia, despite fewer comorbidities. Adjusting for confounders revealed reduced odds with a history of previous caesarean section (aOR 0.73, 95% CI 0.59-0.89, p=0.003) and placement of epidural anaesthesia in the delivery room (aOR 0.49, 95% CI 0.40-0.60, p< 0.001).

CONCLUSIONS

Migrant women in Iceland do not face increased risks of general anaesthesia for emergent caesarean sections. However, their elevated risk of urgent caesarean sections suggests potential challenges, including language barriers or inadequate antenatal care. Early information dissemination and targeted interventions may mitigate these risks in this vulnerable community.

Evaluating screening for autism spectrum disorder using cluster randomization

We evaluated the rate of autism spectrum disorder (ASD) in a group invited to a screening program compared to the rates in two groups who received usual care. The population eligible for screening was all children in Iceland registered for their 30-month well-child visits at primary healthcare centers (PHCs) from March 1, 2016, to October 31, 2017 (N = 7173). The PHCs in the capital area of Reykjavik were the units of cluster randomization. Nine PHCs were selected for intervention (invited group), while eight PHCs received usual care (control group 1). PHCs outside the capital area were without randomization (control group 2). An interdisciplinary team, including a pediatrician contributing with physical and neurological examination, a psychologist evaluating autism symptoms using a diagnostic instrument, and a social worker interviewing the parents, reached a consensus on the clinical diagnosis of ASD according to the ICD-10 diagnostic system. Children in the population were followed up for at least two years and 119 cases were identified. The overall cumulative incidence of ASD was 1.66 (95% confidence interval (CI): 1.37, 1.99). In the invited group the incidence rate was 2.13 (95% CI: 1.60, 2.78); in control group 1, the rate was 1.83 (95% CI: 1.31, 2.50); and in control group 2, the rate was 1.02 (95% CI: 0.66, 1.50). Although the rate of ASD was higher in the invited group than in the control groups, the wide confidence intervals prevented us from concluding definitively that the screening detected ASD more readily than usual care.

Influenza vaccination in pregnant women in Iceland 2010-2020 and the burden of influenza in pregnant women and their infants

INTRODUCTION

Influenza vaccinations are recommended in pregnancy to protect both the pregnant woman and the unborn baby. The aim of this study was to assess the influenza vaccine uptake among pregnant women in Iceland in ten influenza seasons and to estimate the influenza disease burden on pregnant women and their infants.

METHODS

This was a retrospective, descriptive study on influenza vaccine uptake among pregnant women and the burden of influenza and influenza-like illness (ILI) among pregnant women and their infants in ten influenza seasons. All women attending a 20-week ultrasound at Landspitali University Hospital in Reykjavik in August-April each influenza season 2010-2020 were included in the study. Data on influenza vaccinations and influenza/ILI diagnoses was collected from central national databases.

RESULTS

The influenza vaccine uptake increased from 6.2 % in 2011-2012 to 37.5 % in 2019-2020. The incidence rate of influenza/ILI among pregnant women ranged from 5.5 to 22.1/1000 person-years. The estimated vaccine effectiveness in the ten influenza seasons was 34-100 %. The incidence rate of influenza/ILI among infants < 12 months of age was 0-13.4/1000 person-years. Influenza vaccinations in pregnancy are protective against influenza/ILI in pregnant women (IRR 0.36, 95 % CI 0.22-0.58), infants in the season of vaccination (IRR 0.40, 95 % CI 0.17-0.97) and probably for infants < 6 months of age (IRR 0.51, 95 % CI 0.22-1.21).

CONCLUSIONS

Influenza vaccine coverage in pregnancy is suboptimal. Influenza vaccinations in pregnancy provide significant protection against influenza/ILI for pregnant women and infants in the season of vaccination. Initiatives to improve maternal vaccination coverage are needed.

First species record of Strigea falconis Szidat, 1928 (Trematoda, Strigeidae) from gyrfalcon Falco rusticolus in Iceland-pros and cons of a complex life cycle

Strigea falconis is a common parasite of birds of prey and owls widely distributed in the Holarctic. We aimed to characterise S. falconis from Iceland via integrative taxonomic approach and to contribute to the understanding of its circulation in the Holarctic. We recovered adult S. falconis from two gyrfalcons (Falco rusticolus) collected in 2011 and 2012 in Iceland (Reykjanes Peninsula, Westfjords) and characterised them by morphological and molecular genetic (D2 of rDNA, cox1, ND1 of the mDNA) methods. We provide the first species record of S. falconis in Iceland which to the best of our knowledge is its northernmost distributional range. The presence of S. falconis in Iceland is surprising, as there are no suitable intermediate hosts allowing completion of its life cycle. Gyrfalcons are fully sedentary in Iceland; thus, the only plausible explanation is that they acquired their infection by preying upon migratory birds arriving from Europe. Our data indicate that the most likely candidates are Anseriformes and Charadriiformes. Also, we corroborate the wide geographical distribution of S. falconis, as we found a high degree of similarity between our haplotypes and sequences of mesocercariae from frogs in France and of a metacercaria from Turdus naumanni in Japan, and adults from Buteo buteo and Circus aeruginosus from the Czech Republic. The case of Strigea falconis shows the advantages of a complex life cycle and also depicts its pitfalls when a parasite is introduced to a new area with no suitable intermediate hosts. In Iceland, gyrfalcons are apparently dead-end hosts for S. falconis.

Long COVID in Icelandic Children: A Matched Cohort Study of Nonspecific Symptoms Following SARS-CoV-2 Infection

PURPOSE

Pediatric severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections are usually mild and the mortality rates are low, but concerns have been raised about long-term symptoms that may resemble other postinfectious syndromes. Studies with robust control groups and high response rates have been few.

METHODS

We obtained identifiers for all 837 Icelandic children diagnosed with SARS-CoV-2 by PCR between March 2020 and June 2021 and contacted them by telephone. We asked about 10 physical and mental symptoms being present at least twice weekly for at least 2 months. Participants who reported symptoms were contacted again a year later. For each subject who completed the questionnaire, an age- and sex-matched comparator without SARS-CoV-2 infection was asked to complete the same questionnaire, and the risk difference was calculated.

RESULTS

Responses from 643 cases and 602 comparators were analyzed. Children who had been infected with SARS-CoV-2 were more likely to report one or more symptoms, except for anxiety/depression and sleep disturbances. Fatigue and loss of concentration were evidently more common in cases among teenagers (risk difference: 15%; 95% CI: 7-22% and 15%; 95% CI: 7-23%, respectively). At the second follow-up, close to a third of Long COVID cases had resolved but some participants had developed new persistent symptoms.

CONCLUSION

Symptoms of Long COVID in children are common and impact their quality of life. The importance of further unraveling the pathophysiology of acute and long-term symptoms following SARS-CoV-2 infection in children is vital as well as potential preventive measures.

Increase in invasive Streptococcus pyogenes M1 infections with close evolutionary genetic relationship, Iceland and Scotland, 2022 to 2023

Group A Streptococcus isolates of the recently described M1UK clade have emerged to cause human infections in several European countries and elsewhere. Full-genome sequence analysis of M1 isolates discovered a close genomic relationship between some isolates from Scotland and the majority of isolates from Iceland causing serious infections in 2022 and 2023. Phylogenetic analysis strongly suggests that an isolate from or related to Scotland was the precursor to an M1UK variant responsible for almost all recent M1 infections in Iceland.

[Perinatal outcomes of preterm births occuring to native-born and migrant mothers in Iceland]

INTRODUCTION

The aim of this study was to assess the incidence and perinatal outcomes of preterm births in Iceland during 1997-2018 and compare outcomes of Icelandic and migrant mothers.

METHODS

The population in this historical population-based cohort study was all preterm (p<37 weeks gestation) live-born singletons born in Iceland from January 1, 1997 to December 31, 2018 and their mothers; a total of 3837 births. Data was obtained from the Icelandic Medical Birth Registry. The group of migrant women was defined as women with other citizenship than Icelandic. Migrant women were divided into three groups based on their country of citizenship Human Development Index (HDI). Both descriptive and analytical statistics were used in data processing.

RESULTS

The incidence of preterm births in Iceland increased during the study period (3,9% 1998-2001 vs. 4,5% 2012-2018, p<005) and was significantly higher among migrant mothers, especially from countries with the lowest HDI (OR 1,49 (CI 1,21-1,81) p<,001). Infants of mothers from countries with the lowest HDI had a significantly lower prevalence of respiratory distress syndrome compared with infants of Icelandic mothers (4,5% vs. 11,4%, p=0,035) meanwhile infants of mothers from countries with a medium high HDI were more often small for gestational age compared with infants of Icelandic mothers (11,4% vs. 6,9%, p=0,021).

CONCLUSION

Preterm births have become more common in Iceland and the incidence is significantly higher among migrant mothers, however the outcomes of preterm infants are generally good and mostly comparable between Icelandic and migrant mothers.

Respiratory symptoms, exacerbations and sleep disturbances are more common among participants with asthma and chronic airflow limitation: an epidemiological study in Estonia, Iceland and Sweden

BACKGROUND

Chronic airflow limitation (CAL) is a hallmark of chronic obstructive pulmonary disease but is also present in some patients with asthma. We investigated respiratory symptoms, sleep and health status of participants with and without CAL with particular emphasis on concurrent asthma using data from adult populations in Iceland, Estonia and Sweden investigated within the Burden of Obstructive Lung Disease study.

METHODS

All participants underwent spirometry with measurements of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) before and after bronchodilation. CAL was defined as postbronchodilator FEV1/FVC below the lower limit of normal. IgE-sensitisation and serum concentrations of eosinophil-derived neurotoxin (S-EDN) were assessed in a subsample. The participants were divided into four groups: no self-reported doctor's diagnosed asthma or CAL, asthma without CAL, CAL without asthma and asthma and CAL: χ2 test and analysis of variance were used in bivariable analyses and logistic and linear regression when analysing the independent association between respiratory symptoms, exacerbations, sleep-related symptoms and health status towards CAL, adjusting for centre, age, sex, body mass index, smoking history and educational level.

RESULTS

Among the 1918 participants, 190 (9.9%) had asthma without CAL, 127 (6.6%) had CAL without asthma and 50 (2.6%) had CAL with asthma. Having asthma with CAL was associated with symptoms such as wheeze (adjusted OR (aOR) 6.53 (95% CI 3.53 to 12.1), exacerbations (aOR 12.8 (95% CI 6.97 to 23.6), difficulties initiating sleep (aOR 2.82 (95% CI 1.45 to 5.48), nocturnal gastro-oesophageal reflux (aOR 3.98 (95% CI 1.79 to 8.82)) as well as lower physical health status. In these analyses, those with no asthma and no CAL were the reference group. The prevalence of IgE-sensitisation was highest in both asthma groups, which also had higher levels of S-EDN.

CONCLUSION

Individuals with self-reported asthma with CAL suffer from a higher burden of respiratory and sleep-related symptoms, higher exacerbation rates and lower health status when compared with participants with asthma alone or CAL alone.

[Insulin Resistance and Abnormalities in Blood Values of Icelandic Children Receiving Obesity Treatment]

INTRODUCTION

Worldwide, the rates of childhood obesity have risen dramatically in recent decades. Obesity may cause serious sequelae during childhood and throughout adulthood. Insulin resistance is prevalent metabolic abnormality in pediatric obesity. The Pediatric Obesity Clinic was established in 2011 at the Children's Medical Center, Landspítali University Hospital. This study aimed to observe metabolic abnormalities and insulin resistance in blood values of children receiving obesity treatment.

METHODS

The study included all children (n = 180) who received obesity treatment at The Pediatric Obesity Clinic between 2016 and 2020 and had at least eight out of the nine following serum values analyzed while fasting: HbA1c, glucose, insulin, ALAT, total cholesterol, HDL-cholesterol, triglycerides, TSH and free T4. HOMA-IR value was calculated from insulin and glucose values. Decreased insulin sensitivity was defined as HOMA-IR > 3.42.

RESULTS

84% of the children had at least one abnormality in their tested blood values. 50% had abnormal insulin values and 44% had abnormal ALAT values. 78% had decreased insulin sensitivity, and their mean HOMA-IR was 7.3 (± 5.0), surpassing twice the normal value.

CONCLUSION

A large majority of the children undergoing obesity treatment already exhibited signs of metabolic sequelae during their treatment. The prevalence of affected children has increased compared to a similar study conducted in 2013. Of particular concern is the growing number of children with decreased insulin sensitivity. Proper measures must be taken to combat this alarming trend.

[Lower Limb Amputations in Patients with Peripheral Arterial Disease and/or Diabetes in Iceland 2010-2019; revascularisation, comorbidities and risk factors]

INTRODUCTION

No recent studies exist on lower extremity amputations (LLAs) in Iceland. The aim of this study was to investigate LLA incidence in Iceland 2010-2019 and preceding procedures in amputations induced by peripheral arterial disease (PAD) and diabetes mellitus (DM).

MATERIAL AND METHODS

Retrospective study on clinical records of all patients (>18 years) who underwent LLA in Iceland's two main hospitals during 2010-2019. Patients were excluded if LLA was performed for reasons other than DM and/or PAD. Symptoms, medication and circulation assessment were recorded from first hospital visit due to symptoms, and prior to the last LLA, respectively. Previous arterial surgeries and amputations were also recorded.

RESULTS

A total of 167 patients underwent LLA. Thereof, 134 (77 ± 11 years, 93 men and 41 woman) due to DM and/or PAD. The LLA-rate due to those diseases increased from 4.1/100,000 inhabitants in 2010-2013 to 6.7/100,000 in 2016-2019 (p=0,04). Risk factors were mainly hypertension, 84%, and smoking, 69%. Chronic limb-threatening ischemia induced 71% of first hospital visits. Revascularisations were performed (66% endovascular) in 101 patients. Non-diabetic patients were 52% and had statins less frequently prescribed than DM patients (26:45, p<0.001).

CONCLUSION

DM and/or PAD are the leading causes of LLA in Iceland. Amputation rate increased during the period but is low in an international context. Amputation is most often preceded by arterial surgery. DM is present in almost half of cases, similar or less than in most other countries. Opportunities for improved prevention should aim on earlier diagnosis and preventive treatment of non-diabetic individuals with PAD.

A population-based survey of FBN1 variants in Iceland reveals underdiagnosis of Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant condition characterized by aortic aneurysm, skeletal abnormalities, and lens dislocation, and is caused by variants in the FBN1 gene. To explore causes of MFS and the prevalence of the disease in Iceland we collected information from all living individuals with a clinical diagnosis of MFS in Iceland (n = 32) and performed whole-genome sequencing of those who did not have a confirmed genetic diagnosis (27/32). Moreover, to assess a potential underdiagnosis of MFS in Iceland we attempted a genotype-based approach to identify individuals with MFS. We interrogated deCODE genetics' database of 35,712 whole-genome sequenced individuals to search for rare sequence variants in FBN1. Overall, we identified 15 pathogenic or likely pathogenic variants in FBN1 in 44 individuals, only 22 of whom were previously diagnosed with MFS. The most common of these variants, NM_000138.4:c.8038 C > T p.(Arg2680Cys), is present in a multi-generational pedigree, and was found to stem from a single forefather born around 1840. The p.(Arg2680Cys) variant associates with a form of MFS that seems to have an enrichment of abdominal aortic aneurysm, suggesting that this may be a particularly common feature of p.(Arg2680Cys)-associated MFS. Based on these combined genetic and clinical data, we show that MFS prevalence in Iceland could be as high as 1/6,600 in Iceland, compared to 1/10,000 based on clinical diagnosis alone, which indicates underdiagnosis of this actionable genetic disorder.

Potential impact of natural conditions on the rostral oral health: a study of horses in Iceland

OBJECTIVE

In the context of a study of Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH), elderly Icelandic horses were examined in their originating country. The subject of this survey was the impact of dental treatment and keeping and feeding management on the health of the rostral oral cavity.

ANIMALS

A total of 170 horses (aged ≥ 15) located in different areas of Northwest, West, and South Iceland.

METHODS

The horse owners completed a questionnaire about keeping, feeding, and preventative dental care. The horses were clinically examined with particular attention to gingival and dental disorders of the rostral mouth, such as gingivitis, fistula, gingiva retraction, enlargement of the roots and dental calculus as well as integrity of incisors, bite angle, and tooth mobility.

RESULTS

Most of the horses were kept on pasture all year with little supplementary feeding. The frequency of dental treatment in Iceland was low. Only a few horses were affected by tooth loss, gingivitis, gingival recession, and incisor calculus. Calculus occurred more frequently and more severely in canines than in incisors. The findings did not depend on the location of the horse.

CLINICAL RELEVANCE

Assuming that the remarkable health of the rostral oral cavity in elderly Icelandic horses was not caused by preventive dental care, it is likely that it was due to living conditions in Iceland. Continuity, intensity of chewing, and nativeness of forage might promote the health of incisors and tissue surrounding the tooth even in elderly horses.

[Breastfeeding in Iceland: Changes in prevalence and duration over a century]

INTRODUCTION

Worldwide, the health-promoting effects of breastfeeding on children and their mothers are indisputable. The frequency and duration of breastfeeding varies greatly internationally but studies on prevalence and influencing factors of breastfeeding in Iceland are scanty and the published ones deal with small groups. The aim of this research is to describe the epidemiology of breastfeeding duration and its influencing factors in Iceland among a large cohort in a whole population over almost one century.

MATERIAL AND METHODS

This is a historical cohort study, using data from The Cancer Detection Clinic Cohort of The Icelandic Cancer Society, collected retrospectively by questionnaires during the years 1964-2008. The data consisted of mothers´ reported information on breastfeeding of their 81,889 children, 36,537 first-borns and 45,352 younger siblings. The frequency and duration of breastfeeding was calculated and the effects of the following exposure variables were assessed: Maternal age, BMI (N=4950, data collected 1979-2008) and smoking (N=32.087, data collected 1995-2008), the child's year of birth and its order in the sibling group.

RESULTS

The children were born in the period of 1917-2008. In the late 1970s, the average duration of breastfeeding began to increase, in all age groups of mothers, increasing rapidly from 3 months to 7-8 months. At about the same time, the breastfeeding duration increased depending on the birth order of the children, younger children were breastfed for longer than their older siblings. Women with normal weight (BMI 18.5 to 24.9) breastfed their babies the longest, while obese women breastfed the shortest. Women with any history of smoking reported shorter duration of breastfeeding than women who had never smoked.

CONCLUSION

The increase in the average duration of breastfeeding in Iceland a few decades ago is in accordance with the information in the World Health Organization's database from European countries 1975-2000, where the Nordic countries and most Northern European countries promoted breastfeeding at a similar time. High BMI and maternal smoking are important variables when studying breastfeeding and this study indicates their negative association with the duration of breastfeeding.

Association between adverse childhood experiences and perinatal depressive symptoms: a cross-sectional analysis of 16,831 women in Iceland

Emerging data suggest that certain adverse childhood experiences (ACEs) are associated with perinatal depression (PND). However, few studies have comprehensively assessed the cumulative number and types of ACEs and their association to PND. We conducted a cross-sectional analysis among 16,831 female participants from the Stress-And-Gene-Analysis (SAGA) cohort in Iceland, 2018. ACEs were surveyed with the World Health Organization ACE-International questionnaire, while PND symptoms were assessed using the Edinburgh Postnatal Depression Scale (lifetime version). We, while adjusting for confounding factors, estimated the prevalence ratio (PR) of PND in relation to total number of ACEs using the Poisson quasi-likelihood model and further performed analyses for type-specific ACEs. At a mean age of 44 years (SD ± 11.1), 6,201 (36.8%) participants had experienced probable PND. Total number of ACEs was positively associated with PND (PR 1.11 per ACE, 95% CI: 1.10-1.11), also among women without any psychiatric comorbidities (PR 1.13, 95% CI: 1.11-1.14). PRs increased in a dose-response manner with the number of ACEs (P for trend < 0.001); women that endorsed 5 or more ACEs were twice as likely to have experienced PND (PR 2.24, 95% CI: 2.09-2.41). All ACE types (n = 13) were associated with PND, with most pronounced association for emotional neglect by a guardian (PR 1.53, 95% CI: 1.47-1.59). Our findings suggest a positive association between number of ACEs and PND symptoms. If our results are confirmed with prospective data, healthcare providers need to be alert of the risk of PND among expecting mothers with history of ACEs.

Actionable Genotypes and Their Association with Life Span in Iceland

BACKGROUND

In 2021, the American College of Medical Genetics and Genomics (ACMG) recommended reporting actionable genotypes in 73 genes associated with diseases for which preventive or therapeutic measures are available. Evaluations of the association of actionable genotypes in these genes with life span are currently lacking.

METHODS

We assessed the prevalence of coding and splice variants in genes on the ACMG Secondary Findings, version 3.0 (ACMG SF v3.0), list in the genomes of 57,933 Icelanders. We assigned pathogenicity to all reviewed variants using reported evidence in the ClinVar database, the frequency of variants, and their associations with disease to create a manually curated set of actionable genotypes (variants). We assessed the relationship between these genotypes and life span and further examined the specific causes of death among carriers.

RESULTS

Through manual curation of 4405 sequence variants in the ACMG SF v3.0 genes, we identified 235 actionable genotypes in 53 genes. Of the 57,933 participants, 2306 (4.0%) carried at least one actionable genotype. We found shorter median survival among persons carrying actionable genotypes than among noncarriers. Specifically, we found that carrying an actionable genotype in a cancer gene was associated with survival that was 3 years shorter than that among noncarriers, with causes of death among carriers attributed primarily to cancer-related conditions. Furthermore, we found evidence of association between carrying an actionable genotype in certain genes in the cardiovascular disease group and a reduced life span.

CONCLUSIONS

On the basis of the ACMG SF v3.0 guidelines, we found that approximately 1 in 25 Icelanders carried an actionable genotype and that carrying such a genotype was associated with a reduced life span. (Funded by deCODE Genetics-Amgen.).

[Pneumococcal meningitis in children in Iceland - case report and summary]

An eleven month old girl was referred to the pediatric emergency department at Landspitali Hospital due to fever and lethargy. On examination she was acutely ill with fluctuating level of conciousness. She deteriorated quickly after arrival at the emergency department and was diagnosed with pneumococcal meningitis. In the past year several cases of bacterial meningitis have been diagnosed with Streptococcus pneumoniae as the most common pathogen. The disease causing serotypes have been serotypes that were not in the vaccine that was used in iceland and the Icelandic health authorities have decided to change the vaccination programme accordingly.

Nordic region suicide trends 2000-2018; sex and age groups

BACKGROUND AND AIM

Overall, suicide rates in the Nordic region, Denmark, Finland, Iceland, Norway and Sweden, have declined in the past 40 years. The aim of this study was to determine trends in suicide mortality from 2000 to 2018.

METHODS

Data were obtained from official suicide statistics for men and women, 15 years and older. Gender and age groups in four calendar periods were analyzed using Joinpoint Estimated Regression Coefficient.

RESULTS

The crude regional suicide rate was 17.1, 2000-2004, decreased to 14.1 per 100,000 inhabitants in 2015-2018. Age-standardized rates are 13.6-11.3. The crude rate decreased by 19.5% (16.3% age-standardized), 19.3% for males and 20.5% for females. The largest decrease was found in Finland (34.9%), the smallest in Norway (1.4%). In males, the exception was an increased suicide rate among all Icelandic except 15-24-year olds, and in 45-64 year-old Norwegians. Among females, an increase was seen among 15-24-year olds in all countries except Iceland, in all age groups in Norway, and in 25-44-year olds in Sweden. In males, a decline of the suicide rated lower than 10% was noted in 25-44 olds in Norway and in 15-64 year-olds in Sweden.

DISCUSSION

A robust decrease was observed in the overall regional suicide rate in recent years. Exceptions are rising rates in Icelandic males, in Norwegian females, and the youngest female groups in all except Iceland. The small decline among middle-aged males in Norway and Sweden is of concern.

Twin birth rates and obstetric interventions in Iceland: A nationwide study from 1997 to 2018

OBJECTIVE

Twin pregnancies are associated with increased antepartum and intrapartum risks. Limited multiple embryo transfers are associated with decreased twin birth rates. We aimed to study the effect of 2009 Icelandic regulations on twin birth rates and examine obstetric intervention rates for twin births during the study period.

METHODS

The study included all births (N = 94 028) in Iceland during 1997-2018. Twin birth rates and obstetric intervention rates were compared over birth year periods using modified Poisson regression adjusted for confounders.

RESULTS

An observed decrease in the twin birth rate trend was most notable from 2006 until 2009. Twin birth decreased in 2009-2013 (prevalence ratio [PR] 0.74, 95% confidence interval [CI] 0.64-0.86) and in 2014-2018 (PR 0.74, 95% CI 0.64-0.86) compared with 1997-2002. This decrease was only evident for women aged 30+ years in stratified analysis. Induction of labor rates increased from 26% in 1997-2002 to 44% in 2014-2018 (adjusted rate ratio [ARR] 2.10, 95% CI 1.72-2.57) whereas elective cesarean section (ARR 0.80, 95% CI 0.59-1.07) and urgent cesarean section (ARR 0.79, 95% CI 0.63-1.00) rates appeared to decline.

CONCLUSION

Twin births decreased during the study period. International guidelines published before the Icelandic regulations may have affected twin birth rates in Iceland. Induction of labor rates for twins increased while cesarean section rates decreased.

Association of eGFR and mortality with use of a joint model: results of a nationwide study in Iceland

OBJECTIVES

Prior studies on the association of estimated glomerular filtration rate (eGFR) and mortality have failed to include methods to account for repeated eGFR determinations. The aim of this study was to estimate the association between eGFR and mortality in the general population in Iceland employing a joint model.

METHODS

We obtained all serum creatinine and urine protein measurements from all clinical laboratories in Iceland in the years 2008-16. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation and categorized as follows: 0-29, 30-44, 45-59, 60-74, 75-89, 90-104 and >104 mL/min/1.73 m2. A multiple imputation method was used to account for missing urine protein data. A joint model was used to assess risk of all-cause mortality.

RESULTS

We obtained 2 120 147 creatinine values for 218 437 individuals, of whom 84 364 (39%) had proteinuria measurements available. Median age was 46 (range 18-106) years and 47% were men. Proteinuria associated with increased risk of death for all eGFR categories in persons of all ages. In persons ≤65 years, the lowest risk was observed for eGFR of 75-89 mL/min/1.73 m2 without proteinuria. For persons aged >65 years, the lowest risk was observed for eGFR of 60-74 mL/min/1.73 m2 without proteinuria. eGFR of 45-59 mL/min/1.73 m2 without proteinuria did not associate with increased mortality risk in this age group. eGFR >104 mL/min/1.73 m2 associated with increased mortality.

CONCLUSIONS

These results lend further support to the use of age-adapted eGFR thresholds for defining chronic kidney disease. Very high eGFR needs to be studied in more detail with regard to mortality.

Meningococcal carriage in children and young adults: a cross-sectional and longitudinal study, Iceland, 2019 to 2021

BackgroundNeisseria meningitidis is a commensal bacterium which can cause invasive disease. Colonisation studies are important to guide vaccination strategies.AimThe study's aim was to determine the prevalence of meningococcal colonisation, duration of carriage and distribution of genogroups in Iceland.MethodsWe collected samples from 1 to 6-year-old children, 15-16-year-old adolescents and 18-20-year-old young adults. Carriers were sampled at regular intervals until the first negative swab. Conventional culture methods and qPCR were applied to detect meningococci and determine the genogroup. Whole genome sequencing was done on groupable meningococci.ResultsNo meningococci were detected among 460 children, while one of 197 (0.5%) adolescents and 34 of 525 young adults (6.5 %) carried meningococci. Non-groupable meningococci were most common (62/77 isolates from 26/35 carriers), followed by genogroup B (MenB) (12/77 isolates from 6/35 carriers). Genogroup Y was detected in two individuals and genogroup W in one. None carried genogroup C (MenC). The longest duration of carriage was at least 21 months. Serial samples from persistent carriers were closely related in WGS.ConclusionsCarriage of pathogenic meningococci is rare in young Icelanders. Non-groupable meningococci were the most common colonising meningococci in Iceland, followed by MenB. No MenC were found. Whole genome sequencing suggests prolonged carriage of the same strains in persistent carriers.

Wood mouse (Apodemus sylvaticus L.) as intermediate host for Mesocestoides canislagopodis (Rudolphi, 1810) (Krabbe 1865) in Iceland

Mesocestoides canislagopodis is a common parasite of the arctic fox (Vulpes lagopus) in Iceland. In the past, household dogs (Canis familiaris) and cats (Felis catus) were also reported in Iceland to be infected. Recently, scolices of a non-maturing Mesocestoides sp. were detected in the intestines of the gyrfalcon (Falco rusticolus), and tetrathyridia were isolated in the body cavity of rock ptarmigan (Lagopus muta) and subsequently described. All stages were confirmed, using both morphological and molecular methods, to belong to the same species, M. canislagopodis. In the present study, post-mortem examination of wood mice (Apodemus sylvaticus), sampled in autumn 2014 on a farm in Northeast Iceland, revealed the presence of tetrathyridia in the peritoneal cavity and in the liver. Most tetrathyridia in the peritoneal cavity were free, but some were encapsulated in a thin connective tissue stroma and loosely attached to the inner organs. They appear as whitish, heart-shaped, flattened, unsegmented bodies with a slightly pointed posterior end. In the liver, tetrathyridia were seen as pale-tanned nodules embedded in the parenchyma. Comparative molecular analysis, both at the generic level (D1 domain LSU ribosomal DNA), and at the specific level (cytochrome c oxidase subunit I (cox1) and 12S mitochondrial DNA), revealed that the tetrathyridia belonged to M. canislagopodis. A. sylvaticus represents a new second intermediate host record in Iceland, and the first description of a rodent as intermediate host for this species, thus participating in the life cycle of the parasite.

[The many faces of Group A Streptococcal infections, case-series of invasive infections in children in Iceland]

In recent months the incedence of invasive group A streptococcal infections (Streptococcus pyogenes) has increased worldwide. In the Children's Hospital Iceland 20 such cases were admitted during a four month period, until which time the avarage was one or two children admitted with an invasive GAS infection per year. To demonstrate the variability in the presentation of these invasive infections four cases were chosen for discussion in this case-series. Empyema with toxic shock syndrome, meningitis, orbital abscess and fascitis of the leg are reviewed.

Evaluation of Large-Scale Proteomics for Prediction of Cardiovascular Events

Importance

Whether protein risk scores derived from a single plasma sample could be useful for risk assessment for atherosclerotic cardiovascular disease (ASCVD), in conjunction with clinical risk factors and polygenic risk scores, is uncertain.

Objective

To develop protein risk scores for ASCVD risk prediction and compare them to clinical risk factors and polygenic risk scores in primary and secondary event populations.

Design, Setting, and Participants

The primary analysis was a retrospective study of primary events among 13 540 individuals in Iceland (aged 40-75 years) with proteomics data and no history of major ASCVD events at recruitment (study duration, August 23, 2000 until October 26, 2006; follow-up through 2018). We also analyzed a secondary event population from a randomized, double-blind lipid-lowering clinical trial (2013-2016), consisting of individuals with stable ASCVD receiving statin therapy and for whom proteomic data were available for 6791 individuals.

Exposures

Protein risk scores (based on 4963 plasma protein levels and developed in a training set in the primary event population); polygenic risk scores for coronary artery disease and stroke; and clinical risk factors that included age, sex, statin use, hypertension treatment, type 2 diabetes, body mass index, and smoking status at the time of plasma sampling.

Main Outcomes and Measures

Outcomes were composites of myocardial infarction, stroke, and coronary heart disease death or cardiovascular death. Performance was evaluated using Cox survival models and measures of discrimination and reclassification that accounted for the competing risk of non-ASCVD death.

Results

In the primary event population test set (4018 individuals [59.0% women]; 465 events; median follow-up, 15.8 years), the protein risk score had a hazard ratio (HR) of 1.93 per SD (95% CI, 1.75 to 2.13). Addition of protein risk score and polygenic risk scores significantly increased the C index when added to a clinical risk factor model (C index change, 0.022 [95% CI, 0.007 to 0.038]). Addition of the protein risk score alone to a clinical risk factor model also led to a significantly increased C index (difference, 0.014 [95% CI, 0.002 to 0.028]). Among White individuals in the secondary event population (6307 participants; 432 events; median follow-up, 2.2 years), the protein risk score had an HR of 1.62 per SD (95% CI, 1.48 to 1.79) and significantly increased C index when added to a clinical risk factor model (C index change, 0.026 [95% CI, 0.011 to 0.042]). The protein risk score was significantly associated with major adverse cardiovascular events among individuals of African and Asian ancestries in the secondary event population.

Conclusions and Relevance

A protein risk score was significantly associated with ASCVD events in primary and secondary event populations. When added to clinical risk factors, the protein risk score and polygenic risk score both provided statistically significant but modest improvement in discrimination.

Nasopharyngeal competition dynamics are likely to be altered following vaccine introduction: bacteriocin prevalence and diversity among Icelandic and Kenyan pneumococci

Bacteriocins are antimicrobial peptides produced by bacteria to inhibit other bacteria in the surrounding environment. Streptococcus pneumoniae is a leading cause of disease worldwide and colonises the healthy human nasopharynx, where it competes for space and nutrients. Pneumococcal conjugate vaccines have reduced the incidence of disease, but they also restructure the bacterial population, and this restructuring likely alters the nasopharyngeal competition dynamics. Here, the distribution of bacteriocins was examined in over 5000 carriage and disease-causing pneumococci from Iceland and Kenya, recovered before and after the introduction of pneumococcal vaccination. Overall, up to eleven different bacteriocin gene clusters were identified per pneumococcus. Significant differences in the prevalence of bacteriocins were observed before and after vaccine introduction, and among carriage and disease-causing pneumococci, which were largely explained by the bacterial population structure. Genetically similar pneumococci generally harboured the same bacteriocins although sometimes different repertoires of bacteriocins were observed, which suggested that horizontal transfer of bacteriocin clusters had occurred. These findings demonstrated that vaccine-mediated changes in the pneumococcal population altered the prevalence and distribution of bacteriocins. The consequences of this for pneumococcal colonisation and disease remain to be determined.

Development of severe alcohol related liver disease over four decades in Iceland: impact of increased access and use of alcohol

OBJECTIVE

Limited data exist on the association between per capita alcohol consumption and incidence of alcohol related liver disease (ARLD). The aims were to analyse this relationship and assess prevalence of ARLD in Iceland and among patients treated for alcohol use disorder (AUD) and its impact on outcomes.

METHODS

A retrospective study on all patients diagnosed with severe ARLD: alcohol related cirrhosis (ARC) and alcohol related hepatitis (ARH) in Iceland 1984-2020. Medical records were scrutinized for clinical features, severity of ARLD, proportion undergoing treatment for AUD, data on abstinence and long-term outcomes.

RESULTS

A total of 314 patients, males 76%, median age 56 years, fulfilled the predetermined criteria for ARLD. Median MELD was 17, 73% with Child-Pugh B/C and 70/314 (22%) who had ARH. Incidence of ARLD increased from 0.77 cases per 100 000 inhabitants annually 1984-2000 to 6.1 per 100 000 in 2016-2020. Per capita alcohol consumption increased from 4.3 Liters to 7.5 L in in the same time periods. Overall 220/314 (70%) with ARLD had undergone treatment for AUD. Of all individuals who had AUD treatment during the study period (n = 21.845), 1% were diagnosed with ARLD. Patients who underwent treatment for AUD after the ARLD diagnosis had better prognosis than those who had treatment prior to ARLD diagnosis (hazard ratio 2.5 [95% CI 1.3-5.0]).

CONCLUSIONS

The incidence of ARLD increased 8-fold during the study period coinciding with 74% increase in per capita alcohol consumption. Patients with prior diagnosis of AUD had worse prognosis that needs special attention.

Preliminary impact of the adoption of the Icelandic Prevention Model in Tarragona City, 2015–2019: A repeated cross-sectional study

Background

There is a great need for effective primary prevention intervention strategies to reduce and delay onset of adolescent substance use. The Icelandic Prevention Model (IPM) showed great success in Iceland over the past twenty plus years, however, evidence for the transferability of model is still somewhat limited. Using data collected in Tarragona during regional efforts to begin adoption of the IPM in Catalonia, this study tested the transferability and stability of the core risk and protective factor assumptions of the IPM overtime and examined trends of lifetime smoking, e-cigarette-use, alcohol-use, intoxication, and cannabis-use within the same time period.

Methods

This study includes responses from 15- to 16-years-olds from two region-wide samples taken in 2015 and 2019 in Tarragona (N = 2,867). Survey questions assessed frequency of lifetime: smoking, e-cigarette-use, alcohol-use, intoxication, and cannabis-use, and the core model assumptions. Demographic data were also collected. Logistic regression models of main effects with and without time interaction were used to test assumptions and their stability across time. Chi-square tests and Wilcoxon–Mann–Whitney U tests were used to compare prevalence of substance use and mean scores of primary prevention variables respectively.

Results

Lifetime: smoking (−7%, p &lt; 0.001) and cannabis-use (−4%, p &lt; 0.001) decreased, and e-cigarette-use increased (+33%, p &lt; 0.001) in Tarragona. Lifetime intoxication (−7%, p &lt; 0.001) decreased in a single zone exclusively. Most core model assumptions held in their hypothesised direction across time. The strongest positive association was observed between time spent with parents during weekends and reduced odds of lifetime smoking (OR: 0.62, 95%CI: 0.57–0.67) and the strongest negative association was observed between being outside after midnight and increased odds of lifetime intoxication (OR: 1.41, 95%CI: 1.32–1.51). Mean scores of primary prevention variables also changed disproportionately in Tarragona.

Conclusion

This study confirms that the core IPM assumptions are similar in Tarragona as in Iceland and other contexts previously examined. They also indicate that prevalence of lifetime smoking, intoxication, and cannabis-use decreased disproportionately in Tarragona between 2015 and 2019 during the first phase of regional adoption of the model. Thus, targeting model assumptions represents a viable primary prevention strategy for communities that hope to reduce smoking, alcohol-use, intoxication, and cannabis-use among adolescents.

Effect of the COVID-19 pandemic on adolescent mental health and substance use up to March, 2022, in Iceland: a repeated, cross-sectional, population-based study

BACKGROUND

Poor mental health in the first year of the COVID-19 pandemic has been well documented in adolescents; however, less is known about the longer-term effect of the pandemic. We aimed to examine adolescent mental health and substance use as well as covariates associated with these outcomes 1 year or more into the pandemic.

METHODS

A nationwide sample of adolescents aged 13-18 years enrolled in school in Iceland were invited to complete surveys administered during October-November or February-March, 2018, October-November, 2020, February-March or October-November, 2021, and February-March 2022. The survey was in Icelandic for all administrations and offered to adolescents aged 13-15 years in English in 2020 and 2022 and in Polish in 2022. Surveys assessed depressive symptoms (Symptom Checklist-90); mental wellbeing (Short Warwick Edinburgh Mental Wellbeing Scale); and the frequency of cigarette smoking, e-cigarette use, and alcohol intoxication. Covariates comprised age, gender, and migration status as determined by language spoken at home, level of social restrictions based on residency, parental social support, and sleep duration (≥8 h nightly). Weighted mixed-effect models were used to determine the effect of time and the covariates on mental health and substance use. The main outcomes were assessed in all participants with more than 80% of the necessary data, and multiple imputation was used to handle missing data. Bonferroni corrections were used to adjust for multiple testing and analyses were considered significant at a p value of <0·0017.

FINDINGS

64 071 responses were submitted and analysed between 2018 and 2022. Elevated depressive symptoms and worsened mental wellbeing across girls and boys aged 13-18 years were observed to have been maintained up to 2 years into the pandemic (p>0·0017). Alcohol intoxication initially decreased during the pandemic but increased again as social restrictions eased (p<0·0001). No changes were observed in cigarette smoking and e-cigarette use during the COVID-19 pandemic. Higher levels of parental social support and an average sleep duration of 8 h or more per night were associated with mental health better outcomes and less substance use (p<0·0001). Social restrictions and migration background were inconsistently associated with the outcomes.

INTERPRETATION

Population-level prevention targeting adolescent depressive symptoms should be prioritised in health policy in the wake of COVID-19.

FUNDING

Icelandic Research Fund.

Tetracapsuloides bryosalmonae and proliferative kidney disease in Icelandic salmonids - Comparative data from two different time periods

Tetracapsuloides bryosalmonae is a myxozoan parasite and the causative agent of proliferative kidney disease (PKD), a serious, temperature-dependent and emerging disease affecting salmonid fish. It was first identified in Iceland in 2008, from Arctic charr inhabiting a shallow lowland lake. The aim of this study was to investigate the distribution and prevalence of macroscopic and subclinical T. bryosalmonae infections in Icelandic salmonids and compare different time periods, in context with depths, volumes, altitudes and areas of the lakes and fish age. Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) from 34 lakes, sampled between 1994-1998 and 2009-2017, were examined for macroscopic signs of PKD (n = 2,151) and the presence of T. bryosalmonae infections (n = 1,424). In the earlier period, 43% of lakes (10/23) harboured T. bryosalmonae -infected fish. The mean prevalence in those lakes was 62.1%, being most common in shallow lowland lakes whilst deeper lakes at high altitudes were all free from infection. Only a single fish from one lake showed macroscopic signs of PKD, a shallow lowland lake in southwestern Iceland. In the latter period, T. bryosalmonae was found in 16/18 lakes studied (89%), with a mean prevalence of 78-79% (excluding T.b. free lakes), being most common in the smaller, shallower lakes at lower alttudes. Macroscopic signs of PKD were observed in 11 of 18 of the lakes studied (61%) with prevalences up to 67%, most common in younger fish inhabiting small shallow lowland lakes. The results indicate that the distribution of T. bryosalmonae and the presence of PKD in Iceland have increased over the last few decades. The disease was almost non-existent in the 1990s but has become very common during the last decade or two. With further water temperature increases, as predicted by climate models, PKD is likely to increasingly affect wild salmonid populations in Iceland.

Estimates of excess mortality for the five Nordic countries during the COVID-19 pandemic 2020-2021

BACKGROUND

Excess mortality during the COVID-19 pandemic is of major scientific and political interest.

METHODS

We critically reviewed different estimates of all-cause excess mortality for the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), which have been much studied during the COVID-19 pandemic, using the latest register data to discuss uncertainties and implications.

RESULTS

We show using back-calculation of expected deaths from Nordic all-cause deaths that the Institute for Health Metrics and Evaluation model is a clear outlier in the compared estimates and likely substantially overestimates excess mortality of Finland and Denmark, and probably Sweden. Our review suggests a range of total Nordic excess deaths of perhaps 15 000-20 000, but results are sensitive to assumptions in the models as shown.

CONCLUSIONS

We document substantial heterogeneity and uncertainty in estimates of excess mortality. All estimates should be taken with caution in their interpretation as they miss detailed account of demographics, such as changes in the age group populations over the study period.

Cognition and brain health among older adults in Iceland: the AGES-Reykjavik study

The paper aimed to compare how factors previously identified as predictive factors for cognitive decline and dementia related to cognitive performance on the one hand and brain health on the other. To that aim, multiple linear regression was applied to the AGES-Reykjavik study epidemiological data. Additionally, a regression analysis was performed for change in cognition over 5 years, using the same exposure factors. The study ran from 2002 to 2011, and the sample analyzed included 1707 participants between the ages of 66 and 90. The data contains MR imaging, cognitive testing, background data, and physiological measurements. Overall, we conclude that risk factors linked to dementia relate differently to cognition and brain health. Mobility, physical strength, alcohol consumption, coronary artery disease, and hypertension were associated with cognition and brain volume. Smoking, depression, diabetes, and body fat percentage were only associated with brain volume, not cognitive performance. Modifiable factors previously linked to cognitive reserve, such as educational attainment, participation in leisure activities, multilingualism and good self-reported health, were associated with cognitive function but did not relate to brain volume. These findings show that, within the same participant pool, cognitive reserve proxy variables have a relationship with cognitive performance but have no association with relative brain volume measured simultaneously.

Iceland as Stepping Stone for Spread of Highly Pathogenic Avian Influenza Virus between Europe and North America

Highly pathogenic avian influenza viruses (HPAIVs) of hemagglutinin type H5 and clade 2.3.4.4b have widely spread within the northern hemisphere since 2020 and threaten wild bird populations, as well as poultry production. We present phylogeographic evidence that Iceland has been used as a stepping stone for HPAIV translocation from northern Europe to North America by infected but mobile wild birds. At least 2 independent incursions of HPAIV H5N1 clade 2.3.4.4b assigned to 2 hemagglutinin clusters, B1 and B2, are documented for summer‒autumn 2021 and spring 2022. Spread of HPAIV H5N1 to and among colony-breeding pelagic avian species in Iceland is ongoing. Potentially devastating effects (i.e., local losses >25%) on these species caused by extended HPAIV circulation in space and time are being observed at several affected breeding sites throughout the North Atlantic.

Rate of SARS-CoV-2 Reinfection During an Omicron Wave in Iceland

This cohort study estimates the proportion of persons who became reinfected with SARS-CoV-2 during the Omicron wave in Iceland.

Reconstruction of a large-scale outbreak of SARS-CoV-2 infection in Iceland informs vaccination strategies

OBJECTIVES

The spread of SARS-CoV-2 is dependent on several factors, both biological and behavioural. The effectiveness of nonpharmaceutical interventions can be attributed largely to changes in human behaviour, but quantifying this effect remains challenging. Reconstructing the transmission tree of the third wave of SARS-CoV-2 infections in Iceland using contact tracing and viral sequence data from 2522 cases enables us to directly compare the infectiousness of distinct groups of persons.

METHODS

The transmission tree enables us to model the effect that a given population prevalence of vaccination would have had on the third wave had one of three different vaccination strategies been implemented before that time. This allows us to compare the effectiveness of the strategies in terms of minimizing the number of cases, deaths, critical cases, and severe cases.

RESULTS

We found that people diagnosed outside of quarantine (Rˆ=1.31) were 89% more infectious than those diagnosed while in quarantine (Rˆ=0.70) and that infectiousness decreased as a function of time spent in quarantine before diagnosis, with people diagnosed outside of quarantine being 144% more infectious than those diagnosed after ≥3 days in quarantine (Rˆ=0.54). People of working age, 16 to 66 years (Rˆ=1.08), were 46% more infectious than those outside of that age range (Rˆ=0.74).

DISCUSSION

We found that vaccinating the population in order of ascending age or uniformly at random would have prevented more infections per vaccination than vaccinating in order of descending age, without significantly affecting the expected number of deaths, critical cases, or severe cases.

Medication use in populations exposed to the 2010 Eyjafjallajökull eruption: an interrupted time series analysis

OBJECTIVES

To assess the trends in medication use indicative of physical and psychological morbidity following the 2010 volcanic eruption in Eyjafjallajökull immediately after and during a 3-year period following the eruption.

DESIGN

Population-based register study.

SETTING

Eyjafjallajökull eruption in Iceland, 2007-2013.

PARTICIPANTS

All residents in Iceland who received at least one medication dispensing were identified. Residents of exposed areas were classified into exposure groups (individual-level data) and residents in other parts of Iceland were included as a non-exposed group (aggregated data).

INTERVENTION/EXPOSURE

Eyjafjallajökull erupted on 14 April 2010 and continued for 39 days, producing heavy ash fall in South Iceland.

MAIN OUTCOME MEASURES

Using interrupted time series analysis, we examined annual and quarterly changes in medicine use, measured as number of dispensed defined daily dose (DDD) per 1000 individuals. We calculated the level shift (immediate change) and change in slope from pre-eruption to post-eruption (long-term change) in medication dispensing.

RESULTS

Among exposed residents, there was a 6% decrease (95% CI -7% to -4%) in the annual number of dispensed DDDs 1-year post-eruption in the overall medication class, including analgesics (-5%, 95% CI -6% to -3%), hypnotics and sedatives (-9%, 95% CI -11% to -7%) and respiratory medications (-7%, 95% CI -9% to -5%; -8%, 95% CI -11% to -4%). Simultaneously, there was a 9% decrease (95% CI -14% to -4%) in the overall medication class among non-exposed residents. Moreover, among exposed residents, we observed change in slope of -4% (95% CI -7% to -1%) in the overall medication class, including for analgesics (-6%, 95% CI -8% to -3%) and other respiratory drugs (-10%, 95% CI -16% to -4%).

CONCLUSION

Our findings indicate that the eruption did not lead to increases in medication dispensing among residents of exposed areas, rather decreases for some medicine classes. The results should be interpreted with caution since the content of each eruption differs.

Adverse childhood experiences and resilience among adult women: A population-based study

Background

Adverse childhood experiences (ACEs) have consistently been associated with elevated risk of multiple adverse health outcomes, yet their contribution to coping ability and psychiatric resilience in adulthood is unclear.

Methods

Cross-sectional data were derived from the ongoing Stress-And-Gene-Analysis cohort, representing 30% of the Icelandic nationwide female population, 18-69 years. Participants in the current study were 26,198 women with data on 13 ACEs measured with the ACE-International Questionnaire. Self-reported coping ability was measured with the Connor-Davidson Resilience Scale and psychiatric resilience was operationalized as absence of psychiatric morbidity. Generalized linear regression assuming normal or Poisson distribution were used to assess the associations of ACEs with coping ability and psychiatric resilience controlling for multiple confounders.

Results

Number of ACEs was inversely associated with adult resilience in a dose-dependent manner; every 1SD unit increase in ACE scores was associated with both lower levels of coping ability (β = -0.14; 95% CI-0.15,-0.13) and lower psychiatric resilience (β = -0.28; 95% CI-0.29,-0.27) in adulthood. Compared to women with 0 ACEs, women with ≥5 ACEs had 36% lower prevalence of high coping ability (PR = 0.64, 95% CI 0.59,0.70) and 58% lower prevalence of high psychiatric resilience (PR = 0.42; 95% CI 0.39,0.45). Specific ACEs including emotional neglect, bullying, sexual abuse and mental illness of household member were consistently associated with reduced adult resilience. We observed only slightly attenuated associations after controlling for adult socioeconomic factors and social support in adulthood.

Conclusions

Cumulative ACE exposure is associated with lower adult resilience among women, independent of adult socioeconomic factors and social support, indicating that adult resilience may be largely determined in childhood.

Funding

This work was supported by the European Research Council (Consolidator grant; UAV, grant number 726413), and the Icelandic Center for Research (Grant of excellence; UAV, grant number 163362-051). HBD was supported by a doctoral grant from the University of Iceland Research Fund.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

Ambient nitrogen dioxide is associated with emergency hospital visits for atrial fibrillation: a population-based case-crossover study in Reykjavik, Iceland

BACKGROUND

In Iceland air quality is generally good; however, previous studies indicate that there is an association between air pollution in Reykjavik and adverse health effects as measured by dispensing of medications, mortality, and increase in health care utilisation. The aim was to study the association between traffic-related ambient air pollution in the Reykjavik capital area and emergency hospital visits for heart diseases and particularly atrial fibrillation and flutter (AF).

METHODS

A multivariate time-stratified case-crossover design was used to study the association. Cases were those patients aged 18 years or older living in the Reykjavik capital area during the study period, 2006-2017, who made emergency visits to Landspitali University Hospital for heart diseases. In this population-based study, the primary discharge diagnoses were registered according to International Classification of Diseases, 10th edition (ICD-10). The pollutants studied were NO₂, PM₁₀, PM_2.5, and SO_2, with adjustment for H₂S, temperature, and relative humidity. The 24-h mean of pollutants was used with lag 0 to lag 4.

RESULTS

During the study period 9536 cases of AF were identified. The 24-h mean NO₂ was 20.7 μg/m³. Each 10 μg/m³ increase in NO₂ was associated with increased risk of heart diseases (ICD-10: I20-I25, I44-I50), odds ratio (OR) 1.023 (95% CI 1.012-1.034) at lag 0. Each 10 μg/m³ increase in NO₂ was associated with an increased risk of AF (ICD-10: I48) on the same day, OR 1.030 (95% CI: 1.011-1.049). Females were at higher risk for AF, OR 1.051 (95% CI 1.019-1.083) at lag 0, and OR 1.050 (95% CI 1.019-1.083) at lag 1. Females aged younger than 71 years had even higher risk for AF, OR 1.077 (95% CI: 1.025-1.131) at lag 0. Significant associations were found for other pollutants and emergency hospital visits, but they were weaker and did not show a discernable pattern.

CONCLUSIONS

Short-term increase in NO₂ concentrations was associated with heart diseases, more precisely with AF. The associations were stronger among females, and among females at younger age. This is the first study in Iceland that finds an association between air pollution and cardiac arrhythmias, so the results should be interpreted with caution.

Health and well-being of university students before and during COVID-19 pandemic: A gender comparison

Objective

COVID-19 has affected people’s health in various ways. University students are a particularly sensitive group for mental and physical health issues. The aim of this study was to assess and compare the mental and physical health of male and female first-year university students during and before COVID-19.

Method

Total of 115 first-year university students (54% male) answered questions about mental and physical health. The students were asked to estimate their physical activity, sedentary behavior, loneliness, stress, and sleep quality during COVID-19 opposed to before the pandemic.

Result

Males had fewer symptoms of anxiety and depression, and their self-esteem was higher than females (p<0.05). Over 50% of both genders estimated their mental health to be worse than before COVID-19. Larger proportion of males (69%) compared to females (38%) estimated that their physical health had worsened than before the pandemic. Larger proportion of females (38%) than males (14%) experience increased loneliness and stress (68% vs. 48%). Over 70% of both genders estimated increased sedentary behavior than before the pandemic, and larger proportion of males (76%), compared to females (56%), estimated that they were less physically active than before COVID-19. About 50% of participants estimated their sleep quality was worse than before COVID-19.

Conclusion

University students estimated their mental and physical health to have deteriorated during the pandemic. Therefore, it is important that the school and healthcare systems assist students in unwinding these negative health and lifestyle changes that have accompanied the pandemic.

Optimizing Island Refuges against global Catastrophic and Existential Biological Threats: Priorities and Preparations

Human civilization is vulnerable to global catastrophic biological threats and existential threats. Policy to mitigate the impact of major biological threats should consider worst-case scenarios. We aimed to strengthen existing research on island refuges as a mitigating mechanism against such threats by considering five additional factors as well as recent literature on catastrophic risks and resilience. We also analyzed the performance of potential refuge islands during early phases the COVID-19 pandemic. Using a composite indicator (scored from 0-1) based on 14 global macroindices, we present analysis supporting Australia (0.71), New Zealand (0.64), and Iceland (0.58) as the leading candidate island nation refuges to safeguard the survival of humanity and a flourishing technological civilization from the threat of a catastrophic pandemic. Data from the COVID-19 pandemic supports this finding where islands have performed relatively well. We discuss the persisting weaknesses of even the best candidate refuges and the growing literature describing what preparations such a refuge should ensure to enhance resilience. Refuge preparations by Australia and New Zealand, in particular, may additionally provide some immunity against winter-inducing catastrophes such as global nuclear war. Existing disaster resilience frameworks such as the Sendai framework could be worded to mandate preventive measures against global catastrophic and existential threats. The issue of island refuges against certain global catastrophic risks should be raised at relevant international political summits.

Large-Scale Screening for Monogenic and Clinically Defined Familial Hypercholesterolemia in Iceland

Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.

Group B streptococcal infections in infants in Iceland: clinical and microbiological factors

Introduction. Group B streptococcus (GBS) is a leading cause of invasive neonatal infections. These have been divided into early-onset disease (EOD; <7 days) and late-onset disease (LOD; 7-89 days), with different GBS clonal complexes (CCs) associated with different disease presentations.Hypothesis. Different GBS CCs are associated with timing of infection (EOD or LOD) and clinical presentation (sepsis, meningitis or pneumonia).Aim. To study infant GBS infections in Iceland from 1975 to 2019. Are specific GBS CCs related to disease presentation? Is CC17 overrepresented in infant GBS infections in Iceland?Methodology. All culture-confirmed invasive GBS infections in infants (<90 days) in Iceland from 1975 to 2019 were included. Clinical information was gathered from medical records.Results. A total of 127 invasive GBS infections in infants were diagnosed, but 105 infants were included in the study. Of these, 56 had EOD and 49 had LOD. The incidence of GBS infections declined from 2000 onwards but increased again at the end of the study period. Furthermore, there was a significant increase in LOD over the study period (P=0.0001). The most common presenting symptoms were respiratory difficulties and fever and the most common presentation was sepsis alone. Approximately one-third of the cases were caused by GBS CC17 of serotype III with surface protein RIB and pili PI-1+PI-2b or PI-2b. CC17 was significantly associated with LOD (P<0.001).Conclusion. CC17 is a major cause of GBS infection in infants in Iceland. This clone is associated with LOD, which has been increasing in incidence. Because intrapartum antibiotic prophylaxis only prevents EOD, it is important to continue the development of a GBS vaccine in order to prevent LOD infections.

The effect on subsequent fracture risk of age, sex, and prior fracture site by recency of prior fracture

The risk of a recurrent fragility fracture varies by age and sex, as by site and recency of sentinel fracture.

INTRODUCTION

The recency of prior fractures affects subsequent fracture risk. Variable recency may obscure other factors that affect subsequent fracture risk. The aim of this study was to quantify the effect of a sentinel fracture by site, age, and sex where the recency was held constant.

METHODS

The study used data from the Reykjavik Study fracture register that documented prospectively all fractures at all skeletal sites in a large sample of the population of Iceland. Fracture incidence was compared to that of the general population determined at fixed times after a sentinel fracture (humeral, clinical vertebral, forearm, hip, and minor fractures). Outcome fractures comprised a major osteoporotic fracture and hip fracture.

RESULTS

Sentinel osteoporotic fractures were identified in 9504 men and women. Of these, 3616 individuals sustained a major osteoporotic fracture as the first subsequent fracture, of whom 1799 sustained a hip fracture. Hazard ratios for prior fracture were consistently higher in men than in women and decreased progressively with age. Hazard ratios varied according to the site of sentinel fracture with higher ratios for hip and vertebral fracture than for humerus, forearm, or minor osteoporotic fracture.

CONCLUSION

The risk of a recurrent fragility fracture varies by age, sex, and site of sentinel fracture when recency is held constant.

Illness severity and risk of mental morbidities among patients recovering from COVID-19: a cross-sectional study in the Icelandic population

OBJECTIVE

To test if patients recovering from COVID-19 are at increased risk of mental morbidities and to what extent such risk is exacerbated by illness severity.

DESIGN

Population-based cross-sectional study.

SETTING

Iceland.

PARTICIPANTS

A total of 22 861 individuals were recruited through invitations to existing nationwide cohorts and a social media campaign from 24 April to 22 July 2020, of which 373 were patients recovering from COVID-19.

MAIN OUTCOME MEASURES

Symptoms of depression (Patient Health Questionnaire), anxiety (General Anxiety Disorder Scale) and posttraumatic stress disorder (PTSD; modified Primary Care PTSD Screen for DSM-5) above screening thresholds. Adjusting for multiple covariates and comorbidities, multivariable Poisson regression was used to assess the association between COVID-19 severity and mental morbidities.

RESULTS

Compared with individuals without a diagnosis of COVID-19, patients recovering from COVID-19 had increased risk of depression (22.1% vs 16.2%; adjusted relative risk (aRR) 1.48, 95% CI 1.20 to 1.82) and PTSD (19.5% vs 15.6%; aRR 1.38, 95% CI 1.09 to 1.75) but not anxiety (13.1% vs 11.3%; aRR 1.24, 95% CI 0.93 to 1.64). Elevated relative risks were limited to patients recovering from COVID-19 that were 40 years or older and were particularly high among individuals with university education. Among patients recovering from COVID-19, symptoms of depression were particularly common among those in the highest, compared with the lowest tertile of influenza-like symptom burden (47.1% vs 5.8%; aRR 6.42, 95% CI 2.77 to 14.87), among patients confined to bed for 7 days or longer compared with those never confined to bed (33.3% vs 10.9%; aRR 3.67, 95% CI 1.97 to 6.86) and among patients hospitalised for COVID-19 compared with those never admitted to hospital (48.1% vs 19.9%; aRR 2.72, 95% CI 1.67 to 4.44).

CONCLUSIONS

Severe disease course is associated with increased risk of depression and PTSD among patients recovering from COVID-19.

Low levels of respiratory syncytial virus activity in Europe during the 2020/21 season: what can we expect in the coming summer and autumn/winter?

Since the introduction of non-pharmacological interventions to control COVID-19, respiratory syncytial virus (RSV) activity in Europe has been limited. Surveillance data for 17 countries showed delayed RSV epidemics in France (≥ 12 w) and Iceland (≥ 4 w) during the 2020/21 season. RSV cases (predominantly small children) in France and Iceland were older compared with previous seasons. We hypothesise that future RSV epidemic(s) could start outside the usual autumn/winter season and be larger than expected. Year-round surveillance of RSV is of critical importance.