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.

Comparing COVID-19 pandemic health responses in two high-income island nations: Iceland and New Zealand.

AIMS: We aimed to compare COVID-19 control measures, epidemiological characteristics and economic performance measures in two high-income island nations with small populations, favorable border control options, and relatively good outcomes: Iceland and New Zealand (NZ). METHODS: We examined peer-reviewed journal articles, official websites, reports, media releases and press articles for data on pandemic preparedness and COVID-19 public health responses from 1 January 2020 to 1 June 2022 in Iceland and NZ. We calculated epidemiological characteristics of the COVID-19 pandemic, as well as measures of economic performance. RESULTS: Both nations had the lowest excess mortality in the OECD from the start of the pandemic up to June 2022. Iceland pursued a mitigation strategy, never used lockdowns or officially closed its border to foreign nationals, and instead relied on extensive testing and contact tracing early in the pandemic. Meanwhile, NZ pursued an elimination strategy, used a strict national lockdown to stop transmission, and closed its international border to everyone except citizens and permanent residents going through quarantine and testing. Iceland experienced a larger decrease in gross domestic product in 2020 (relative to 2019) than NZ (-8·27% vs. -1·22%, respectively). In late 2021, NZ announced a shift to a suppression strategy and in 2022 began to reopen its border in stages, while Iceland ended all public restrictions on 25 February 2022. CONCLUSIONS: Many of Iceland's and NZ's pandemic control measures appeared successful and features of the responses in both countries could potentially be adopted by other jurisdictions to address future disease outbreaks and pandemic threats.

Effect of booster vaccination against Delta and Omicron SARS-CoV-2 variants in Iceland.

By the end of July 2021, the majority of the Icelandic population had received vaccination against COVID-19. In mid-July a wave of SARS-CoV-2 infections, dominated by the Delta variant, spread through the population, followed by an Omicron wave in December. A booster vaccination campaign was initiated to curb the spread of the virus. We estimate the risk of infection for different vaccine combinations using vaccination data from 276,028 persons and 963,557 qPCR tests for 277,687 persons. We measure anti-Spike-RBD antibody levels and ACE2-Spike binding inhibitory activity in 371 persons who received one of four recommended vaccination schedules with or without an mRNA vaccine booster. Overall, we find different antibody levels and inhibitory activity in recommended vaccination schedules, reflected in the observed risk of SARS-CoV-2 infections. We observe an increased protection following mRNA boosters, against both Omicron and Delta variant infections, although BNT162b2 boosters provide greater protection against Omicron than mRNA-1273 boosters.

SARS-CoV-2 Infections in Icelandic Children: Close Follow-up of All Confirmed Cases in a Nationwide Study.

INTRODUCTION: Children are less likely to acquire SARS-CoV-2 infections than adults and when infected, usually have milder disease. True infection and complication rates are, however, difficult to ascertain. In Iceland, a strict test, trace and isolate policy was maintained from the start of the pandemic and offers more accurate information of the number of truly infected children in a nationwide study. MATERIAL AND METHODS: All children with positive PCR for SARS-CoV-2 infections from February 28, 2020 to August 31, 2021 were followed up through telephone consultations for at least 14 days and their symptoms were registered. Symptom severity and duration were categorized based on age groups and the source of infection was registered. RESULTS: A total of 1749 children were infected with SARS-CoV-2 in 3 waves of infections. All waves had similar disease severity whereas the incidence was 5-fold higher in the third wave (3.5 vs. 0.73/1000 children/month). No children had severe symptoms, 81 (4.6%) had moderate symptoms, 1287 (73.9%) had mild and 374 (21.5%) were asymptomatic. Symptoms from upper (n = 839, 48%) and lower respiratory tract (n = 744, 43%) were most common. Median duration of symptoms was 5 days and adolescents had a higher risk of prolonged duration [OR:1.84 (1.39-2.43)]. Nineteen (1.1%) children needed medical attention, but no child was hospitalized. The source of infection was a household member in 65% of cases. DISCUSSION: During the first 3 waves of the pandemic, SARS-CoV-2 infections in Icelandic children were mild and none were hospitalized. The most common symptoms were respiratory symptoms followed by fever, headache and tiredness. This study helps shed light on true complication rates of children with confirmed SARS-CoV-2 infection.

Longitudinal changes in inflammatory biomarkers among patients with COVID-19: A nationwide study in Iceland.

OBJECTIVES: All SARS-CoV-2-positive persons in Iceland were prospectively monitored and those who required outpatient evaluation or were admitted to hospital underwent protocolized evaluation that included a standardized panel of biomarkers. The aim was to describe longitudinal changes in inflammatory biomarkers throughout the infection period of patients with COVID-19 requiring different levels of care. DESIGN: Registry-based study. SETTING: Nationwide study in Iceland. PATIENTS: All individuals who tested positive for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) from February 28 to December 31, 2020 in Iceland and had undergone blood tests between 5 days before and 21 days following onset of symptoms. MEASUREMENTS AND MAIN RESULTS: Data were collected from the electronic medical record system of Landspitali-The National University Hospital of Iceland. Data analyses were descriptive and the evolution of biomarkers was visualized using locally weighted scatterplot smoothing curves stratified by the worst clinical outcome experienced by the patient: outpatient evaluation only, hospitalization, and either intensive care unit (ICU) admission or death. Of 571 included patients, 310 (54.3%) only required outpatient evaluation or treatment, 202 (35.4%) were hospitalized, and 59 (10.3%) were either admitted to the ICU or died. An early and persistent separation of the mean lymphocyte count and plasma C-reactive protein (CRP) and ferritin levels was observed between the three outcome groups, which occurred prior to hospitalization for those who later were admitted to ICU or died. Lower lymphocyte count, and higher CRP and ferritin levels correlated with worse clinical outcomes. Patients who were either admitted to the ICU or died had sustained higher white blood cell and neutrophil counts, and elevated plasma levels of procalcitonin and D-dimer compared with the other groups. CONCLUSIONS: Lymphocyte count and plasma CRP and ferritin levels might be suitable parameters to assess disease severity early during COVID-19 and may serve as predictors of worse outcome.

The impact of the COVID-19 pandemic on cancer diagnosis based on pathology notifications: A comparison across the Nordic countries during 2020.

The severity of the COVID-19 pandemic and subsequent mitigation strategies have varied across the Nordic countries. In a joint Nordic population-based effort, we compared patterns of new cancer cases and notifications between the Nordic countries during 2020. We used pathology notifications to cancer registries in Denmark, the Faroe Islands, Finland, Iceland, Norway and Sweden to determine monthly numbers of pathology notifications of malignant and in situ tumours from January to December 2020 compared to 2019 (2017-2019 for Iceland and the Faroe Islands). We compared new cancer cases per month based on unique individuals with pathology notifications. In April and May 2020, the numbers of new malignant cases declined in all Nordic countries, except the Faroe Islands, compared to previous year(s). The largest reduction was observed in Sweden (May: -31.2%, 95% CI -33.9, -28.3), followed by significant declines in Finland, Denmark and Norway, and a nonsignificant decline in Iceland. In Denmark, Norway, Sweden and Finland the reporting rates during the second half of 2020 rose to almost the same level as in 2019. However, in Sweden and Finland, the increase did not compensate for the spring decline (annual reduction -6.2% and -3.6%, respectively). Overall, similar patterns were observed for in situ tumours. The COVID-19 pandemic led to a decline in rates of new cancer cases in Sweden, Finland, Denmark and Norway, with the most pronounced reduction in Sweden. Possible explanations include the severity of the pandemic, temporary halting of screening activities and changes in healthcare seeking behaviour.

[Effects of the COVID-19 pandemic and associated non-pharmaceutical interventions on diagnosis of myocardial infarction and selected infections in Iceland 2020].

INTRODUCTON: Nonpharmaceutical interventions to contain the spread of COVID-19 infections in Iceland in 2020 were successful, but the effects of these measures on incidence and diagnosis of other diseases is unknown. The aim of this study was to evaluate the impact of the COVID-19 pandemic on the diagnosis of myocardial infarction (MI) and selected infections with different transmission routes. MATERIALS AND METHODS: Health records of individuals 18 years or older who were admitted to Landspitali University Hospital (LUH) in 2016-2020 with pneumonia or MI were extracted from the hospital registry. We acquired data from the clinical laboratories regarding diagnostic testing for Chlamydia trachomatis, influenza, HIV and blood cultures positive for Enterobacterales species. Standardized incidence ratio (SIR) for 2020 was calculated with 95% confidence intervals (95%CI) and compared to 2016-2019. RESULTS: Discharge diagnoses due to pneumonia decreased by 31% in 2020, excluding COVID-19 pneumonia (SIR 0.69 (95%CI 0.64-0.75)). Discharge diagnoses of MI decreased by 18% (SIR 0.82 (95%CI 0.75-0.90)), and emergency cardiac catheterizations due to acute coronary syndrome by 23% (SIR 0.77 (95%CI 0.71-0.83)), while there was a 15% increase in blood stream infections for Enterobacterales species (SIR 1.15 (95%CI 1.04-1.28)). Testing for Chlamydia trachomatis decreased by 14.8% and positive tests decreased by 16.3%. Tests for HIV were reduced by 10.9%, while samples positive for influenza decreased by 23.6% despite doubling of tests being performed. CONCLUSION: The number of pneumonia cases of other causes than COVID-19 requiring admission dropped by a quarter in 2020. MI, chlamydia and influensa diagnoses decreased notably. These results likely reflect a true decrease, probably due to altered behaviour during the pandemic.

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.

A year of Covid-19: experiences and lessons learnt by small European island states-Cyprus, Iceland and Malta.

BACKGROUND: COVID-19 became a global pandemic within weeks, as every country including small states and islands experienced a surge in cases. Small islands are known to face several challenges in the quest to curb the viral spread, but with the absence of land boarders and small population size, these factors should have played to their advantage to minimize the spread. The aim of this article was to compare and contrast the COVID-19 situation, restrictions, preparedness, management and the healthcare systems between the small population island states of Cyprus, Iceland and Malta. METHODS: Data were obtained from Ministry of Health websites and COVID dashboards of the three respective Island states in Europe. Comparisons were made between the reported cases, deaths, excess deaths, years of life lost, swabbing rates, restrictive measures, vaccination roll-out and healthcare system structures. RESULTS: Cyprus and Malta contained the COVID-19 spread better than Iceland during the first wave. However, a significantly higher viral spread and mortality rates were observed in Malta during the second waves. Similar healthcare preparedness and services, restrictions and relaxation measures were implemented across the three islands with some exceptions. Covid-19 vaccination has initiated across all Islands with Malta leading the vaccination roll-out. CONCLUSION: The small population size and island status proved to be an asset during the first wave of COVID-19, but different governance approaches led to a different COVID-19 outcomes, including high mortality rates during the transition phases and the subsequent waves.

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.

Monoclonal gammopathy of undetermined significance and COVID-19: a population-based cohort study.

Multiple myeloma (MM) patients have increased risk of severe coronavirus disease 2019 (COVID-19) when infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Monoclonal gammopathy of undetermined significance (MGUS), the precursor of MM has been associated with immune dysfunction which may lead to severe COVID-19. No systematic data have been published on COVID-19 in individuals with MGUS. We conducted a large population-based cohort study evaluating the risk of SARS-CoV-2 infection and severe COVID-19 among individuals with MGUS. We included 75,422 Icelanders born before 1976, who had been screened for MGUS in the Iceland Screens Treats or Prevents Multiple Myeloma study (iStopMM). Data on SARS-CoV-2 testing and COVID-19 severity were acquired from the Icelandic COVID-19 Study Group. Using a test-negative study design, we included 32,047 iStopMM participants who had been tested for SARS-CoV-2, of whom 1754 had MGUS. Among these participants, 1100 participants, tested positive, 65 of whom had MGUS. Severe COVID-19 developed in 230 participants, including 16 with MGUS. MGUS was not associated with SARS-CoV-2 infection (Odds ratio (OR): 1.05; 95% confidence interval (CI): 0.81-1.36; p = 0.72) or severe COVID-19 (OR: 0.99; 95%CI: 0.52-1.91; p = 0.99). These findings indicate that MGUS does not affect the susceptibility to SARS-CoV-2 or the severity of COVID-19.

Molecular benchmarks of a SARS-CoV-2 epidemic.

A pressing concern in the SARS-CoV-2 epidemic and other viral outbreaks, is the extent to which the containment measures are halting the viral spread. A straightforward way to assess this is to tally the active cases and the recovered ones throughout the epidemic. Here, we show how epidemic control can be assessed with molecular information during a well characterized epidemic in Iceland. We demonstrate how the viral concentration decreased in those newly diagnosed as the epidemic transitioned from exponential growth phase to containment phase. The viral concentration in the cases identified in population screening decreased faster than in those symptomatic and considered at high risk and that were targeted by the healthcare system. The viral concentration persists in recovering individuals as we found that half of the cases are still positive after two weeks. We demonstrate that accumulation of mutations in SARS-CoV-2 genome can be exploited to track the rate of new viral generations throughout the different phases of the epidemic, where the accumulation of mutations decreases as the transmission rate decreases in the containment phase. Overall, the molecular signatures of SARS-CoV-2 infections contain valuable epidemiological information that can be used to assess the effectiveness of containment measures.

Nordic responses to Covid-19: Governance and policy measures in the early phases of the pandemic.

This paper explores and compares health system responses to the COVID-19 pandemic in Denmark, Finland, Iceland, Norway and Sweden, in the context of existing governance features. Content compiled in the Covid-19 Health System Response Monitor combined with other publicly available country information serve as the foundation for this analysis. The analysis mainly covers early response until August 2020, but includes some key policy and epidemiological developments up until December 2020. Our findings suggest that despite the many similarities in adopted policy measures, the five countries display differences in implementation as well as outcomes. Declaration of state of emergency has differed in the Nordic region, whereas the emphasis on specialist advisory agencies in the decision-making process is a common feature. There may be differences in how respective populations complied with the recommended measures, and we suggest that other structural and circumstantial factors may have an important role in variations in outcomes across the Nordic countries. The high incidence rates among migrant populations and temporary migrant workers, as well as differences in working conditions are important factors to explore further. An important question for future research is how the COVID-19 epidemic will influence legislation and key principles of governance in the Nordic countries.

Cell-phone traces reveal infection-associated behavioral change.

Epidemic preparedness depends on our ability to predict the trajectory of an epidemic and the human behavior that drives spread in the event of an outbreak. Changes to behavior during an outbreak limit the reliability of syndromic surveillance using large-scale data sources, such as online social media or search behavior, which could otherwise supplement healthcare-based outbreak-prediction methods. Here, we measure behavior change reflected in mobile-phone call-detail records (CDRs), a source of passively collected real-time behavioral information, using an anonymously linked dataset of cell-phone users and their date of influenza-like illness diagnosis during the 2009 H1N1v pandemic. We demonstrate that mobile-phone use during illness differs measurably from routine behavior: Diagnosed individuals exhibit less movement than normal (1.1 to 1.4 fewer unique tower locations; [Formula: see text]), on average, in the 2 to 4 d around diagnosis and place fewer calls (2.3 to 3.3 fewer calls; [Formula: see text]) while spending longer on the phone (41- to 66-s average increase; [Formula: see text]) than usual on the day following diagnosis. The results suggest that anonymously linked CDRs and health data may be sufficiently granular to augment epidemic surveillance efforts and that infectious disease-modeling efforts lacking explicit behavior-change mechanisms need to be revisited.

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.

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.