Human prion disease surveillance in Spain, 1993-2018: an overview.

In Spain, human transmissible spongiform encephalopathies (TSEs) have been undergoing continuous surveillance for over 25 years. In 1995, the system was launched as an EU Concerted Action, with EU surveillance network procedures being incorporated from 2002 onwards. The aim of this report was to describe performance and outcomes of this surveillance system across the period 1993-2018. Neurology and public health specialists from every region reported cases to a central hub at the Carlos III Health Institute, Madrid. In all, eight accidentally transmitted cases and five definite variant Creutzfeldt-Jakob disease (vCJD) patients were reported. All vCJD cases were diagnosed between 2005 and 2008. Two of these were family/dietary-related and spatially linked to a third. Yearly incidence of sporadic CJD per million was 1.25 across the period 1998-2018, and displayed a north-south gradient with the highest incidence in La Rioja, Navarre and the Basque Country. Genetic TSEs were observed to be clustered in the Basque Country, with a 4-fold incidence over the national rate. A total of 120 (5.6%) non-TSE sporadic, conformational, rapidly progressing neurodegenerative and vascular brain disorders were reported as suspect CJD. We conclude that TSEs in Spain displayed geographically uneven, stable medium incidences for the sporadic and genetic forms, a temporal and spatial family cluster for vCJD, and decreasing numbers for dura-mater-associated forms. The vCJD surveillance, framed within the EU network, might require continuing to cover all prion disorders. There is need for further strategic surveillance research focusing on case definition of rapid-course, conformational encephalopathies and surgical risk.

Guillain-Barré syndrome following the 2009 pandemic monovalent and seasonal trivalent influenza vaccination campaigns in Spain from 2009 to 2011: outcomes from active surveillance by a neurologist network, and records from a country-wide hospital discharge database.

BACKGROUND: Studies have shown a slight excess risk in Guillain-Barré syndrome (GBS) incidence associated with A(H1N1)pdm09 vaccination campaign and seasonal trivalent influenza vaccine immunisations in 2009-2010. We aimed to assess the incidence of GBS as a potential adverse effect of A(H1N1)pdm09 vaccination. METHODS: A neurologist-led network, active at the neurology departments of ten general hospitals serving an adult population of 4.68 million, conducted GBS surveillance in Spain in 2009-2011. The network, established in 1996, carried out a retrospective and a prospective study to estimate monthly alarm thresholds in GBS incidence and tested them in 1998-1999 in a pilot study. Such incidence thresholds additionally to observation of GBS cases with immunisation antecedent in the 42 days prior to clinical onset were taken as alarm signals for 2009-2011, since November 2009 onwards. For purpose of surveillance, in 2009 we updated both the available centres and the populations served by the network. We also did a retrospective countrywide review of hospital-discharged patients having ICD-9-CM code 357.0 (acute infective polyneuritis) as their principal diagnosis from January 2009 to December 2011. RESULTS: Among 141 confirmed of 148 notified cases of GBS or Miller-Fisher syndrome, Brighton 1-2 criteria in 96 %, not a single patient was identified with clinical onset during the 42-day time interval following A(H1N1)pdm09 vaccination. In contrast, seven cases were seen during a similar period after seasonal campaigns. Monthly incidence figures did not, however, exceed the upper 95 % CI limit of expected incidence. A retrospective countrywide review of the registry of hospital-discharged patients having ICD-9-CM code 357.0 (acute infective polyneuritis) as their principal diagnosis did not suggest higher admission rates in critical months across the period December 2009-February 2010. CONCLUSIONS: Despite limited power and underlying reporting bias in 2010-2011, an increase in GBS incidence over background GBS, associated with A(H1N1)pdm09 monovalent or trivalent influenza immunisations, appears unlikely.

Drivers: A Biologically Contextualized, Cross-Inferential View of the Epidemiology of Neurodegenerative Disorders.

BACKGROUND: Sutherland et al. (2011) suggested that, instead of risk factors for single neurodegenerative disorders (NDDs), there was a need to identify specific "drivers", i.e., risk factors with impact on specific deposits, such as amyloid-ß, tau, or α-synuclein, acting across entities. OBJECTIVES AND METHODS: Redefining drivers as "neither protein/gene- nor entity-specific features identifiable in the clinical and general epidemiology of conformational NDDs (CNDDs) as potential footprints of templating/spread/transfer mechanisms", we conducted an analysis of the epidemiology of ten CNDDs, searching for patterns. RESULTS: We identified seven potential drivers, each of which was shared by at least two CNDDs: 1) an age-at-exposure-related susceptibility to Creutzfeldt-Jakob disease (CJD) and several late-life CNDDs; 2) a relationship between age at onset, survival, and incidence; 3) shared genetic risk factors for CJD and late-life CNNDs; 4) partly shared personal (diagnostic, educational, behavioral, and social risk factors) predating clinical onset of late-life CNDDs; 5) two environmental risk factors, namely, surgery for sporadic CJD and amyotrophic lateral sclerosis, and Bordetella pertussis infection for Parkinson's disease; 6) reticulo-endothelial system stressors or general drivers (andropause or premenopausal estrogen deficiency, APOEɛ4, and vascular risk factors) for late-life CNDDs such as dementia/Alzheimer's disease, type-2 diabetes mellitus, and some sporadic cardiac and vascular degenerative diseases; and 7) a high, invariant incidence ratio of sporadic to genetic forms of mid- and late-life CNDDs, and type-2 diabetes mellitus. CONCLUSION: There might be a systematic epidemiologic pattern induced by specific proteins (PrP, TDP-43, SOD1, α-synuclein, amyloid-ß, tau, Langerhans islet peptide, and transthyretin) or established combinations of these.

Comparative Incidence of Conformational, Neurodegenerative Disorders.

BACKGROUND: The purpose of this study was to identify incidence and survival patterns in conformational neurodegenerative disorders (CNDDs). METHODS: We identified 2563 reports on the incidence of eight conditions representing sporadic, acquired and genetic, protein-associated, i.e., conformational, NDD groups and age-related macular degeneration (AMD). We selected 245 papers for full-text examination and application of quality criteria. Additionally, data-collection was completed with detailed information from British, Swedish, and Spanish registries on Creutzfeldt-Jakob disease (CJD) forms, amyotrophic lateral sclerosis (ALS), and sporadic rapidly progressing neurodegenerative dementia (sRPNDd). For each condition, age-specific incidence curves, age-adjusted figures, and reported or calculated median survival were plotted and examined. FINDINGS: Based on 51 valid reported and seven new incidence data sets, nine out of eleven conditions shared specific features. Age-adjusted incidence per million person-years increased from ≤1.5 for sRPNDd, different CJD forms and Huntington's disease (HD), to 1589 and 2589 for AMD and Alzheimer's disease (AD) respectively. Age-specific profiles varied from (a) symmetrical, inverted V-shaped curves for low incidences to (b) those increasing with age for late-life sporadic CNDDs and for sRPNDd, with (c) a suggested, intermediate, non-symmetrical inverted V-shape for fronto-temporal dementia and Parkinson's disease. Frequently, peak age-specific incidences from 20-24 to ≥90 years increased with age at onset and survival. Distinct patterns were seen: for HD, with a low incidence, levelling off at middle age, and long median survival, 20 years; and for sRPNDd which displayed the lowest incidence, increasing with age, and a short median disease duration. INTERPRETATION: These results call for a unified population view of NDDs, with an age-at-onset-related pattern for acquired and sporadic CNDDs. The pattern linking age at onset to incidence magnitude and survival might be explained by differential pathophysiological mechanisms associated with specific misfolded protein deposits.

Medical, environmental and personal factors of disability in the elderly in Spain: a screening survey based on the International Classification of Functioning / Factores médicos, ambientales y personales de discapacidad en las personas mayores en España: un estudio de detección basado en la Clasificación Internacional del Funcionamiento

Objectives: The International Classification of Functioning, Disability and Health (ICF) advocates a multifactorial and multifaceted conceptualization of disability. The objective of this study was to ascertain major medical, environmental and personal determinants of severe/extreme disability among the elderly population in Spain. The assessment scheme was consistent with the ICF model of disability. Methods: Nine populations contributed probabilistic or geographically-defined samples following a two-phase screening design. The Mini-Mental State Examination and the 12-item version of the World Health Organization-Disability Assessment Schedule, 2nd ed. (WHO-DAS II), were used as cognitive and disability screening tools, respectively. Positively screened individuals underwent clinical work-up for dementia and were administered the 36-item version of the WHO-DAS II to estimate ICF disability levels. We used logistic regression for the purposes of data combination, adjusted for age and sex in all analyses. Results: The sample was composed of 503 participants aged ≥ 75 years. Alzheimer¿s disease and depression were highly predictive of severe/extreme disability (OR: 17.40, 3.71). Good access to social services was strongly associated with a low level or absence of disability (OR: 0.05 to 0.18). Very difficult access to services and having dementia or another psychiatric disorder were associated with an increase in disability (OR: 66.06). There was also a significant interaction effect between access to services and neurological disorders (OR: 12.74). Conclusions: Disability is highly prevalent among the Spanish elderly and is influenced by medical, social and personal factors. Disability could potentially be reduced by ensuring access to social services, preventing dementia and stroke, and treating depression (AU)

Objetivos: La Clasificación Internacional del Funcionamiento, la Discapacidad y la Salud (CIF) propone un enfoque multifactorial de la discapacidad. El presente estudio analiza los principales determinantes médicos, ambientales y personales de la discapacidad grave y extrema en población anciana española siguiendo una evaluación congruente con el modelo CIF. Métodos: Nueve poblaciones aportaron muestras probabilísticas o definidas geográficamente siguiendo un diseño de cribado. Se usaron el Minimental State Examination y el World Health Organization-Disability Assessment Schedule, 2nd ed. (WHO-DAS II, 12 ítems), como cribados cognitivo y de discapacidad, respectivamente. Se evaluaron la presencia de demencia y los grados de discapacidad de la CIF usando la escala WHO-DAS II (36 ítems) entre los positivos al cribado. Los datos se combinaron usando regresión logística, ajustando por edad y sexo en todos los análisis. Resultados: Participaron 503 sujetos de 75 y más años de edad. Los individuos con enfermedad de Alzheimer y/o depresión tenían una mayor probabilidad de presentar discapacidad grave o extrema (OR: 17,40, 3,71). El acceso a los servicios sociales tuvo un efecto protector (OR: 0,05 a 0,18), mientras que el acceso «muy difícil» y la presencia de demencia u otro trastorno psiquiátrico se asociaron a un incremento de la discapacidad (OR: 66,06). Hubo una interacción significativa entre acceso a servicios y diagnóstico neurológico (OR: 12,74). Conclusiones: La discapacidad es altamente prevalente entre los ancianos españoles y está muy asociada a factores médicos, sociales y personales. La accesibilidad a los servicios sociales, la prevención de la demencia y del infarto cerebral, y el tratamiento de la depresión, pueden reducir la discapacidad entre los ancianos españoles (AU)

Medical, environmental and personal factors of disability in the elderly in Spain: a screening survey based on the International Classification of Functioning.

OBJECTIVES: The International Classification of Functioning, Disability and Health (ICF) advocates a multifactorial and multifaceted conceptualization of disability. The objective of this study was to ascertain major medical, environmental and personal determinants of severe/extreme disability among the elderly population in Spain. The assessment scheme was consistent with the ICF model of disability. METHODS: Nine populations contributed probabilistic or geographically-defined samples following a two-phase screening design. The Mini-Mental State Examination and the 12-item version of the World Health Organization-Disability Assessment Schedule, 2(nd) ed. (WHO-DAS II), were used as cognitive and disability screening tools, respectively. Positively screened individuals underwent clinical work-up for dementia and were administered the 36-item version of the WHO-DAS II to estimate ICF disability levels. We used logistic regression for the purposes of data combination, adjusted for age and sex in all analyses. RESULTS: The sample was composed of 503 participants aged ≥ 75 years. Alzheimers disease and depression were highly predictive of severe/extreme disability (OR: 17.40, 3.71). Good access to social services was strongly associated with a low level or absence of disability (OR: 0.05 to 0.18). Very difficult access to services and having dementia or another psychiatric disorder were associated with an increase in disability (OR: 66.06). There was also a significant interaction effect between access to services and neurological disorders (OR: 12.74). CONCLUSIONS: Disability is highly prevalent among the Spanish elderly and is influenced by medical, social and personal factors. Disability could potentially be reduced by ensuring access to social services, preventing dementia and stroke, and treating depression.

ICF-based disability survey in a rural population of adults and older adults living in Cinco Villas, Northeastern Spain: design, methods and population characteristics.

BACKGROUND: This article describes the methods of a door-to-door screening survey exploring the distribution of disability and its major determinants in northeastern Spain. This study will set the basis for the development of disability-related services for the rural elderly in northeastern Spain. METHODS: The probabilistic sample was composed of 1,354 de facto residents from a population of 12,784 Social Security card holders (age: > or = 50 years). Cognitive and disability screenings were conducted (period: June 2008-June 2009). Screening instruments were the MMSE and the World Health Organization Disability Assessment Schedule. Participants screened positive for disability underwent an assessment protocol focusing on primary care diagnoses, disability, lifestyle, and social and health service usage. Participants screened positive for cognitive functioning went through in-depth neurological evaluation. RESULTS: The study sample is described. Usable data were available for 1,216 participants. A total of 625 individuals (51.4%) scored within the positive range in the disability screening, while 135 (11.1%) scored within the positive range of the cognitive screening. The proportion of positively screened individuals was higher for women and increased with age. CONCLUSIONS: Screening surveys represent a feasible design for examining the distribution of disability and its determinants among the elderly. Data quality may benefit from methodological developments tailored to rural populations with a low education level.