Características Epidemiológicas de los brotes de Hepatitis A en España (años 2015-2019).

[ES] Aunque España sea considerada actualmente como un país de baja endemicidad de hepatitis A, en los últimos años se siguen produciendo en nuestro país brotes causados por este virus. Se realizó una revisión de los brotes de hepatitis A notificados a la Red Nacional de Vigilancia Epidemiológica (RENAVE) de 2015 a 2019, periodo durante el cual se notificaron 500 brotes. El principal ámbito de exposición fue el hogar familiar y el principal mecanismo de transmisión el contacto directo persona-persona. La mediana del tamaño y duración de los brotes fue de 2 casos y 26 días respectivamente, siendo superior en determinados ámbitos como las escuelas o guarderías y la restauración colectiva. Además, el 8% de los brotes fueron declarados como importados, fundamentalmente de países del norte de África (Marruecos y Argelia). En el 91% de los brotes con información sobre vacunación post-exposición de contactos susceptibles constaba la aplicación de esta medida. [EN] In recent years, major hepatitis A outbreaks continue to occur in Spain, even in a context of low endemicity. Hepatitis A outbreaks reported to the National Epidemiological Surveillance Network (RENAVE in Spanish) from 2015 to 2019 were reviewed. During that period, 500 outbreaks were reported, most of them in households and transmitted from person-to-person. Median size and duration of outbreaks were 2 cases and 26 days, respectively, being greater in certain settings such as kindergartens/schools and restaurants/bars/canteens. Furthermore, 8% of the outbreaks were notified as imported, mainly from North African countries (Morocco and Algeria). In 91% of outbreaks with information on post-exposure vaccination of susceptible contacts, this measure was applied.N

Botulism in Spain: Epidemiology and Outcomes of Antitoxin Treatment, 1997-2019

Background: Botulism is a low incidence but potentially fatal infectious disease caused by neurotoxins produced mainly by Clostridium botulinum. There are different routes of acquisition, food-borne and infant/intestinal being the most frequent presentation, and antitoxin is the treatment of choice in all cases. In Spain, botulism is under surveillance, and case reporting is mandatory. Methods: This retrospective study attempts to provide a more complete picture of the epidemiology of botulism in Spain from 1997 to 2019 and an assessment of the treatment, including the relationship between a delay in antitoxin administration and the length of hospitalization using the Cox proportional hazards test and Kruskal-Wallis test, and an approach to the frequency of adverse events, issues for which no previous national data have been published. Results: Eight of the 44 outbreaks were associated with contaminated commercial foods involving ≤7 cases/outbreak; preserved vegetables were the main source of infection, followed by fish products; early antitoxin administration significantly reduces the hospital stay, and adverse reactions to the antitoxin affect around 3% of treated cases.S

Real time surveillance of COVID-19 space and time clusters during the summer 2020 in Spain

Background: On June 21st de-escalation measures and state-of-alarm ended in Spain after the COVID-19 first wave. New surveillance and control strategy was set up to detect emerging outbreaks. Aim: To detect and describe the evolution of COVID-19 clusters and cases during the 2020 summer in Spain. Methods: A near-real time surveillance system to detect active clusters of COVID-19 was developed based on Kulldorf's prospective space-time scan statistic (STSS) to detect daily emerging active clusters. Results: Analyses were performed daily during the summer 2020 (June 21st - August 31st) in Spain, showing an increase of active clusters and municipalities affected. Spread happened in the study period from a few, low-cases, regional-located clusters in June to a nationwide distribution of bigger clusters encompassing a higher average number of municipalities and total cases by end-August. Conclusion: STSS-based surveillance of COVID-19 can be of utility in a low-incidence scenario to help tackle emerging outbreaks that could potentially drive a widespread transmission. If that happens, spatial trends and disease distribution can be followed with this method. Finally, cluster aggregation in space and time, as observed in our results, could suggest the occurrence of community transmission.This research has been financed by Carlos III Health Institute (ISCIII) under the project COV20–00881.S

Perimeter confinements of basic health zones and COVID-19 incidence in Madrid, Spain

Background: A unique policy of perimeter closures of Basic Health Zones (small administrative health units) was implemented in the Autonomous Community of Madrid from September 21st 2020 to May 23rd 2021 to face the COVID-19 pandemic. Aim: To assess the impact of local perimeter confinements on the 14-days cumulative incidence of SARS-CoV-2 during the second wave of the pandemic in Madrid, Spain. Methods: We compare the errors in estimation of two families of mathematical models: ones that include the perimeter closures as explanatory covariables and ones that do not, in search of a significant improvement in estimation of one family over the other. We incorporate leave-one-out cross-validation, and at each step of this process we select the best model in AIC score from a family of 15 differently tuned ones. Results: The two families of models provided very similar estimations, for a 1- to 3-weeks delay in observed cumulative incidence, and also when restricting the analysis to only those Basic Health Zones that were subject to at least one closure during the time under study. In all cases the correlation between the errors yielded by both families of models was higher than 0.98 (±10- 3 95% CI), and the average difference of estimated 14-days cumulative incidence was smaller than 1.49 (±0.33 95% CI). Conclusion: Our analysis suggests that the perimeter closures by Basic Health Zone did not have a significant effect on the epidemic curve in Madrid.This research has been financed by Carlos III Health Institute (ISCIII) under the project COV20–00881.S

Assessing the effect of non-pharmaceutical interventions on COVID-19 transmission in Spain, 30 August 2020 to 31 January 2021

Background: After a national lockdown during the first wave of the COVID-19 pandemic in Spain, regional governments implemented different non-pharmaceutical interventions (NPIs) during the second wave. Aim: To analyse which implemented NPIs significantly impacted effective reproduction number (Rt) in seven Spanish provinces during 30 August 2020-31 January 2021. Methods: We coded each NPI and levels of stringency with a 'severity index' (SI) and computed a global SI (mean of SIs per six included interventions). We performed a Bayesian change point analysis on the Rt curve of each province to identify possible associations with global SI variations. We fitted and compared several generalised additive models using multimodel inference, to quantify the statistical effect on Rt of the global SI (stringency) and the individual SIs (separate effect of NPIs). Results: The global SI had a significant lowering effect on the Rt (mean: 0.16 ± 0.05 units for full stringency). Mandatory closing times for non-essential businesses, limited gatherings, and restricted outdoors seating capacities (negative) as well as curfews (positive) were the only NPIs with a significant effect. Regional mobility restrictions and limited indoors seating capacity showed no effect. Our results were consistent with a 1- to 3-week-delayed Rt as a response variable. Conclusion: While response measures implemented during the second COVID-19 wave contributed substantially to a decreased reproduction number, the effectiveness of measures varied considerably. Our findings should be considered for future interventions, as social and economic consequences could be minimised by considering only measures proven effective.This research was financed by Carlos III Health Institute (ISCIII) under the project COV20–00881.S

Sensitivity analysis of the botulism surveillance system in Spain between 1997 and 2019

Artículo BES V.31 N.1Introducción: El botulismo es una enfermedad de baja incidencia, grave y capaz de producir brotes. Las Comunidades Autónomas notifican casos sospechosos, probables y confirmados a la Red Nacional de Vigilancia Epidemiológica (RENAVE), gestionada por el Centro Nacional de Epidemiología (CNE). El objetivo del estudio fue evaluar la sensibilidad del sistema de vigilancia de botulismo alimentario, intestinal y de heridas. Método: Se empleó metodología captura-recaptura, utilizando como fuentes de información todos los casos notificados en RENAVE y los registros del Conjunto Mínimo Básico de Datos (CMBD) con diagnóstico principal de botulismo. Debido a cambios metodológicos en CMBD se dividió el periodo en dos tramos: 1997-2015 y 2016-2019. Se identificaron los casos coincidentes en ambas bases mediante las variables fecha de nacimiento, sexo y fecha y provincia de hospitalización. Se estimó el número total de casos aplicando el método Chapman-Seber. Los casos incluidos en el CMBD pero ausentes en RENAVE se analizaron en un estudio complementario utilizando información procedente de otras fuentes. Resultados: La sensibilidad de la RENAVE fue del 64,4% y del 78,7% para el botulismo alimentario, siendo inferior a la obtenida por el CMBD. Para botulismo intestinal la RENAVE fue más sensible que el CMBD en el segundo periodo, con un nivel cercano al 90%. No se identificaron casos asociados a heridas en la RENAVE. Conclusiones: La sensibilidad de RENAVE aumentó en el segundo periodo, aunque es necesario reforzar la notificación individualizada para reducir la pérdida de casos.N

Epidemic Diffusion Network of Spain: A Mobility Model to Characterize the Transmission Routes of Disease

Human mobility drives the geographical diffusion of infectious diseases at different scales, but few studies focus on mobility itself. Using publicly available data from Spain, we define a Mobility Matrix that captures constant flows between provinces by using a distance-like measure of effective distance to build a network model with the 52 provinces and 135 relevant edges. Madrid, Valladolid and Araba/Álaba are the most relevant nodes in terms of degree and strength. The shortest routes (most likely path between two points) between all provinces are calculated. A total of 7 mobility communities were found with a modularity of 63%, and a relationship was established with a cumulative incidence of COVID-19 in 14 days (CI14) during the study period. In conclusion, mobility patterns in Spain are governed by a small number of high-flow connections that remain constant in time and seem unaffected by seasonality or restrictions. Most of the travels happen within communities that do not completely represent political borders, and a wave-like spreading pattern with occasional long-distance jumps (small-world properties) can be identified. This information can be incorporated into preparedness and response plans targeting locations that are at risk of contagion preventively, underscoring the importance of coordination between administrations when addressing health emergencies.This research has been financed by Carlos III Health Institute (ISCIII) under the project COV20-00881 and the project Fundación BBVA.DGVI 256/22 “COVID-19 Urban Atlas Spain”.S

Epidemiological Characteristics and Spatio-Temporal Distribution of Hepatitis A in Spain in the Context of the 2016/2017 European Outbreak

The aim of our study was to describe the results of the epidemiological surveillance of hepatitis A infections in Spain in the context of the 2016/2017 European outbreak, particularly of hepatitis A outbreaks reported in the MSM population, incorporating the results of a spatiotemporal analysis of cases. Hepatitis A cases and outbreaks reported in 2016–2017 to the National Epidemiological Surveillance Network were reviewed: outbreaks in which some of the cases belonged to the MSM group were described, and clusters of hepatitis A cases in men and women were analysed using a space–time scan statistic. Twenty-six outbreaks were identified, with a median size of two cases per outbreak, with most of the outbreak-related cases belonging to the 15–44 years-old group. Nearly 85% occurred in a household setting, and in all outbreaks, the mode of transmission was direct person-to-person contact. Regarding space–time analysis, twenty statistically significant clusters were identified in the male population and eight in the female population; clusters in men presented a higher number of observed cases and affected municipalities, as well as a higher percentage of municipalities classified as large urban areas. The elevated number of cases detected in clusters of men indicates that the number of MSM-related outbreaks may be higher than reported, showing that spatio-temporal analysis is a complementary, useful tool which may improve the detection of outbreaks in settings where epidemiological investigation may be more challenging.The APC was funded by the Programme of Prevention, Surveillance, and Control of Transmissible Diseases (PREVICET), CIBER de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain)

Epidemiological Characteristics and Spatio-Temporal Distribution of Hepatitis A in Spain in the Context of the 2016/2017 European Outbreak

Altres ajuts: The APC was funded by the Programme of Prevention, Surveillance, and Control of Transmissible Diseases (PREVICET), CIBER de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid (Spain).The aim of our study was to describe the results of the epidemiological surveillance of hepatitis A infections in Spain in the context of the 2016/2017 European outbreak, particularly of hepatitis A outbreaks reported in the MSM population, incorporating the results of a spatio-temporal analysis of cases. Hepatitis A cases and outbreaks reported in 2016-2017 to the National Epidemiological Surveillance Network were reviewed: outbreaks in which some of the cases belonged to the MSM group were described, and clusters of hepatitis A cases in men and women were analysed using a space-time scan statistic. Twenty-six outbreaks were identified, with a median size of two cases per outbreak, with most of the outbreak-related cases belonging to the 15-44 years-old group. Nearly 85% occurred in a household setting, and in all outbreaks, the mode of transmission was direct person-to-person contact. Regarding space-time analysis, twenty statistically significant clusters were identified in the male population and eight in the female population; clusters in men presented a higher number of observed cases and affected municipalities, as well as a higher percentage of municipalities classified as large urban areas. The elevated number of cases detected in clusters of men indicates that the number of MSM-related outbreaks may be higher than reported, showing that spatio-temporal analysis is a complementary, useful tool which may improve the detection of outbreaks in settings where epidemiological investigation may be more challenging

Vigilancia epidemiológica de Shigelosis en España, 2016-2021

[ES] Se analizaron los casos y brotes de shigelosis notificados entre los años 2016 y 2021 a la Red Nacional de Vigilancia Epidemiológica (RENAVE), que recoge, entre otra, información relativa a edad y sexo de los casos, posibles mecanismos de transmisión y características microbiológicas de los aislados, aunque no incluye información sobre resistencias antibióticas. Durante el periodo de estudio, se notificaron 1.985 casos y 18 brotes de shigelosis. La incidencia acumulada aumentó en el periodo 2016-2019 (con un máximo de 1,2 casos por 100.000 habitantes en el año 2019), disminuyendo posteriormente durante los años 2020 y 2021, con 0,3 casos por 100.000 habitantes en ambos años. No obstante, en el año 2021, a pesar de que sólo algunas Comunidades Autónomas notificaron casos a la RENAVE, el número de casos fue ligeramente superior al año previo. La enfermedad fue más frecuente en hombres que en mujeres, fundamentalmente en individuos entre 15 y 49 años, siendo estos grupos de edad los que presentaron mayor razón hombre/mujer. La especie de Shigella más aislada durante el periodo de estudio fue S. sonnei, seguida de S. flexneri, aunque no se disponía de información en aproximadamente la mitad de los casos. Únicamente en 9 casos constaba como mecanismo de transmisión las relaciones sexuales, aunque la información sobre el posible mecanismo de transmisión no se recogió en más del 90% de los casos. Es necesario reforzar la notificación de la enfermedad en España, especialmente la información relativa a la transmisión, a la caracterización microbiológica y a las resistencias a los antimicrobianos. [EN] Cases and outbreaks of shigelosis reported from 2016 to 2021 to the National Epidemiological Surveillance Network (RENAVE in Spanish) were analysed, including information about age and sex of cases, possible routes of transmission and microbiological characteristics of isolates, although information about antimicrobial resistance was not reported. During the study period, 1,985 cases and 18 outbreaks of shigelosis were reported. The cumulative incidence raised during 2016-2019 period (with a maximum of 1.2 cases per 100.000 inhabitants in 2019), declining in 2020 and 2021, with 0.3 cases per 100.000 inhabitants both years. Nevertheless, during 2021, although only some Autonomous Regions reported cases to RENAVE, the number of cases was slightly higher than the previous year, due to some regions reporting similar or higher figures than in the pre-pandemic period. The disease was more frequent in men than in women, mainly in individuals from 15 to 49 years old, being these age groups those that presented the highest maleto-female ratio. S. sonnei was the most frequent species of Shigella isolated, followed by S. flexneri, although the information was not available in approximately half of the cases. Sexual transmission was mentioned only in a small percentage of cases, but information about exposure/transmission was not available for more than 90% cases. It is necessary to strengthen the epidemiological surveillance of this disease in Spain, regarding the transmission, microbiological characterization and antimicrobial resistance.N