Climatic Factors and Influenza Transmission, Spain, 2010-2015

The spatio-temporal distribution of influenza is linked to variations in meteorological factors, like temperature, absolute humidity, or the amount of rainfall. The aim of this study was to analyse the association between influenza activity, and meteorological variables in Spain, across five influenza seasons: 2010-2011 through to 2014-2015 using generalized linear negative binomial mixed models that we calculated the weekly influenza proxies, defined as the weekly influenza-like illness rates, multiplied by the weekly proportion of respiratory specimens that tested positive for influenza. The results showed an association between influenza transmission and dew point and cumulative precipitation. In increase in the dew point temperature of 5 degrees produces a 7% decrease in the Weekly Influenza Proxy (RR 0.928, IC: 0.891-0.966), and while an increase of 10 mm in weekly rainfall equates to a 17% increase in the Weekly Influenza Proxy (RR 1.172, IC: 1.097-1.251). Influenza transmission in Spain is influenced by variations in meteorological variables as temperature, absolute humidity, or the amount of rainfall.This study has been funded by Instituto de Salud Carlos III through the project “PI15/01398” (Co-funded by European Regional Development Fund/European Social Fund “Investing in your future”).S

Geographical variation in relative risks associated with heat: Update of Spain's Heat Wave Prevention Plan

A decade after the implementation of prevention plans designed to minimise the impact of high temperatures on health, some countries have decided to update these plans in order to improve the weakness detected in these ten years of operation. In the case of Spain, this update has fundamentally consisted of changing the so-called "threshold" or "trigger" temperatures used to activate the plan, by switching from temperature values based on climatological criteria to others obtained by epidemiological studies conducted on a provincial scale. This study reports the results of these "trigger" temperatures for each of Spain's 52 provincial capitals, as well as the impact of heat on mortality by reference to the relative risks (RRs) and attributable risks (ARs) calculated for natural as well as circulatory and respiratory causes. The results obtained for threshold temperatures and RRs show a more uniform behaviour pattern than those obtained using temperature values based on climatological criteria; plus a clear decrease in RRs of heat-associated mortality due to the three causes considered, at both a provincial and regional level as well as for Spain as a whole. The updating of prevention plans is regarded as crucial for optimising the operation of these plans in terms of reducing the effect of high temperatures on population health.This study was supported by grants FIS ENPY 1001/13 & SEPY 1037/14 from Spain's Health Research Fund.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

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

Excess mortality in Spain during transmission of pandemic influenza in 2009

Fundamento: El sistema español de monitorización de la mortalidad y el "Programa Europeo de monitorización de excesos de mortalidad para la acción en salud pública" detectaron dos excesos de mortalidad en España en noviembre y diciembre de 2009. El objetivo de este trabajo es valorar su posible asociación con la transmisión de gripe pandémica. Métodos: Se analizó la evolución de la mortalidad en España en los meses citados utilizando métodos de análisis de series temporales basados en las series históricas de mortalidad y se comparó en el tiempo con la transmisión de gripe. Resultados: La mortalidad observada en la población total fue mayor de lo esperado en dos periodos: semanas 46-47/2009 con 5,75% de exceso y las semanas 51-52/2009 con 7,35% de exceso. También se registró un exceso de mortalidad en niños de 5 a 14 años en las semanas 46-48/2009 con 41 defunciones vs las 21 esperadas. El exceso de mortalidad en noviembre fue concomitante con las mayores tasas de gripe. El exceso de diciembre se observó 5 semanas después del pico de gripe y coincidió con un descenso dramático de las temperaturas. El virus sincitial respiratorio y los accidentes de tráfico fueron descartados como factores asociados. Conclusiones: Mientras que las temperaturas podrían explicar la mayoría del exceso de mortalidad observado en diciembre, ningún factor por si solo podría explicar el exceso de noviembre. BACKGROUND: The Spanish daily mortality monitoring system and the program «European monitoring of excess mortality for public health action» found two excesses of mortality in Spain in November and December 2009. METHODS: We analyzed the evolution of mortality in Spain during those months using time-series analysis methods based on historical mortality series and compared it in the time with influenza transmission. RESULTS: Observed mortality for the total population was higher than expected in two periods: weeks 46-47/2009 with 5.75% excess and weeks 51-52/2009 with 7.35% excess. Observed mortality higher than expected, was also observed in children 5-14 years old during weeks 46-48/2009 with 41 deaths vs 21 expected. Exces mortality in November occurred before or was concomitant with highest influenza incidence rates. Excess mortality in December occurred five weeks after the influenza incidence peak and along with dramatic drop in temperatures. RSV and traffic accidents were ruled out as factor associated to these excesses. CONCLUSIONS: While temperatures could explain most of the excess mortality observed in December, no single factor could be associated with observed excess mortality in November

Vigilancia de la gripe en España. Temporada 2014-2015 (desde la semana 40/2014 hasta la semana 20/2015).

La actividad gripal en España en la temporada 2014-2015 fue moderada y se asoció a una circulación mayoritaria de virus de la gripe A(H3N2) con una creciente contribución de virus B a partir del pico de la epidemia. La onda epidémica gripal tuvo una presentación normal en el tiempo con el pico de máxima actividad gripal a finales de enero de 2015. Los menores de 15 años fueron el grupo de edad más afectado, con mayores tasas de incidencia acumulada en el grupo de 5-14 años. Se notificaron 19 brotes confirmados de gripe en ocho Comunidades Autónomas (CCAA), el 58% de ellos ubicados en residencias geriátricas y como agente causal se confirmó el virus A(H3N2). El análisis filogenético de los virus gripales que circularon en España durante la temporada muestra que el 66,8 % de los virus A(H3N2) presentarían diferencias antigénicas con respecto al virus vacunal de la temporada 2014-2015 en el hemisferio norte. Sin embargo, los virus A(H1N1)pdm09 y los virus B del linaje Yamagata estarían cubiertos por la vacuna de esta temporada. Se notificaron 1.724 casos graves hospitalizados confirmados de gripe (CGHCG) de los que 33% fueron admitidos en UCI y 16% fallecieron. El mayor porcentaje de casos graves de gripe se registró en los mayores de 64 años y en el grupo de 45-64 años. En el 77% de los casos se confirmó el virus de la gripe tipo A, siendo el 83% de los subtipados A(H3N2). El 88% de los CGHCG presentó algún factor de riesgo de complicaciones de gripe y el 48% no había recibido la vacuna antigripal en la temporada. Las defunciones en los CGHCG se concentraron fundamentalmente en los mayores de 64 años. La letalidad observada en términos de defunciones entre CGHCG fue la más alta observada después de la pandemia de 2009. En consonancia con estos indicadores de gravedad, el sistema MOMO (Monitorización de la mortalidad diaria) estimó un exceso de mortalidad por todas las causas, concentrado fundamentalmente en el grupo de mayores de 64 años, coincidiendo con el periodo epidémico de la gripe. La actividad gripal en la región templada del hemisferio norte ha sido moderada con predominio de virus A(H3N2) en Europa y Norte de América. La actividad gripal en los países templados del hemisferio sur se ha mantenido en niveles propios de inter-temporada.N

Vigilancia de Gripe en España. Resumen de la temporada 2014-2015, semanas 40/2014-08/2015 (29/Septiembre/2014 al 22/Febrero/2015)

[ES] La actividad gripal registrada en España, desde el inicio de la temporada 2014-2015, hasta la semana 08/2015 ha sido moderada y asociada a una circulación mayoritaria de virus de la gripe A(H3N2). Su presentación en el tiempo estuvo dentro de lo esperado, con el pico de máxima actividad en la semana 05/2015. Los menores de 15 años fueron el grupo de edad más afectado, con mayores tasas acumuladas de incidencia de gripe en el grupo de 5-14 años. Se notificaron 19 brotes confirmados de gripe en ocho CCAA, diez en residencias geriátricas y ocho en instituciones sanitarias, en los que se confirmó mayoritariamente como virus causante el A(H3N2). El 62% de los virus A(H3N2) caracterizados hasta el momento pertenecen a grupos genéticos que presentarían diferencias con el virus vacunal de esta temporada 2014-2015. Se han notificado 1.221 casos graves hospitalizados confirmados de gripe (CGHCG), de los cuales 143 han fallecido. Más del 50% de los CGHCG se registró en mayores de 64 años y en su mayoría correspondieron a infecciones por virus de la gripe A(H3N2). El 32% ingresó en UCI y el 50% de los casos pertenecientes a los grupos elegibles para vacunación no había recibido la vacuna antigripal de esta temporada.Se ha observado un exceso de la mortalidad por todas las causas, por encima de lo esperado desde el inicio del 2015, en personas mayores de 64 años, coincidiendo con el periodo de máxima actividad de la gripe. La actividad gripal en la región templada del hemisferio norte ha sido moderada con predominio de virus A(H3N2) en Europa y Norte de América. La actividad gripal en los países templados del hemisferio sur se ha mantenido en niveles propios de inter-temporada. [EN] Since the beginning of the 2014-15 season up to week 08/2015, the influenza activity in Spain has been moderate and dominated by influenza A(H3N2) viruses with an epidemic peak in 05/2015 week. Children under 15 years old have been the most affected. Nineteen laboratory-confirmed influenza outbreaks were reported in eight CCAA, 10 in long-term care facilities and eight in hospital settings, the majority of them were caused by influenza A(H3N2) virus. The 62% of genetically characterised influenza A(H3N2) viruses belong to subgroups distinct from the recommended vaccine-strain of the 2014–2015 season. A total of 1,221 severe hospitalized laboratory-confirmed influenza cases (SHCIC) were reported, including 143 deaths. Over 50% of SHCIC of adults ≥65 years of age were mostly influenza A(H3N2). The 32% of cases were admitted to ICU and 50% of target groups for vaccination cases had received seasonal influenza vaccine. Excess all-cause mortality has been observed since the beginning of the year 2015 among people aged 65 years and older, concomitant with the period of maximum influenza activity. In the northern hemisphere, influenza activity remained moderate with influenza A(H3N2) viruses predominating in Europe and North America. In the southern hemisphere, influenza activity remained at inter-seasonal levels.N

Vigilancia de la gripe en España Temporada 2015-2016 (desde la semana 40/2015 hasta la semana 20/2016)

[ES] La actividad gripal en España en la temporada 2015-16 fue baja y asociada a una circulación mayoritaria de virus de la gripe A(H1N1)pdm09, con una creciente contribución de virus de la gripe B a medida que ha ido avanzando la temporada. La epidemia gripal se inició de forma tardía, presentando posteriormente una onda epidémica atípica, con una meseta de incidencia de gripe estable durante varias semanas consecutivas y una duración total en el rango de las 10 temporadas previas. Los menores de 15 años fueron el grupo de edad más afectado, con mayores tasas de incidencia acumulada en el grupo de 0-4 años. Se notificaron 12 brotes confirmados de gripe en siete CCAA. El 92% de los brotes se asoció a virus tipo A (siete A(H1N1)pdm09, 3 ANS y uno A(H3N2)) todos ellos en centros sanitarios, geriátricos o instituciones de larga estancia. De las 2.716 detecciones centinela identificadas a lo largo de la temporada, el 66% fueron virus de la gripe A, 98% de A(H1N1)pdm09, entre los subtipados. A nivel global se puede distinguir una primera onda de circulación de virus A(H1N1)pdm09 y posteriormente otra con circulación de virus B. En las redes centinela con picos de intensidad gripal más tempranos se ha observado una mayor contribución de virus A(H1N1)pdm09, mientras que en aquellas con periodos epidémicos más tardíos se observó una mayor contribución de virus B. La caracterización genética de los virus circulantes esta temporada indicó que todos aquellos virus A(H1N1) caracterizados eran semejantes a A/SouthAfrica/3626/2013, todos los virus A(H3N2) eran semejantes a A/HongKong/4801/2014 y la práctica totalidad (96%) de virus de la gripe B eran semejantes a B/Brisbane/60/2008 (linaje Victoria). Se notificaron 3.101 casos graves hospitalizados confirmados de gripe (CGHCG) en 19 CCAA, de los que 1.071 (35%) fueron admitidos en UCI y 352 (11,4%) fallecieron. La mayor proporción de casos se concentró en los mayores de 64 años (40%), seguido del grupo de 45-64 años (33%). Las mayores tasas de hospitalización se observaron en los mayores de 64 años y en el grupo de 0 a 4 años. En el 85% de los casos se confirmó el virus de la gripe tipo A, siendo el 98% de los subtipados (H1N1)pdm09. El 75% de los CGHCG presentó algún factor de riesgo de complicaciones de gripe. El 64,5% de los pacientes pertenecientes a grupos donde estaba recomendada la vacunación, no habían recibido la vacuna antigripal de esta temporada. Las defunciones en casos graves hospitalizados confirmados de gripe se concentraron fundamentalmente en los mayores de 64 años (59%) y el 88% de los casos fatales presentó algún factor de riesgo de complicaciones. El 59% de los pacientes recomendados de vacunación no habían recibido la vacuna antigripal de esta temporada. La letalidad observada en términos de defunciones entre CGHCG fue inferior a la temporada previa, y similar a las anteriores. El sistema MOMO (Monitorización de la mortalidad diaria) estimó un exceso de mortalidad por todas las causas en las semanas 9, 11, 13 y 14/2016 que se concentró en el grupo de 15 a 64 años. Excesos similares se han informado en varios países europeos. [EN] Influenza activity in Spain during the 2015-16 season was low and dominated by influenza A(H1N1)pdm09 virus circulation, with an increasing contribution from B virus as the season progressed. Influenza epidemic had a late time presentation, showing an atypical epidemic wave afterwards, with a stable incidence plateau for several consecutive weeks. The total duration was in the range of the previous 10 seasons. Children under 15 years old have been the most affected with higher rates of cumulative incidence in 0-4 age group. Twelve laboratory-confirmed influenza outbreaks were reported in seven autonomous regions (AR), 92% of them associated with type A virus (seven A(H1N1)pdm09, 3 A not subtyped and one A (H3N2), all in health centers, nursing homes or long-stay institutions. Of the 2,716 specimens from sentinel sources tested positive for influenza virus throughout the season, 66% were influenza A virus, with A(H1N1)pdm09 representing 98% of those subtyped. Globally, a first wave associated with A(H1N1)pdm09 can be distinguished, and then another associated with B virus. In those sentinel networks with early intensity peak, a greater contribution of virus A (H1N1) pdm09 has been observed, while those with later epidemic periods where associated with greater contribution of B virus. All A(H1N1)pdm09 virus genetically characterized have been similar to A/ SouthAfrica/3626/2013, all A(H3N2) were similar to A/HongKong/4801/2014 and almost all (96%) of influenza B viruses were similar to B/Brisban /60/2008 (Victoria lineage). A total of 3,101 severe hospitalized laboratory-confirmed influenza cases (SHCIC) were reported in 19 AR, of which 1,071 (35%) were admitted to ICU and 352 (11.4%) died. The highest percentage of SHCIC occurred over 64 years (40%), followed by the 45-64 age group (33%). The highest hospitalization rates were observed over 64 years and in the group of 0-4 years. The 85% of SHCIC were associated with influenza A virus, and the vast majority of the subtyped A viruses (98%) were A(H1N1)pdm09. Seventy-five percent had underlying conditions and 64.5% had not received a seasonal influenza vaccine. Most of the deaths of SHCIC (59%) were in adults over 64 years old. Eighty-eight percent had underlying conditions and 59% of patients with recommended vaccination condition had not received a seasonal influenza vaccine. MOMO system (Monitoring daily mortality) estimated an excess mortality from all causes in weeks 9, 11, 13 and 14/2016 which focused on the group of 15-64 years. Similar excesses have been reported in several European countrie