European all-cause excess and influenza-attributable mortality in the 2017/18 season: should the burden of influenza B be reconsidered?

OBJECTIVES: Weekly monitoring of European all-cause excess mortality, the EuroMOMO network, observed high excess mortality during the influenza B/Yamagata dominated 2017/18 winter season, especially among elderly. We describe all-cause excess and influenza-attributable mortality during the season 2017/18 in Europe. METHODS: Based on weekly reporting of mortality from 24 European countries or sub-national regions, representing 60% of the European population excluding the Russian and Turkish parts of Europe, we estimated age stratified all-cause excess morality using the EuroMOMO model. In addition, age stratified all-cause influenza-attributable mortality was estimated using the FluMOMO algorithm, incorporating influenza activity based on clinical and virological surveillance data, and adjusting for extreme temperatures. RESULTS: Excess mortality was mainly attributable to influenza activity from December 2017 to April 2018, but also due to exceptionally low temperatures in February-March 2018. The pattern and extent of mortality excess was similar to the previous A(H3N2) dominated seasons, 2014/15 and 2016/17. The 2017/18 overall all-cause influenza-attributable mortality was estimated to be 25.4 (95%CI 25.0-25.8) per 100,000 population; 118.2 (116.4-119.9) for persons aged 65. Extending to the European population this translates into over-all 152,000 deaths. CONCLUSIONS: The high mortality among elderly was unexpected in an influenza B dominated season, which commonly are considered to cause mild illness, mainly among children. Even though A(H3N2) also circulated in the 2017/18 season and may have contributed to the excess mortality among the elderly, the common perception of influenza B only having a modest impact on excess mortality in the older population may need to be reconsidered.

Pertinence of electronic death certificates for real-time surveillance and alert, France, 2012-2014.

OBJECTIVES: In France, the early mortality monitoring, conducted by Santé publique France, the French National Public Health agency (SpFrance) (formerly French Institute for public health surveillance-InVS), is based on the administrative data provided by the National Institute for Statistic and Economic Studies (INSEE) and consequently does not allow analyses on medical causes of death. Since 2007, the physicians can certify deaths electronically. In this electronic system (Electronic Death Registration System; EDRS), the medical causes of death, in free-text format, are directly transmitted to SpFrance. In the future, these data could be used in a real-time surveillance system by medical causes of death. The objective of this study was to evaluate the pertinence of e-death certification using the following assessment criteria: timeliness, representativeness, and completeness of sociodemographic and medical information included in the e-death certificates. STUDY DESIGN: This study consisted of a descriptive analysis of the information collected by e-death certificates recorded between January 1, 2012 and July 31, 2014. METHODS: The study quantified the temporal and geographical evolution of the deployment of the EDRS between 2012 and 2014. The timeliness of the system was estimated by calculating the delay between the dates of death and of data availability for analysis. Sociodemographic and death-related characteristics were described. The frequency of missing data was measured for each variable. The number of completed fields per certificate and the number of words per field and per certificate were calculated for the medical causes of death. RESULTS: Between January 2012 and July 2014, 77,776 e-death certificates were collected. A slight increase in the use of the e-death certification was observed during the study period, reaching 6.1% of the total number of deaths in 2014. Good national coverage was noted. Nearly 79% of e-certificates were submitted to SpFrance on the day of the death. We observed a high completeness of the e-certificates. The rate of missing data did not exceed 2.7% for sociodemographic variables. On average, 10 words, distributed in three fields, were used to describe the medical causes of death. CONCLUSIONS: E-death certificates constitute a reactive source of information on medical causes of death. The deployment of EDRS is of major public health interest for the development of a real-time warning surveillance system of mortality by cause.

[Surveillance and detection of unusual events in toxicovigilance: Review of relevant methods]. / Surveillance et détection des événements inhabituels en toxicovigilance : revue des méthodes pertinentes.

BACKGROUND: Declared cases of exposures related to potential toxic agents are reported through a national database, the French Network of Poison Centers, and account on average for 200,000 cases per year, including 75,000 to 80,000 symptomatic cases. These data are currently used to investigate signals from local, national or international institutional partners (such as hospitals, local health authorities, and the Rapid Alert System for Food and Feed). Our objective is to complete this classical toxicovigilance activity through the automated detection of unexpected or unusual events in order to identify precociously signals representing potential threats for public health. To reach this objective, the inventory of surveillance and detection methods of unexpected events is necessary. METHODS: A literature review was conducted via Scopus(®) and Pubmed(®) databases, completed with grey literature and data available on worldwide vigilance systems' websites. RESULTS: The most commonly used methods are disproportional measures in the field of pharmacovigilance, some of which are subject to a routine detection at regular time intervals. Criteria of signal generation differ from one system to another, which have implemented data filtering strategies before or after analysis, in order to decrease the number of generated signals and improve their priority level. These signals are then transmitted to an experts committee for a clinical and epidemiological evaluation, and at times, for informing the patient's medical records. We also notice an interest in other approaches such as surveillance methods of temporal series or symbolic methods for associative rules extraction between one or more drugs and one or more adverse effects, with the possibility to include other types of variables, such a demographic data. The developments of probabilistic-based algorithms have also been recently developed, opening new opportunities. CONCLUSION: These surveillance and detection methods are of high interest for the automated detection of signals from the French toxicovigilance network. The initial step to developing these methods consists in studying the statistical quality of data and targeting the needs and expectations of the toxicovigilance network for what we want and what we can detect.

Excess mortality among the elderly in European countries, December 2014 to February 2015.

Since December 2014 and up to February 2015, the weekly number of excess deaths from all-causes among individuals ≥ 65 years of age in 14 European countries have been significantly higher than in the four previous winter seasons. The rise in unspecified excess mortality coincides with increased proportion of influenza detection in the European influenza surveillance schemes with a main predominance of influenza A (H3N2) viruses seen throughout Europe in the current season, though cold snaps and other respiratory infections may also have had an effect.

[Syndromic surveillance: review and prospect of a promising concept]. / La surveillance syndromique: bilan et perspective d'un concept prometteur.

Syndromic surveillance appeared in the field of public health surveillance in the late 90's. Initially proposed for public health identification of bioterrorism events, the method failed to provide convincing evidence of its usefulness and potential benefits. The definition which is proposed today by the Centers for Disease Control and Prevention (CDC) of Atlanta is the most commonly accepted. It defines syndromic surveillance as an automatic process that goes from registration to transfer of data recorded within the framework of a professional rather than public health goal. Systems operating today have integrated a public health approach through routine surveillance procedures with a broader focus than bioterrorism, implying active participation of the official public health surveillance structures. Syndromic surveillance offers several advantages including quick access to a large volume of data in real time, no extra-work for data registration and construction of a historical dataset useful as an historical baseline. Nevertheless, the limitations of this type of surveillance should not be forgotten (sometimes limited sensitivity, specificity, important technical burden…). Today, recorded experience shows that there is no opposition between syndromic surveillance and classical surveillance. On the contrary, they should be presented as complementary procedures. Syndromic surveillance should be analyzed from a temporal perspective, examining its short-term use as an alert mechanism, mid-term use for constitution of historical time series, and long-term use for a description of human health in the 21st century.

Excess mortality among the elderly in 12 European countries, February and March 2012.

In February and March 2012, excess deaths among the elderly have been observed in 12 European countries that carry out weekly monitoring of all-cause mortality. These preliminary data indicate that the impact of influenza in Europe differs from the recent pandemic and post-pandemic seasons. The current excess mortality among the elderly may be related to the return of influenza A(H3N2) virus, potentially with added effects of a cold snap.

CCL2 binding is CCR2 independent in primary adult human astrocytes.

Chemokines are low relative molecular mass proteins, which have chemoattractant actions on many cell types. The chemokine, CCL2, has been shown to play a major role in the recruitment of monocytes in central nervous system (CNS) lesions in multiple sclerosis (MS). Since resident astrocytes constitute a major source of chemokine synthesis including CCL2, we were interested to assess the regulation of CCL2 by astrocytes. We showed that CCL2 bound to the cell surface of astrocytes and binding was not modulated by inflammatory conditions. However, CCR2 protein was not detected nor was activation of the classical CCR2 downstream signaling pathways. Recent studies have shown that non-signaling decoy chemokine receptors bind and modulate the expression of chemokines at site of inflammation. Here, we show that the D6 chemokine decoy receptor is constitutively expressed by primary human adult astrocytes at both mRNA and protein level. In addition, CCL3, which binds to D6, but not CCL19, which does not bind to D6, displaced CCL2 binding to astrocytes; indicating that CCL2 may bind to this cell type via the D6 receptor. Our results suggest that CCL2 binding to primary adult human astrocytes is CCR2-independent and is likely to be mediated via the D6 decoy chemokine receptor. Therefore we propose that astrocytes are implicated in both the establishment of chemokine gradients for the migration of leukocytes into and within the CNS and in the regulation of CCL2 levels at inflammatory sites in the CNS.

A review of the dynamics and severity of the pandemic A(H1N1) influenza virus on Réunion island, 2009.

On Reunion Island, in response to the threat of emergence of the pandemic influenza A(H1N1)2009 virus, we implemented enhanced influenza surveillance from May 2009 onwards in order to detect the introduction of pandemic H1N1 influenza and to monitor its spread and impact on public health. The first 2009 pandemic influenza A(H1N1) virus was identified in Réunion on July 5, 2009, in a traveller returning from Australia; seasonal influenza B virus activity had already been detected. By the end of July, a sustained community pandemic virus transmission had been established. Pandemic H1N1 influenza activity peaked during week 35 (24-30 August 2009), 4 weeks after the beginning of the epidemic. The epidemic ended on week 38 and had lasted 9 weeks. During these 9 weeks, an estimated 66 915 persons who consulted a physician could have been infected by the influenza A(H1N1)2009 virus, giving a cumulative attack rate for consultants of 8.26%. Taking into account the people who did not consult, the total number of infected persons reached 104 067, giving a cumulative attack rate for symptomatics of 12.85%. The crude fatality rate (CFR) for influenza A(H1N1)2009 and the CFR for acute respiratory infection was 0.7/10 000 cases. Our data show that influenza pandemic did not have a health impact on overall mortality on Réunion Island. These findings demonstrate the value of an integrated epidemiological, virological and hospital surveillance programme to monitor the scope of an epidemic, identify circulating strains and provide some guidance to public health control measures.

Has the impact of heat waves on mortality changed in France since the European heat wave of summer 2003? A study of the 2006 heat wave.

BACKGROUND: In July 2006, a lasting and severe heat wave occurred in Western Europe. Since the 2003 heat wave, several preventive measures and an alert system aiming at reducing the risks related to high temperatures have been set up in France by the health authorities and institutions. In order to evaluate the effectiveness of those measures, the observed excess mortality during the 2006 heat wave was compared to the expected excess mortality. METHODS: A Poisson regression model relating the daily fluctuations in summer temperature and mortality in France from 1975 to 2003 was used to estimate the daily expected number of deaths over the period 2004-2006 as a function of the observed temperatures. RESULTS: During the 2006 heat wave (from 11 to 28 July), about 2065 excess deaths occurred in France. Considering the observed temperatures and with the hypothesis that heat-related mortality had not changed since 2003, 6452 excess deaths were predicted for the period. The observed mortality during the 2006 heat wave was thus markedly less than the expected mortality (approximately 4400 less deaths). CONCLUSIONS: The excess mortality during the 2006 heat wave, which was markedly lower than that predicted by the model, may be interpreted as a decrease in the population's vulnerability to heat, together with, since 2003, increased awareness of the risk related to extreme temperatures, preventive measures and the set-up of the warning system.

Excess mortality related to the August 2003 heat wave in France.

OBJECTIVES: From August 1st to 20th, 2003, the mean maximum temperature in France exceeded the seasonal norm by 11-12 degrees C on nine consecutive days. A major increase in mortality was then observed, which main epidemiological features are described herein. METHODS: The number of deaths observed from August to November 2003 in France was compared to those expected on the basis of the mortality rates observed from 2000 to 2002 and the 2003 population estimates. RESULTS: From August 1st to 20th, 2003, 15,000 excess deaths were observed. From 35 years age, the excess mortality was marked and increased with age. It was 15% higher in women than in men of comparable age as of age 45 years. Excess mortality at home and in retirement institutions was greater than that in hospitals. The mortality of widowed, single and divorced subjects was greater than that of married people. Deaths directly related to heat, heatstroke, hyperthermia and dehydration increased massively. Cardiovascular diseases, ill-defined morbid disorders, respiratory diseases and nervous system diseases also markedly contributed to the excess mortality. The geographic variations in mortality showed a clear age-dependent relationship with the number of very hot days. No harvesting effect was observed. CONCLUSIONS: Heat waves must be considered as a threat to European populations living in climates that are currently temperate. While the elderly and people living alone are particularly vulnerable to heat waves, no segment of the population may be considered protected from the risks associated with heat waves.