Evaluation using latent class models of the diagnostic performances of three ELISA tests commercialized for the serological diagnosis of Coxiella burnetii infection in domestic ruminants.

ELISA methods are the diagnostic tools recommended for the serological diagnosis of Coxiella burnetii infection in ruminants but their respective diagnostic performances are difficult to assess because of the absence of a gold standard. This study focused on three commercial ELISA tests with the following objectives (1) assess their sensitivity and specificity in sheep, goats and cattle, (2) assess the between- and within-herd seroprevalence distribution in these species, accounting for diagnostic errors, and (3) estimate optimal sample sizes considering sensitivity and specificity at herd level. We comparatively tested 1413 cattle, 1474 goat and 1432 sheep serum samples collected in France. We analyzed the cross-classified test results with a hierarchical zero-inflated beta-binomial latent class model considering each herd as a population and conditional dependence as a fixed effect. Potential biases and coverage probabilities of the model were assessed by simulation. Conditional dependence for truly seropositive animals was high in all species for two of the three ELISA methods. Specificity estimates were high, ranging from 94.8% [92.1; 97.8] to 99.2% [98.5; 99.7], whereas sensitivity estimates were generally low, ranging from 39.3 [30.7; 47.0] to 90.5% [83.3; 93.8]. Between- and within-herd seroprevalence estimates varied greatly among geographic areas and herds. Overall, goats showed higher within-herd seroprevalence levels than sheep and cattle. The optimal sample size maximizing both herd sensitivity and herd specificity varied from 3 to at least 20 animals depending on the test and ruminant species. This study provides better interpretation of three widely used commercial ELISA tests and will make it possible to optimize their implementation in future studies. The methodology developed may likewise be applied to other human or animal diseases.

Spread and impact of the Schmallenberg virus epidemic in France in 2012-2013.

BACKGROUND: The Schmallenberg virus (SBV) emerged in Europe in 2011 and caused a widespread epidemic in ruminants.In France, SBV emergence was monitored through a national multi-stakeholder surveillance and investigation system. Based on the monitoring data collected from January 2012 to August 2013, we describe the spread of SBV in France during two seasons of dissemination (vector seasons 2011 and 2012) and we provide a large-scale assessment of the impact of this new disease in ruminants. RESULTS: SBV impact in infected herds was primarily due to the birth of stillborns or deformed foetuses and neonates. Congenital SBV morbidity level was on average moderate, although higher in sheep than in other ruminant species. On average, 8% of lambs, 3% of calves and 2% of kids born in SBV-infected herds showed typical congenital SBV deformities. In addition, in infected herds, farmers reported retrospectively a lower prolificacy during the vector season, suggesting a potential impact of acute SBV infection during mating and early stages of gestation. CONCLUSIONS: Due to the lack of available control and prevention measures, SBV spread quickly in the naive ruminant population. France continues to monitor for SBV, and updated information is made available online on a regular basis [http://www.plateforme-esa.fr/]. Outbreaks of congenital SBV are expected to occur sporadically from now on, but further epidemics may also occur if immunity at population level declines.

Main barriers to effective implementation of stroke care pathways in France: a qualitative study.

BACKGROUND: Stroke Care Pathways (SCPs) aim to improve quality of care by providing better access to stroke units, rehabilitation centres, and home care for dependent patients. The objective of this study was to identify the main barriers to effective implementation of SCPs in France. METHODS: We selected 4 types of SCPs currently implemented in France that differed in terms of geographical location, population size, socio-economic conditions, and available health care facilities. We carried out 51 semi-structured interviews of 44 key health professionals involved in these SCPs and used the interview data to (i) create a typology of the organisational barriers to effective SCP implementation by axial coding, (ii) define barrier contents by vertical coding. The typology was validated by a panel of 15 stroke care professionals. RESULTS: Four main barriers to effective SCP implementation were identified: lack of resources (31/44 interviewees), coordination problems among staff (14/44) and among facilities (27/44), suboptimal professional and organisational practices (16/44), and inadequate public education about stroke (13/44). Transposition of the findings onto a generic SCP highlighted alternative care options and identified 10 to 17 barriers that could disrupt continuity of care. CONCLUSION: Lack of resources was considered to be the chief obstacle to effective SCP implementation. However, the main weakness of existing SCPs was poor communication and cooperation among health professionals and among facilities. We intend to use this knowledge to construct a robust set of quality indicators for use in SCP quality improvement initiatives, in comparisons between SCPs, and in the assessment of the effective implementation of clinical practice guidelines.

The role of calling EMS versus using private transportation in improving the management of stroke in France.

OBJECTIVE: To compare the time from symptom onset to brain imaging between patients calling emergency medical services (EMS) and those using private means for transportation. METHODS: We focused on symptom onset-to-brain imaging times of ≤2 hours and ≤3 hours 30 minutes, assuming a one-hour interval between imaging and thrombolysis. Other variables were the patient's age, gender, stroke type, National Institutes of Health Stroke Scale (NIHSS) score, presence of an on-site stroke unit, and period of symptom onset. Univariate analyses and a hierarchical linear regression model were used, as appropriate, and adjusted for these variables. RESULTS: A total of 1,105 stroke patients (28%) were included in the analyses, 40.6% of them transported by EMS. Patients using EMS were significantly older (72.8 vs. 70.5 years; p = 0.008), they had a higher NIHSS score (8 vs. 6.1; p = 0.0001), fewer were ischemic (85.1% vs. 90.6%; p = 0.005), and more of them reached hospitals with an on-site stroke unit (81.3% vs. 72.9%; p = 0.002). For the EMS-call patients, the median symptom onset-to-brain imaging time was significantly shorter (3 hours 21 minutes vs. 5 hours 57 minutes), and after adjustment, maximum delays of 2 hours and 3 hours 30 minutes were independently associated with EMS call: 28% vs. 18% (p = 0.015) and 66% vs. 45% (p < 0.0001) of patients, respectively, leading to an adjusted odds ratio of 2.77 (95% confidence interval, 2.007-3.828; p < 0.0001) for the threshold of 3 hours 30 minutes. CONCLUSIONS: The symptom onset-to-brain imaging time was significantly shorter in case of EMS transportation, but most patients did not reach the hospital in time to be eligible for thrombolysis. Efforts are still needed to reduce delays, especially public education and EMS activation. These efforts should be combined with new approaches for the quality management of stroke patients.

The 2009 A(H1N1) influenza pandemic in the French Armed Forces: evaluation of three surveillance systems.

BACKGROUND: The French military forces had to modify their epidemiological surveillance systems at the time of the 2009 A(H1N1) influenza pandemic. The aim of this article was to present an evaluation of the different systems used. METHODS: Two influenza surveillance systems are usually used in the French forces: one permanent (Surveillance épidémiologique des armées or SEA) and one seasonal (Système militaire d'observation de la grippe or SMOG). The pandemic required the implementation of a daily surveillance system (Surveillance quotidienne--SQ), which aimed to monitor disrupted activity owing to 2009 A(H1N1) influenza. The qualitative evaluation of these three systems during the period from September 2009 to February 2010 was performed using 11 criteria based on the list defined by Centers for Disease Control and Prevention of Atlanta. RESULTS: Although it included only 30 sentinel units vs. 320 for the other systems, the SMOG system was the best-performing system in terms of relevance, feasibility, efficacy, quality of data, usefulness, acceptability, efficiency and cost/benefits/costs ratio. The SQ proved very expensive in terms of logistics. CONCLUSION: The SQ did not bring any significant advantage compared with the weekly surveillance schemes. In the eventuality of another similar episode, influenza surveillance could be significantly improved by using the SMOG system extended to more units for better geographical coverage.

Swab cloths as a tool for revealing environmental contamination by Q fever in ruminant farms.

Q fever is a zoonotic abortive disease of ruminants mostly transmitted by inhalation of aerosols contaminated by Coxiella burnetii. Clusters of cases or even epidemics regularly occur in humans but, to date, there is no consensus about the best way to carry out outbreak investigations in order to identify potential farms at risk. Although environmental samples might be useful during such investigations, there are few baseline data on the presence of C. burnetii in the environment of ruminant farms. We thus investigated dust samples from cattle, sheep and goat farm buildings in order to (a) estimate C. burnetii detection frequency and bacterial loads in the environment, and (b) determine whether this environmental contamination is associated with series of abortions attributed to Q fever. We considered 113 herds with a recent abortive episode potentially related (n = 60) or not (n = 53) to C. burnetii. Dust was sampled using a swab cloth and tested by a quantitative PCR method targeting the IS1111 gene. Coxiella burnetii DNA was detected on 9 of 50 cattle farms, 13 of 19 goat farms and 30 of 40 sheep farms. On 16 cloths, bacterial loads were higher than 108 genome equivalents, levels as high as in infectious materials such as placentas and aborted foetuses. Overall, the probability of detecting C. burnetii DNA was higher on small ruminant farms than cattle farms, in herds suspected of Q fever and in large herds. We conclude that swab cloths are a putative indicator of contamination of ruminant farms by C. burnetii.

Was the French clinical surveillance system of bovine brucellosis influenced by the occurrence and surveillance of other abortive diseases?

The bovine brucellosis clinical surveillance system implemented in France aims to detect early any case of bovine brucellosis, a disease of which the country has been declared free since 2005. It relies on the mandatory notification of every bovine abortion. Following the spread of the Schmallenberg virus (SBV) in France in 2012 and 2013, and the implementation in 2012 of a clinical surveillance programme of Q fever based on abortion notifications in ten pilot départements, our objective was to study whether these two events influenced the brucellosis clinical surveillance system. The proportion of notifying farmers was analyzed over each semester from June 1, 2009 to June 30, 2013 according to the size and production type of herds, SBV status of départements and the implementation of the Q fever surveillance. Our analysis showed a slight increase in the proportion of notifying farmers as départements became infected by SBV, and after the implementation of Q fever surveillance (during the first semester of 2013). These variations might be explained by an increase in abortion occurrence (congenital deformities in newborns, due to SBV) and/or by an increase in farmers' and veterinarians' awareness (due to the spread of SBV and the implementation of the Q fever surveillance). These results highlight the difficulties in interpreting variations in the proportion of notifying farmers as a consequence of an increase in abortion occurrence. As bovine abortion surveillance can play an important role in the early warning for several diseases, there is a need to explore other ways to monitor abortions in cattle, such as syndromic surveillance using the dates of artificial insemination or calving data.

The Schmallenberg virus epidemic in Europe-2011-2013.

During the Schmallenberg virus (SBV) epidemic, the European Food Safety Authority (EFSA) collected data on SBV occurrence across Europe in order to provide an assessment of spread and impact. By May 2013, twenty-nine countries were reporting to EFSA and twenty-two countries had reported cases of SBV. The total number of SBV herds reported was 13,846 and the number of SBV laboratory confirmed herds was 8730. The surveillance activities were based on the detection of SBV clinical cases (either adults or newborns). Malformation in newborns was the most commonly reported clinical sign of SBV-infection. All countries were able to provide the date when the first suspicion of SBV in the herd was reported and nineteen could report the location of the herd at a regional level. This allowed the spread of SBV in Europe to be measured both temporally and spatially. The number of SBV confirmed herds started to increase in December 2011 and two peaks were observed in 2012 (February and May). Confirmed herds continued to be reported in 2012 and into 2013. An increase during winter 2012 and spring 2013 was again observed, but the number of confirmed herds was lower than in the previous year. SBV spread rapidly throughout Europe from the initial area of detection. SBV was detected above the latitude of 60° North, which exceeds the northern expansion observed during the bluetongue virus serotype 8 epidemic in 2006-2009. The impact of SBV was calculated as ratio of the number of herds with at least one malformed SBV positive foetus and the total number of herds in this region. The 75th percentile of the malformations ratio in the various affected countries for the whole reporting period was below 1% and 3% for cattle and sheep herds, respectively. International data collection on emerging diseases represents a challenge as the nature of available data, data quality and the proportion of reported cases may vary widely between affected countries. Surveillance activities on emerging animal diseases are often structured only for case detection making the estimation of infection/diseases prevalence and the investigation of risk factors difficult. The impact of the disease must be determined to allow risk managers to take appropriate decisions. Simple within-herd impact indicators suitable for emerging disease outbreaks should be defined that could be measured as part of routine animal health surveillance programmes and allow for rapid and reliable impact assessment of emerging animal health diseases.

Schmallenberg virus-two years of experiences.

In autumn 2011, a novel species of the genus Orthobunyavirus of the Simbu serogroup was discovered close to the German/Dutch border and named Schmallenberg virus (SBV). Since then, SBV has caused a large epidemic in European livestock. Like other viruses of the Simbu serogroup, SBV is transmitted by insect vectors. Adult ruminants may show a mild transient disease, while an infection during a critical period of pregnancy can lead to severe congenital malformation, premature birth or stillbirth. The current knowledge about the virus, its diagnosis, the spread of the epidemic, the impact and the possibilities for preventing infections with SBV is described and discussed.

Adverse events following pandemic influenza vaccine Pandemrix® reported in the French military forces--2009-2010.

BACKGROUND: In the face of the A(H1N1) 2009 influenza pandemic, in October 2009 the French military health service (SSA) initiated a large vaccination campaign with Pandemrix(®) vaccine in the military forces. The aim of this study was to describe vaccine adverse events (VAE) reported during this campaign. METHODS: VAE and the number of people vaccinated were surveyed by the SSA Epidemiological network across all military forces during the campaign, from October 2009 to April 2010. For each case, a notification form was completed, providing patient and clinical information. Three types of VAE were considered: non-serious, serious and unexpected. RESULTS: There were 315.4 reported VAE per 100,000 vaccinations. Vaccination and VAE incidence rate peaks coincided with influenza epidemic peak in early December. The number of injected doses was 49,138, corresponding to a 14.5% vaccination coverage among military personnel, and 155 VAE were reported, including 5 serious VAE (1 Guillain-Barre syndrome, 2 malaises and 1 convulsive episode). Most VAE were non-serious (97.1%). Among these, 6 cases of local, rapidly regressive paresthesia were observed. DISCUSSION: The military VAE surveillance system constitutes the only observatory on benign VAE in France. The reporting rate was much higher after the pandemic vaccine than after the seasonal vaccine, which may be a reflection of stimulated reporting. This report provides a useful description of VAE among military personnel during a mass emergency vaccination program, showing that the tolerance of the pandemic vaccine appeared acceptable.