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1.  Assessing pneumococcal meningitis association with viral respiratory infections and antibiotics: insights from statistical and mathematical models 
Pneumococcus is an important human pathogen, highly antibiotic resistant and a major cause of bacterial meningitis worldwide. Better prevention requires understanding the drivers of pneumococcal infection incidence and antibiotic susceptibility. Although respiratory viruses (including influenza) have been suggested to influence pneumococcal infections, the underlying mechanisms are still unknown, and viruses are rarely considered when studying pneumococcus epidemiology. Here, we propose a novel mathematical model to examine hypothetical relationships between Streptococcus pneumoniae meningitis incidence (SPMI), acute viral respiratory infections (AVRIs) and antibiotic exposure. French time series of SPMI, AVRI and penicillin consumption over 2001–2004 are analysed and used to assess four distinct virus–bacteria interaction submodels, ascribing the interaction on pneumococcus transmissibility and/or pathogenicity. The statistical analysis reveals strong associations between time series: SPMI increases shortly after AVRI incidence and decreases overall as the antibiotic-prescription rate rises. Model simulations require a combined impact of AVRI on both pneumococcal transmissibility (up to 1.3-fold increase at the population level) and pathogenicity (up to threefold increase) to reproduce the data accurately, along with diminished epidemic fitness of resistant pneumococcal strains causing meningitis (0.97 (0.96–0.97)). Overall, our findings suggest that AVRI and antibiotics strongly influence SPMI trends. Consequently, vaccination protecting against respiratory virus could have unexpected benefits to limit invasive pneumococcal infections.
PMCID: PMC3712413  PMID: 23782877
antibiotic resistance fitness cost; mathematical model; statistical model; Streptococcus pneumonia meningitis; virus–bacteria interaction; influenza
2.  Outpatient Antibiotic Use in France between 2000 and 2010: after the Nationwide Campaign, It Is Time To Focus on the Elderly 
Antibiotic overconsumption is the main force driving the emergence of multidrug-resistant bacterial strains. To promote better antibiotic use in France, a nationwide campaign has been run every year from October to March since 2002. In 2007, it was shown that winter outpatient antibiotic consumption had decreased by 26.5% compared to the 2000-2002 baseline period. Here, we quantified outpatient antibiotic use between 2000 and 2010 as a follow-up analysis of the nationwide campaign. Reimbursed outpatient antibiotic prescriptions were extracted from computerized French National Health Insurance databases. Entire series and age group and antibiotic class analyses were computed. Time series analyses used autoregressive moving-average models with exogenous variables and intervention functions. Two periods were considered: October to March “campaign” periods and April to September “warm” periods. Compared to the precampaign (2000-2002) baseline period, the numbers of weekly antibiotic prescriptions per 1,000 inhabitants during campaign periods decreased until winter 2006 to 2007 (−30% [95% confidence interval {CI}, −36.3 to −23.8%]; P < 0.001) and then stabilized except for individuals >60 years of age, for whom prescriptions reached the precampaign level. During the warm periods from April to September, no significant differences were estimated compared to the baseline level for the entire series, but seniors had an increasing trend that became significant as of 2005, reaching +21% (95% CI, +12.9 to +29.6%) in 2009 (P < 0.0001). These results highlight the need for a better understanding of antibiotic use by the elderly, requiring research with targeted and tailored public health actions for this population.
PMCID: PMC3910776  PMID: 24126584
3.  Insights into Persistence Mechanisms of a Zoonotic Virus in Bat Colonies Using a Multispecies Metapopulation Model 
PLoS ONE  2014;9(4):e95610.
Rabies is a worldwide zoonosis resulting from Lyssavirus infection. In Europe, Eptesicus serotinus is the most frequently reported bat species infected with Lyssavirus, and thus considered to be the reservoir of European bat Lyssavirus type 1 (EBLV-1). To date, the role of other bat species in EBLV-1 epidemiology and persistence remains unknown. Here, we built an EBLV-1−transmission model based on local observations of a three-cave and four-bat species (Myotis capaccinii, Myotis myotis, Miniopterus schreibersii, Rhinolophus ferrumequinum) system in the Balearic Islands, for which a 1995–2011 serological dataset indicated the continuous presence of EBLV-1. Eptesicus serotinus was never observed in the system during the 16-year follow-up and therefore was not included in the model. We used the model to explore virus persistence mechanisms and to assess the importance of each bat species in the transmission dynamics. We found that EBLV-1 could not be sustained if transmission between M. schreibersii and other bat species was eliminated, suggesting that this species serves as a regional reservoir. Global sensitivity analysis using Sobol's method revealed that following the rate of autumn−winter infectious contacts, M. schreibersii's incubation- and immune-period durations, but not the infectious period length, were the most relevant factors driving virus persistence.
PMCID: PMC3995755  PMID: 24755619
4.  Management of Upper Respiratory Tract Infections by Different Medical Practices, Including Homeopathy, and Consumption of Antibiotics in Primary Care: The EPI3 Cohort Study in France 2007–2008 
PLoS ONE  2014;9(3):e89990.
Prescribing of antibiotics for upper respiratory tract infections (URTI) varies substantially in primary care.
To describe and compare antibiotic and antipyretic/anti-inflammatory drugs use, URTI symptoms' resolution and occurrence of potentially-associated infections in patients seeking care from general practitioners (GPs) who exclusively prescribe conventional medications (GP-CM), regularly prescribe homeopathy within a mixed practice (GP-Mx), or are certified homeopathic GPs (GP-Ho).
The EPI3 survey was a nationwide population-based study of a representative sample of 825 GPs and their patients in France (2007–2008). GP recruitment was stratified by self-declared homeopathic prescribing preferences. Adults and children with confirmed URTI were asked to participate in a standardized telephone interview at inclusion, one-, three- and twelve-month follow up. Study outcomes included medication consumption, URTI symptoms' resolution and potentially-associated infections (sinusitis or otitis media/externa) as reported by patients. Analyses included calibration to account for non-respondents and groups were compared using multivate analyses adjusting for baseline differences with a propensity score.
518 adults and children with URTI (79.3% rhinopharyngitis) were included (36.9% response rate comparable between groups). As opposed to GP-CM patients, patients in the GP-Ho group showed significantly lower consumption of antibiotics (Odds ratio (OR) = 0.43, 95% confidence interval (CI): 0.27–0.68) and antipyretic/anti-inflammatory drugs (OR = 0.54, 95% CI: 0.38–0.76) with similar evolution in related symptoms (OR = 1.16, 95% CI: 0.64–2.10). An excess of potentially-associated infections (OR = 1.70, 95% CI: 0.90–3.20) was observed in the GP-Ho group (not statistically significant). No difference was found between GP-CM and GP-Mx patients.
Patients who chose to consult GPs certified in homeopathy used less antibiotics and antipyretic/anti-inflammatory drugs for URTI than those seen by GPs prescribing conventional medications. No difference was observed in patients consulting GPs within mixed-practice. A non-statistically significant excess was estimated through modelling for associated infections in the GP-Ho group and needs to be further studied.
PMCID: PMC3960096  PMID: 24646513
5.  Antibiotic Reduction Campaigns Do Not Necessarily Decrease Bacterial Resistance: the Example of Methicillin-Resistant Staphylococcus aureus 
Interventions designed to reduce antibiotic consumption are under way worldwide. While overall reductions are often achieved, their impact on the selection of antibiotic-resistant selection cannot be assessed accurately from currently available data. We developed a mathematical model of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) transmission inside and outside the hospital. A systematic simulation study was then conducted with two objectives: to assess the impact of antibiotic class-specific changes during an antibiotic reduction period and to investigate the interactions between antibiotic prescription changes in the hospital and the community. The model reproduced the overall reduction in MRSA frequency in French intensive-care units (ICUs) with antibiotic consumption in France from 2002 to 2003 as an input. However, the change in MRSA frequency depended on which antibiotic classes changed the most, with the same overall 10% reduction in antibiotic use over 1 year leading to anywhere between a 69% decrease and a 52% increase in MRSA frequency in ICUs and anywhere between a 37% decrease and a 46% increase in the community. Furthermore, some combinations of antibiotic prescription changes in the hospital and the community could act in a synergistic or antagonistic way with regard to overall MRSA selection. This study shows that class-specific changes in antibiotic use, rather than overall reductions, need to be considered in order to properly anticipate the impact of an antibiotic reduction campaign. It also highlights the fact that optimal gains will be obtained by coordinating interventions in hospitals and in the community, since the effect of an intervention in a given setting may be strongly affected by exogenous factors.
PMCID: PMC3754303  PMID: 23817383
6.  Comparing human papillomavirus prevalences in women with normal cytology or invasive cervical cancer to rank genotypes according to their oncogenic potential: a meta-analysis of observational studies 
BMC Infectious Diseases  2013;13:373.
Mucosal human papillomavirus (HPV) infection is a necessary cause of cervical cancer. Vaccine and non-vaccine genotype prevalences may change after vaccine introduction. Therefore, it appears essential to rank HPV genotypes according to their oncogenic potential for invasive cervical cancer, independently of their respective prevalences.
We performed meta-analyses of published observational studies and estimated pooled odds ratios with random-effects models for 32 HPV genotypes, using HPV-16 as the reference.
Twenty-seven studies yielded 9,252 HPV-infected women: 2,902 diagnosed with invasive cervical cancer and 6,350 with normal cytology. Expressed as (odds ratio [95% confidence interval]), HPV-18 (0.63 [0.51, 0.78]) ranked closest to HPV-16, while other genotypes showed continuously decreasing relative oncogenic potentials: HPV-45 (0.35 [0.22, 0.55]), HPV-69 (0.28 [0.09, 0.92]), HPV-58 (0.24 [0.15, 0.38]), HPV-31 (0.22 [0.14, 0.35]), HPV-33 (0.22 [0.12, 0.38]), HPV-34 (0.21 [0.06, 0.80]), HPV-67 (0.21 [0.06, 0.67]), HPV-39 (0.17 [0.09, 0.30]), HPV-59 (0.17 [0.09, 0.31]), HPV-73 (0.16 [0.06, 0.41]), and HPV-52 (0.16 [0.11, 0.23]).
Our results support the markedly higher oncogenic potentials of HPV-16 and -18, followed by HPV-31, -33, -39, -45, -52, -58 and -59, and highlight the need for further investigation of HPV-34, -67, -69 and -73. Overall, these findings could have important implications for the prevention of cervical cancer.
PMCID: PMC3751808  PMID: 23941096
Human papillomavirus; Genotype; Cervical cancer; Oncogenic potential; Meta-analysis
7.  Did Media Attention of the 2009 A(H1N1) Influenza Epidemic Increase Outpatient Antibiotic Use in France?: A Time-Series Analysis 
PLoS ONE  2013;8(7):e69075.
In France, the 2009 A(H1N1) influenza epidemic occurred between September 2009 and January 2010. Sparking widespread controversy, it was intensely reported in the media. Despite therapeutic inefficacy, antibiotic consumption and viral respiratory infections are positively correlated, particularly in France, where antibiotic overconsumption is well-known. We first determined the period when media coverage was high, and then compared, during this period, observed outpatient antibiotic consumption to estimated outpatient antibiotic consumption “without media attention”.
Materials and Methods
To evaluate media coverage, two online databases were consulted: Factiva and Europresse. To quantify outpatient antibiotic consumption, we used data on reimbursements of outpatient systemic antibiotics from the computerized databases of the two main National Health Insurance agencies. Influenza-like syndromes data came from the French GPs Sentinelles Network. Weekly time-series of antibiotic consumption were modeled by autoregressive moving-average models with exogenous inputs and interventions. Analyses were computed for the entire series and by age group (0–5, 6–15, 16–60, and >60 years).
Media coverage was intense between April 2009 and January 2010. No effect on total outpatient antibiotic consumption was observed during the whole mediatic period. However, during the epidemic in France (September 2009-January 2010), we found an antibiotic underconsumption for the entire series, 0–5 and >60 years. Additionally, at the beginning of the pandemic, when cases were still outside France (June 2009-August 2009), we found an antibiotic overconsumption for patients >16 years.
The early period of A(H1N1) virus circulation compared with seasonal influenza or an overdeclaration of ILS cases might explain the antibiotic underconsumption observed during the period of active A(H1N1) virus transmission in France. At the pandemic onset, when uncertainty was high, the overconsumption observed for individuals >16 years might have been caused by alarmist media reporting. Additional analyses are needed to understand the determinants of antibiotic consumption during this period.
PMCID: PMC3722179  PMID: 23894409
8.  Limits of patient isolation measures to control extended-spectrum beta-lactamase–producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward 
BMC Infectious Diseases  2013;13:187.
Extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) are a growing concern in hospitals and the community. How to control the nosocomial ESBL-E transmission is a matter of debate. Contact isolation of patients has been recommended but evidence supporting it in non-outbreak settings has been inconclusive.
We used stochastic transmission models to analyze retrospective observational data from a two-phase intervention in a pediatric ward, successively implementing single-room isolation and patient cohorting in an isolation ward, combined with active ESBL-E screening.
For both periods, model estimates suggested reduced transmission from isolated/cohorted patients. However, most of the incidence originated from sporadic sources (i.e. independent of cross-transmission), unaffected by the isolation measures. When sporadic sources are high, our model predicted that even substantial efforts to prevent transmission from carriers would have limited impact on ESBL-E rates.
Our results provide evidence that, considering the importance of sporadic acquisition, e.g. endogenous selection of resistant strains following antibiotic treatment, contact-isolation measures alone might not suffice to control ESBL-E. They also support the view that estimating cross-transmission extent is key to predicting the relative success of contact-isolation measures. Mathematical models could prove useful for those estimations and guide decisions concerning the most effective control strategy.
PMCID: PMC3640926  PMID: 23618041
ESBL-E; Healthcare epidemiology; Bacterial pathogens; Mathematical modeling; Statistical inference
9.  Who seeks primary care for sleep, anxiety and depressive disorders from physicians prescribing homeopathic and other complementary medicine? Results from the EPI3 population survey 
BMJ Open  2012;2(6):e001498.
To describe and compare patients seeking treatment for sleep, anxiety and depressive disorders (SADD) from physicians in general practice (GPs) with three different practice preferences: strictly conventional medicine (GP-CM), mixed complementary and conventional medicine (GP-Mx) and certified homeopathic physicians (GP-Ho).
Design and setting
The EPI3 survey was a nationwide, observational study of a representative sample of GPs and their patients, conducted in France between March 2007 and July 2008.
1572 patients diagnosed with SADD.
Primary and secondary outcomes
The patients’ attitude towards complementary and alternative medicine; psychotropic drug utilisation.
Compared to patients attending GP-CM, GP-Ho patients had healthier lifestyles while GP-Mx patients showed similar profiles. Psychotropic drugs were more likely to be prescribed by GP-CM (64%) than GP-Mx (55.4%) and GP-Ho (31.2%). The three groups of patients shared similar SADD severity.
Our results showed that patients with SADD, while differing principally in their sociodemographic profiles and conventional psychotropic prescriptions, were actually rather similar regarding the severity of SADD in terms of comorbidities and quality of life. This information may help to better plan resource allocation and management of these common health problems in primary care.
PMCID: PMC3532988  PMID: 23180389
10.  Identifying More Epidemic Clones during a Hospital Outbreak of Multidrug-Resistant Acinetobacter baumannii 
PLoS ONE  2012;7(9):e45758.
Infections caused by multidrug-resistant bacteria are a major concern in hospitals. Current infection-control practices legitimately focus on hygiene and appropriate use of antibiotics. However, little is known about the intrinsic abilities of some bacterial strains to cause outbreaks. They can be measured at a population level by the pathogen’s transmission rate, i.e. the rate at which the pathogen is transmitted from colonized hosts to susceptible hosts, or its reproduction number, counting the number of secondary cases per infected/colonized host. We collected data covering a 20-month surveillance period for carriage of multidrug-resistant Acinetobacter baumannii (MDRAB) in a surgery ward. All isolates were subjected to molecular fingerprinting, and a cluster analysis of profiles was performed to identify clonal groups. We then applied stochastic transmission models to infer transmission rates of MDRAB and each MDRAB clone. Molecular fingerprinting indicated that 3 clonal complexes spread in the ward. A first model, not accounting for different clones, quantified the level of in-ward cross-transmission, with an estimated transmission rate of 0.03/day (95% credible interval [0.012–0.049]) and a single-admission reproduction number of 0.61 [0.30–1.02]. The second model, accounting for different clones, suggested an enhanced transmissibility of clone 3 (transmission rate 0.047/day [0.018–0.091], with a single-admission reproduction number of 0.81 [0.30–1.56]). Clones 1 and 2 had comparable transmission rates (respectively, 0.016 [0.001–0.045], 0.014 [0.001–0.045]). The method used is broadly applicable to other nosocomial pathogens, as long as surveillance data and genotyping information are available. Building on these results, more epidemic clones could be identified, and could lead to follow-up studies dissecting the functional basis for variation in transmissibility of MDRAB lineages.
PMCID: PMC3459964  PMID: 23029226
11.  Prior Caspofungin Exposure in Patients with Hematological Malignancies Is a Risk Factor for Subsequent Fungemia Due to Decreased Susceptibility in Candida spp.: a Case-Control Study in Paris, France▿ 
Antimicrobial Agents and Chemotherapy  2011;55(11):5358-5361.
Infections due to caspofungin-resistant Candida isolates in patients exposed to caspofungin therapy are increasing. We report here a nested case-control study which aimed at identifying factors associated with bloodstream infections caused by Candida spp. having reduced susceptibility to caspofungin (CRSC) in adults suffering from hematological malignancies. In univariate and multivariate analyses, infections with CRSC were associated with caspofungin exposure in the previous 30 days (odds ratio [OR] = 5.25; 95% confidence interval [95% CI], 1.68–16.35) and with an age of ≤65 years (OR = 3.27; 95% CI, 1.26–8.50).
PMCID: PMC3194997  PMID: 21859944
12.  Intrinsic Epidemicity of Streptococcus pneumoniae Depends on Strain Serotype and Antibiotic Susceptibility Pattern▿ † 
Antimicrobial Agents and Chemotherapy  2011;55(11):5255-5261.
Streptococcus pneumoniae is a major cause of invasive diseases worldwide. It spreads through an interindividual transmission, followed by usually harmless colonization of the host. Possible transmission differences reflecting intrinsic strain features (e.g., serotype and antibiotic susceptibility) have been little studied so far. In this study, we used epidemiological data from an interventional trial of S. pneumoniae carriage among kindergartners and developed a mathematical model to estimate the transmission parameters of the different strains isolated during that study. We found small but significant transmissibility differences between the observed serotypes: serotypes 3, 6A, and 19A were found to be the most epidemic, while serotypes 23F, 9V, and 14 were the least epidemic. Further analysis indicated that, within a serotype, susceptible and resistant strains had different abilities to be transmitted. Susceptible-to-resistant transmission rate ratios were computed for five serotypes; susceptible strains were significantly more epidemic than resistant strains for serotypes 6A (mean, 1.02) and 19F (1.05). Serotype 19A resistant strains were not outcompeted by susceptible strains (0.97). Nonsignificant trends were observed for serotypes 6B (1.01) and 15A (0.98). Our results support the existence of heterogeneous abilities of the different serotypes for host-to-host transmission. They also suggest that antibiotic susceptibility within a serotype affects this transmissibility. We conclude that pneumococcal strains should not be considered equally at-risk in terms of transmission. Further quantification of strain-specific epidemic potential is needed, especially in a context of extensive use of conjugate vaccines with the aim of preventing pneumococcal infections.
PMCID: PMC3195016  PMID: 21788454
13.  Impact of Antibiotic Exposure Patterns on Selection of Community-Associated Methicillin-Resistant Staphylococcus aureus in Hospital Settings▿† 
Antimicrobial Agents and Chemotherapy  2011;55(10):4888-4895.
Community-associated methicillin-resistant S. aureus (CA-MRSA) is increasingly common in hospitals, with potentially serious consequences. The aim of this study was to assess the impact of antibiotic prescription patterns on the selection of CA-MRSA within hospitals, in a context of competition with other circulating staphylococcal strains, including methicillin-sensitive (MSSA) and hospital-associated methicillin-resistant (HA-MRSA) strains. We developed a computerized agent-based model of S. aureus transmission in a hospital ward in which CA-MRSA, MSSA, and HA-MRSA strains may cocirculate. We investigated a wide range of antibiotic prescription patterns in both intensive care units (ICUs) and general wards, and we studied how differences in antibiotic exposure may explain observed variations in the success of CA-MRSA invasion in the hospitals of several European countries and of the United States. Model predictions underlined the influence of antibiotic prescription patterns on CA-MRSA spread in hospitals, especially in the ICU, where the endemic prevalence of CA-MRSA carriage can range from 3% to 20%, depending on the simulated prescription pattern. Large antibiotic exposure with drugs effective against MSSA but not MRSA was found to promote invasion by CA-MRSA. We also found that, should CA-MRSA acquire fluoroquinolone resistance, a major increase in CA-MRSA prevalence could ensue in hospitals worldwide. Controlling the spread of highly community-prevalent CA-MRSA within hospitals is a challenge. This study demonstrates that antibiotic exposure strategies could participate in this control. This is all the more important in wards such as ICUs, which may play the role of incubators, promoting CA-MRSA selection in hospitals.
PMCID: PMC3187008  PMID: 21788461
14.  Benchmarking the burden of 100 diseases: results of a nationwide representative survey within general practices 
BMJ Open  2011;1(2):e000215.
To assess the burden of diseases and quality of life (QOL) of patients for a large variety of diseases within general practice.
In a representative nationwide cross-sectional study, a total of 825 general practitioners (GPs) were randomly selected from across France. Independent investigators recruited 8559 patients attending the GPs' practices. Data on QOL (12-Item Short Form questionnaire) and other individual characteristics were documented by the independent investigators for all participants in the waiting room. Medical information was recorded by GPs. Sampling was calibrated to national standards using the CALMAR (CALage sur MARges) weighting procedure. Associations of lower scores (ie, below vs above the first quartile) of physical and mental component scores (physical component summary score (PCS) and mental component summary score (MCS), respectively) with main diseases and patients characteristics were estimated using multivariate logistic regression. Weighted morbidity rates, PCS and MCS were computed for 100 diagnoses using the International Classification of Diseases (9th version).
Overall mental impairment was observed among patients in primary care with an average MCS of 41.5 (SD 8.6), ranging from 33.0 for depressive disorders to 45.3 for patients exhibiting fractures or sprains. Musculoskeletal diseases were found to have the most pronounced effect on impaired physical health (OR=2.31; 95% CI 2.08 to 2.57) with the lowest PCS (45.6 (SD 8.8)) and ranked first (29.0%) among main diagnoses experienced by patients followed by cardiovascular diseases (26.7%) and psychological disorders (22.0%). When combining both prevalence and QOL, musculoskeletal diseases represented the heaviest burden in general practice.
Etude épidémiologique de l'Impact de santé public sur 3 groupes de pathologies (EPI3) is the first study to provide reference figures for burden of disease in general practice across a wide range of morbidities, particularly valuable for health-economics and healthcare-system evaluation.
Article summary
Article focus
The impact of diseases on quality of life (QOL) in general practice has been assessed among selected samples of patients, usually from studies including a limited number of medical practices and/or focusing mainly on chronic conditions.
There is a clear need for more data on QOL of patients in primary care; the aim of the Etude épidémiologique de l'Impact de santé public sur 3 groupes de pathologies (EPI3) survey was to provide reference figures for disease burden in this setting.
Key messages
The EPI3 study was a cross-sectional survey combining unique data from patients and general practitioners (GPs), and allowed provision of reference figures for the vast majority of diseases encountered in primary care for a large number of patients.
The study highlighted the burden of musculoskeletal and psychological disorders, experienced by more than half the patients.
Although social and medical determinants of patients' QOL were somewhat similar than those found in previous studies in primary care, the EPI3 survey showed more pronounced mental impairment in French patients.
Strengths and limitations of this study
No nationwide study on burden of disease combining both prevalence measures and QOL assessment has been conducted to date, addressing such a large variety of diseases in general practice.
On-site selection and recruitment by an independent investigator limited the possibility of selection bias among patients, and the participation of physicians added high specificity to medical data collection.
A study design providing a high specificity in data collection led to a relatively low response rate from GPs. However, stratified recruitment phases and sample sizes from both GPs and patients highly representative of national standards ensured the strong external validity of the results.
Home consultations, which are common among GPs in France, were not surveyed which could have led to an underestimation of the burden of disease.
PMCID: PMC3221295  PMID: 22102638
15.  Benchmarking clinical management of spinal and non-spinal disorders using quality of life: results from the EPI3-LASER survey in primary care 
European Spine Journal  2011;20(12):2210-2216.
Concerns have been raised regarding sub-optimal utilization of analgesics and psychotropic drugs in the treatment of patients with chronic musculoskeletal disorders (MSDs) and their associated co-morbidities. The objective of this study was to describe drug prescriptions for the management of spinal and non-spinal MSDs contrasted against a standardized measure of quality of life. A representative population sample of 1,756 MSDs patients [38.5% with spinal disorder (SD) and 61.5% with non-spinal MSDs (NS-MSD)] was drawn from the EPI3-LASER survey of 825 general practitioners (GPs) in France. Physicians recorded their diagnoses and prescriptions on that day. Patients provided information on socio-demographics, lifestyle and quality of life using the Short Form 12 (SF-12) questionnaire. Chronicity of MSDs was defined as more than 12 weeks duration of the current episode. Chronic SD and NS-MSD patients were prescribed less analgesics and non-steroidal anti-inflammatory drugs than their non-chronic counterpart [odds ratios (OR) and 95% confidence intervals (CI), respectively: 0.4, 0.2–0.7 and 0.5, 0.3–0.6]. They also had more anxio-depressive co-morbidities reported by their physicians (SD: 16.1 vs.7.4%; NS-MSD: 21.6 vs. 9.5%) who prescribed more antidepressants and anxiolytics with a difference that was statistically significant only for spinal disorder patients (OR, 95% CI: 2.0, 1.1–3.6). Psychotropic drugs were more often prescribed in patients in the lower quartile of SF-12 mental score and prescriptions of analgesics in the lower quartile of SF-12 physical score (P < 0.001). In conclusion, anxiety and depressive disorders were commonly reported by GPs among chronic MSD patients. Their prescriptions of psychotropic and analgesic drugs were consistent with patients’ self-rated mental and physical health.
PMCID: PMC3229736  PMID: 21487774
Spinal disorders; Musculoskeletal disorders; Epidemiology; Population health
16.  Troublesome Heterotopic Ossification after Central Nervous System Damage: A Survey of 570 Surgeries 
PLoS ONE  2011;6(1):e16632.
Heterotopic ossification (HO) is a frequent complication after central nervous system (CNS) damage but has seldom been studied. We aimed to investigate features of HO for the first time in a large sample and the rate of early recurrence of HO in terms of the time of surgery.
Methodology/Principal Findings
We retrospectively analyzed data from an anonymous prospective survey of patients undergoing surgery between May 1993 and November 2009 in our institution for troublesome HO related to acquired neurological disease. Demographic and HO characteristics and neurological etiologies were recorded. For 357 consecutive patients, we collected data on 539 first surgeries for HO (129 surgeries for multiple sites). During the follow-up, recurrences requiring another surgery appeared in 31 cases (5.8% [31/539]; 95% confidence interval [CI]: 3.8%–7.8%; 27 patients). Most HO requiring surgery occurred after traumatic brain injury (199 patients [55.7%]), then spinal cord injury (86 [24.0%]), stroke (42 [11.8%]) and cerebral anoxia (30 [8.6%]). The hip was the primary site of HO (328 [60.9%]), then the elbow (115 [21.3%]), knee (77 [14.3%]) and shoulder (19 [3.5%]). For all patients, 181 of the surgeries were performed within the first year after the CNS damage, without recurrence of HO. Recurrence was not associated with etiology (p = 0.46), sex (p = 1.00), age at CNS damage (p = 0.2), multisite localization (p = 0.34), or delay to surgery (p = 0.7).
In patients with CNS damage, troublesome HO and recurrence occurs most frequently after traumatic brain injury and appears frequently in the hip and elbow. Early surgery for HO is not a factor of recurrence.
PMCID: PMC3031592  PMID: 21304993
17.  Who seeks primary care for musculoskeletal disorders (MSDs) with physicians prescribing homeopathic and other complementary medicine? Results from the EPI3-LASER survey in France 
There is a paucity of information describing patients with musculoskeletal disorders (MSDs) using complementary and alternative medicines (CAMs) and almost none distinguishing homeopathy from other CAMs. The objective of this study was to describe and compare patients with MSDs who consulted primary care physicians, either certified homeopaths (Ho) or regular prescribers of CAMs in a mixed practice (Mx), to those consulting physicians who strictly practice conventional medicine (CM), with regard to the severity of their MSD expressed as chronicity, co-morbidity and quality of life (QOL).
The EPI3-LASER study was a nationwide observational survey of a representative sample of general practitioners and their patients in France. The sampling strategy ensured a sufficient number of GPs in each of the three groups to allow comparison of their patients. Patients completed a questionnaire on socio-demographics, lifestyle and QOL using the Short Form 12 (SF-12) questionnaire. Chronicity of MSDs was defined as more than twelve weeks duration of the current episode. Diagnoses and co-morbidities were recorded by the physician.
A total of 825 GPs included 1,692 MSD patients (predominantly back pain and osteoarthritis) were included, 21.6% in the CM group, 32.4% Ho and 45.9% Mx. Patients in the Ho group had more often a chronic MSD (62.1%) than the CM (48.6%) or Mx (50.3%) groups, a result that was statistically significant after controlling for patients' characteristics (Odds ratio = 1.43; 95% confidence interval (CI): 1.07 - 1.89). Patients seen by homeopaths or mixed practice physicians who were not the regular treating physician, had more often a chronic MSD than those seen in conventional medicine (Odds ratios were1.75; 95% CI: 1.22 - 2.50 and 1.48; 95% CI: 1.06 - 2.12, respectively). Otherwise patients in the three groups did not differ for co-morbidities and QOL.
MSD patients consulting primary care physicians who prescribed homeopathy and CAMs differed from those seen in conventional medicine. Chronic MSD patients represented a greater proportion of the clientele in physicians offering alternatives to conventional medicine. In addition, these physicians treated chronic patients as consulting rather than regular treating physicians, with potentially important impacts upon professional health care practices and organisation.
PMCID: PMC3034723  PMID: 21247493
18.  Antibiotic Dose Impact on Resistance Selection in the Community: a Mathematical Model of β-Lactams and Streptococcus pneumoniae Dynamics▿ †  
Streptococcus pneumoniae is a major pathogen in the community and presents high rates of resistance to the available antibiotics. To prevent antibiotic treatment failure caused by highly resistant bacteria, increasing the prescribed antibiotic dose has recently been suggested. The aim of the present study was to assess the influence of β-lactam prescribed doses on the emergence of resistance and selection in the community. A mathematical model was constructed by combining S. pneumoniae pharmacodynamic and population-dynamic approaches. The received-dose heterogeneity in the population was specifically modeled. Simulations over a 50-year period were run to test the effects of dose distribution and antibiotic exposure frequency changes on community resistance patterns, as well as the accuracy of the defined daily dose as a predictor of resistance. When the frequency of antibiotic exposure per year was kept constant, dose levels had a strong impact on the levels of resistance after a 50-year simulation. The lowest doses resulted in a high prevalence of nonsusceptible strains (≥70%) with MICs that were still low (1 mg/liter), whereas high doses resulted in a lower prevalence of nonsusceptible strains (<40%) and higher MICs (2 mg/liter). Furthermore, by keeping the volume of antibiotics constant in the population, different patterns of use (low antibiotic dose and high antibiotic exposure frequency versus high dose and low frequency) could lead to markedly different rates of resistance distribution and prevalence (from 10 to 100%). Our results suggest that pneumococcal resistance patterns in the community are strongly related to the individual β-lactam doses received: limiting β-lactam use while increasing the doses could help reduce the prevalence of resistance, although it should select for higher levels of resistance. Surveillance networks are therefore encouraged to collect both daily antibiotic exposure frequencies and individual prescribed doses.
PMCID: PMC2876390  PMID: 20231396
19.  Imported Episodic Rabies Increases Patient Demand for and Physician Delivery of Antirabies Prophylaxis 
Imported cases threaten rabies reemergence in rabies-free areas. During 2000–2005, five dog and one human rabies cases were imported into France, a rabies-free country since 2001. The Summer 2004 event led to unprecedented media warnings by the French Public Health Director. We investigated medical practice evolution following the official elimination of rabies in 2001; impact of subsequent episodic rabies importations and national newspaper coverage on demand for and delivery of antirabies prophylaxis; regular transmission of epidemiological developments within the French Antirabies Medical Center (ARMC) network; and ARMC discussions on indications of rabies post-exposure prophylaxis (RPEP).
Methodology/Principal Findings
Annual data collected by the National Reference Center for Rabies NRCR (1989–2006) and the exhaustive database (2000–2005) of 56 ARMC were analyzed. Weekly numbers of patients consulting at ARMC and their RPEP- and antirabies-immunoglobulin (ARIG) prescription rates were determined. Autoregressive integrated moving-average modeling and regression with autocorrelated errors were applied to examine how 2000–2005 episodic rabies events and their related national newspaper coverage affected demand for and delivery of RPEP. A slight, continuous decline of rabies-dedicated public health facility attendance was observed from 2000 to 2004. Then, during the Summer 2004 event, patient consultations and RPEP and ARIG prescriptions increased by 84%, 19.7% and 43.4%, respectively. Moreover, elevated medical resource use persisted in 2005, despite communication efforts, without any secondary human or animal case.
Our findings demonstrated appropriate responsiveness to reemerging rabies cases and effective newspaper reporting, as no secondary case occurred. However, the ensuing demand on medical resources had immediate and long-lasting effects on rabies-related public health resources and expenses. Henceforth, when facing such an event, decision-makers must anticipate the broad impact of their media communications to counter the emerging risk on maintaining an optimal public health organization and implement a post-crisis communication strategy.
Author Summary
Rabies has been eliminated from a large part of the European Union and, thus, any newly imported cases threaten its reemergence. The 2000–2005 data derived from the exhaustive surveillance system implemented in France was analyzed to evaluate the impact on demand for and delivery of antirabies prophylaxis following introduction of five rabies-infected dogs and one infected human into this rabies-free area. Using these events, we were able to illustrate the difficulties encountered in reducing the demand for and prescription of post-exposure rabies prophylaxis in this context of episodic importation. Moreover, we highlighted the need for public health decision-makers to anticipate the broad spectrum of consequences of their media communications and to prepare appropriate responses (in terms of health resources) to maintain an optimally effective public health organization after importation of an exotic infectious agent or its emergence. These responses are particularly relevant in the context of limited availability of rabies post-exposure prophylaxis, especially antirabies immunoglobulin.
PMCID: PMC2889823  PMID: 20582307
20.  Multicenter Study of Prevalence of Nontuberculous Mycobacteria in Patients with Cystic Fibrosis in France ▿  
Journal of Clinical Microbiology  2009;47(12):4124-4128.
We performed a multicenter prevalence study of nontuberculous mycobacteria (NTM) involving 1,582 patients (mean age, 18.9 years; male/female ratio, 1.06) with cystic fibrosis in France. The overall NTM prevalence (percentage of patients with at least one positive culture) was 6.6% (104/1,582 patients), with prevalences ranging from 3.7% (in the east of France) to 9.6% (in the greater Paris area). Mycobacterium abscessus complex (MABSC; 50 patients) and Mycobacterium avium complex (MAC; 23 patients) species were the most common NTM, and the only ones associated with fulfillment of the American Thoracic Society bacteriological criteria for NTM lung disease. The “new” species, Mycobacterium bolletii and Mycobacterium massiliense, accounted for 40% of MABSC isolates. MABSC species were isolated at all ages, with a prevalence peak between 11 and 15 years of age (5.8%), while MAC species reached their highest prevalence value among patients over 25 years of age (2.2%).
PMCID: PMC2786646  PMID: 19846643
21.  Significant Reduction of Antibiotic Use in the Community after a Nationwide Campaign in France, 2002–2007 
PLoS Medicine  2009;6(6):e1000084.
Didier Guillemot and colleagues describe the evaluation of a nationwide programme in France aimed at decreasing unnecessary outpatient prescriptions for antibiotics. The campaign was successful, particularly in reducing prescriptions for children.
Overuse of antibiotics is the main force driving the emergence and dissemination of bacterial resistance in the community. France consumes more antibiotics and has the highest rate of beta-lactam resistance in Streptococcus pneumoniae than any other European country. In 2001, the government initiated “Keep Antibiotics Working”; the program's main component was a campaign entitled “Les antibiotiques c'est pas automatique” (“Antibiotics are not automatic”) launched in 2002. We report the evaluation of this campaign by analyzing the evolution of outpatient antibiotic use in France 2000–2007, according to therapeutic class and geographic and age-group patterns.
Methods and Findings
This evaluation is based on 2000–2007 data, including 453,407,458 individual reimbursement data records and incidence of flu-like syndromes (FLSs). Data were obtained from the computerized French National Health Insurance database and provided by the French Sentinel Network. As compared to the preintervention period (2000–2002), the total number of antibiotic prescriptions per 100 inhabitants, adjusted for FLS frequency during the winter season, changed by −26.5% (95% confidence interval [CI] −33.5% to −19.6%) over 5 years. The decline occurred in all 22 regions of France and affected all antibiotic therapeutic classes except quinolones. The greatest decrease, −35.8% (95% CI −48.3% to −23.2%), was observed among young children aged 6–15 years. A significant change of −45% in the relationship between the incidence of flu-like syndromes and antibiotic prescriptions was observed.
The French national campaign was associated with a marked reduction of unnecessary antibiotic prescriptions, particularly in children. This study provides a useful method for assessing public-health strategies designed to reduce antibiotic use.
Editors' Summary
In 1928, Alexander Fleming discovered penicillin, the first antibiotic (a drug that kills bacteria). By the early 1940s, large amounts of penicillin could be made and, in the following decades, several other classes of powerful antibiotics were discovered. For a time, it looked like bacteria and the diseases that they cause had been defeated. But bacteria rapidly became resistant to these wonder drugs and nowadays, antibiotic resistance is a pressing public-health concern. Almost every type of disease-causing bacteria has developed resistance to one or more antibiotic in clinical use, and multidrug-resistant bacteria are causing outbreaks of potentially fatal diseases in hospitals and in the community. For example, multidrug-resistant Streptococcus pneumoniae (multidrug-resistant pneumococci or MRP) is now very common. S. pneumoniae colonize the nose and throat (the upper respiratory tract) and can cause diseases that range from mild ear infections to life-threatening pneumonia, particularly in young children and elderly people.
Why Was This Study Done?
For years, doctors have been prescribing (and patients have been demanding) antibiotics for viral respiratory infections (VRIs) such as colds and flu even though antibiotics do not cure viral infections. This overuse of antibiotics has been the main driving force in the spread of MRP. Thus, the highest rate of S. pneumoniae antibiotic resistance in Europe occurs in France, which has one of the highest rates of antibiotic consumption in the world. In 2001 France initiated “le plan national pour préserver l'efficacité des antibiotiques” to reduce the inappropriate use of antibiotics, particularly for the treatment of VRIs among children. The main component of the program was the “Antibiotiques c'est pas automatique” (“Antibiotics are not automatic”) campaign, which ran from 2002 to 2007 during the winter months when VRIs mainly occur. The campaign included an educational campaign for health care workers, the promotion of rapid tests for diagnosis of streptococcal infections, and a public information campaign about VRIs and about antibiotic resistance. In this study, the researchers evaluate the campaign by analyzing outpatient antibiotic use throughout France from 2000 to 2007.
What Did the Researchers Do and Find?
The researchers obtained information about antibiotic prescriptions and about the occurrence of flu-like illnesses during the study period from the French National Health Insurance database and national disease surveillance system, respectively. After adjusting for variations in the frequency of flu-like illnesses, compared to the preintervention period (2000–2002), the number of antibiotic prescriptions per 100 inhabitants decreased by a quarter over the five winters of the “Antibiotics are not automatic” campaign. The use of all major antibiotic classes except quinolones decreased in all 22 regions of France. Thus, whereas in 2000, more than 70 prescriptions per 100 inhabitants were issued during the winter in 15 regions, by 2006/7, no regions exceeded this prescription rate. The greatest decrease in prescription rate (a decrease of more than a third by 2006/7) was among children aged 6–15 years. Finally, although the rates of antibiotic prescriptions reflected the rates of flu-like illness throughout the campaign, by 2006/7 this relationship was much weaker, which suggests that fewer antibiotics were being prescribed for VRIs.
What Do These Findings Mean?
These findings indicate that the “Antibiotics are not automatic” campaign was associated with a reduction in antibiotic prescriptions, particularly in children. Because the whole French population was exposed to the campaign, these findings do not prove that the campaign actually caused the reduction in antibiotic prescriptions. The observed decrease might have been caused by other initiatives in France or elsewhere or by the introduction of a S. pneumoniae vaccine during the study period, for example. However, an independent survey indicated that fewer members of the public expected an antibiotic prescription for a VRI at the end of the campaign than at the start, that more people knew that antibiotics only kill bacteria, and that doctors were more confident about not prescribing antibiotics for VRIs. Thus, campaigns like “Antibiotics are not automatic” may be a promising way to reduce the overuse of antibiotics and to slow the spread of antibiotic resistance until new classes of effective antibiotics are developed.
Additional Information
Please access these Web sites via the online version of this summary at
This study is further discussed in a PLoS Medicine Perspective by Stephen Harbarth and Benedikt Huttner
The Bugs and Drugs Web site from the UK National electronic Library of Infection provides information about antibiotic resistance and links to other resources
The US National Institute of Allergy and Infectious Diseases provides information on antimicrobial drug resistance and on pneumococcal pneumonia
The US Centers for Disease Control and Prevention also have information on antibiotic resistance (in English and Spanish)
The European Surveillance of Antimicrobial Consumption Web site provides information on antibiotic consumption in European countries
Les antibiotiques c'est pas automatique provides information about the “Antibiotics are not automatic” campaign (in French)
Information on the Plan National pour Pérserver l'efficacité des antibiotiques is also available (in French)
PMCID: PMC2683932  PMID: 19492093
22.  Impact of Capsular Switch on Invasive Pneumococcal Disease Incidence in a Vaccinated Population 
PLoS ONE  2008;3(9):e3244.
Despite the dramatic decline in the incidence of invasive pneumococcal disease (IPD) observed since the introduction of conjugate vaccination, it is feared that several factors may undermine the future effectiveness of the vaccines. In particular, pathogenic pneumococci may switch their capsular types and evade vaccine-conferred immunity.
Methodology/Principal Findings
Here, we first review the literature and summarize the available epidemiological data on capsular switch for S. pneumoniae. We estimate the weekly probability that a persistently carried strain may switch its capsule from four studies, totalling 516 children and 6 years of follow-up, at 1.5×10−3/week [4.6×10−5–4.8×10−3/week]. There is not enough power to assess an increase in this frequency in vaccinated individuals. Then, we use a mathematical model of pneumococcal transmission to quantify the impact of capsular switch on the incidence of IPD in a vaccinated population. In this model, we investigate a wide range of values for the frequency of vaccine-selected capsular switch. Predictions show that, with vaccine-independent switching only, IPD incidence in children should be down by 48% 5 years after the introduction of the vaccine with high coverage. Introducing vaccine-selected capsular switch at a frequency up to 0.01/week shows little effect on this decrease; yearly, at most 3 excess cases of IPD per 106 children might occur due to switched pneumococcal strains.
Based on all available data and model predictions, the existence of capsular switch by itself should not impact significantly the efficacy of pneumococcal conjugate vaccination on IPD incidence. This optimistic result should be tempered by the fact that the selective pressure induced by the vaccine is currently increasing along with vaccine coverage worldwide; continued surveillance of pneumococcal populations remains of the utmost importance, in particular during clinical trials of the new conjugate vaccines.
PMCID: PMC2531230  PMID: 18802466
23.  Major Role for Amphotericin B–Flucytosine Combination in Severe Cryptococcosis 
PLoS ONE  2008;3(8):e2870.
The Infectious Diseases Society of America published in 2000 practical guidelines for the management of cryptococcosis. However, treatment strategies have not been fully validated in the various clinical settings due to exclusion criteria during therapeutic trials. We assessed here the optimal therapeutic strategies for severe cryptococcosis using the observational prospective CryptoA/D study after analyzing routine clinical care of cryptococcosis in university or tertiary care hospitals.
Methodology/Principal Findings
Patients were enrolled if at least one culture grew positive with Cryptococcus neoformans. Control of sterilization was warranted 2 weeks (Wk2) and 3 months (Mo3) after antifungal therapy onset. 208 HIV-positive or -negative adult patients were analyzed. Treatment failure (death or mycological failure) at Wk2 and Mo3 was the main outcome measured. Combination of amphotericin B+flucytosine (AMB+5FC) was the best regimen for induction therapy in patients with meningoencephalitis and in all patients with high fungal burden and abnormal neurology. In those patients, treatment failure at Wk2 was 26% in the AMB+5FC group vs. 56% with any other treatments (p<0.001). In patients treated with AMB+5FC, factors independently associated with Wk2 mycological failure were high serum antigen titer (OR [95%CI] = 4.43[1.21–16.23], p = 0.025) and abnormal brain imaging (OR = 3.89[1.23–12.31], p = 0.021) at baseline. Haematological malignancy (OR = 4.02[1.32–12.25], p = 0.015), abnormal neurology at baseline (OR = 2.71[1.10–6.69], p = 0.030) and prescription of 5FC for less than 14 days (OR = 3.30[1.12–9.70], p = 0.030) were independently associated with treatment failure at Mo3.
Our results support the conclusion that induction therapy with AMB+5FC for at least 14 days should be prescribed rather than any other induction treatments in all patients with high fungal burden at baseline regardless of their HIV serostatus and of the presence of proven meningoencephalitis.
PMCID: PMC2483933  PMID: 18682846
24.  Correction: Antibiotic Innovation May Contribute to Slowing the Dissemination of Multiresistant Streptococcus pneumoniae: The Example of Ketolides 
PLoS ONE  2008;3(5):10.1371/annotation/968c3453-14aa-4300-b743-cdb4f4c90a36.
PMCID: PMC2637104
25.  Antibiotic Innovation May Contribute to Slowing the Dissemination of Multiresistant Streptococcus pneumoniae: The Example of Ketolides 
PLoS ONE  2008;3(5):e2089.
Despite increasingly frequent bacterial resistance to antibiotics, antibacterial innovation is rare. Ketolides constitute one of the very few new antibiotic classes active against Streptococcus pneumoniae developed during the last 25 years. Their mechanism of action resembles that of macrolides, but they are unaffected by common resistance mechanisms. However, cross-resistance to ketolides has been observed in some macrolide-resistant strains. We examined how new antibiotic exposure may affect overall pneumococcal resistance patterns in the population. The aims of this study were to assess the potential dissemination of newly emerged resistances and to control the selection of strains already multiresistant to existing antimicrobials.
Methodology/Principal Findings
We developed an age-structured population model for S. pneumoniae transmission in a human community exposed to heptavalent vaccine, and β-lactams, macrolides and ketolides. The dynamics of intra-individual selection of resistant strains under antibiotic exposure and interindividual transmission were simulated, with antibiotic-specific resistance mechanisms defining the path to co-resistances and cross-resistances, and parameters concerning the French situation. Results of this simulation study suggest that new antibiotic consumption could markedly slow the diffusion of multiresistant strains. Wider use was associated with slower progression of multiresistance. When ketolides were prescribed to all ages, resistance to them reached 10% after >15 years, while it took >40 years when they were prescribed only to adults. In the scenario according to which new antibiotics totally replaced former antimicrobials, the β-lactam resistance rate was limited at 70%.
In a context of widespread vaccination and rational use of antibiotics, innovative antibiotic, prescribed to all age groups, may have an added impact on multiresistant-strain dissemination in the population.
PMCID: PMC2330086  PMID: 18461139

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