Biomedical subjects

Y Le Strat

Publications and source records attributed to Y Le Strat.

7 recordsLinked to original sources

PubMed2006

[Incidence and risk factors of HCV infection in a cohort of intravenous drug users in the North and East of France].

BACKGROUND: In order to evaluate the incidence and risk factors of infection by hepatitis C virus (HCV) among intravenous drug users we conducted a prospective cohort study of HCV and HIV negative IVDU in the North and East of France. METHODS: Two hundred and thirty-one IVDU who had injected drug at least once in their lifetime and were negative for anti-HCV and anti-HIV were followed-up every three months over a 12-month period. Serum anti-HCV and anti-HIV antibodies were tested at inclusion in the study and at the end of the follow-up. Data on injection practices and behaviours were collected at inclusion and at each visit, and a test for anti-HCV antibodies was performed on a saliva sample. When this proved positive, an ELISA test for serum anti-HCV antibodies was carried out. RESULTS: Of the 231 participants included, 165 (71.4%) underwent a final HCV and HIV serum test. The incidence was nil for HIV infection and 9% (95% CI: 4.6-13.4) person-years for HCV infection. Among IVDU who injected at least once during the last 6 months HCV infection incidence was 11% (95% CI: 4.7-17.1) person-years. The multivariate analysis carried out on the inclusion data found female sex alone to be an independent predictive factor of HCV seroconversion. In a Cox proportional hazard multivariate analysis that took into account time-dependent exposures and covariates, we found that syringe and cotton sharing were, after adjusting for other covariates, the only independent predictive factors of HCV seroconversion: hazard ratio: 6.3 [corrected] (95% CI: 1.1-35.4; [corrected] p<0.05) and 16.4 (95% CI: 1.4-190.6; [corrected] p<0.05), respectively. CONCLUSION: The transmission of the HCV virus persists among French IVDU despite an ongoing national harm reduction program. Injecting material and cotton sharing are the two major determinants of transmission in this cohort.

Adult↗

PubMed2005

Foodborne infections in France.

To quantify the impact of foodborne diseases on health, and set priorities for data collection, prevention and control of these diseases, we compiled and analyzed information from surveillance systems and other sources on the morbidity and mortality due to foodborne infectious diseases in mainland France in the last decade of the 20th century. Illness due to 13 bacteria, two viruses, and eight parasites were studied. The number of foodborne infections, hospitalizations, and deaths were estimated from multiple data sources. For each agent, several estimates were derived from the different sources. Estimates were ranked according to their plausibility, based on an assessment of the validity of the data source, and are presented as a "plausible interval" consisting of a low and high estimate. We estimate that these pathogens caused 10,200-17,800 hospitalizations per year. Salmonella is the most frequent cause (5,700-10,200 cases), followed by Campylobacter (2,600-3,500 cases) and Listeria (304 cases). Toxoplasmosis accounts for the majority of hospitalizations (426 cases) attributable to the studied parasitic infections. The number of deaths related to foodborne infection was estimated between 228 and 691. Bacterial pathogens account for the majority (191 to 652) of deaths of which 92 to 535 are attributable to salmonellosis, ranking as the first cause of death, and 78 to listeriosis, the second cause. Salmonella, Campylobacter, and Listeria are the main causes of severe foodborne illness in France. For several pathogens, data are insufficient to derive exact estimates of the disease burden. Nevertheless, it has been possible to derive plausible estimates for the majority, and to rank them according to their impact on public health.

Campylobacter Infections↗

PubMed2005

Exploring the determinants of treatment success for tuberculosis cases in Europe.

SETTING: Pooled tuberculosis (TB) notifications from 13 European countries. OBJECTIVE: To analyse the determinants of TB treatment success in different countries using individual data. DESIGN: We asked 18 European countries with both outcome data and individual TB records to code outcomes for cases notified in 2000 and/or 2001. Cases completing treatment regardless of bacteriological proof of cure were considered successful. RESULTS: Ten European Union countries and Iceland, Norway and Romania participated (72% response). Among 24 660 TB cases (Romania excluded), 'success' was reported in 69% (country range 60-88%), 9% (0-11%) died, 1% (0-5%) failed, 4% defaulted or transferred (2-15%) and 12% (0-23%) were 'unknown'. On logistic regression among cases with drug susceptibility results (n = 10 303), 'success' was associated with younger age (>74 years: reference; 55-74 years: OR = 2.0, 95%CI 1.8-2.4; 35-54 years: 3.0, 95%CI 2.6-3.5; 15-34 years: 3.7, 95%CI 3.2-4.4; <15 years: 4.4, 95%CI 2.9-6.7), female sex (1.4, 95%CI 1.3-1.6), and no polyresistance (9.2, 95%CI 6.8-12.4). The Netherlands (1.6, 95%CI 1.3-2.0) and Slovakia (1.8, 95%CI 1.4-2.2) had higher success than Estonia (reference: lowest percentage success), while Austria was lower (0.64, 95%CI 0.52-0.78). CONCLUSION: Preventing drug resistance, increasing adherence and improving care in the elderly should be priorities. Inter-country variations in treatment success suggest differences in the completeness of monitoring data and in the efficacy of national control programmes.

Adolescent↗

PubMed2004

Incidence and risk factors of HCV and HIV infections in a cohort of intravenous drug users in the North and East of France.

In order to evaluate the incidence and risk factors of infection by hepatitis C virus (HCV) among injecting drug users (IDUs), we conducted a prospective cohort study of HCV- and human immunodeficiency virus (HIV)-negative IDUs in the North and East of France. A total of 231 HCV and HIV IDUs who had injected drugs at least once in their lifetime were followed up every 3 months over a 12-month period. Serum anti-HCV and anti-HIV were tested at inclusion in the study and at the end of the follow-up. Data on injecting practices were collected at inclusion and at each visit. Of the 231 participants included, 165 (71.4%) underwent a final HCV and HIV serum test. The incidence was nil for HIV infection and 9/100 person-years (95% CI 4.6-13.4) for HCV infection. In a multivariable analysis, we found that syringe and cotton sharing were the only independent predictive factors of HCV seroconversion.

Adult↗

PubMed2002

Measuring cervical length with ultrasound: evaluation of the procedures and duration of a learning method.

OBJECTIVE: To evaluate the learning curve and principal learning steps for a novice ultrasound operator to master the technique for measuring cervical length by transvaginal ultrasound. SUBJECTS AND METHODS: The study involved asymptomatic patients with a singleton pregnancy between 21 and 38 weeks attending for a routine ultrasound scan. Two operators new to cervical ultrasound including one with experience in transvaginal gynecological ultrasound were assessed during their training. After an initial lecture session on the technique of cervical measurement, the trainees had one or two supervised practice sessions, validated by two interobserver agreement studies with 30 patients at a time; these compared the level of agreement between trainer and trainee throughout. Five examinations were performed in the first practice session; a second session was planned if the trainee could not perform all five examinations alone satisfactorily, in agreement with four quality criteria predefined for good cervical measurements. The second session lasted until five consecutive examinations could be performed adequately without the trainer's aid. Agreement between the two operators was assessed by intraclass correlation coefficient (ICC). The ICCs were compared with Fisher's Z transformation. RESULTS: Of the 150 patients included, 2.7% gave birth before term. The trainee with no experience in transvaginal ultrasound required two practice sessions; none of the five ultrasound scans performed in the first session was correct. In the second session, 18 consecutive ultrasound examinations were necessary to obtain five consecutive adequate results. During interobserver studies with the trainer, the ICC progressed from 0.43 in the first study to 0.64 in the second and 0.77 in the third (P = 0.049 between the first and third studies). The trainee with experience in transvaginal ultrasound required only one practice session. The ICC increased from 0.73 to 0.85 in the two interobserver studies with the trainer. CONCLUSIONS: Measurement of cervical length by transvaginal ultrasound examination is a technique that can be learnt rapidly. While roughly 23 supervised ultrasound scans appear necessary for an operator with no experience in transvaginal ultrasound, substantially fewer are required for an operator already familiar with this approach for other indications.

Adult↗

PubMed2001

Analysis of postpartum lactational amenorrhoea in relation to breast-feeding: some methodological and practical aspects.

A large multicentre epidemiological study was carried out by WHO between 1991 and 1995 to analyse the duration of lactational amenorrhoea in relation to breast-feeding. The main results of this analysis, which used classical statistical modelling, have been already published. However, some specific aspects of the postpartum fertility amenorrhoea and breast-feeding covariates, and more specifically the observed progressive exhaustion of the breast-feeding inhibitory effect on the reproductive axis, may justify a closer look at the validity of the statistical tools. Indeed, as has already been emphasized, analysis of large longitudinal data sets in reproduction often faces three difficulties: (i) the precise determination of the event of interest, (ii) the way to handle the time evolution of both the studied variables and their effect on the event of interest and (iii) the often discrete nature of the data and the associated problem of tied events. The first objective of the present work was to give additional insights into the estimation and quantification of the dynamics of the effect of breast-feeding over time, considering this covariate either as fixed or time-dependent. The second objective was to show how to perform the analyses using corresponding adapted procedures in widely available statistical packages, without the need for acquiring particular programming skills.

Amenorrhea↗

PubMed1999

Monitoring epidemiologic surveillance data using hidden Markov models.

The analysis of routinely collected surveillance data is an important challenge in public health practice. We present a method based on a hidden Markov model for monitoring such time series. The model characterizes the sequence of measurements by assuming that its probability density function depends on the state of an underlying Markov chain. The parameter vector includes distribution parameters and transition probabilities between the states. Maximum likelihood estimates are obtained with a modified EM algorithm. Extensions are provided to take into account trend and seasonality in the data. The method is demonstrated on two examples: the first seeks to characterize influenza-like illness incidence rates with a mixture of Gaussian distributions, and the other, poliomyelitis counts with mixture of Poisson distributions. The results justify a wider use of this method for analysing surveillance data.

Disease Outbreaks↗