Prevalence of hepatitis B and hepatitis C virus infections in France in 2004: social factors are important predictors after adjusting for known risk factors.

To monitor the prevalence of hepatitis B and hepatitis C a cross-sectional survey was conducted in 2004 among French metropolitan residents. A complex sampling design was used to enroll 14,416 adult participants aged 18-80 years. Data collected included demographic and social characteristics and risk factors. Sera were tested for anti-HCV, HCV-RNA, anti-HBc and HBsAg. Data were analyzed with SUDAAN software to provide weighted estimates for the French metropolitan resident population. The overall anti-HCV prevalence was 0.84% (95% CI: 0.65-1.10). Among anti-HCV positive individuals, 57.4% (95% CI: 43.2-70.5) knew their status. Factors associated independently with positive anti-HCV were drug use (intravenous and nasal), blood transfusion before 1992, a history of tattoos, low socioeconomic status, being born in a country where anti-HCV prevalence >2.5%, and age >29 years. The overall anti-HBc prevalence was 7.3% (95%: 6.5-8.2). Independent risk factors for anti-HBc were intravenous drug use, being a man who has sex with men, low socioeconomic status, a stay in a psychiatric facility or facility for the mentally disabled, <12 years of education, being born in a country where HBsAg prevalence >2%, age >29 and male sex. The HCV RNA and HBsAg prevalence were 0.53% (95% CI: 0.40-0.70) and 0.65% (95% CI: 0.45-0.93), respectively. Among HBsAg positive individuals, 44.8% (95% CI: 22.8-69.1) knew their status. Anti-HCV prevalence was close to the 1990s estimates whereas HBsAg prevalence estimate was greater than expected. Screening of hepatitis B and C should be strengthened and should account for social vulnerability.

[Alcohol, tobacco and colorectal adenomas and cancer. Case-control study in a population with positive fecal occult blood tests]. / Le tabac et l'alcool augmentent le risque d'adénomes et de cancers colorectaux. Etude comparant 3292 cas avec 5456 témoins dans une population à risque moyen ayant eu un test de dépistage de sang dans les selles positif.

OBJECTIVE: To analyze the associations between lifestyle factors and colorectal adenomas or cancers in a population 50-74 years old. METHOD: The study population underwent colonoscopy after positive fecal occult blood test in Health examination centers of the French general health insurance. The two sets of cases (n= 674 cancers, n=2618 adenomas) were compared with controls (n=5456). Associations between risk of colorectal disease and health data (mainly tobacco and alcohol consumption, physical activity, obesity, and laboratory test results) were analyzed with logistic regression models to estimate odds ratios. RESULTS: The probability of colorectal cancer or adenoma was statistically associated with age (60 years or older in men and women). A significant relation between these diseases was observed with smoking (in both smokers and ex-smokers) and with alcohol consumption, with odds ratios above 1.30. The other risk factors studied were not significantly associated with these colorectal diseases. CONCLUSION: This result provides still more evidence of the need for actions against these risk behaviors.

Colorectal cancer screening in Health Examination Centers.

OBJECTIVES: The aim of this study was to describe the results of colorectal cancer screening performed in the Health Examination Centers of the French general health insurance system. METHODS: The population consisted of 1,262,833 subjects (52.6% men) aged 50 to 74 years old who attended periodic health consultations from 1998 to 2003 in 89 Health Examination Centers in France. Subjects with increased risk for colorectal cancer and subjects with a positive fecal occult blood test (Hemoccult II') were invited to undergo colonoscopy. Subsequent follow-up and diagnostic data were collected. RESULTS: Prior screening practices for colorectal cancer (recent colonoscopy or fecal occult blood test, local screening campaign) were noted in 18% of the subjects attending Health Examination Center consultations. High risk for colorectal cancer (familial or personal factor) without ongoing surveillance or prior screening was observed in 3% of the study population. A fecal occult blood test was proposed to 79% of the population and of them, 89% effectively performed the test: 3.2% of tests were positive. A follow-up protocol was initiated for 63,357 subjects. A colonic exploration was performed in 69% of high-risk subjects and enabled detection of cancer in 85 and adenomas in 1683. A colonic exploration was performed in 88% of subjects with a positive fecal occult blood test and enabled detection of 674 cancers (positive predictive value of fecal occult blood test (PPV)=4.7%) including 174 Dukes A, and 2618 adenomas (PPV=18%) including 776 adenomas measuring more than 10 mm (PPV=5.4%). CONCLUSION: This study confirms the importance of implementing organized screening practices within Health Examination Centers before undertaking a generalized screen campaign targeting the entire French population.

[Colorectal cancer: assessment of two-yearly screening of the population in health care examination centres]. / Cancer colorectal: évaluation du dépistage biennal dans la population des centres d'examens de santé

OBJECTIVE: To present the first assessment of the two-yearly faecal occult blood test used to screen patients attending health care centres for examinations. Method The Hemoccult II test was proposed by correspondence to 26 530 subjects aged 52-74 years, having exhibited a negative test during their periodical check-up 2 years before. RESULTS: The test was performed by 20 590 subjects and the corrected participation rate, taking into account unjustified sending, was of 83.1%. The positivity rate was 3.5%. In the 519 colonoscopies performed (71% of positive Hemoccult II), 23 cancers and 91 adenomas (31 larger than 1 cm) were observed (positive predictive value=22%). In 213 subjects, the information on the follow-up of the positive Hemoccult II were unavailable or unexploitable (lost to follow-up, coloscopy refused, inappropriate examinations). DISCUSSION: These results show that the two-yearly screening for colorectal cancer in an informed population after a periodical check-up results in a good participation rate. The follow-up rate of positive subjects, fundamental for the assessment of the program, is lower than during the regular check-up but remains relatively satisfactory.

Standardization of gamma-glutamyltransferase assays by intermethod calibration. Effect on determining common reference limits.

BACKGROUND: The improvement of the consistency of gamma-glutamyltransferase (GGT) activity results among different assays after calibration with a common material was estimated. We evaluated if this harmonization could lead to reference limits common to different routine methods. METHODS: Seven laboratories measured GGT activity using their own routine analytical system both according to the manufacturer's recommendation and after calibration with a multi-enzyme calibrator [value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference procedure]. All samples were re-measured using the IFCC reference procedure. Two groups of subjects were selected in each laboratory: a group of healthy men aged 18-25 years without long-term medication and with alcohol consumption less than 44 g/day and a group of subjects with elevated GGT activity. RESULTS: The day-to-day coefficients of variation were less than 2.9% in each laboratory. The means obtained in the group of healthy subjects without common calibration (range of the means 16-23 U/L) were significantly different from those obtained by the IFCC procedure in five laboratories. After calibration, the means remained significantly different from the IFCC procedure results in only one laboratory. For three calibrated methods, the slope values of linear regression vs. the IFCC procedure were not different from the value 1. The results obtained with these three methods for healthy subjects (n=117) were gathered and reference limits were calculated. These were 11-49 U/L (2.5th-97.5th percentiles). The calibration also improved the consistency of elevated results when compared to the IFCC procedure. CONCLUSIONS: The common calibration improved the level of consistency between different routine methods. It permitted to define common reference limits which are quite similar to those proposed by the IFCC. This approach should lead to a real benefit in terms of prevention, screening, diagnosis, therapeutic monitoring and for epidemiological studies.

Stepwise strategies in analysing haematuria and leukocyturia in screening.

The aim of the present work was to compare in a supposed healthy population of 680 subjects several algorithms for positive selection of urine samples requiring microscopic examination for erythrocytes and leukocytes after screening by automated test-strip measurement and particle counting on a Sysmex UF-50 flow cytometer. Four strategies have been formulated and the sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, false negative rate, and microscopic review rate were measured. The strategy combining test strip analysis and automated counting on all samples, followed by microscopic examination of only discordant samples gave the best results. When the two methods of haematuria screening were in agreement (91% of samples), the false negative rate for microscopy was 1.1%, with a false positive rate of 0.8%, sensitivity of 66% and specificity of 99%, and the results are acceptable without any other examination. When the two methods of haematuria screening were discrepant, visual microscopic analysis was necessary to obtain definitive results. For leukocyturia screening, 80% of results were in agreement by test strip and automatic sediment urinalysis, with only ten results considered as false negatives (1.8%) and four as false positives (0.7%). Agreement was good and the other criteria were good (sensitivity 79%, specificity 99%). On conflicting samples, there was no agreement between methods and microscopic analysis was essential. The benefit of such an algorithm would be optimisation of the workflow without any loss of sensitivity and specificity at the expense of a two-fold increase in cost.