Hepatitis C virus genotypes distribution and transmission risk factors in Luxembourg from 1991 to 2006

AIM： To analyze the Hepatitis C virus （HCV） genotype distribution and transmission risk factors in a population of unselected patients in Luxembourg. METHODS： Epidemiological information （gender, age and transmission risks） were collected from 802 patients newly diagnosed for hepatitis C and living in Luxembourg, among whom 228 patients referred from prison. Genotyping using 5＇noncoding （5＇NC） sequencing was performed. We compared categorical data using the Fisher＇s exact F-test and odds ratios （OR） were calculated for evaluating association of HCV genotype and risk factors. RESULTS： The sex ratio was predominantly male （2.2） and individuals aged less than 40 years represented 49.6% of the population. Genotype 1 was predominant （53.4%） followed by genotype 3 （33%）. Among risk factors, intravenous drug usage （IVDU） was the most frequently reported （71.4%） followed by medical-related transmission （17.6%） including haemophilia, transfusion recipients and other nosocomial reasons. Genotype 3 was significantly associated to IVDU （OR = 4.84, P 〈 0.0001） whereas genotype 1 was significantly associated with a medical procedure （OR = 2.42, P 〈 0.001）. The HCV genotype distribution from inmate patients differed significantly from the rest of the population （Chi-square test with four degrees of freedom, P 〈 0.0001） with a higher frequency of genotype 3 （46.5% vs 27.5%） and a lower frequency of genotype 1 and 4 （44.7% vs 56.8% and 5.3% vs 9.6%, respectively）. IVDU was nearly exclusively reported as a risk factor in prison. CONCLUSION： We report the first description of the HCV genotype distribution in Luxembourg. The repartition is similar to other European counties, with one of the highest European prevalence rates of genotype 3 （33%）. Since serology screening became available in 2992, IVDU remains the most common way of HCV transmission in Luxembourg.