Changes in the epidemiology of hepatitis C infection in Germany: Shift in the predominance of hepatitis C subtypes

Hepatitis C virus (HCV) subtype distribution was studied in 395 chronically infected patients from Germany. HCV genotype 1 was most frequent (80.5%). One hundred forty-three individuals (36.2%) were infected with subtype la a nd 175 (44.3%) were suffering from subtype 1b infection, respectively. HCV subtype 3a was found in 53 (13.42%) persons. Subtypes 2a, 2b, and 2e have b een detected in 5 (1.27%), 10 (2.53%), and 4 (1.01%) individuals. Genotypes 4 and 5a accounted for HCV infections in 4 (1.01%) and 1 (0.25%) subjects. There was a notable variation in the distribution of the prevalent subtype s 1a and 1b in different age groups. Subtype la was detected in 53.3% and 6 8.0% of patients aged 1-10 and 11-20 years, whereas subtype 1b in the same groups was present only in 33.3% and 28.0% of patients, respectively. In co ntrast, in Individuals older than 50 years subtype 1b was most frequent. Th us, subtype 1b has been gradually substituted for subtype 1a during the las t 20 years. Logistic regression analysis with adjustment for sex and differ ent modes of HCV acquisition demonstrated that age of the infected subjects was a direct explanatory variable for subtype 1a and 1b distribution. Ther efore, the observed shift in HCV subtype prevalence could not be attributed to changes in the epidemiological relevance of different known risk factor s of HCV transmission, as had been assumed in previous studies. The altered subtype pattern reported here may have a profound influence on the future epidemiology of HCV infection. J. Med. Virol. 60:122-725, 2000. (C) 2000 Wi ley-Liss, Inc.