Distribution of HCV genotypes among risk groups in Serbia G. Stamenkovic 1 , S. Zerjav 2 , Z.M. Velickovic 3 , K. Krtolica 1 , V. Libek Samardzija 4 , L. Jemuovic 2 , D. Nozic 5 & B. Dimitrijevic 1 1 Institute for Nuclear Sciences `Vinca', Belgrade; 2 Institute for Infections and Tropical Diseases, CC Serbia, Belgrade; 3 Department of Pathology, Wellington School of Medicine, Wellington, New Zealand; 4 Clinical Hospital Zemun, Belgrade; 5 Military Medical Academy, Belgrade, Yugoslavia Accepted in revised form 14 December 2000 Abstract. Blood samples from 190 patients that were anti-hepatitis C virus (HCV) positive were genotyped and 165 were found to contain HCV±RNA. Geno- typing was performed by PCR based on type-speci®c primers (117 isolates) and LiPA test (48 isolates) and verifying by sequencing. In Serbia, the most frequent genotype was 1b (49.1%), followed by genotype 3 (21.2%) and genotype 1a (8.5%). The frequency of genotypes 2 and 4 was below 5% and mixed infec- tions were encountered in 9.1% of cases. Distribution of genotypes was monitored in dierent risk groups: intravenous drug abusers, patients under blood transfusion, patients with previous history of surgery, patients undergoing hemodialysis and those with unknown risk factors. Genotype distribution is es- sentially the same in all the groups, except for the patients undergoing hemodialysis and those with previous history of surgery where signi®cant dier- ence exists compared with the group with unknown route of transmission (p < 0.001 and p < 0.05, respectively). There exists signi®cant age-dependent genotype 3 distribution in Serbian population (p < 0.01). Key words: Hepatitis C virus genotypes, Serbia, Sources of infection Introduction Hepatitis C virus (HCV) infection has been well documented across the world and represents the major etiological agent in chronic liver disease. In- fected individuals have an increased risk for liver cirrhosis and hepatocellular carcinoma [1, 2]. Al- though it has been assumed that parenteral exposure to blood is the major route of infection, no obvious source of infection is very frequent [3, 4]. HCV genome displays considerable sequence vari- ability among dierent isolates as typical for RNA viruses [5, 6]. Phylogenetic analysis of the genomic sequence de®ned 10 major types depicted as 1, 2, 3, etc., and more than 15 subtypes depicted as 1a, 1b, 1c, etc. [6, 7]. Type de®nes nucleotide sequence di- vergence of up to 30% over the complete virus ge- nome and each includes subtypes with the sequence divergence of up to 20% [8]. These genomic dier- ences have important phenotypic consequences clin- ically presented as altered severity of infection and treatment responses [9, 10]. Distribution of HCV genotypes displays geo- graphical dependence. Genotypes 1, 2 and 3 have speci®c distribution pattern in almost all regions of the world [8, 11] while genotypes 4, 5 and 6 are mostly connected with Africa, South Africa and Hong Kong [11, 12]. Genotypes 7, 8 and 9 were more recently isolated from Vietnamese patients [13]. This research was aimed to determine distribution of HCV genotypes in the speci®c part of the Balkan Peninsula not typed before. Geographical speci®city was expected to re¯ect crossroads between Mediter- ranean, Middle east and Central Europe and the fact that recent war(s) caused signi®cant migrations and substantial proportion of refugees among the popu- lation of Serbia. Since genotyping HCV may provide useful information about the severity of infection and treatment management, risk groups and sporadic cases were examined for genotype distribution. Methods Patients and specimens Patient selection was based on positive ®nding of anti- HCV antibody (HCV 3.0 ELISA Test System, Ortho Diagnostic Systems, Germany). Samples from 167 patients were collected at the Clinical Center of Serbia, Institute for Infectious and Tropical Diseases, De- partment for Viral Hepatitis from Belgrade, at the Military Medical Academy in Belgrade and samples from patients undergoing hemodialysis were obtained from Clinical Hospital Zemun in Belgrade. These in- stitutions are major centers where patients from all parts of Serbia are admitted and can regarded as rep- resentative sample of population of the whole Serbia European Journal of Epidemiology 16: 949±954, 2000. Ó 2001 Kluwer Academic Publishers. Printed in the Netherlands.