UNEXPECTED HIGH PREVALENCE OF HEPATITIS-C VIRUS GENOTYPE-4 IN SOUTHERN SPAIN

Background/Aims: A unusually high rate of HCV-infected individuals in whom the HCV genotype cannot be ascertained by means of single PCR and LIPA. procedures has recently been reported in our area. The aim of t he present study was to investigate the epidemiological, clinical and molecular characteristics of these patients. Methods: Cross-sectional study Eighty anti-HCV-positive patients with chronic liver disease, 45 (56.25%) of them intravenous drug users, were included. HCV genotypin g was carried out in all patients using commercial single PCR and LIPA procedures. Samples where no HCV RNA amplification and/or indetermina te HCV genotype were found mere also tested by means of a nested PCR, HCV viral load was measured in all patients. Results: HCV genotyping w as not achieved in 23 (28.75%) individuals. No amplification of HCV RN A was found in 19 of them, and in four other cases the LIPA procedure did not allow identification of a distinct HCV genotype. After the use of nested PCR+LIPA, it was found that the HCV genotype 4 was found in 11 of those 23 individuals (47.82%), Ten of these 11 HCV genotype 4-h arboring individuals mere intravenous drug users. The HCV viral load w as lower in HCV genotype 4-harboring individuals than in those whom th e genotypes 1, 2 or 3 were found (p<0.001). Conclusions: A high rate o f HCV genotype 4-harboring cases has been found among HCV-infected ind ividuals in Southern Spain. Had only single PCR been used, these indiv iduals could have been wrongly regarded as non-viremic.