Detection of a cluster of hepatitis C infections in a renal transplant unit by analysis of sequence variation of the NS5a gene

Hepatitis C virus (HCV) genotype 1 isolates from 31 patients on dialysis or with renal transplants were studied for evidence of patient-to-patient spread of infection. Nucleotide sequences from a variable region (NSSV) of the NS5a (nonstructural 5a) gene and the hypervariable region of the second envelope gene (env2) were compared. Investigation of phylogenetically related isolates of HCV type la with identical derived amino acid sequences in the NSSV led to recognition of a cluster of 4 patients who had received renal transplants within an 8-day period in 1984. This demonstrates the value of molecular epidemiologic techniques in reconstructing routes of infection and adds to the evidence for nosocomial transmission of HCV by routes other than blood transfusion.