Epidemiologic and molecular investigation of outbreaks of hepatitis C virus infection on a pediatric oncology service.

BACKGROUND

Despite screening of blood donors, hepatitis C virus (HCV) infection can occur in patients who receive multiple transfusions.

OBJECTIVE

To clarify mechanisms of nosocomial transmission of HCV.

DESIGN

Epidemiologic and molecular analyses of hepatitis C outbreaks.

SETTING

Pediatric oncology ward.

PATIENTS

Children with cancer.

MEASUREMENTS

Epidemiologic analysis, HCV RNA detection, genotyping, and hypervariable region 1 (HVR1) sequencing.

RESULTS

Ten cases of infection with acute HCV genotype 3a occurred between 1990 and 1993. Sequencing of HVR1 revealed three related strains. Despite an overhaul of hygiene procedures, a patient infected with genotype 1b generated nine subsequent infected patients in 1994. Several patients had high virus titers and strongly delayed anti-HCV antibody responses. All had permanent intravenous catheters. Multidose vials used for flushing or treatment had probably been contaminated during periods of overlapping treatment.

CONCLUSIONS

Contamination of multidose vials was the most likely mode of HCV transmission; therefore, use of such vials should be restricted. Rigorous adherence to hygiene routines remains essential to preventing transmission of bloodborne infections.