Transmission of hepatitis C virus in a gynecological surgery setting

A cluster of hepatitis C virus (HCV) infections among gynecological patient s who underwent surgical intervention in the same setting is described. An epidemiological investigation was conducted to identify the cases, the like ly source of infection, and the route of transmission. Four recent HCV infe ctions were identified. Based on molecular fingerprinting analysis and epid emiological investigation, transmission between the putative source patient (an HCV-positive woman who was the first patient of the surgical session) and outbreak patients was highly suggestive. All patients, including the so urce patient, were infected with HCV type lb. Molecular characterization of HCV clones by sequence analysis of both structural envelope regions (20 cl ones from the source patient and 58 from the outbreak patients) and the non structural NS5 region of the viral genome (12 clones from the source patien t and 32 from the outbreak patients) showed close homology between the vira l isolates from the source and those from the outbreak patients that was hi gher than that observed between the viral isolates from the source and thos e from four unrelated, HCV type lb-infected patients from the same geograph ical area (in the latter case, 33 clones were sequenced for the envelope re gions and 30 were sequenced for the NS5 region). The mean percent divergenc e between clones was 4.69 for the envelope and 3.71 for the NS5 region in t he source patient and the outbreak patients compared with 6.76 (P = 0.001) and 5.22 (P = 0.01) in the source patient and control patients, respectivel y. Among the risk factors investigated, only that of having undergone surge ry in the morning session of the same day reached statistical significance (P = 0.003). The investigation showed that the source patient and outbreak patients shared only the administration of propofol in multidose vials. The study documents the risk of nosocomial transmission of HCV and the importa nce of infection control procedures in the operating room and highlights th e crucial role of molecular strategies, especially sequence-based phylogene tic analysis of cloned viral isolates, in the investigation of HCV outbreak s.