July 28, 1997

Sexual Transmission of the Hepatitis C Virus and Efficacy of Prophylaxis With Intramuscular Immune Serum GlobulinA Randomized Controlled Trial

Author Affiliations

From the Istituto di Malattie Infettive, Universitá degli Studi di Napoli Federico II, Naples (Drs Piazza, Tosone, Orlando, and Borgia); the Servizio Epidemiologia e Prevenzione ASL Napoli 1 Regione Campania, Campania (Dr Sagliocca); the Facoltá di Medicina e Chirurgia di Catanzaro, Universitá degli Studi di Reggio Calabria, Calabria (Dr Guadagnino); the Laboratorio Epidemiologia e Biostatistica, Istituto Superiore di Sanitá, Rome (Ms Stazi); the Research Institute of Chiron-Biocine, Siena (Drs Rosa and Abrignani); the Osservatorio Epidemiologico Regione Campania, Campania (Dr Palumbo); the Istituto di Microbiologia, Universitá degli Studi di Ancona, Ancona (Dr Manzin); and the Dipartimento di Scienze Biomediche, Universitá degli Studi di Trieste, Trieste (Dr Clementi), Italy.

Arch Intern Med. 1997;157(14):1537-1544. doi:10.1001/archinte.1997.00440350037004

Objectives:  To estimate the risk of sexual transmission of hepatitis C and to assess the value of prophylaxis with periodic intramuscular immune serum globulin administration.

Methods:  Of 1102 steady heterosexual partners of patients with antibodies to the hepatitis C virus (HCV), 899 were enrolled in a single-blind, randomized, controlled trial. All the partners tested negative for antibodies to HCV and had normal baseline serum aminotransferase concentrations. The partners were assigned to receive 4 mL of 16% polyvalent immune serum globulin prepared from unscreened donors every 2 months (n=450) or a placebo (n=449). Tests for HCV infection were performed every 4 months.

Results:  Eight hundred eighty-four partners completed the study. Seven partners became infected with HCV: 6 in the control group (incidence density, 12.00 per 1000 person-years; 95% confidence interval, 3.0-21.61) and 1 in the immune serum globulin group (incidence density, 1.98 per 1000 person-years; 95% confidence interval, 0-5.86). The risk of infection was significantly higher for partners in the control group (P=.03): for each year approximately 1% of the partners became infected. Sequence homology studies strongly suggest the sexual transmission of HCV. All immune serum globulin lots used had high enzyme-linked immunosorbent assay titers of neutralizing antibodies to HCV envelope glycoproteins and high neutralization titers in the neutralization of binding assay.

Conclusions:  Hepatitis C can be sexually transmitted. Immune serum globulin prepared from unscreened donors significantly reduced the risk. The treatment was safe and well tolerated. Because only immune serum globulin from unscreened donors (and not from those screened for HCV) contain anti-HCV neutralizing antibodies, hyperimmune anti-HCV immune serum globulin should be prepared from blood testing positive for antibodies to HCV, which is currently discarded.Arch Intern Med. 1997;157:1537-1544