TRANSMISSION OF HEPATITIS-C VIRUS TO INFANTS OF HUMAN IMMUNODEFICIENCY VIRUS-NEGATIVE INTRAVENOUS DRUG-USING MOTHERS - RATE OF INFECTION AND ASSESSMENT OF RISK-FACTORS FOR TRANSMISSION

The risk of perinatal transmission of hepatitis C virus (HCV) from a c ohort of 95 human immuno-deficiency virus (HIV)-negative intravenous d rug users (IVDU) is described, 89 of whom were positive for antibodies to HCV (anti-HCV), Infection, defined as the presence of HCV RNA in a serum sample collected from an infant at any time during follow-up, w as detected in six of 63 (9.5%) infants born to HCV antibody-positive viraemic mothers, No mother who was HCV RNA negative at delivery trans mitted HCV to her infant, Hepatitis C virus antibodies became undetect able in uninfected infants by 15 months, but persisted in all HCV-infe cted infants throughout follow-up, An abnormal alanine aminotransferas e (ALT) level was observed on at least one occasion in all HCV-infecte d infants and in six occasions in uninfected infants, Two of the six H CV-infected infants became HCV RNA negative during follow-up by 27 and 29 months, Both of these infants had a large ALT elevation (mean peak AIT 398 U l(-1)) at around 12 months of age, Analysis of a range of p otential risk factors revealed that maternal HCV RNA load was importan t in predicting transmission, but suggested that other factors play a role in perinatal transmission from mother to child, No difference was found between mothers who transmitted HCV to their infants and those who did not for HCV genotype, duration of drug use, duration of methad one use, methadone dose, history of alcohol abuse, past hepatitis B vi rus (HBV) infection, mode of delivery, maternal and gestational age, b irth weight and incidence of breast-feeding, Mothers who transmitted H CV to their infants had a longer duration between membrane rupture and delivery than the mothers who did not transmit (P = 0.03). HCV RNA wa s not detected in breast milk and colostrum samples from 38 viraemic m others, including two who transmitted HCV to their infant.