SEN virus co-infection among HCH-RNA-positive mothers, risk of transmission to the offspring and outcome of child infesction during a 1-year follow-up

SUMMARY. SEN is a newly discovered blood-transmissible virus. Among its variants, SENV-D and -H are most often associated with non-A, -E hepatitis. Very little is known about the risk of vertical transmission of the virus. By using polymerase chain reaction with specific primers for SENV-D and -H, we investigated the prevalence of SENV-H and -D infection, the transmission rate of SENV infection and clinical features of SENV-infected children in 89 hepatitis C virus (HCV)-positive human immunodeficiency virus type 1-negative mothers. SENV infection was found in 36 (40%) mothers, and SENV-D was more frequent than SENV-H infection (34/36, 94% vs 5/36, 14%, P < 0.01). No differ- ence in SENV infection rates was found between injection drug user (IDU) mothers (17/51, 33%) and mothers with no INTRODUCTION A new virus, designated as SEN, was recently discovered in the serum of an i.v. drug abuser infected with human immunodeficiency virus type 1 (HIV-1) [1]. SEN virus (SENV) is a deoxyribonucleic acid (DNA) virus with a gen- ome length of 3900 nucleotides that contains three open reading frames (ORF). The virus belongs to the family of Circoviridae. It is distantly but directly related to transfusion trans- mitted (TT) virus and is similarly transmissible via blood- product transfusion. To date, nine different SENV variants (A through I) have been identified. Among them, two SENV Abbreviations: ALT, alanine aminotransferase; DNA, deoxyribonu- cleic acid; HBV, hepatitis B virus; HCV, hepatitis C virus; HIV-1, human immunodeficiency virus type 1; IDU, injection drug user; NR, nonresponder; ORF, open reading frame; PCR, polymerase chain reaction; SENV, SEN virus; TT, transfusion transmitted. Correspondence: Chiara Azzari, MD, Department of Pediatrics, Uni- versity of Florence, Via Luca Giordano 13, 50132 Firenze, Italy. E-mail: chiara.azzari@unifi.it Ó 2006 The Authors Journal compilation Ó 2006 Blackwell Publishing Ltd risk for bloodborne infection (19/38, 50%, P 1⁄4 ns). SENV-H infection was found only in IDU mothers and mothers with HCV genotype1b. Both SENV-D and -H can be transmitted to the offspring with an overall rate of 47%. Vertical transmission of HCV does not facilitate SENV infection of the offspring. Among 17 SENV-infected children, none was co-infected with HCV. Maternal HCV genotype or viral load does not interfere with mother-to-infant transmission of SENV. Persistence of SENV infection was demonstrated in 100% of infected children after 1-year follow-up, but none had clinical evidence of liver disease.