Vertical transmission is an important route of HCV infection. Infants are considered to be infected if two or more HCV-RNA results are positive and/or anti-HCV+ over 18 mo of age. HCV-RNA RT-PCR testing requires high quality certificated centers. Anti-HCV ELISA commercial tests are cheaper and may be performed in all laboratories.
Aim: To estimate sufficiency of anti-HCV testing over 18 mo in the diagnostic process of HCV mother-to-child infection.
Methods: 317 children born to HCV infected mothers were observed for 2-4 years. HCV-RNA was determined first at the age of 2-5 mo and subsequent in 6 months intervals, anti-HCV every 3-6 months.
Results: HCV infection (HCV-RNA twice presence) was recognized in 26/317 (8.2%). Anti-HCV+ were found in: 288 (91%) children in 3-6 mo of age, 213 (67.2%) in 7-9 mo, 21 (6.6%) above 18 mo. HCV-RNA was negative during all observation in the group with anti-HCV results group in all determinations in the first year of life. Among 21 children anti-HCV+ over 18 mo there were: 18 with chronic infection (HCV-RNA+, anti-HCV+), 3 achieved HCV-RNA clearance (2 became anti-HCV-, 1 anti-HCV+ during following observation). Among 296 children anti-HCV over 18 mo there were 5 children HCV-RNA+ twice in the first year of life, but all became HCV-RNA- during follow up. In 4 of them (4/296, 1.3%) in spite of anti-HCV- we transiently found HCV-RNA+ above 18 mo of age.
Conclusions: Anti-HCV presence in children born to HCV infected mothers: a) up to 18 mo of age do not confirm HCV infection. b) over 18 mo of age are indicative of HCV infection, but not always with active HCV replication. Negative results of anti-HCV above 18 mo of age usually allow us to exclude HCV replication, but in 1.3% we found HCV-RNA in anti-HCV- children. Anti-HCV testing over 18 mo of age as only diagnostic procedure may be not enough. Missing HCV replication in the first period of life prevents HCV microreplication follow up.