Direct
percutaneous inoculation is the most efficient mode of transmitting HCV,
although sexual, household occupational and vertical transmission of HCV
may also occur (
63-67).
HCV
intra-spousal transmission appears to be rare in the absence of a parenteral
risk in the partner. In case-control studies sexual co-habitation with
an anti-HCV-positive person was not identified as a risk for infection.
Therefore HCV is not considered to be a sexually transmitted disease. Some
factors, however, such as sexual promiscuity, HIV and HSV2 co-infections
are associated with sexual transmission of hepatitis C (
66,67).
It is not clear whether the probability of transmission between partners
increases with decades of marriage and/or age (
68,69).
This does not necessarily represent sexual transmission.
Rates of transmission
of hepatitis C from mother to newborn infant vary between 0 and 3% according
to different reports (
70-73)
.Two
risk factors have been identified, HIV infection in the mother, and high
maternal viral load (
70,73).
It is controversial whether caesarian section prevents transmission of
HCV. Results of testing breast milk for HCV RNA are conflicting. However,
transmission from breast milk has not been documented.
Breast feeding is considered safe and is not contraindicated.
Anti-HCV testing in the neonate is not helpful, because there is passive
transfer of antibody across the placenta. This may take 12-18 months to
clear.
Testing for hepatitis C infection within the first 18 months
of life should be by PCR
assays. There is very limited information in the literature concerning
the rate of chronicity after neonatal transmission. Clearance of the virus
may occur more frequently than in adult infection.