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Recommendations to Prevent HCV Transmission from NIH HCV Consensus Conference
Panel draft report (june 2002)
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The large global reservoir of individuals infected with HCV provides a source
of
transmission to others at risk. Direct percutaneous exposure is the most
efficient method for
transmitting HCV, and IDU accounts for over two-thirds of all new infections.
Needle and
syringe exchange programs and comprehensive risk-modifying educational
programs that are
highly effective in preventing HIV transmission are likely to be useful for
decreasing HCV
transmission. HCV is rarely transmitted by transfusion of blood products or
transplantation of
organs or tissues in the United States and other countries where screening
tests exclude
infectious donors.
The majority of other cases can be attributed to sexual transmission and
occupational
exposures to blood, although the actual risk of transmission through these
routes is low. Data
regarding transmissibility by sexual contact have been confounded in part by
other exposures,
including IDU, that can increase the risk of transmission of HCV. HCV genot
ypes appear to
have no impact on the risk of transmission.
In the United States, the estimated seroprevalence of HCV is 2 to 3 percent
among
partners of HCV-infected persons who are in long-term monogamous
relationships and is 4 to
6 percent among persons with multiple sex partners, sex workers, and men who
have sex with
men (those at risk for sexually transmitted diseases). For heterosexual,
discordant monogamous
couples, the risk of transmission is estimated to be 0 to 0.6 percent
annually, with the risk to
females being threefold greater than to male partners. Because of the low
risk of HCV
transmission, couples need not use barrier protection (condoms); however,
couples should be
advised that the use of condoms may decrease the risk of HCV transmission.
Based on studies in
persons at risk for sexually transmitted diseases, HCV transmission is
approximately 1 percent
annually. HCV-infected individuals with multiple sexual partners or in
short-term relationships
should be advised to use condoms to prevent transmission of HCV and other
sexually transmitted diseases. The sharing of common household items, such as
razors and toothbrushes, is another potential source of transmission of HCV.
There is no evidence that kissing, hugging, sneezing, coughing, food, water,
sharing eating utensils or drinking glasses, casual contact, or other contact
without exposure to blood is associated with HCV transmission.
Health care workers may have a slightly higher prevalence of HCV infection
than the
general population, although they may have acquired infection from
nonoccupational sources.
Transmission from health care workers to patients has also been documented,
but it is rare and is confounded by other risk factors.
The risk of HCV infection from needle sticks is estimated to be 2 percent. At
this time,
antiviral prophylaxis is not recommended following needle stick exposure. It
is recommended
that the source and exposed individual should be tested for antibody to HCV.
If the source
individual is HCV EIA positive, an HCV RNA assay should be done. The exposed
individual
should be tested for HCV antibody and ALT at exposure and repeated at
4&endash;6 months. If
seroconversion occurs, recommendations for persons following acute HCV
infection should be
followed.
Percutaneous exposures, such as body piercing and tattooing, are other
potential sources
of transmission if contaminated equipment or supplies are used. However, the
rates of
transmission are less than 1 percent, and these data are confounded by other
risk factors.
Perinatal transmission has been documented. Higher maternal HCV RNA load
appears to
be associated with a greater risk for HCV transmission to the infant. The
risk of transmission is
approximately 2 percent for infants when the mother is HCV seropositive; this
risk increases up
to 7 percent when a pregnant woman has two positive assays for HCV RNA. HCV
transmission
may be increased to approximately 10 percent with maternal injection drug use
and up to
20 percent in women coinfected with HCV and HIV. There are no prospective
studies evaluating
the use of elective Cesarean section for the prevention of mother-to-infant
transmission of HCV.
There are currently no data to determine if antiviral therapy reduces
perinatal transmission.
Ribavirin and interferons are contraindicated during pregnancy.
Breast-feeding does not appear to transmit HCV. Children and personnel should
not be
excluded from daycare centers because of hepatitis C infection. Standard
universal precautions
should be used in any situation where blood or blood products are used.
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