|HCV Risk Factor Chart||RISK OF INFECTION|
|Sharing needles or syringes to inject illegal drugs||High|
|Received clotting factors made before 1987||High|
|Received blood and/or solid organs before 1992||Intermediate|
|People with undiagnosed liver problems||Intermediate|
|Infants born to infected mothers||Intermediate|
|Healthcare/public safety workers||Low|
|People having sex with multiple partners||Low|
|People having sex with an infected steady partner||Low|
(http://www.cdc.gov/ncidod/diseases/hepatitis/c/fact.htm) Accessed and adapted 3/6/08
Individuals who have shared
needles and syringes to inject illegal drugs have the highest risk of HCV infection
of any group. HCV viral infectivity can persist for days or longer given favorable conditions. HCV is efficiently transmitted
via contaminated dried blood on injection paraphernalia including shared needles, syringes, cookers and filters (e.g., cotton or a cigarette filter used to strain particulates from a drug solution); even longer under favorably moist conditions, like the barrel of a syringe.
Some studies also link HCV infection with the sharing of straws to snort cocaine. Apparently blood to blood transfer can occur when a soda straw is shared to "sniff" illegal drugs. Past or current users of illegal drugs should be evaluated carefully, and when necessary, referred to drug treatment programs prior to antiviral therapy.
factor concentrate produced before 1987.
People who received clotting factor concentrates prepared from pooled plasma, before 1987, are at risk for HCV and chronic liver disease. They are also at risk for co-infection with HIV. Studies have demonstrated that 87% of hemophiliacs contracted HCV from blood products before 1987. Many were co-infected with HIV. The HIV co-infection often resulted in more severe symptoms and rapid progression of the HCV related symptoms.
Today blood donors are screened for risk factors and their blood is tested for evidence of current or previous bloodborne disease. Blood which tests positive for exposure to bloodborne disease is excluded. Blood products, such as clotting factors VIII and IX, have been treated to inactivate undetected encapsulated viruses such as HIV-1, HBV and HCV since 1987. The inactivation methods include prolonged exposure to heat (pasteurization), and a solvent/detergent process which disrupts the viral coat. However, there is some evidence that HCV may be more or less resistant to some of these processes.
Transfusion of blood or blood components or a solid organ transplant before 1992
HCV infection:per unit transfused
2008 to present
While the guidelines suggest that transplants after 1992 are safe, that has not been the case. In 2000, an organ donor who tested negative for hepatitis C using the standard blood tests of the time, transmitted the virus through organ and tissue transplants to a number of recipients. Three of 6 organ recipients died of hepatitis C and 5 of 32 tissue recipients became infected. According to the CDC, the donor was asymptomatic and had no history that put the donor at high risk for infection. It was likely that the donor was recently infected and not yet generating detectable antibodies. While RNA tests are more accurate than antibody screens, not all health facilities have easy access to RNA testing and delays in getting results could jeopardize the viability of the tissue and success of the transplant. Therefore, requiring RNA testing of all donors poses problems. The number of infected individuals is likely quite small, but not insignificant.
In 2003, a study reported that about 300 musculoskeletal tissue specimens infected with hepatitis C were distributed by US tissue procurement centers each year. The problem was that the FDA had no approved test to detect the presence of HCV in cadaver donor tissues. About 18,000 cadavers provide 650,000 allografts for transplantation, such as the cartilage for joint surgeries.
Tissues from one infected donor could be distributed among dozens of recipients, resulting in multiple infections in recipients and those who have contact with them. In June 2004, the FDA approved the first nucleic acid test (NAT) for cadaver specimens, but did not require at that time that tissue banks use the test. However, in response to concerns about the safety of cadaver donor tissue, in August 2004, the American Association of Tissue Banks (AATB) required its accredited facilities to implement nucleic acid testing for both HIV-1 and HCV. Therefore, banks accredited by AATB began testing immediately. Nationwide testing was not required until March 2005, so further infected tissue may have been distributed.
There is very little difference in the rates of hepatitis C among health care workers (2%) than in the general population. However, the prevalence of HCV in hospitalized patients could be as high as 18%, so there is always the danger of exposure to blood, especially through needlesticks. The risk of becoming infected after a needlestick injury involving HCV positive blood ranges from 0% to 10%. The general rule followed for risk related to needle-stick is called the Rule of 3's: HBV is transmitted in 30% of exposures, HCV in 3%, and HIV in 0.3%. Because there is no approved prophylactic treatment for hepatitis C, only treatment for active disease, a health care or other worker who is exposed to HCV infected blood should receive follow-up testing for 6 to 9 months to determine if infection occurred.
The risk for transmitting
HCV from sexual exposure tends to be lower than for HIV transmission, with
only about 15% of cases of hepatitis C related to sexual intercourse. However,
a substantial portion of the adult population in the United States has
had unprotected sex with multiple partners and, because of the large number
of people infected with HCV, some of these contacts are with infected individuals.
Studies of long-term spouses of HCV infected partners found infection rates
of 0% to 4%. Additional studies found that males with an HCV-infected female
partner had rates no higher than those with a non-infected partner. However,
female patients with an HCV-infected partner were almost 4 times as likely
to develop HCV than females with a negative partner. This suggests that
transmission from male to female is more efficient than from female to
male. The HCV rates for males having sex with males (MSM) is similar to
There is very little
danger involved in sharing living space with someone infected with
HCV, other than through sexual transmission. However, it is possible
to become infected by coming into contact with blood contaminated
items, such as razors and toothbrushes.
The prevalence of HCV infection in prison inmates is substantially higher than that of the general U.S. population. Of the 2.2 million people in US jails and prisons, about 30% have chronic Hepatitis C. HCV infection is primarily associated with a history of injection drug use but HCV can also be spread by contaminated tattoo, body art, or piercing equipment. CDC recommends that correctional facilities ask inmates questions about their risk factors for HCV infection during their entry medical evaluations. Inmates reporting risk factors should be tested for HCV infection and those who test positive for HCV should receive further medical evaluation to determine if they have chronic infection and/or liver disease.
While HIV infection is not usually listed as a risk factor for HCV, they often exist as co-infections. Therefore, an infection with one should trigger testing for the other. Estimates suggest that 30% of the people infected with HIV are co-infected with HCV, and that of those who contract HIV from intravenous drug use (IDU), 60 to 90% are co-infected with HCV. There are about 300,000 people in the United States with HIV/HCV, with African Americans and Hispanics disproportionately affected. While patients with HIV alone can often be maintained with antiretroviral drugs, HCV progresses more rapidly with HCV-related liver disease and cirrhosis in the presence of HIV, putting these co-infected patients at risk for liver failure.