HCV is mainly transmitted when infected blood from one person directly enters another person's bloodstream. HCV has been detected in semen and vaginal fluid, so genital fluids may be infectious. Saliva and tears are not.
HCV, like HIV, cannot be transmitted by touching, kissing, hugging, sharing eating utensils, or drinking from the same glass. However, unlike HIV, which dies in less than a minute outside the body, HCV survives and is infectious in dried blood for days or even weeks. People can become infected by sharing items that contain only tiny traces of dried blood.
HCV can be transmitted through:
Hepatitis C can also be transmitted from a pregnant woman to her fetus in the womb or to an infant during labor and delivery.
Before thorough screening of the blood supply began in the early 1990s, some people received blood or blood products containing HCV. Since then, infection control procedures have virtually eliminated the risk in the United States and Western Europe.
However, up to 90% of people with hemophilia were infected with HIV and HCV after being treated with unscreened clotting factors; screening and viral inactivation procedures were introduced in the late 1980s.
In some countries, infections still occur from blood transfusions because blood is not screened. Unsafe medical procedures, such as using unsterilized equipment to vaccinate people, continue to spread HIV and hepatitis C in many parts of the world.
Worldwide, most HCV infections are attributable to injection drug use. This happens when people share injection equipment, including syringes, cookers, possibly cottons, and other injection paraphernalia.
Hepatitis C is a smaller, more durable virus than HIV. As discussed above, the hepatitis C virus can live in syringes and other objects for days or weeks. This is why it's so important to talk to people you get high with about how to make sure you're getting high safely, and in a way that protects everyone.
Cleaning syringes with bleach reduces the risk for HIV transmission but may be less effective against hepatitis C. If you're getting high, use a new set each time you inject. If you're injecting drugs with other people, mark your equipment and be sure that everyone has his/her own spoon or cooker. Using clean needles and your own works each time you inject stops both HIV and HCV transmission.
"I also worry about sharing a rolled-up note when I do coke -- but it doesn't stop me from doing it or my friends from being willing to share. I guess this all comes down to individuals agreeing to own and share risks that they feel to be acceptable. These risks feel okay most but not all of the time."
Hepatitis C is more common among non-injection drug users than among the general population. Researchers are not sure why. Since HCV is so common among IDUs, most drug users -- whether they inject or not -- know people who have HCV.
It may be possible to get HCV from sharing straws or rolled dollar bills for snorting drugs, and possibly from sharing crack pipes. Use your own bills and straws, and if you're smoking crack or heroin, use a stem to protect yourself.
Worldwide, sexual transmission accounts for the majority of new HIV infections each year. The risk of sexual transmission is greatly reduced by using condoms during sex.
The ways that HIV is transmitted are well understood. HIV is present in blood, semen, vaginal fluid, and breast milk.
We also know that different sexual acts carry different risk factors. For example, mutual masturbation and body rubbing are zero risk, and oral sex is very low risk. On the other hand, anal or vaginal sex without a condom is high risk. A high viral load in the HIV-positive partner increases the risk for infection, and a low or undetectable viral load will reduce the risk.
An HIV-positive person with untreated STDs (such as herpes, gonorrhea, and syphilis), is more likely to transmit HIV. This is because STDs increase the amount of HIV virus in genital fluids and make the HIV-positive partner more infectious. Similarly, an HIV-negative partner with untreated STDs is more vulnerable to HIV infection.
The risk for sexually transmitted HCV is very low in monogamous, HIV-negative, heterosexual couples in which one partner has HCV. One study following almost 900 heterosexual monogamous couples did not report any HCV infections over ten years of follow-up. These couples did not use condoms, but also did not have anal sex or sex during menstruation. Presumably, the uninfected partner in these couples may have had less exposure to blood, and therefore less chance of catching HCV during sex.
The risk for sexually transmitted HCV is higher for HIV-positive gay men and is probably also higher for men or women who have numerous partners and/or lots of anal or vaginal sex without condoms.
HCV is usually contracted when infected blood from one person enters another person's body. Although the hepatitis C virus has been found in semen and vaginal fluid, it is unclear whether and to what extent these fluids are infectious.
Sex is riskier if it involves exposure to blood. This could include longer and more energetic sex, anal sex, fisting, sex with a woman during menstruation, and group sex. Condoms can reduce these risks. Latex gloves can reduce exposure to blood during fisting.
In the United Kingdom, more than 300 cases of sexually transmitted HCV infection have been reported in HIV-positive gay men. A similar link between HCV sexual transmission and HIV-positive gay men has been reported in some other European and US cities.
So far, new cases of HCV sexual transmission in HIV-negative gay men are not being reported nearly as often. This suggests that HIV plays an important role.
Some studies have reported associations between HCV transmission and the following risk factors among gay men:
We can speculate about each of these points, but there is still a lack of clear information about why HIV-positive gay men seem more likely than HIV-negative gay men to acquire HCV through sexual contact.
|Crystal Meth, Ecstasy, Cocaine and HCV Infection|
Although sex seems to be the route of HCV infection among the HIV-positive gay men discussed above, taking drugs in this situation can increase the risk, even if the drugs are not injected. Drugs like ecstasy, coke, and crystal meth, all of which can make people less careful than usual, are frequently found at parties where there is group sex. Under these circumstances, the desire to dispense with condoms may be high.
"We need a lot more information and research about transmission of mother to child -- and transmission in general. A friend who is coinfected recently had a child. Even though her HIV viral load was undetectable, and her CD4 count was high, she had to have a caesarean section because of her HCV."
HCV, like HIV, can pass from a pregnant woman to her fetus in the womb or to an infant during labor and delivery. The risk of transmitting HCV to an infant is three to four times higher if you have both HCV and HIV. This means that up to 20% of pregnant women who are coinfected may pass HCV to their infants.
HIV treatment dramatically reduces the risk of mother-to-child transmission of HIV, regardless of the mother's hepatitis C status, and it may also lower the risk of HCV transmission.
It is not currently possible to take hepatitis C treatment during pregnancy to reduce the chance of HCV transmission. This is because one of the two primary HCV drugs (ribavirin) causes birth defects, and the other (interferon) can cause brain damage in infants less than two years old. Planned delivery by caesarean section (C-section) reduces the risk of mother-to-child transmission among coinfected mothers. But this is not a standard recommendation in the United States for women who have HCV alone, due to the invasive nature of the procedure.
Generally, HCV either spontaneously clears or progresses slowly in people who were infected at birth or during early childhood. HCV may progress more rapidly in coinfected children.
For more information about HIV and pregnancy, see the i-Base guide to HIV, pregnancy, and women's health, available online at www.i-base.info/guides/pregnancy/index.html.