HIV, HCV and sex
HIV transmission
Worldwide, sexual transmission of HIV accounts for the majority of new HIV infections each year.
The ways that HIV is transmitted are well understood.
HIV is present in blood, semen, genital fluids and breast milk. The risk of sexual transmission is greatly reduced by using condoms during sex.
Different types of sex carry different risks, for example body rubbing and mutual masturbation is zero risk, oral sex is low risk, and anal or vaginal sex without a condom is high risk. Higher viral load in the HIV-positive partner will increase each of these risks and lower or undetectable viral load will reduce them.
Other sexually transmitted infections (STIs), including herpes, gonorrhea and syphilis, increase the risk of transmitting HIV. This is because they increase the amount of HIV virus in genital fluids and make the HIV-positive partner more infectious. STIs in an HIV-negative partner make them more vulnerable to HIV infection.
All this information is important when talking about HCV.
HCV transmission
The risk for sexually transmitted HCV is very low in monogamous, HIV-negative heterosexual couples (in which one partner has HCV), but it is higher for HIV-positive gay men. The mechanism involved with sexual transmission among HIV-positve gay men remains unclear.
HCV is mainly contracted when infected blood from one person enter another person’s body. Although the hepatitis C virus has been found in semen and vaginal fluid it is unclear whether this is infectious. Sex will be 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 and latex gloves reduce these risks.
With HIV/HCV coinfection, sexual transmission of HCV appears to be different for gay male and straight partners.
Heterosexual transmission of HCV
The risk of heterosexual sexual transmission of HCV in people who are HIV-negative is very low.
One study following almost 900 heterosexual monogamous couples did not report any HCV infections over up to 10 years of follow-up. The risk is generally reported as less than 1%.
These couples did not use condoms, but also did not have anal sex or have sex during menstruation. The mechanism for this protection is likely to be through reduced exposure to blood-to-blood contact, but is not clearly understood.
Sexual transmission of HCV in HIV-positive gay men
In the UK, sexual transmission of HCV to HIV-positive gay men has been reported since 2003.
A similar link between HCV sexual transmission and HIV-positive gay men has been reported in some other European, U.S. and Australian cities. HIV is clearly an important factor because, so far at least, new cases of HCV sexual transmission in HIV-negative gay men are not being reported nearly as often.
Other risk factors for gay men include:
- Unprotected anal intercourse (not using condoms).
- ‘Heavier’ sex including ‘fisting’, longer sex and sharing sex toys.
- Group sex.
- Use of some recreational drugs.
- Having other sexually transmitted infections.
- Among some groups of gay men, many of who meet partners online.
There is still a lack of clear information about sexual transmission of HCV between HIV-positive gay men.
Crystal meth, ecstacy, coke and HCV infection
Although sex seems to be the source of infection, among HIV-positive men who have sex with men, non-injection drug use increased the risk.
This includes “party drugs” such as crystal meth. cocaine and ecstasy. Injecting crystal is as high a risk as injecting any other drug.
These drugs can lower your immune systyem so you may be more vulnerable to HCV infection.