Tilted Forum Project Discussion Community - View Single Post - Oral Sex and Sexually Transmitted Diseases: What risks?

snowy · 10-25-2005, 05:51 PM

Here is a good article about transmission of HBV rates amongst various groups in Canada:

Quote:

The Sexual Transmission of HBV

The highest titres of HBV are found in blood. However, HBV has also been found in semen and saliva (Heathcote, Cameron, & Dane, 1974) and vaginal secretions (Darani & Gerber, 1974). Further, saliva (by injection but not oral application) and semen (by intravaginal application) have transmitted HBV infection to non-human primates (Scott, Snitbhan, Bancroft, Alter, & Tingpalapong, 1980).

Hersh, Melnick, Goyal, and Hollinger (1971) were the first to provide evidence for the sexual transmission of HBV, describing eight female cases of HBV that were linked to intimate contact with six infected males. In a more recent series of studies, Alter et al. (1986; 1989) provided strong epidemiologic evidence of heterosexual transmission. During the 1970s, it became clear that male homosexuals were at high risk for HBV, one reason why homosexuals were the prime subjects for the early HBV vaccine trials (Szmuness et al., 1980). More recently, Kingsley et al. (1990) demonstrated that among homosexual men, HBV is more easily transmitted than human immunodeficiency virus (HIV). The estimated risk of HBV transmission from a single unprotected sexual contact with an infected person is 1-3% (Hadler & Margolis, 1993). It is now accepted that, in the developed world, sexual transmission is the major recognized mode of transmission; in the developing world, while perinatal and early childhood horizontal transmission are of prime importance, sexual transmission is a significant contributor (Hadler & Margolis, 1993).

Epidemiologic studies focusing on the sexual transmission of HBV have usually examined homosexual/bisexual males, female sex trade workers, clients at STD clinics, and sexual partners of HBV infected persons. All of these groups have been found to have a high prevalence of HBV infection, past or present. Data for Ontario suggest that of acute cases of HBV in which risk factors have been identified, about one third are attributable to sexual transmission (Ontario Ministry of Health, 1995). Data on the epidemiology of acute cases of HBV infection in the Montreal area indicate that 55% are related to sexual transmission (Dion, 1994).

Data from an active surveillance study of viral hepatitis in several cities in the United States indicate that between 1982 and 1991, the distribution of risk factors for HBV infection shifted, with cases linked to male homosexual transmission and intravenous drug use decreasing, while cases linked to heterosexual transmission increased to become the most frequently identified risk category (Alter & Mast, 1994). It is noteworthy that the reduced rate of transmission among homosexual men may be due to the incorporation of safer sex practices on the part of gay men in response to the Acquired Immune Deficiency Syndrome (AIDS) epidemic. The risk factors associated with the sexual transmission of HBV are summarized in Table 2.
Prevention of Sexual Transmission of HBV
Immunization

HBV infection is the only STD for which an effective and safe vaccine is available. HBV vaccine has been available in Canada since 1982. Beginning with British Columbia in 1992, all provinces, except Manitoba, now have a universal hepatitis B vaccination program for pre-adolescents, and New Brunswick, Prince Edward Island and Northwest Territories also have a universal infant vaccination program (Tepper & Gully, 1997). The targeting of pre-adolescents for a universal vaccination program was predicated, to a large extent, on the recognition that sexual activity is an important mode of HBV transmission in Canada (Health Canada, 1994). These universal immunization programs are expected to have a significant effect on the incidence of HBV infection in the next decade as those young people who are immunized now will be protected from HBV infection during adolescence and young adulthood, a period in which sexual activity is likely.

Despite the universal immunization programs currently aimed at young people, targeted immunization of high risk groups remains important (Health Canada, 1993). These groups include sexually active homosexual/bisexual males, males and females with multiple sexual partners, those with a recent history of STD, sexual contacts of HBV carriers, and international travellers who are likely to have sexual contact with residents in areas with high levels of endemic disease. Most Canadian provinces provide publicly funded vaccine for some, but not all, of these risk groups. Reports from programs to immunize STD clinic patients at risk for HBV have documented vaccine completion rates of 24% (three doses) (Bhatti et al., 1991) and 21% (two doses) (Weinstock et al., 1995). A similar Canadian study (Yuan & Robinson, 1994) indicated completion rates (three doses) of 47% for homosexual/bisexual men and 25% for heterosexual men. A randomized trial in Canada found that compliance with immunization among STD patients can be enhanced with more aggressive follow-up (telephone and mail as opposed to mail only) (Sellors et al., 1994). A 1990 STD clinic study in the U.S. indicated that if vaccine was offered to all of an estimated 18,000 new STD encounters who visited the clinic each year, 636 infections would be prevented annually at a cost of $875 (U.S.) per infection prevented (Weinstock et al., 1995).
Safer Sex

The recommendations for safer sex made in light of the HIV epidemic apply equally to the sexual transmission of HBV (Health Canada, 1995). Laboratory testing indicates that latex condoms provide an effective barrier to HBV (Minuk et al., 1987). A study by Rosenblum et al. (1992) of female prostitutes found an association between spermicide and/or diaphragm use and a reduction in risk of HBV infection. However, the efficacy of the spermicide nonoxynol-9, included on some condoms, in inactivating HBV is not known.

Unprotected anal intercourse appears to be a particularly high risk behaviour for acquisition of HBV infection, and unprotected vaginal intercourse also carries a demonstrated risk. As a result, STD prevention education programs that emphasize the reduction of high risk behaviours and promote the consistent use of condoms, particularly those targeted at specific STD risk groups, may be beneficial in preventing the spread of HBV in the Canadian population.

http://www.phac-aspc.gc.ca/publicat/cjhs/cjhs6.html

Here is also a link to a PDF regarding the epidemiology of STDs in Manitoba. I'm sure if you take a look at it you'll find a specific figure somewhere.
http://www.gov.mb.ca/health/publiche...ance/desti.pdf

I could dig up some more case studies for you, but I'm tired of saying the same things over and over again in my posts, since obviously this is like talking to a wall.