BBBJ is safer, but still has risks
lustyhombre said:
Conventional Wisdom seems to say : BBBJ is low risk ( i.e. acceptable ) but BBFS is high risk ( i.e. avoid at all cost ) .
My understanding, is that the current theory is that saliva tends to kill the AIDS virus. Saliva, and stomach acid are designed to kill bacteria and viruses. Essentially all food contains some bacterial and viral contamination. Saliva and stomach acid are designed to suppress (but not completely eliminate) many types of bacteria and viruses, so we don't get sick every time we eat.
That said, if blood or open wounds are present, it is thought (but unproven) that AIDS can spread in the mouth from blood to blood contact.
Other diseases have properties that allow them to survive in saliva and/or stomach acid. These include the obvious examples of stuff like E.Coli (Walkerton) and Cholera (3rd World). Some STDs can be spread this way as well, like gonorrhea.
Vaginal secretions do not have the same properties as saliva. Vaginal secretions do suppress many types of bacteria, however they do not pose significant barriers to sexually transmitted diseases.
Anal sex tends to result in semen to blood and blood to blood contact (worse for the reciever.) Most transmissable diseases can be transmitted via blood to blood contact. As such, it permits the spread of almost all transmissable diseases. Even if blood to blood contact is not present, semen to blood contact encourages the spread of many STDs. Some cases have shown that anal sex (rape) can result in disease (ex. AIDS, Hepatitis C) transmission after one encounter.
Simply put, each transmissable disease has its own preferred method of transmission. The preferred method of transmission for sexually transmitted diseases (STDs) is SEX. Hence, the recommendation to avoid BBFS to avoid STDs.
Oral sex is still a form of SEX, so many STDs will still spread through oral sex, however oral sex is not the preferred method of transmission. This will make transmission more difficult, but not impossible.