Exposure to sexually transmitted disease (STD) can occur any time you have sexual contact with anyone that involves the genitals, the mouth or the rectum.
Condoms can help prevent sexually transmitted infections. However, condoms do not provide 100% protection; a lesion may be in a place the condom doesn't cover. For e.g. condoms help protect against unrecognized herpes by protecting or covering only the most likely sites of transmission.
You should avoid sexual practices that might result in oral exposure to feces (e.g., oral-anal contact) to reduce the risk for intestinal infections.
The use of condoms is strongly encouraged if you choose to have often sex with multiple partners. In these circumstances there is no such thing as "safe sex". Condoms make sex safer but not 100% safe.
Of course the best prevention of STD is to develop and nourish close and lasting relationship with one partner and avoid frequent intercourse with people you know little about.
Here are some of the STD that could be transmitted through saliva:
Spread by sexual contact, including vaginal, anal and oral sex. Gonorrhea can be treated and cured with antibiotics. All your sexual partners should be treated at the same time you are.
This is similar to the virus that causes mononucleosis (Epstein-Barr virus). In adults, CMV infection usually causes no symptoms, but at times an illness with symptoms like fever, chills, sore throat, swollen glands, body aches and fatigue may develop. The illness is usually much more severe in people who have impaired immune systems, especially those with AIDS. Scientists are testing new antiviral drugs that might be effective against CMV infections.
The virus for hepatitis B, formerly called serum hepatitis, is found in semen, blood and saliva. It is not known for sure if infected saliva can transmit the disease. It is thought that HBV can be transmitted through the sharing of toothbrushes and razors. You can get vaccinated against this virus.
It is a sexually transmitted disease caused by bacteria. Chlamydia is spread by sexual contact, including vaginal, anal and oral sex. Chlamydia can be treated and cured with antibiotics. Your sexual partner should be treated at the same time you are.
Can be spread to the mouth, causing cold sores; and cold sores can be spread to the genital area. The virus can be spread even when a person does not have visible blisters or sores. Medication can reduce the number and severity of herpes outbreaks, but it cannot eliminate the infection.
Caused by the human papillomavirus may continue to grow and spread or may go away with or without treatment. A person infected with HPV remains infected, even if he or she is treated to remove visible warts or if the warts go away without treatment.
This common viral infection most often affects young children, who pass it to each other through saliva. In adults, however, the virus is transmitted sexually, resulting in lesions on the genitals, lower abdomen, buttocks or inner thighs. Most people with the infection do not have noticeable symptoms, although sometimes the lesions, which are painless wart-like bumps, may itch or become irritated. The lesions often heal without treatment, although physicians may sometimes scrape them off or treat them with chemical irritants.
References and More Informative Sites are listed below: