Specific STDs
Diseases transmitted through sexual activity

STD Information continued..
Updated: January 2001

Chancroid is an infection by the bacterium Haemophilus ducreyi that causes painful sores on the skin of the genitals in men and women. The disease can occur worldwide but is especially common in subtropical and tropical areas. Symptoms occur 3 to 5 days, or as long as 14 days, following sex with an infected person. Chancroid is contagious as long as the infected person has open sores, and reinfection can occur immediately following cure. There is no evidence of natural resistance. Even though chancroid bacteria are increasingly resistant to antibiotics, treatment is still effective. Condoms reduce the risk of transmission.

Chlamydia is a common and serious infection caused by the Chlamydia trachomatis bacterium and occurs worldwide. If left untreated, it can lead to pelvic inflammatory disease (PID) and infertility in women and urethritis in men. Chlamydia is transmitted during vaginal, oral or anal sexual contact with an infected partner. A pregnant woman may pass the infection to her newborn during delivery, causing serious eye infection or pneumonia. Though most often symptomless, chlamydia may produce symptoms, such as abnormal genital discharge or pain during urination, usually 6 to 19 days following sex with an infected person. Chlamydia can be treated and cured with oral antibiotics. Condoms reduce the risk of transmission.

Genital herpes is a very common and serious STD caused by herpes simplex viruses (HSV). There are two types of HSV occurring worldwide: Type 1 causes fever blisters or cold sores on the lips, and Type 2 typically causes genital sores. However, both types can cause oral or genital infection through skin-to-skin contact. HSV produces lesions in and around the genital area, and can affect the buttocks, anus or thighs. A pregnant woman may pass the infection to her newborn during delivery, causing skin lesions, pneumonia or neurological damage. Some infected individuals may be symptomless, while others can have recurrent episodes more than once a month. Initial symptoms usually occur within 2 weeks after the virus is transmitted. Emerging as painful blisters, the lesions generally scab and heal in 2 to 12 days. It is possible to pass the virus during sex even when there are no sores. There is no cure for genital herpes, but treatment may shorten the attacks and make the sores less painful. Condoms may reduce the risk of transmission.

Genital warts is a common viral STD caused by the human papillomavirus (HPV). Occurring worldwide, HPV is spread through skin-to-skin contact, especially through sexual activity with an infected partner. Certain strains of HPV are associated with the development of cervical cancer. Some individuals may have no signs of warts, but HPV is highly contagious whether or not warts are visible. Warts will appear from months to years after sex with an infected partner. Treatment of the warts may reduce, but does not eliminate, infectiousness. Although some people have had no recurrences after treatment, a permanent cure of HPV cannot be guaranteed. Condoms may reduce the risk of transmission.

Gonorrhea is a common and serious bacterial infection caused by the Neisseria gonorrhoeae bacterium and occurs worldwide. Also referred to as the "clap" or "dose", gonorrhea is transmitted through oral, vaginal and anal sex. A pregnant woman can pass gonorrhea to her baby during birth, causing serious eye infection or blindness. If left untreated, gonorrhea can lead to sterility in both women and men. Gonorrhea may be symptomless or have symptoms, such as discharge from the vagina or penis and extremely painful or difficult urination, appearing 2 to 7 days after sex. Gonorrhea is treated and can be cured with antibiotics. Condoms reduce the risk of transmission.

Hepatitis occurs worldwide and is caused by different but related viral organisms that attack the liver. Hepatitis B and C appear in the blood, semen and vaginal fluids of infected persons, meaning that sexual and skin-piercing activities (e.g., injection drug use, tattooing, acupuncture) can transmit the virus. Hepatitis B is much more easily transmitted through sexual activity than hepatitis C. In most developed countries, hepatitis C occurs in intravenous drug users, but some countries have high rates in the general population as well.

The incubation period is similar for both diseases, approximately 45 to 180 days. Symptoms are also similar, including gradual development of fever, loss of appetite, abdominal discomfort, nausea and vomiting, joint pain, rash and jaundice. Its severity varies, but hepatitis B can cause liver failure and death. For hepatitis C, symptoms may be absent or mild, such as general tiredness and pain in the liver. Hepatitis C in adults is more likely to result in chronic infection than hepatitis B, causing cirrhosis of the liver or liver cancer years after the initial infection, which can lead to death. A vaccination against hepatitis B is available. Condoms may reduce the risk of transmission.

HIV or human immunodeficiency virus, attacks the body's immune system and weakens it, resulting in chronic, progressive illness. The advanced stage of the illness is called the acquired immunodeficiency syndrome, or AIDS. HIV makes infected individuals vulnerable to other infections and cancers. It is usually these "opportunistic diseases" that become fatal. HIV is spread through the exchange of infected body fluids: blood, semen, vaginal fluids and breast milk. If HIV-infected blood is present in saliva, there may be a risk of transmission. A blood test or series of blood tests can confirm the presence of HIV in an individual. There is no licensed vaccine and no cure for HIV. Condoms can reduce the risk of transmission. For more information on HIV/AIDS, click here.

Intestinal infections comprise a variety of intestinal disorders transmitted through anal-oral sexual activity that can cause diarrhea, blood poisoning and abscesses. Symptoms can include diarrhea, abdominal cramps and inflammation of the rectum. Intestinal infections can be treated and cured with antibiotics. Condoms reduce the risk of infection.

Pubic lice and scabies are parasitic infestations of the skin caused by a crab louse (Phthirus pubis) and a mite (Sarcoptes scabiei) respectively. Pubic lice and scabies occur worldwide and are transmitted through sex and other close body contact, such as the sharing of bed sheets, towels or clothes of an infected person. Symptoms occur when the insects bite or burrow into the skin to lay their eggs. For scabies, severe itching and a rash on fingers, wrists, elbows, abdomen, genitals and ankles, begins 2 to 6 weeks after the first exposure or 1 to 4 days after re-exposure. For lice, some people have no symptoms, while others experience severe itching around the genitals and may see white eggs on pubic hair. Secondary bacterial infections of the skin may result from scratching. Lice and scabies are treated with special creams, lotions or shampoos. The only protection against these parasites is knowing your partner's sexual history. If you think you've been infected, dry clean or wash clothing and linen in hot water.

Syphilis is a serious disease caused by the bacterium, Treponema pallidum and occurs worldwide. The bacterium is found in sores and rashes anywhere on the skin or inside the mouth or genitals. It is transmitted between partners during sexual activity and from an infected mother to her unborn child, sometimes causing birth defects or death. If untreated, syphilis develops as a three-stage disease. Stage 1, in which a painless sore on the genitals or in the mouth may appear where bacteria first entered the body, usually occurs 9 to 90 days after sexual contact with an infected person. This sore will resolve on its own, but the individual remains infected. Stage 2 takes place a few months later with flu-like symptoms that may include a rash. Again, the symptoms may resolve, but the infection remains. Stage 3 leads to serious health problems a few years later, such as heart disease or brain damage that can lead to death. Syphilis can be treated and cured with antibiotics, although the late stages of syphilis can cause permanent damage to the heart, brain, skin, bones and other organs. Condoms reduce the risk of transmission.

Vaginitis is a vaginal irritation, with a discharge, of varying severity that can be caused by a parasite, bacteria or fungus (yeast). A common forms of vaginitis - trichomoniasis - is sexually transmitted and occurs worldwide. Trichomoniasis is caused by the single-celled protozoan parasite, Trichomonas vaginalis. Most men with trichomoniasis have no symptoms. Symptoms in women usually appear within 5 to 28 days of exposure and can include vaginal discharge with a strong odour, discomfort during intercourse and urination, genital itching and lower abdominal pain. Treatment of vaginitis depends on its cause, and infected individuals who have no symptoms must nevertheless be treated. Condoms reduce the risk of transmission.

STD prevention and the Canadian traveller

For more information on how to reduce your risk of STDs while travelling, return to the page entitled Disease Information on Sexually Transmitted Diseases.