Venereal diseases, called sexually transmitted infections (STIs) are infections caused by various bacteria, viruses, and parasites. The Centers for Disease Control reports that about 19 million new cases of STIs occur annually. Infections from venereal diseases can result in arthritic disease, pelvic inflammatory disease, ectopic pregnancy, infertility, cervical cancer, and transmission of infections from mother to infant.
Human papillomavirus infection (HPV) is the most common sexually transmitted infection in the United States, according to the National Institute of Allergy and Infectious Disease. The infection causes genital warts, although not everyone develops them. Some types of HPV infections are associated with an increased risk of cervical cancer.
Chlamydia is the most common type of bacterial STI in the United States. Although the infection usually has no symptoms, it is responsible for a number of disease states, including pelvic inflammatory disease in women, and an inflammation near the testicles in men called epididymitis.
Genital herpes is caused by the herpes simplex virus and can cause painful episodes of ulcerating blisters in the genital area. Complications of the infection are generally limited to those with poor immunity. If a woman has an active case of genital herpes at the time of delivery, a life threatening herpes infection can be passed to the baby.
Gonorrhea is caused by the bacteria Neisseria gonorrhoeae. Although it usually causes no symptoms, the infection often results in cervical and urethral infections, according to the Merck Manuals Medical Library. It is a common cause of pelvic inflammatory disease in women. Men may have painful, swollen testicles with a white, yellow, or green discharge from the penis.
Syphilis is caused by the bacteria Treponema pallidum. In it's earliest stage, syphilis causes sores to develop in the area of exposure. If left untreated, syphilis can result in serious infection in the brain, nervous system and eyes.
This STI is caused by the parasite Trichomonas vaginalis. The infection is more common in women than men. Women often have few symptoms, but may develop a large amount of yellow, frothy, vaginal discharge. Men generally have no symptoms.
The Human Immunodeficiency Virus causes AIDS, or acquired immune deficiency syndrome, according to the Centers for Disease Control. A person with AIDS is susceptible to diseases associated with a dramatically weakened immune system, including swollen glands, weight loss, pneumonia, nervous system disorders and cancer.