Genitourinary System Diseases

Viral Sexually Transmitted Diseases

Herpes simplex virus, human papillomavirus, and human immunodeficiency virus are spread through sexual contact, are carried by their host for life, and cause incurable diseases.

Several viruses are able to cause inflammatory diseases of the reproductive tract. The herpes simplex virus (HSV) is one of the most common viral causes of genital and oral ulcers, or herpes. HSV type 1 is typically associated with oral ulcers, but can be spread to the genitals, causing genital herpes. HSV type 2 is associated with genital ulcers, though both it can occur in either location or in other portions of the body. Both are spread during physical contact, including sexual contact, when an individual has ulcers present. While there is no cure for herpes, antiviral drugs such as acyclovir and valacyclovir can reduce the frequency of ulcer breakouts. Stress and compromised immune systems can increase the frequency of ulcers. Infected individuals may be carriers that do not develop symptoms. Individuals who have had HSV ulcers heal retain the virus in latent form, and recurrent infections are possible. The preferred diagnostic method is with PCR since it is rapid and precise.

When a women has herpes or contracts it while pregnant, she can pass on neonatal herpes to her infant. Mothers who contract herpes in their third trimester are the most likely to pass herpes on to their infant during vaginal delivery. The virus must be present in the vaginal canal, but if there are not active sores, a woman can give birth vaginally. If there are active sores, the delivery must take place by way of C-section. It is difficult to diagnose neonatal herpes. Symptoms include irritability, lethargy, fever, blisters, jaundice, and poor eating. Diagnosis is made with a blood test or spinal tap or by testing skin and fluid cells on sores. The mother is also tested for herpes to confirm diagnosis. Untreated herpes can cause infant death or lasting disabilities including cerebral palsy, seizures, vision and hearing loss, and intellectual disabilities. The antiviral acyclovir is used to treat babies born with herpes.
Herpes simplex (transmission electron microscope) are double stranded DNA viruses that causes skin ulcers on the genitals or around the mouth.
Credit: CDC/Dr. Fred Murphy; Sylvia Whitfield
Human papillomavirus (HPV) is the most common sexually transmitted infection. HPV is the main cause of cervical cancer and is spread through vaginal, anal, or oral sexual contact and can present no symptoms. Symptoms such as genital warts or cancer can present years after the virus was contracted. HPV-triggered cancers include cervical, vulvar, vaginal, penile, anal, throat, and oropharyngeal (tongue and tonsils). Females 30 years old and older are routinely screened for HPV at the same time as Pap smear testing for abnormal cervical cells. The presence of koilocytes, cells that have undergone structural changes, in a Pap smear are diagnostic for the presence of HPV. There are two vaccines for HPV that guard against specific strains of HPV and are recommended for children who are at least nine years old. These vaccines should be given before a person becomes sexually active. Using condoms lowers the risk of contracting HPV but does not completely eliminate it since HPV can infect areas not covered by condoms. There is no cure for HPV. Human immunodeficiency virus (HIV) weakens a person's immune system. Symptoms include pain in the abdomen, pain while swallowing, fatigue, fever, loss of appetite, night sweats, nausea, diarrhea, vomiting, ulcers or white tongue, groin sores or swelling, opportunistic infection, headache, and swollen lymph nodes. HIV destroys T cells, a type of lymphocyte white blood cell that fight disease and infections. HIV is spread by bodily fluids such as semen, vaginal fluid, blood, rectal fluids, and breast milk. The fluid must come from a person who has HIV and must come into contact with another person's mucous membrane or damaged tissue or be injected directly into the bloodstream. Some of the common behaviors leading to transmission of HIV include anal sex, vaginal sex, and needle sharing among intravenous drug users.
HIV-1 is a virus that buds out of host cells. The virion envelope is constructed from parts of the host plasma membrane in the process.
Credit: CDC/C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus
There is no vaccine for HIV, though a pre-exposure prophylaxis (PrEP) is available and when taken daily substantially reduces the risk of contracting HIV in at-risk individuals. To test for HIV, a blood test detects viral particles in the blood. When a person is infected with HIV, an antigen called p24 is produced, and the infected immune system makes antibodies against p24. An antigen/antibody test can detect HIV p24 antigens and antibodies targeted against p24. HIV treatment slows the progression of the virus through administration of antiretroviral therapy (ART) drugs. There is no cure for HIV, and it ultimately leads to acquired immunodeficiency syndrome (AIDS).