Glossary A-D
Glossary E-I
Glossary J-Q


Rape—A situation where a person is forced to have sex against her or his will.

Rash—A general term applied to any eruption of the skin, especially those pertaining to communicable diseases. A rash is usually a shade of red, which varies with disease and is usually temporary.

Rectum—The last 6 to 8 inches of the large intestine. The rectum stores solid waste until it leaves the body through the anus.

Recurrence—The return of symptoms after a time without symptoms. An example of this is outbreaks of herpes after periods of time without herpes lesions.

Reproductive system—In women, the organs that are directly involved in producing eggs and in conceiving and carrying babies.

Resistance—Reduction in a pathogen’s sensitivity to a particular drug. Resistance is thought to result usually from a genetic mutation. In HIV, such mutations can change the structure of viral enzymes and proteins so that an antiviral drug can no longer bind with them as well as it used to. High-level resistance reduces a drug’s virus-suppressing activity hundreds of times. Low-level resistance represents only a few-fold reduction in drug effectiveness. Depending on the toxicity of the drug, low-level resistance may be overcome by using higher doses of the drug in question.

Retrovirus—A type of virus that, when not infecting a cell, stores its genetic information on a single-stranded DNA. HIV is an example of a retrovirus. After a retrovirus penetrates a cell, it constructs a DNA version of its genes using a special enzyme, reverse transcriptase. This DNA then becomes part of the cell’s genetic material.

Risk factor—Something that increases the chance of developing a disease.


Sacral ganglion—The nerve root at the base of the spine. The sacral ganglion serves as the site of latency in genital herpes infections.

Schiller Test —A test in which iodine is applied to the cervix. The iodine colors healthy cells brown; abnormal cells remain unstained, usually appearing white or yellow.

Scrotum —The sac of skin that surrounds the testicles.

Selective abstinence—Many people are sexually active but limit what they do to avoid STD/STIs and/or pregnancy or because they do not feel ready to do some sexual things. Someone who chooses to be selectively abstinent might have some kinds of sex but not others. Someone who practices selective abstinence may or may not run the risk of contracting an STD/STI and/or having an unwanted pregnancy, depending on the activities in which he or she does.

Seroconversion—Development of detectable antibodies to HIV in the blood serum as a result of infection. It may take several months or more after HIV transmission for antibodies to the virus to develop. After antibodies to HIV appear in the blood, a person will test positive in the standard ELISA test for HIV.

Serology—A test that identifies the antibodies in serum (a clear fluid that is a component of the blood).

Seroprevalence —For HIV, the rate at which a given population tests positive on the ELISA test for HIV antibodies. The seroprevalence rate is nearly the same as the rate of HIV infection in a given population, leaving out mainly those who were recently infected.

Serostatus —The condition of having or not having detectable antibodies to a particular microbe in the blood as a result of infection—for example, HSV-1, HSV-2, or HIV. One may have either a positive or negative serostatus.

Sex (gender) reassignment surgery—Surgery to change the appearance of a person’s anatomy to match as closely as possible the anatomy of the opposite sex.

Shingles—A skin condition caused by reactivation of a varicella zoster virus (VZV) infection, usually acquired in childhood, when it appears as chicken pox. It consists of painful, inflammatory blisters on the skin that follow the path of individual peripheral nerves. The blisters generally dry and scab, leaving minor scarring. Standard treatment is with famciclovir or acyclovir.

Side Effects—Problems that occur when treatment affects healthy cells. For example, common side effects of cancer treatment are fatigue, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

Speculum—An instrument used to spread the vagina open so that the cervix can be seen.

Spermicide—An agent which kills spermatozoa.

Squamous cell carcinoma—Cancer that begins in squamous cells, which are thin, flat cells resembling fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the passages of the respiratory and digestive tracts.

Squamous intraepithelial lesion—A general term for the abnormal growth of squamous cells on the surface of the cervix. The changes in the cells are described as low grade or high grade, depending on how much of the cervix is affected and how abnormal the cells are. Also called SIL.

Staging—Doing exams and tests to learn the extent of the cancer, especially whether it has spread from its original site to other parts of the body.

STD (Sexually Transmitted Disease)—Any disease that is acquired through sexual contact in a substantial number of cases.

STI (Sexually Transmitted Infection)—Any infection that is acquired through sexual contact in a substantial number of cases.

Symptom—Any perceptible change in the body or its functions that indicates disease or the kind or phases of disease. Often STIs produce symptoms; however, particularly in women, there may be no symptoms.

Symptomatic reactivation—The presence of lesions or any other symptoms caused by reactivation of herpes simplex virus; a “recurrence.”

Systemic—Concerning or affecting the body as a whole. A systemic therapy is one that the entire body is exposed to, rather than just the target tissues affected by a disease.


TB (Tuberculosis)—A lung infection that occurs more often in people with weakened immune systems. TB can be easily passed to others and can lead to death if not treated. TB can be successfully treated with the right medications.

Testicles—Part of the male reproductive system. The testicles produce sperm and the male hormone testosterone. The testicles are located inside the scrotum.

Testicular self examinations—A self-examination of the testicles to look for any lumps that may be an early sign of testicular cancer.

Testosterone—A naturally occurring male hormone. When administered as a drug it can cause gain in lean body mass, increased sex drive and possibly aggressive behavior.

Thrush—See Candidiasis.

Toxoplasmosis—A disease caused by the protozoa Toxoplasma gondii. Toxoplasmosis can affect a number of organs, but it most commonly causes encephalitis (brain inflammation).

Transgender—A term used to describe individuals who identify with a gender other than the one society expects of them, based on their genitalia and physical appearance. Transgender individuals may display characteristics (manner of dress, for example) of either gender (male or female), and may or may not choose to alter their bodies through the use of hormones or through surgery.

Transmission—The spread of disease, including a sexually transmitted disease, from one person to another.

Travesvestite—A term once used to describe a person who chooses to dress in a way that is more typically associated with the opposite sex. This term is now considered outdated and derogatory. See cross dressing.

Trichomoniasis—An infection with a flagellated protozoan, Trichomonas vaginalis. When symptomatic, the infection results in vaginitis in women and urethritis in men. Many infected persons, however, remain asymptomatic.


Ureaplasma—A genus of bacteria found in the human genitourinary tract, occasionally in the pharynx and rectum. In males, they are associated with nongonococcal urethritis (NGU) and prostatitis; in females, with genitourinary tract infections and reproductive failure.

Urethritis—Inflammation of the urethra. STDs, if they are symptomatic, often cause urethritis.

Urologist—doctor who specializes in the physiology and pathology of the urinary and genital functions of the body.

Uterus—The small, hollow pear-shaped organ in a woman’s pelvis. This is the organ in which an unborn child develops. Also called the womb.


Vaccine—A suspension of infectious agents or some part of them, given for the purpose of establishing resistance to an infectious disease. It stimulates development of specific defensive mechanisms in the body which result in more or less permanent protection against a disease.

Vagina—The muscular canal between the uterus and the outside of the body.

Vaginitis —Inflammation of the female vagina. More information available.

Varicella Zoster Virus (VZV)—The cause of chicken pox in children. Its reactivation in adults causes shingles (see Shingles).

Vasectomy—A permanent sterilization procedure for males, involving cutting and sealing the vas deferens, the tubes that carry sperm. The procedure prevents sperm from mixing with the semen that is ejaculated from the penis.

Viral Load—The number of viral particles (usually HIV) in a sample of blood plasma. HIV viral load is increasingly employed as a surrogate marker for disease progression. It is measured by PCR and bDNA tests and is expressed in number of HIV copies or equivalents per milliliter.

Viral replication—The process by which a virus makes more copies of itself.

Viral STDs/STIs—Viral STDs/STIs, including genital herpes, human papillomavirus (HPV), hepatitis B, and HIV (the cause of AIDS), are as yet incurable, although the symptoms can be treated.


Wart—A raised growth on the surface of the skin or other organ.

Western Blot—A test for detecting the specific antibodies to HIV in a person’s blood. It commonly is used to double-check positive ELISA tests. A western blot test is more reliable that the ELISA, but it is harder to do and costs more money.

Womb—The uterus.

Wrestler’s herpes—The presence of herpes lesions on the body caused by HSV infection that is usually transmitted through the abrasion of skin during a contact sport, such as wrestling. Also known as herpes gladitorum.



Yeast Infection—See Candidiasis.


Zidovudine—See AZT.

Zoster—Acute inflammatory disease with vesicles grouped in the course of cutaneous nerves, as in herpes zoster.