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STI Dictionary

These are words that are useful for facilitators to know and be able to use in conversations about sexually transmitted infections. Some of these words are probably familiar to you (like abstinence) and some are probably less familiar (like cervical motion tenderness). Participants may have specific questions if they or someone in their life has been exposed to or diagnosed with an STI. Participants do not typically need to know all, or even most, of the words included here. They become necessary if a particular participant needs to be able to talk in more detail with medical professionals.

noun The decision to refrain from sexual contact. In the context of STI prevention, abstinence requires that the person refrain from all contact that may result in exposure to an infection. This includes oral, anal, and vaginal sex and may also include certain kinds of skin-to-skin contact with people who are STI-positive and are having a skin outbreak.

Acquired Immunodeficiency Syndrome (AIDS)
noun A diagnosis that is received when a person who is infected with HIV has a sufficiently reduced immune system according to the definitions of the US Centers for Disease Control and Prevention (CDC). An AIDS diagnosis means that the person has fewer than 200 white blood cells (CD4+ T cells) per cubic millimeter of blood. Other possible causes for diagnosis include when CD4+ T cells account for less than 14% of all lymphocytes or when the person has one or more of a list of illnesses called opportunistic infections that are highly specific to HIV infections.


noun A type of medication that is used to treat bacterial infections.

noun Proteins in the blood that are produced in response to an antigen to fight potential infections from bacteria and viruses. Specific antibodies are produced in response to specific infections.

Antibody Tests
noun A lab test, typically through blood, that checks to see whether a specific antibody is present and how much of that antibody is present. Antibodies are produced in response to stimulation of the immune system, and may take 1-3 months after exposure to be detected. For example, diagnosis of HIV is through an antibody test, so it is important to wait 1 - 3 months after exposure before getting tested for HIV; or, if your initial test is negative, to repeat testing in 3 months for final verification.

noun A substance such as bacteria, virus, or fungi that the body sees as foreign. Antigens stimulate the immune system to mount an immune response to fight the infection.

Antigen Tests
noun A lab test, which typically uses blood, to detect whether a specific antigen is present. Examples of typical antigen tests are rapid antigen test (RAT) or rapid antigen detection test (RADT).

noun A medication that targets retroviruses such as HIV. Also referred to as Antiretroviral Therapy (ART) or Antiretroviral Drugs (ARV). Antiretroviral drugs do not cure the virus, but, when taken in combination, can slow the disease progression by preventing the growth of the virus.

noun Drugs used to treat viral infections. They do not kill or cure the virus, but instead suppress the growth of the virus and its ability to replicate. This slows the progression of the viral infection. Antiviral drugs also decrease the viral shedding, which decreases, but does not eliminate, the amount of virus being passed to another person.

noun Microorganisms that are found everywhere. They can cause diseases, or they can be beneficial and support many processes of the body. In reference to STIs, bacteria can cause infection and are destructive to the body. Bacterial STIs include gonorrhea, syphilis, and chlamydia. Bacterial STIs are treated with antibiotics.

Cervical Motion Tenderness (CMT)
noun Intense pelvic pain that is indicative of either pelvic inflammatory disease or ectopic pregnancy. CMT is assessed during a pelvic exam.

noun A painless, single sore or ulcer on the skin that is due to an infection. The most common cause of a chancre sore is the primary stage of syphilis.

noun An STI caused by the bacterium Haemophilus ducreyi. It typically presents with painful genital ulcers and painful swollen lymph nodes in the groin. The initial ulcer can be mistaken for primary syphilis. The main distinguishing factor between the two is that the ulcer in chancroid is painful, while in primary syphilis, it is painless. Chancroid is treated with antibiotics.

noun A bacterial STI caused by the bacterium chlamydia trachomatis. Chlamydia can also be spread to an infant during childbirth. Many people infected with chlamydia do not have any symptoms of disease. When they do have symptoms, they include pain during urination, infertility, vaginal and penile discharge, lower abdomen pain, pain during penetration, bleeding between periods, and testicular pain. Chlamydia is treated with an antibiotic.

Congenital Infection
noun When a fetus contracts an infection while still in utero.

noun A laboratory test for viruses or bacteria. Cells that are potentially infected are collected from the person and then put onto a substance called a culture medium, creating an environment that allows potential pathogens (bacteria or viruses) to multiply. From here, the lab can determine what organisms are present.

noun Fluid or other substance that is excreted from the human body, including the vagina and penis. There are both normal and abnormal kinds of discharge.

noun As it applies to the topic of sexually transmitted infections, describes a specific set of symptoms caused by a group of disorders that is able to be spread through sexual activity. The group of disorders described by the term sexually transmitted diseases is the same group that is described by the term sexually transmitted infections.

noun The medical term describing painful intercourse. This can happen for people with a wide range of body types, but it is most common for people with vaginas. Dyspareunia can be caused by infection, vaginismus, not enough lubrication, different genital structures, and emotional factors. Treatment depends on the cause of the pain.

noun The experience of pain, burning, or discomfort during urination. The causes can include STI or infection in the kidneys, ureters, bladder, or urethra.

noun Inflammation of the epididymis, typically caused by infection. The epididymis is a tube that sits on the back side of the testicles, where the sperm mature.

Exposure Moment
noun When a pathogen enters the body and begins to move to the organ or tissue of choice to replicate and infect the body.

External condom
noun The most common type of intervention to prevent STI transmission during sexual activities. It works by covering the penis, hand, or sex toy in order to provide a barrier between the bodily fluids of the people involved. Usually made from latex, external condoms can also be made out of polyisoprene, polyurethane, or lamb intestine. Many external condoms come with a small amount of lubricant.

Fluid Bonded
verb When people agree to stop using barrier methods of safer sex, this means that they will exchange sexual fluids. For some partners, this is an important emotional and physical step denoting trust in their relationship.

Fluid Transfer
verb The primary way that STIs are transmitted, fluid transfer involves an exchange of sexual fluids between people. This can include semen, vaginal lubrication, anal fluids, and sometimes breast milk and blood. It does not include saliva. If neither person is infected with an STI, fluid transfer will not cause an STI.

noun A bacterial STI. Gonorrhea can be spread to an infant during childbirth. Many people infected with gonorrhea do not have any symptoms of disease. When they do have symptoms, they include pain during urination, itchiness, discharge, bleeding between periods, and testicular pain.

noun Inflammation of the liver. The most common cause of hepatitis is viral. There are five kinds of viral hepatitis: A, B, C, D, and E. Types A (HAV), B (HBV), and C (HCV) are the most likely to be contracted through sexual contact. HAV is usually contracted through contaminated water or food. HAV is a mild infection and has a vaccine to prevent contraction. HBV is usually contracted through blood, semen, other bodily fluids, and during birth. There is a vaccine to prevent HBV infection. HBV has the greatest potential to be sexually transmitted. HCV is usually contracted through blood and sometimes through sexual contact with fluid transmission. There is no HCV vaccine.

Herpes Simplex Virus (HSV)
noun A viral infection caused by the herpes simplex virus. There are two types of HSV: Type 1, which is more robust, and Type 2, which is not quite as strong. Both of these types can be either oral (which is usually called a cold sore) or genital (which is usually called herpes). HSV can be transmitted through oral, anal, and vaginal sex. Many people are infected with HSV without ever having had an outbreak of sores. A person can contract HSV and be symptom-free for many years and then have their first outbreak, potentially leading a partner to incorrectly assume that they have been recently sexually intimate with someone else. The first HSV outbreak is typically the most extreme. Some people are aware when they are about to experience an outbreak due to a tingly feeling in the affected area. Transmitting HSV to a sexual partner is most likely during an outbreak, but HSV can be transmitted anytime, even when no sores are present. Antiviral treatments are effective at reducing HSV outbreaks, but they do not cure the virus. Antiviral treatments are used during an outbreak to decrease symptoms and can also be taken daily to reduce the likelihood of spreading of HSV to sexual partners.

Human Immunodeficiency Virus (HIV)
noun A retrovirus that attacks white blood cells, which are a part of the immune system. When white blood cells are sufficiently diminished, the immune system is unable to fight off basic infections, which increases the susceptibility to uncommon infections. If our immune system is unable to defend against infection, a person can become very ill, and at times, this can lead to death. There are antiretroviral treatments that are effective at reducing the impact on the immune system. They are so effective that someone who is HIV-positive may have entirely undetectable and non-transmittable levels of the virus in their system. These treatments, however, are expensive and often have side effects. They also need consistent monitoring to ensure that they remain effective against any viral mutations.

Human Papillomavirus (HPV)
noun A virus that causes abnormal cell growth. HPV has multiple types that are expressed differently in the body. HPV can affect any tissues in the body, but the forms that are most important to the conversation of STIs are genital warts and genital, anal, and oral cancers that are contracted through sexual contact. Skin-to-skin contact can transmit HPV when there is a skin expression such as warts, or through fluid exchange. Often, a person is exposed to HPV, contracts the virus, and the body’s immune system will clear the infection before they are aware they are infected. The primary health concerns are the types of HPV linked to cancer and warts. It is important to follow regular cancer screening recommendations for HPV.

Incubation Period
noun The time between the exposure moment and the beginning of clinical symptoms. Some STIs have very long incubation periods, such as HSV, which can incubate for many years. Others have much shorter periods, such as HIV, which is between two weeks and forty months, with an average that is close to three months. Pubic lice, on the other hand, can have an incubation period as short as a few hours between infection and symptoms.

noun As it applies to the topic of sexually transmitted infections, describes a specific set of disorders (caused by bacteria, virus, parasite, or fungus) that are able to be spread through sexual activity, including but not limited to oral, anal, and vaginal intercourse with a person who is already infected. STIs can be contracted even when ejaculation does not occur. An infection begins when the body begins to have an immune response to a pathogen that can be detected through medical diagnostics. However, an infection may or may not have symptoms, depending on its incubation period. The group of disorders described by the term sexually transmitted diseases is the same group that is described by the term sexually transmitted infections.

Internal Condom
noun Prevents STI transmission during sexual activities. It is inserted into the vagina or the anus in order to provide a barrier between the bodily fluids of the people involved. There is a ring on the closed end that sits either around the cervix or high inside the anus, holding it in place; and a second ring around the outside of the vulva or anus, keeping it from slipping in. The internal condom is made from polyurethane plastic, which means it is naturally latex-free. Internal condoms come with a small amount of lubricant.

noun A yellowing of the skin due to liver dysfunction, which is often caused by infections such as hepatitis.

Latent Period
noun The time between the exposure moment and the onset of symptoms.

noun A substance that reduces or eliminates the friction between two surfaces as they move back and forth across each other. Intercourse requires lubricant in order for it to feel good. The vagina naturally creates lubricant, although this often needs to be augmented with additional synthetic lubricant. When there is not enough lubricant, the abrasions that may occur in the vagina or anus due to friction increase the possibility of STI transmission.

Molluscum contagiosum
noun A virus that involves firm, painless bumps on the skin. Popping the bumps may spread them to the adjacent skin. Skin-to-skin contact between people spreads the infection. The infection usually resolves without treatment within six to twelve months. A healthcare practitioner can also remove them. The person is not infectious after the bumps are no longer there.

Nucleic Acid Test (NAT)
noun Laboratory tests that detect genetic material of a microorganism, including bacteria and viruses in blood, plasma, or other tissue. This allows for earlier detection of the infection.

noun An organism that lives on or in another organism. A parasite uses the host organism for nourishment and protection, keeping it alive.

noun A bacteria, virus, protozoa, fungus, parasite, or prion that causes an infection.

Pelvic Inflammatory Disease (PID)
noun An infection of the reproductive system that leads to swelling, abdominal pain, and potential infertility due to the scarring of the reproductive organs.

noun Post-exposure prophylaxis is a medication that is taken as soon as possible, but no later than 72 hours, after a potential exposure to HIV. PEP is very effective, but not 100%. Its effectiveness is dependent on how soon after exposure the medication is initiated.

noun Pre-exposure prophylaxis is a medication that is taken daily to reduce the chances of contracting HIV. When taken correctly, reduction is estimated at 90% for sexual contact and 70% for IV drug use.

Pubic Lice
noun Parasitic insects, also sometimes called crabs, that live in human genital hair and bite human skin to access blood for food. This causes itching and general discomfort. The lice that live in pubic hair may rarely be found in underarm hair, facial hair, or even eyebrow hair, but not in head hair. Contracting pubic lice usually involves skin-to-skin sexual contact with an infected person. It is possible to get it through shared towels, clothes, or sheets. Contracting it through furniture or toilets is highly unlikely. Getting rid of pubic lice can include the following options: medicated shampoos, nit combs, and shaving the region.

Rapid HIV Test
noun The most common of HIV tests, the rapid tests look for HIV antibodies. Rapid tests provide results within a few minutes, while the confirmatory tests take longer. If the rapid test is reactive, a confirmatory lab test is required to assure an accurate diagnosis.

Rapid Plasma Reagin (RPR)
noun A rapid blood test to screen for syphilis. If RPR is reactive, a second confirmation test is required for diagnosis of syphilis.

noun A type of virus that modifies cell structures to mirror and then produce replicas of the retrovirus. This is a particularly damaging kind of virus, because it is able to reproduce itself at far faster rates than a typical virus. Retroviruses cannot be killed nor necessarily eradicated through medications. They can, however, be treated with medications called antiretrovirals that slow disease progression through inhibiting further growth of the retrovirus.

noun The process of examining blood serum for pathogens

Skin-to-skin contact
noun A less-common way that STIs are transmitted, skin-to-skin contact involves people touching their skin together. When one person is infected with an STI AND that STI is shedding through an open sore or through their skin, the person who is not infected can contract it. If neither person is infected with an STI, skin-to-skin contact will not cause an STI.

noun A bacterial infection, caused by Treponema pallidum, that is expressed in three stages. The primary stage involves a chancre at the site of infection, and potential flu-like symptoms. The secondary stage involves a rash in one or more areas of the body, up to and including a full body rash, often involving the palms of the hands and the soles of the feet. The tertiary stage involves debilitation of many organ structures, leading to cancer, dementia, joint deterioration, and more. Syphilis can be transmitted during pregnancy to the fetus. Between the stages, the bacteria are latent, meaning they are dormant, during which time there are no symptoms.

noun The ways in which STI pathogens are transmitted from one person to another. The most common method is fluid exchange, followed by skin-to-skin contact. Many STIs can also be transmitted through sharing drug paraphernalia, such as needles

Trichomoniasis (Trich)
noun The most common curable STI, trich, is a protozoan parasite. Trich is contracted through fluid exchange. Only 30% of people with trich develop any symptoms. When trich does cause symptoms, they include genital itching and irritation, burning during urination, genital discharge, and genital smell. Trich is treated with an antibiotic.


noun An open sore on the skin. Examples include chancres, chancroids, and ulcers from HSV. The most common STIs presenting with ulcers in the United States are from HSV or syphilis.

noun Inflammation of the urethra, often caused by infection.

noun Inflammation of the vagina resulting in discharge, itching, and pain. The most common causes are bacterial vaginosis, trichomoniasis, and yeast infections.

Viral shedding
verb When a virus reproduces and the new viral cells move to a new part of the host’s body, or into the environment, where they can infect a new host.

noun A very small structure of cells that disrupts the body’s process in one or more ways. Viral STIs include HPV, HIV, and HSV. Because viruses are not alive in the biological sense, they cannot be killed nor necessarily eradicated through medications. They can, however, be treated effectively through medications called antivirals, slowing disease progression.

noun Inflammation of the vulva. Usually caused by an allergic reaction to a hygiene product, clothing, a yeast infection, or lack of cleanliness. Also sometimes caused by scabies, pubic lice, herpes, eczema, or dermatitis.

Wet prep/mount
noun A gynecological test of vaginal discharge. A sample of discharge is collected, mixed with a solution, and viewed under a microscope to determine the cause of abnormal discharge leading to vaginitis and vulvitis.