Adherence refers to the extent to which a person uses a medication according to medical recommendations, inclusive of timing, dosing and consistency.

Adolescents: individuals who are between puberty and the completion of physical growth, roughly from 11 to 19 years of age.

Adolescent/Youth-Friendly Services refers to services that are: Available, accessible and equitable, so that the core interventions for HIV are provided in ways that all young people, including those most at risk of HIV, can use them. Acceptable; with health and related staff trained to provide services for young people with dignity and respect, also ensuring privacy and confidentiality; Appropriate and effective, so that the necessary skills, equipment and supplies are available to provide quality services for HIV prevention, treatment, care and support for young people.

Antiretroviral Therapy (ARV) consists of the use of at least three antiretroviral (ARV) drugs to maximally suppress the HIV virus and stop the progression of HIV disease. Huge reductions have been seen in rates of death and suffering when use is made of a potent ARV regimen.

Behavior Change Communication is an interactive process with communities (as integrated with an overall program) to develop tailored messages and approaches using a variety of communication channels to develop positive behaviors; promote and sustain individual, community and societal behavior change; and maintain appropriate behaviors.

Combination Antiretroviral Treatment (cART) refers to a patient taking three or more antiretroviral drugs at a time. Also known as HAART.

CD4 Count: CD4 cells are a type of lymphocyte (white blood cell) and are an important part of the immune system. HIV most often infects CD4 cells and over time, the number of CD4 cells drops, signaling that the immune system is becoming weak.

Community-based Care is holistic care, treatment, and psychological support for HIV and AIDS patients and their families provided by relatives, friends or community volunteers from non-governmental organizations who are in turn supported to a greater or lesser extent by health professionals, mostly nurses.

Directly Observed Therapy (DOT) is a strategy devised to help clients adhere to Tuberculosis (TB) treatment. A TB case manager or another designated person watches the TB client swallow each dose of the prescribed drugs. The goal of DOT is to ensure that clients with active tuberculosis receive and adequately complete their treatment to minimize the risk of spreading the disease to others and developing drug-resistant TB.

Disclosure refers to revealing ones HIV status after testing positive.

Extensively-Drug Resistant Tuberculosis (XDR-TB) occurs when TB becomes resistant to both first- and second-line drugs as result of misuse or mismanagement. XDR-TB is due to bacteria that are resistant to any fluoroquinolone, and at least one of three injectable second-line drugs (capreomycin, kanamycin and amikacin), in addition to isoniazid and rifampicin .

Exclusive Breastfeeding refers to feeding infants only breast milk, without any additional food or drink, including water, for at least 6 months after birth.

Gender-based Violence refers to violence on the basis of ones gender.

Gender Equality means equal treatment of women and men in laws and policies, and equal access to resources and services within families, communities and society at large.

Gender Equity is the process of being fair to women and men. To ensure fairness, measures must often be available to compensate for historical and social disadvantages that prevent women and men from otherwise operating on a level playing field. Equity leads to equality.

Harm Reduction refers to policies, programs and practices that aim to reduce the harms associated with the use of psychoactive drugs in people unable or unwilling to stop. The defining features are the focus on the prevention of harm, rather than on the prevention of drug use itself, and the focus on people who continue to use drugs.

HIV ELISA Test ELISA stands for "enzyme-linked immunosorbent assay." This is a rapid immunochemical test that uses an enzyme to test for HIV antibody. If antibodies to HIV are present (positive), the test is usually repeated to confirm the diagnosis.

Highly Active Antiretroviral Therapy (HAART) A combination of three or more antiretroviral drugs consisting of one or more PIs or one NNRTI or the NRTIs - Abacavir or Tenofovir, or an integrase or an entry inhibitor.

HIV Testing: immunologic tests for the identification of HIV antibodies.

Home-based Care is the care of persons living with HIV infection and AIDS in their homes. This involves the provision of comprehensive care by community members, NGOs, Community-based organizations (CBOs), health workers and family members. This type of care is complementary to the existing health care services.

Human rights: the rights to which one is just entitled as a human being.

Injecting Drug Users (IDU) refers to those who inject drugs into their bodies. The most commonly injected drugs are heroin and other opiates, cocaine and amphetamines. Also referred to as people who inject drugs (PWID)

Intermittent Preventive Treatment (IPT) IPT refers to using the anti-malarial drug Sulfudoxine Pyrimenthamine (SP) as a proactive and effective intervention that prevents and controls the effects of malaria on mothers and their unborn children.

Internally Displaced Persons (IDP) refers to those who are displaced within their own national borders and are therefore not covered by international refugee law.

Key Populations are those most likely to be exposed to HIV or to transmit HIV and therefore are key to the epidemic and the response.

Legal Rights are rights that exist under the rules of legal systems.

Lesbians are women who are sexually attracted to other women. Lesbians prefer intimate relationships with women.

LGBT is an acronym for lesbian, gay, bisexual and transgender. LGBT can refer to individual people or a community of people. Lesbian: A homosexual woman. Gay: A homosexual person; can refer to both men and women, but more often to men. Bisexual: A person who is attracted to men and women. Transgender: An umbrella term for people whose gender presentation or identity is different from their biological sexfor example, a biological male who appears or identifies at least in some respects as female, or a biological female who appears or identifies in at least some respects as male.

Mass media: instruments or technological means of communication that reach large numbers of people with a common message; includes radio, television, newspapers, magazines, billboards, banners, posters, store windows and match covers.

Men Who Have Sex With Men (MSM) refers to all men who have sex with other men, regardless of how they identify themselves gay, bisexual, or heterosexual.

Microcredit programs extend small loans to very poor people for self-employment projects that generate income, allowing them to care for themselves and their families.

Microfinance is often defined as financial services for poor and low-income clients. In practice, the term is often used more narrowly to refer to loans and other services from providers that identify themselves as microfinance institutions.

Millennium Development Goals (MDGs) The Millennium Development Goals (MDGs) are eight goals to be achieved by 2015 that respond to the world's main development challenges. The MDGs are drawn from the actions and targets contained in the Millennium Declaration that was adopted by 189 nations-and signed by 147 heads of state and governments during the UN Millennium Summit in September 2000. The eight MDGs break down into 21 quantifiable targets that are measured by 60 indicators.

Mixed Feeding refers to feeding a baby both breast milk and other foods or liquids, such as water, glucose water, tea, infant formula, cow milk or other breast-milk substitutes, porridge or rice.

Multi-Drug Resistant Tuberculosis (MDR-TB) MDR-TB is defined as TB with resistance to isoniazid and rifampicin, the two most powerful first line drugs.

Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) are one of the 3 component drug treatments for HAART. These drugs stop HIV from multiplying by blocking the reverse transcriptase enzyme. This enzyme changes HIV's genetic material (RNA) into the form of DNA. This step has to occur before HIV's genetic code gets combined with an infected cell's own genetic codes. Non-nucleoside reverse transcriptase inhibitors, called NNRTIs or non-nukes, physically prevent the reverse transcriptase enzyme from working.

Orphans and Vulnerable Children (OVC) generally refers to orphans and other groups of children who are more exposed to risks than their peers. In an operational context, they are the children who are most likely to fall through the cracks of regular programs, or, using social protection terminology: OVC are groups of children that experience negative outcomes, such as the loss of their education, morbidity, and malnutrition, at higher rates than do their peers.

Peer Education Training people to teach people of their own age group or background.

People Living with AIDS (PLWA) refers to those both infected and affected by HIV/AIDS.

People Who Inject Drugs/Use Drugs (PWID/PWUD) refers to those who inject drugs. Also females who inject drugs (FWID) and males who inject drugs.

Personal Protective Equipment (PPE) is any type of face mask, glove, or clothing that acts as a barrier between infectious materials and the skin, mouth, nose, or eyes (mucous membranes). When used properly, personal protective equipment can help prevent the spread of infection from one person to another.

Postpartum (PP) Postpartum (PP), also termed puerperium, refers to the 6-week period following childbirth.

Post-exposure prophylaxis (PEP) is short-term antiretroviral treatment to reduce the likelihood of HIV infection after potential exposure, either occupationally or through sexual intercourse..

Preventive therapy (PT) is drug treatment to prevent opportunistic infections among people living with HIV/AIDS who have weakened immune systems. One example of PT is PT consisting of treatment with the antibiotics cotrimoxazole and isoniazid; the former is used to prevent a variety of bacterial infections and the latter is used to prevent and treat tuberculosis.

Prophylaxis is a measure taken to maintain health and prevent the spread of disease.

Protective behavior is any activity undertaken by a person believing himself to be healthy, for the purpose of preventing disease or detecting it in an asymptomatic stage.

Providers are health care personnel attending to those who seek health care.

R0 The reproduction number R0 is the number of secondary cases which one case would produce in a completely susceptible population. It depends on the duration of the infectious period, the probability of infecting a susceptible individual during one contact, and the number of new susceptible individuals contacted per unit of time. Therefore R0 may vary considerably for different infectious diseases but also for the same disease in different populations.

Replacement Feeding, sometimes referred to as infant formula feeding, is the process of feeding a child who is not breastfeeding with a diet that provides all the nutrients the child needs, until the child is fully fed on family food. Replacement feeding includes replacement of breast milk with a suitable breast-milk substitute in the first 6 months of life, and ensuring adequate complementary food and replacement of breast milk from 6 months to 2 years.

Risk Behavior: A behavior whose outcomes may endanger either the individual engaging in it or those affected by it.

Self-perception: an individuals view of self.

Seroconversion refers to the development of detectable HIV antibodies in serum as a result of infection.

Sex behavior: sexual behavior of humans.

Sexual debut refers to one having first sexual intercourse.

Sex education: instruction in all aspects of human reproduction and sexuality.

Sexuality is a central aspect of being human throughout life encompassing sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships.

Sexually transmitted infections are infections that are spread primarily through person-to-person sexual contact.

Social marketing: use of marketing techniques to improve social well-being by changing attitudes and behavior in regard to a specific product or concept.

Squamous Intraepithelial Lesion (SIL): precancerous abnormalities of the cervix that can progress to cervical cancer.

Superinfection occurs when an HIV-infected individual acquires a new viral strain.

Training programs: programs aimed at the acquisition of defined skills.

Unintended Pregnancy An unintended pregnancy is one that is either mistimed or unwanted at the time of conception.

Violence Against Women Violence against women can include physical, sexual, psychological and economic abuse, and it cuts across boundaries of age, race, culture, wealth and geography. It takes place in the home, on the streets, in schools, the workplace, in farm fields, refugee camps, during conflicts and crises. It has many manifestations from the most universally prevalent forms of domestic and sexual violence, to harmful practices, abuse during pregnancy, so-called honour killings and other types of femicide.

Viral Load refers to the amount of HIV virus in the blood.

Voluntary Counseling and Testing (VCT) The most widely implemented model of HIV counseling and testing is generally referred to as voluntary counseling and testing or VCT, where people specifically seek the HIV test. In this model, people receive counseling about their risks for HIV, obtain an HIV test, learn their HIV status, receive counseling on how to cope with the test results and implications, and develop a plan with a provider to minimize their risk of acquiring HIV or transmitting the virus to others. The VCT model emphasizes pretest counseling, a risk assessment, and the voluntary seeking of the test.

Window Period: The period of time between when a person is first infected with HIV and when they develop antibodies, usually between two weeks and three months, and sometimes up to six months. During the window period standard antibody tests would test negative, but the person is still infectious to others.

Womens Empowerment: Political, economic, and social advancement of women.

Women Who Have Sex With Women (WSW) The term is often used when discussing sexual behavior. It is inclusive of all women who participate in sex with women regardless of how they identify their sexual orientation..

WHO Stages of HIV disease is an approach for use in resource-poor communities where medical facilities are sometimes poorly equipped, and therefore is not possible to use CD4 and viral load test results to determine the right time to begin antiretroviral treatment. The four stages are Stage 1: HIV disease is asymptomatic and not categorized as AIDS. Stage 2: includes mild symptoms such as minor mucocutaneous manifestations and recurrent upper respiratory tract infections. Stage 3: includes advanced symptoms unexplained chronic diarrhea for longer than a month, severe bacterial infections and pulmonary tuberculosis. Stage 4: includes severe symptoms, such as toxoplasmosis of the brain, candidiasis of the esophagus, trachea, bronchi or lungs and Kaposi's sarcoma; these diseases are used as indicators of AIDS.

Youth/Young people: primarily people under age 21 (can include persons up to 25 years old).

For additional SRH-related term definitions, please see Center for Communication, 2007.