Glossary of HIV/AIDS Terms

D4T

Stavudine, an antiretroviral drug belonging to the reverse transcriptase class that inhibits HIV growth.

DDC

Zalcitabine, a reverse transcriptase inhibitor.

DDI

Didanosine stavudine, an antiretroviral drug belonging to the reverse transcriptase class that inhibits HIV growth.

Dementia

Chronic impairment of thinking (i.e. loss of mental capacity) that affects a person's ability to function in a social or occupational setting.

See AIDS Dementia Complex (ADC).

Demyelination

Destruction, removal, or loss of the myelin sheath of a nerve or nerves.

Dendritic Cells

Immune system cells that may initiate HIV infection by carrying the virus from the site of the infection to the lymph nodes, where other cells, such as CD4 T-cells, become infected. Dendritic cells circulate through the body and bind to infectious agents in tissues, such as the skin and membranes lining the intestinal tract, lungs, and reproductive tract. Once in contact with CD4 T-cells they initiate an immune response to the virus.

Deoxyribonucleic Acid (DNA)

The twisted double-stranded molecular chain found in genes within the nucleus of each cell. DNA carries the genetic information that enables cells to reproduce and transmit hereditary characteristics.

Desensitization

Gradually increasing the dose of a medicine in order to overcome severe reactions.

Diabetes Mellitus (DM)

A disorder of carbohydrate (sugar) metabolism characterized by elevated blood glucose (blood sugar) levels and glucose in the urine resulting from inadequate production or use of insulin (e.g. hyperglycemia).

Diagnosis

The decision that a patient has a specific disease or infection, usually accomplished by evaluating clinical symptoms and laboratory tests.

Diarrhea

Uncontrolled, loose, and frequent bowel movements caused by diet, infection, medication, and irritation or inflammation of the intestine. Severe or prolonged diarrhea can lead to weight loss and malnutrition. The excessive loss of fluid that may occur with AIDS-related diarrhea can be life threatening. There are many possible causes of diarrhea in persons who have AIDS. The most common infectious organisms causing AIDS-related diarrhea include Cytomegalovirus (CMV), the parasites Cryptosporidium, Microsporidia, and Giardia lamblia, and the bacteria Mycobacterium avium and Mycobacterium intracellulare. Other bacteria and parasites that cause diarrheal symptoms in otherwise healthy people may cause more severe, prolonged, or recurrent diarrhea in persons with HIV or AIDS.

Diplopia

Double vision.

Disseminated

Spread of a disease throughout the body.

DLV

Delavirdine, a drug in the non-nucleoside reverse transcriptase inhibitor class.

DNA

See Deoxyribonucleic Acid (DNA).

Dormant

Inactive infection that is still present in the body.

DOT (S)

Directly observed therapy (short course). Treatment that is given under the observation of a health care worker.

Double-Blind Study

A clinical trial design in which neither the patient nor the study staff know which patients are receiving the experimental drug and which are receiving a placebo (or another therapy).

Drug Resistance

The ability of some disease-causing infectious agents, such as bacteria and viruses, to adapt themselves, grow, and multiply even in the presence of drugs that usually kill them.

See Cross-Resistance.

Drug-Drug Interaction

A change in the effect of a drug when administered with another drug. The effect may be an increase or a decrease in the action, or it may be an adverse effect that is not normally associated with either drug.

Dysplasia

Any abnormal development of tissues or organs.

Dyspnea

Difficult or labored breathing.