- Tabes dorsalis
- Neurological features of tertiary syphilis.
- Taenia solium
- A species of tapeworm which is transmitted by inadequately cooked pork or by human hosts excreting its eggs in their stools. The adult worm causes intestinal infection, while the larval worm may infect the brain, eye, or muscle, a condition called cysticercosis.
- Tapeworms (Cestodes)
- Parasitic flatworms whose adult forms live in the intestines and whose larval forms may infect internal organs and the brain.
- Tatumella
- A bacterium associated with bacteraemia and UTI’s.
- Taxonomy
- The study of scientific classification and nomenclature involving the organization or classification of objects into logical relationships.
- T cell
- A thymus-derived lymphocyte primarily involved in cellular-type immunity.
- T lymphocyte (T cell)
- A type of immune cell produced by the thymus gland.
- Temperate phage
- A bacterial virus that can become integrated into host cell DNA or replicates as a virulent virus.
- Tetanus (Clostridium tetani)
- A severe infection that develops when spores contaminate wounds. If there is sufficient anaerobic areas, the spores germinate, multiply locally, producing a toxin that causes sustained and involuntary muscular contractions.
- Thermoacidphile
- An organism that lives at high temperatures under very acidic conditions.
- Thermophile
- A microbe capable of growing in temperatures above the 45-80°C (104-176°F), lethal to ordinary organisms.
- Thrush
- An infection of the oral mucous membranes caused by the fungus Candida albicans. Oral thrush in adults is usually an indication of an underlying disease as diabetes or a malignancy. Those who regularly inhale steroids in an effort to control asthma are advised to rinse their mouths out afterwards to help prevent oral thrush. Any baby who has a sore throat and shows discomfort during feeding should be examined.
- Thymus
- An endocrine gland located behind the breastbone near the throat. It is large in childhood and decreases in size with age. It is an important organ for the immune system, producing the T cells needed to fight invasive organisms.
- Tinea
- A name applied to many different kinds of fungal infections of the skin, with specific types being determined by the area infected. Some examples are as follows: Tinea capitis is the strain that infects the scalp; Tinea pedis, or athlete’s foot; Tinea cruris is known as “jock itch;” Tinea barbae often infects men with beards.
- Togaviruses
- A virus belonging to the family Togaviridae, producing diseases that are arthropod-borne.
- Tonsillitis
- An inflammation and enlargement of the tonsil, especially the palatine tonsils. Tonsils are part of the lymphatic system which aids the body in filtering out pathogens and other foreign matter.
- Toxemia
- The accumulation of toxins in the blood.
- Toxic shock syndrome
- An acute infection consisting of fever, low blood pressure, a red rash, and various combinations of confusion, watery diarrhea, kidney failure, liver failure, and a low platelet count. The largest outbreak was linked to super-absorbent tampons that became colonized with Staphylococcus aureu toxins. Several other toxins, including pyrogenic exotoxins similar to those implicated in group A srep, can play a role in the syndrome.
- Toxin
- Any poisonous substance, including those produced by a living organism. Microbial toxins are among the most poisonous substances known. Toxins are frequently responsible for the characteristic symptoms associated with infectious diseases.
- Toxocaria canis
- Dog roundworms that cause a disease called visceral larva migrans in humans, mainly children.
- Toxocaria cati
- Cat roundworms that cause a disease called visceral larva migrans in humans, mainly children.
- Toxoid
- A treated toxin that it is no longer poisonous, but is still able to cause the formation of antibodies that will neutralize it (e.g., tetanus toxoid). It is often used as a vaccine.
- Toxoplasma
- A protozoan parasite (Toxoplasma gondii) of the domestic cat, that causes the disease toxoplasmosis contracted through contact with cat feces. Toxoplasmosis is marked by tissue alterations in the brain and eye, with lesions affecting the lungs, liver, heart, and muscles. Human infection normally causes only a mild disease, but is more serious when it reaches a developing fetus or infects a person with a weakened immune system.
- Trachoma
- A chronic infectious disease of the conjunctiva and cornea of the eye, producing blindness, caused by the bacterium Chlamydia trachomatis, spread by fingers, flies, towels, etc. The eyelids turn inwards, producing abrasions of the cornea, resulting in ulcerations.
- Transaminase
- A normal tissue enzyme that can transfer an amino group from one compound to another. Increased levels of serum transminase indicate tissue injury.
- Transformation
- The transfer of genetic information via free DNA. It is also a process sometimes initiated by certain viruses that cause a normal animal cell to become a cancer cell.
- Trematodes
- Leaf-shaped flatworms, also known as flukes, of the class Trematoda, phylum Platyhelminthes. Important ones affecting man are blood flukes, intestinal flukes, lung flukes, and liver flukes.
- Trichinella
- A genus of nematode parasites that cause a disease in humans called trichinosis. The intestinal roundworm Trichinella spiralis infects humans when they eat undercooked meat, usually pork, infected with a parasite.
- Trichinosis
- A disease of muscle caused by a parasitic roundworm and transmitted by eating undercooked pork or bear meat. Over a period of 4-6 weeks after ingestion, the microscopic creatures go through their life cycle placing offspring in organs that cause pain, fever, hemorrhaging, and occasionally death.
- Trichomes
- Filamentous or hairlike structures formed by many cyanobacteria. A trichome is a row of cells that have remained attached to one another following cell division.
- Trichomonas vaginalis
- A parasitic protozoan that produces a sexually transmitted infection called Trichomoniasis.
- Trichophyton
- A genus of fungi that causes various infections of the skin, hair, and nails.
- Trichous
- Hairlike.
- Trophozoite (trophs)
- The active, motile feeding stage of a protozoan parasite (Sporozoa class).
- Trypanosomiasis
- A protozoan infection caused by one of three species of the genus Trypanosoma: T. brucei gambiense and T. brucei rhodesiense cause African sleeping sickness transmitted by the tsetse fly; T. cruzi causes South American sleeping sickness or Chagas’ disease transmitted by the “kissing bug” or reduviid bug.
- Tubercle
- A firm granulomatous lesion resulting from an infection with Mycobacterium tuberculosis.
- Tuberculicide
- Kills tuberculosis bacteria.
- Tuberculin
- A protein extract from the Mycobacterium cell wall that is injected intracutaneously to test for tuberculosis.
- Tuberculosis
- A disease produced from the bacterium Mycobacterium tuberculosis, caused by one of three species of mycobacteria – Mycobacterium tuberculosis, M. bovis, and M. africanum. However, M. tuberculosis is generally recognized as the prime cause in humans and commonly referred to as the tubercle bacillus. Tuberculosis is a bacterial infection of the lungs, that may spread throughout the body. Transmission is via droplets in the air. A single cough from an infected person can discharge 3,000 bacteria each time, but breathing in just one organism can cause infection.
- Tuberculosis leprosy
- A chronic skin infection caused by Mycobacterium leprae.
- Tularemia
- A disease cause by the bacterium Francisella tularensis.
- Typhoid
- A bacterial infection caused by the Salmonella bacteria and transmitted via food or water contaminated by an infected person who may be asymptomatic.
- Typhus
- An infectious disease caused by parasitic organisms of Rickettsia. Epidemic typhus (classical) is caused by Rickettsia prowazekii carried by body lice. Endemic typhusis caused by Rickettsia typhi carried by rat fleas that can also transport bubonic plague (Yersinia pestis).
