Dictionary of Tropical Medicine

C.P.R.

See Cardio-pulmonary resuscitation.

Cachexia

Wasting of body tissues. Extremely thin (cachectic).

Cancer

Malignant neoplasm. Uncontrolled cell growth with local invasion and/or distant spread.

Carcinogen

A chemical or other agent that has been implicated in causing cancer.

Carcinoma

Cancer of the tissues which cover or line the body surfaces and internal organs.

Carcinoma simplex

Poorly differentiated adenocarcinoma.

Carcinoma-in-situ

Malignant epithelial tumour showing no invasion.

Cardiac arrest

Absence of a palpable pulse, and thus of circulation of blood around the body by the heart contraction. The cause may be asystole or ventricular fibrillation.

Cardio-pulmonary resuscitation

A combination of mouth to mouth resuscitation (E.A.R.) to oxygenate the blood, and external chest compression (E.C.C.) to compress the heart to help pump this artificially oxygenated blood around the body to maintain tissue oxygen concentration and prevent death.

Carrier

A carrier is an infected person (or animal) that harbours a specific infectious agent in the absence of discernible clinical disease and thus serve as a potential source of infection for human.

Carybdeids

Jellyfish members of the Class Cubozoa with a single tentacle in each of the four corners (except in certain rare species).

Case

A particular instance of disease; as in a case of typhoid fever. A case is not synonymous with a patient, for the latter is the human being affected with the disease.

Case control study

A design for epidemiological studies that matches individuals with a disease or health problem (cases) with others who do not have that condition (controls). Frequently, individuals included in the study are matched for factors such as age, race, socioeconomic status, occupation and area of residence. Comparisons are then made between the two groups.

Case fatality rate

The number of fatal cases of specific disease, divided by total number of known cases and it is usually expressed as percent. Case fatality is one index of disease severity and is of more interest in acute than in chronic disease.

Catecholamines

Hormones released by the body under any stressful reaction, or after envenomation (eg Irukandji), that affect the circulatory system, often increasing heart rate and blood pressure.

Caudal papillae

A group of sensory organs at the posterior end of some male nematodes (excluding "phasmids" which are situated on the lateral aspects of the tip of the tail); the number and arrangement of caudal papillae are used for identification of nematodes such as in Ascarididae and Thelaziidae.

Cause specific

These rates commonly are also age, death rate sex, or race specific. They are expressed as numbers of deaths assigned to a stated cause in a calendar year, divided by total population as of July 1st of that year, expressed in 100,000.

Cell

The smallest unit of living material that can function independently.

Cell-mediated immunity

A defence mechanism involving the coordinated activity of two subpopulations of T-Lymphocytes, helper T-Cells and killer T-Cells. Helper T-Cells produce a variety of substances that stimulate and regulate other participants in the immune response. Killer T-Lymphocytes destroy cells in the body that bear foreign antigens (e.g. cells that are infected with viruses or other microorganisms).

Cephalic papillae

A group of sensory organs around the mouth opening (excluding amphids which are situated on the lateral aspects of the mouth); the number and arrangement of the cephalic papillae are significant for the classification of nematodes.

Cephalopod

Octopus. See blue-ringed octopus.

Cercariae

The infective stages of the Schistosomes and other trematodes, which are free living in water.In some trematodes (e.g. Fasciola), the cercariae develope into metacercariae for infection.

Cestoda

Tapeworms, which are segmented Platyhelminths (Flatworms) consisting, in their adult stage, of a scolex for attachment to the gut of the final host, an unsegmented neck region and a long segmented strobila consisting of immature, mature and gravid proglottids (segments).

Chagas Disease

A zoonotic protozoan disease endemic to parts of Latin America and caused by Trypanosmoma cruzi with reduviid (Triatomid or assassin) bugs as the vectors.

Chancroid

Tropical sexually transmitted disease caused by Haemophilus ducreyi . Also known as Soft sore. It is characterised by soft, extremely painful ulcers on the genitals and enlarged inguinal lymph nodes (buboes).

Chemoprophylaxis

The administration of a chemical, including antibiotics, to prevent the development of an infection or the progression of the infection to active manifest infectious disease.

Chemotherapy

The use of chemicals/pharmaceuticals to treat disease.

Childhood immunization schedule

The schedule laid down by most countries to recommend which routine immunizations should be given to children and the intervals at which boosters should be administered. Such routine immunizations usually include tetanus, diphtheria, pertussis, polio, Hepatitis B, Haemophilus influenzae type b (H.I.B.) and after one year of age, measles, rubella and mumps vaccines.

Chirodropids

Jellyfish members of the Class Cubozoa with more than one (and up to 15) tentacles in each corner. The jellyfish group causing more morbidity and mortality than any other in the world. At present there are 5 common species acknowledged, but current research may change this.

Chironomid

A family of biting flies known as biting midges.

Chloroform

A chemical used for immobilising mosquitoes to facilitate their handling. It is toxic and should be used with extreme care.

Chloroquine

A 4-aminoquinoline drug commonly used for treating malaria. Resistence is widespread in Plasmodium falciparum.

Cholangiocarcinoma

A cancer in the bile ducts of the liver associated with opisthorchiasis. See Opisthorchiasis.

Chromoblastomycosis

A subcutaneous fungal disease caused by the dermatiacious fungi belonging to the genera Phialophora, Fonsecaea and Cladosporium.

Chronic

A term that is used to describe a disease of long duration or one that is progressing slowly.

Chronic diarrhoea

Refers to diarrhoeal episodes of presumed infectious aetiology that begin acutely but have an unusually long duration, usually more than 14 days (see also WHO Classification).

Ciguatera

Tropical fish poisoning occurring some 1-24hrs after ingestion of fish containing ciguatoxin. Symptoms are diverse and include (in approximate frequency): lassitude, muscle pains, burning of skin when cold objects are touched, itching, joint pains, paraesthesiae (especially hands, feet and lips), headache and diarrhoea, as well as many other less common symptoms. Ciguatera is a major world health problem in Countries relying on reef fish as the main source of protein and has caused many deaths. Neurological signs and symptoms may last for months, even years.

Ciguatoxin

The toxin causing ciguatera. It is produced by dinoflagellates which are then eaten by small fish. As these fish get eaten by larger ones progressing up the food chain the toxin becomes concentrated in the flesh (and liver) and can then intoxicate humans. In humans the toxin is not destroyed and so further ingestion of ciguatoxin causes a cumulative effect.

Cilia

Tiny hair-like cells that beat together, `wafting', like a field of corn. They have the specialised function of moving substances (eg. food) across an area. Cilia also serve as organs of locomotion for ciliate protozoa.

Ciliophora

(Syn = Ciliata) Protozoa moving by means of short hair-like cilia covering the cell. There is only one species of medical importance, Balantidium coli, the cause of balantidial dysentery.

Cirrus

The male copulatory organ in helminths.

Cirrus pore

The opening through which the cirrus is protruded.

Cirrus pouch

A hollow organ surrounding the inverted cirrus.

Class

The taxonomic group below a Phylum, and above Order. See Taxonomy.

Clinical trial

Studies which test drug safety and efficacy prior to registration.1. Phase I: a study in human volunteers to establish safety of a pharmaceutical agent.2. Phase II: the first investigation of a new drug in patients to determine the preliminary evidence of efficacy and to confirm safety.3. Phase III: trials designed to determine long term safety, efficacy and cost-effectiveness of a new drug in large numbers of patients.

Cloaca

A common opening of the alimentary and reproductive systems of male nematodes, normally situated on the ventral side at the posterior end of the body.

Cnidaria

The specific term now used by biologists to describe members of a Phylum which are principally marine animals, radially symmetrical, and which have tentacles (i.e. jellyfish). Reproduction usually encompasses a polyp and/or medusa stage. Previously this Phylum was aggregated with others under the term coelenterates.

CNS

Central nervous system; refers to the brain and spinal cord.

Cobalt Treatment

Radiation that uses gamma rays generated by cobalt-60, a radioactive isotope of the element cobalt.

Cobra

Snakes belonging to the Family Elapidae. They have fixed front fangs and are widespread throughout Africa and Asia. Possess a potent neurotoxin.

Coelenterates

Animals having no spine. This group originally contained Spongiaria, Cnidaria and Ctenophora. Coelenterata is a term which generally includes the cnidarians and ctenophores. As the phylum Cnidaria does not include the ctenophores, the two terms are not interchangeable.

Cofactor

A factor other than the basic causative agent of a disease that increases the likelihood of developing that disease. Cofactors may include the presence of other microorganisms or psychological factors such as stress.

Cold packs

An excellent analgesic treatment for the skin pain of many envenomations, especially those of jellyfish stings. It is usually less effective than heat for the treatment of stonefish, stingray and other venomous-spined fish envenomations.

Colonisation

The development of cells in a part to which they have been carried by metastasis. Can also be used to describe bacteria establishing and multiplying on a particular part of the body.

Colostomy

A temporary or permanent opening in the colon and the abdominal wall to allow faeces to pass out before reaching the anus.

Communicability

Capability of being transmitted from one person to another.

Communicable disease

An illness due to a specific infectious agent or its toxic products which arises through transmission of that agent or its products from a reservoir to a susceptible host - either directly, through the agency of an intermediate plant or animal host, vector, or the inanimate environment.

Communicable period

The time or times during which the infectious agent may be transferred directly or indirectly from an infected person to another person, from an infected animal to human, or from an infected human to an animal, including arthropods.In diseases such as diphtheria and scarlet fever, in which mucous membranes are involved from the first entry of the pathogen, the period of communicability is from the date of first exposure to a source of infection until the infective microorganism is no longer disseminated from the involved mucous membranes, ie, from the period before the prodromata until termination of a carrier stage, if this develops. Most diseases are not communicable during the early incubation period or after full recovery.In diseases transmitted by arthropods, such as malaria and yellow fever, the periods of communicability are those during which the infectious agent occurs in infective form in the blood or other tissues of the infected person in sufficient numbers to permit vector infections. A period of communicability is also to be distinguished for the arthropod vector - namely, that time during which the agent is present in the tissues of the arthropod in such form and locus (infective stage) as to be transmissible.

Complex

A group of closely related species once thought to be a single species.

Compression/immobilisation bandage

A firmly-applied, broad, elastic bandage applied to a limb to prevent the spread of venom injected after certain bites or stings. The pressure is enough to compress veins and lymphatic vessels, but not to cut off arterial supply and so it can remain on indefinitely. The bandage is first applied directly over the envenomated area, and then extended over the entire limb which is then immobilised in a splint.

Cone shells

Molluscs with cone-shaped shells, at least two species of which (Conus geographicus and C. textile) have been responsible for some 18 human deaths, usually from respiratory arrest. C. geographicus has caused at least one Australian death.

Congo-Crimean Haemorrhagic Fever

A tick-borne arboviral infection extending in distribution from Eastern Europe and Asia through to Southern Africa.

Conjunctivitis

Inflammation and redness of the lining of the white part (conjunctiva) of the eye.

Contact

A person or animal that has been in such association with an infected person or animal or a contaminated environment as to have had opportunity to acquire the infection.

Contagious

An infectious disease which is transmissible from one person to another. Sometimes used synonymously with infectious.

Coracidium

A ciliated oncosphere which develops in the eggs of pseudophyllidean tapeworms.

Coronatae

The taxonomic order of grooved jellyfish.

Coronavirus

RNA viruses causing the common cold

Crablice

Pthirus pubis also known as the Pubic louse.

Crown-of-thorns starfish

Colloquial term for the starfish Acanthaster planci. See Acanthaster planci.

Cubomedusae

A term that included all box jellyfish species, now mainly replaced by cubozoa.

Cubos

Colloquial name used in the Philippines and other Indo-Pacific countries to describe Chiropsalmus quadrigatus.

Cubozoa

The taxonomic class of box-shaped jellyfish consisting both of chirodropids and carybdeids.

Culicine

Most mosquitoes that are not anophelines fall into this group. Culicines are not vectors of human malaria, but the subfamily includes the important genera Aedes, Culex and Mansonia. May transmit a number of diseases (eg, yellow fever, dengue fever, filariasis, viral encephalitis).

Cumulative incidence

The proportion of number of newly detected cases that developed during follow-up by the number of disease-free subjects at the start of follow-up.

Cutaneous larva migrans

A cutaneous eruption resulting from exposure of the skin the infective filariform larva of non-human hookworms, Ancylostoma braziliense, A. caninum and some Strongyloides spp (especially S. procyormis of the raccoon and S. myopotami of the nutria).

Cutaneous leishmaniasis

A spectrum of skin disease caused by protozoan Leishmania spp, with a lifecycle and vectors identical to that of Leishmania donovani (see visceral leishmaniasis). The spectrum of disease ranges from a single, dry cutaneous lesion (L. tropica) through to destructive mucocutaneous lesions (L. braziliensis braziliensis).

CVS

Cardiovascular system. The heart, arteries, veins and capillaries.

Cystadenoma

Benign tumour of epithelial tissue forming cysts.

Cysticercoid

A larval form of a tapeworm (e.g. Hymenolepis) which has a solid body and no bladder.

Cysticercus

Larval stage of tapeworms belonging to the genus Taenia. Also known as bladderworms. The cysticercus of the Pork Tapeworm is called Cysticercus cellulosae and is the cause of human cysticercosis.

Cytology

Study of cells removed from surface of organs (exfoliated cells) for the purpose of diagnosing cancer; e.g., Papanicolaou smear.

Cytotoxic drugs

Chemicals used to kill cancerous cells. Most cytotoxic drugs also kill normal cells. There is a delicate balance between killing enough cancer cells and not so many normal cells.