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Solutions today for reefs tomorrow


Disease-Related Terms

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Anthropogenic – of, relating to, or resulting from the influence of human beings on nature. (Merriam-Webster 2006)

Autolysis – spontaneous disintegration of cells or tissues by autologous (self) enzymes, as occurs after death (post mortem) and in some pathologic conditions; lysis, enzymatic digestion, of cells by the enzymes present within them. (Stedman 1995)


Biomarker – any measurable sign (including visual and molecular) indicating the status of an organisms physiology, health, etc. that can be used in the diagnosis of a disease or syndrome4; includes a variety of measures of specific molecular, cellular, and physiological responses of key species to either contaminant exposure or poor health. (Allen and Moore 2004)

Bleach – to make or become white or colorless by means of chemicals, by exposure to sunlight, etc. In coral – bleaching or bleached – the reduction in intensity or complete absence of coloration within living coral, due to loss of pigmentation, death, or expulsion of endosymbiotic zooxanthellae. (Merriam-Webster 2006; CDHC Nomenclature Working Group 2004)

Bleaching – the loss or expulsion of symbiotic dinoflagellates (Symbiodinium spp.) by corals; can be caused by various stressors, including increased temperatures (Hoegh-Guldberg et al. 2007) and toxins produced by bacterial pathogens (Rosenberg and Falkovitz 2004). During temperature-induced bleaching, caspase-mediated apoptosis and autophagy are reciprocally activated to expel the dinoflagellate symbionts (Dunn et al. 2007). (Teplitski and Ritchie 2009)


Degeneration – a nonspecific term applied to retrogressive but sometimes reversible pathological change in cells or tissues, resulting in impairment or destruction of functions; deterioration; preferably the specific changes observed should be fully described. (Dorland 2006; Stedman 1995)

Degradation – conversion of a chemical compound to one less complex as by splitting off one or more groups of atoms. Degeneration, not degradation, should be used to describe the deterioration or change of functionality of living tissue. (Merriam-Webster 2006, CDHC Nomenclature Working Group 2004)

Diagnosis – the determination of the nature of a disease. (Stedman 1995)

Field Diagnosis – made from the study of the macroscopic changes of a coral disease observed in the field.

Laboratory Diagnosis – made by a chemical, virological, parasitological, microbiological, or immunological study of secretions, discharges, or tissues.

Morphologic Diagnosis – made from an anatomical or histological study of the lesions present.

Etiologic Diagnosis – the determination of the cause of the disease.

Differential Diagnosis – a systematic comparison and contrasting of similar disease signs and findings to determine which of two or more diseases is considered to be most likely present in the organism, although one or more other diseases are considered less likely to be present but possible. (See also Pathognomonic) A differential diagnosis is also made to distinguish between closely related species in taxonomy.

Disease – any deviation from, or interruption of, the normal structure or function of any body part, organ, or system that is manifested by a characteristic set of signs and whose etiology, pathology, and prognosis may be known or unknown (Dorland 2006); any impairment that interferes with or modifies the performance of normal function, including responses to environmental factors such as nutrition, toxicants, and climate; infectious agents; inherent or congenital defects, or combinations of these factors. (Wobeser 1981)


Epizootic – attacking many animals in any region at the same time; widely diffused and rapidly spreading; a disease of high morbidity which is only occasionally present in an animal community. (Dorland 2004)

Epizootiology – the scientific study of factors determining the frequency and distribution of diseases among animals; animal epidemiology. (Dorland 2004)

Etiology – the study or theory of the factors that cause disease and the method of their introduction to the host; the causes or origin of a disease or disorder. (Dorland 2004)


Hypertrophy – The enlargement or overgrowth of an organ or part due to an increase in size of its constituent cells (Medi-lexicon 2006).


Incidence – the rate at which a certain event occurs; e.g., the number of new cases of a specific disease occurring during a certain time period in a population at risk. (Dorland 2004)

Infection – invasion and multiplication of parasitic organisms within the body. (Stedman 1995)


Koch’s Postulates – to establish the specificity of a pathogenic microorganism, it must be present in all cases of the disease, inoculations of its pure cultures must produce disease in animals, and from these it must be again obtained and be propagated in pure culture. (Stedman 2006)


Lesion – a wound or injury, or any pathologic change in the tissues. (Stedman 1995)

Lesion Distribution – distinguished on the basis of number of that particular type of lesion (focal: single, localized area; multifocal: relating to, arising from, or occurring in more than one place; diffuse: spread about, not restricted; systemic: spread throughout the entire organism). Lesion Severity – semiquantitative, subjective ranking of the degree of damage or extent of pathological change seen in tissues or an organism (ranging from minimal: smallest amount or lowest limit; mild; moderate; marked; to severe: intensely or extremely bad, very poor condition, or greatest in degree or extent). Morbidity – a diseased condition or state; the incidence or prevalence of a disease, or of all diseases, in a population. (Dorland 2004)


Morphology – the form and structure of a particular organism, organ or part. (Dorland 2004)

Mortality – the death rate; the ratio of the total number of deaths to the population of a specified area in a given time period. (Stedman 2006)


Necrosis – cell death characterized by irreversible damage, the earliest of which is mitochondrial. Changes visible with light microscopy are nuclear (pyknosis, karyolysis, or karyorrhexis) and generally accompanied by cytoplasmic hyper-eosinophilia, shrinkage, or fragmentation. After such changes, the outlines of individual cells are indistinct and affected cells may become merged, sometimes forming a focus of coarsely granular, amorphous, or hyaline material. (Stedman 1995)


Pathogen – any virus, microorganism, or other substance causing disease. pathogenic, adj. (Stedman 1995)

Pathogenicity – the quality of producing or the ability to produce pathologic changes or disease. (Dorland 2004)

Pathophysiology – the physiologic changes in the host as the disease progresses. Prevalence – the number of cases of a specific disease that are present in a given population at a specified time. (Dorland 2004)


Sign – an indication of the existence of something; any objective evidence of a disease, i.e., such evidence as is perceptible to the examiner, as opposed to the subjective sensations of the patient (symptom). (Dorland 2004). Sign, not symptom should be used to describe lesions or conditions observed in coral, as the ability to convey sensations (feelings) is not a characteristic of coral. (comment by the CDHC Nomenclature Working Group 2004)

Syndrome – a set of symptoms occurring together; the sum of signs of any morbid (disease) state. (Dorland 2004)


Ulceration – The formation or development of an ulcer, a local defect or excavation, of the surface of an organ or tissue, which is produced by the sloughing of inflammatory necrotic tissue. (Medi-lexicon 2006)


The original list of terms was generated for the NOAA CHAMP Coral Disease Webpage in 2002 by Dr. Laurie Richardson based on published definitions. The list of terms was expanded based on the original CDHC Nomenclature Committee Report developed in 2002.

The term ‘biomarker’ was modified based on the Toxicology & Ecological Epidemiology working group’s definition in the report Coral Health and Disease in the Pacific: Vision for Action (Galloway et al., 2009) and the definition by Moore (Moore et al., 2006).


Galloway S.B., Bruckner A.W., Woodley C.M. (2009) Coral Health andDisease in the Pacific: Vision for Action NOAA Technical Memorandum NOS NCCOS 97 and CRCP 7, National Oceanic and Atmospheric Administration, Silver Spring, MD. pp. 314.

Moore M.N., Icarus Allen J., McVeigh A. (2006) Environmental prognostics: An integrated model supporting lysosomal stress responses as predictive biomarkers of animal health status. Marine Environmental Research 61:278-304. DOI: 10.1016/j.marenvres.2005.10.005.

Allen JI and MN Moore (2004). Environmental prognostics: Is the current use of biomarkers appropriate for environmental risk evaluation? Mar. Environ. Res. 58(2-5)227-232.

CDHC Nomenclature Working Group (2004). Report in preparation.

Dorland (2004). Dorland’s Illustrated Medical Dictionary, online 2004.

Dunn, S. R., C. E. Schnitzler, et al. (2007). “Apoptosis and autophagy as mechanisms of dinoflagellate symbiont release during cnidarian bleaching: every which way you lose.” Proceedings of the Royal Society B: Biological Sciences 274(1629): 3079-3085.

Hoegh-Guldberg, O., P. J. Mumby, et al. (2007). “Coral Reefs Under Rapid Climate Change and Ocean Acidification.” Science 318(5857): 1737-1742.

Medi-lexicon (2006). A web-based medical dictionary.

Merriam-Webster Online (2006). A web-based dictionary.

Rosenberg, E. and L. Falkovitz (2004). “The Vibrio shiloi/Oculina Patagonica model system of coral bleaching.” Annual Review of Microbiology 58: 143-159.

Stedman (2006). Stedman’s Medical Dictionary online 2006. 

Teplitski, M. and K. Ritchie (2009). “How feasible is the biological control of coral diseases?” Trends in Ecology & Evolution 24(7): 378-385.

Wobeser, G. A. (1981). Diseases of Wild Waterfowl. New York, NY, Plenum Press