Diagnosis

Definition

The identification and characterization of a disease, pathogen, or condition based on signs, symptoms, and confirmatory evidence. In medical and veterinary entomology, diagnosis specifically refers to determining whether an arthropod or its products (venom, saliva, parasite stage) is the causative agent of a clinical presentation, or to identifying the infectious agent an arthropod vector carries. In taxonomy, diagnosis refers to the formal statement of distinguishing characters that separate a taxon from its closest relatives.

Etymology

Greek diagnōsis, 'discrimination, distinguishing', from diagignōskein, 'to distinguish, discern'

Example

A diagnosis of malaria requires identification of Plasmodium parasites in blood smears; the entomological component confirms Anopheles mosquitoes as the vector through species identification and parasite detection in salivary glands.

Related Terms

• differential diagnosis
• vector competence
• pathogen detection
• clinical entomology
• taxonomic diagnosis

Usage Notes

Distinguish clinical diagnosis (patient presentation) from etiological diagnosis (identifying the specific agent) and entomological diagnosis (identifying the vector species and its infection status). In taxonomy, a diagnosis is a required component of species descriptions, contrasting with the description itself which documents all observed characters.