Table 1.
WHO classification of malaria cases3
| Term | Description |
|---|---|
| Imported case | Malaria case or infection in which the infection was acquired outside the area in which it is diagnosed |
| Introduced case | A case contracted locally, with strong epidemiological evidence linking it directly to a known imported case (first-generation local transmission) |
| Indigenous case | A case contracted locally with no evidence of importation and no direct link to transmission from an imported case |
| Induced case | A case the origin of which can be traced to a blood transfusion or other form of parenteral inoculation of the parasite but not to transmission by a natural mosquito-borne inoculation |
Furthermore, WHO defines a case as the occurrence of malaria infection in a person in whom the presence of malaria parasites in the blood has been confirmed by a diagnostic test3; therefore cases are defined on infection status and not on clinical symptoms.