Clinical evidence of illness1 with laboratory confirmation of infection:
- positive acid fast stain with typical morphology for Mycobacterium leprae;
OR
- histopathological report from skin or nerve biopsy compatible with leprosy.
- Clinical illness1 in a person who is epidemiologically linked to a confirmed case.
Notes:
- Clinical illness is characterized by the involvement primarily of skin as well as peripheral nerves and the mucosa of the upper airway. Clinical forms of Hansen's disease represent a spectrum reflecting the cellular immune response to M. leprae. The following characteristics are typical of the major forms of the disease:
Tuberculoid: one or a few well-demarcated, hypopigmented, and anesthetic skin lesions, frequently with active, spreading edges and a clearing centre; peripheral nerve swelling or thickening also may occur.
Lepromatous: a number of erythematous papules and nodules or an infiltration of the face, hands, and feet with lesions in a bilateral and symmetrical distribution that progress to thickening of the skin.
Borderline (dimorphous): skin lesions characteristic of both the tuberculoid and lepromatous forms.
Indeterminate: early lesions, usually hypopigmented macules, without developed tuberculoid or lepromatous features.