American mucocutaneous leishmaniasis.

American mucocutaneous leishmaniasis is produced by several species of Leishmania. The microorganism lives in jungle reservoirs and is transmitted by sandflies. After infection, a complex set of immunologic phenomena takes place. Most lesions tend to heal, but some clinical forms are relentlessly progressive and resistant to available therapy. Diagnosis is usually possible with classical or modern techniques. Current treatment is effective in most cases, but it is expensive and difficult to manage under field conditions. Research on the immune response has been interesting, and vaccine prevention and treatment are objects of current interest. American leishmaniasis may not always remain a sylvan disease, and urban adaptation is a distressing possibility.