Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania (class - Kinetoplastidea , order - Trypanosomatids) and is transmitted by the bite of blood-sucking double winged insect of the genera Phlebotomus and Lutzomyia. In humans it is present in the form of a small amastigotes in macrophages.
The genus Leishmania involves a lot of very similar and usually morphologically indistinguishable species. A definitive diagnosis of the disease is performed on the basis of a complex assessment of its clinical image, geographical distribution and ecologic factors, by which the disease is accompanied. Recently, Leishmanias have been distinguished by molecular biological and biochemical techniques (PCR, sequencing, typization by using the isoenzymal formulas).
Three basic forms of leishmaniasis exist: cutaneous, mucocutaneous and visceral. Among these basic types there are also many transitional forms which are determined by the abilities of the concrete strain of parasite and a current interplay of diseases with the defense mechanisms of the host.
L. tropica (southern Europe, northern Africa, the Middle East, Central Asia, India), L. major (Middle East), L. mexicana complex (Central America), L. braziliensis complex (South America), L. donovani complex (Mediterranean - L. infantum, South America - L. chagasi, India, Middle East and Africa - L. Donovani).
We detect leishmania by PCR amplifying a fragment of kinetoplast minicircles. In cutaneous leishmaniasis it is necessary to remove the material to be examined from the edge of a lesion and not from the middle, where leishmanias have already been suppressed by the immune reaction. It is also possible to investigate organ biopsies in visceral leishmaniasis.
- Jiří Vávra. Biologie parazitických protozoí. Biologická fakulta JU, České Budějovice
- Safaei A, Motazedian MH, Vasei M. Polymerase chain reaction for diagnosis of cutaneous leishmaniasis in histologically positive, suspicious and negative skin biopsies. Dermatology. 2002;205(1):18-24.