Cutaneous leishmaniasis in Tunisia: results of the iso-enzymatic characterization of 71 strains

Abstract

Three clinico-epidemiological forms of cutaneous leishmaniasis (CL) exist in Tunisia: zoonotic cutaneous leishmaniasis (ZCL; epidemic in the centre and the south-west); sporadic cutaneous leishmaniasis (SCL; found in the north); and chronic cutaneous leishmaniasis (CCL; originally described from Tataouine, in the south-east). As few isolates of Leishmania from Tunisian cases of CL have been typed, isolates were collected, using NNN medium, from 71 such cases. Most (59) of the cases investigated came from the north of the country, including 16 from Sidi Bourouis, where there was an epidemic outbreak of SCL in early 2001; the other 12 cases were natives of the centre or south of the country. The 71 strains were then characterized, at the Centre National de Référence des Leishmania, in Montpellier, France, by iso-enzyme analysis. This revealed four zymodemes: two of L. infantum and one each of L. major and L. killicki. The MON-1 zymodeme of L. infantum, which is more usually associated with visceral leishmaniasis, was recovered from seven of the cases, including six natives of Sidi Bourouis. The MON-24 zymodeme of this species, which appears to be responsible for the SCL, was isolated from 48 cases, all of whom lived in the north of the country. Another 15 cases (nine from the centre, four from the north, and two from the south-east of the country) were found to be harbouring L. major MON-25, the zymodeme usually causing ZCL. Only a single isolate of L. killicki was made; this was of the MON-8 zymodeme responsible for the CCL, and came from a native of Gafsa, in the south-west. Six of the cases investigated (five infected with L. infantum MON-24 and one with L. major MON-25) showed involvement of their nasal and labial mucosae. These results increase the number of strains typed from Tunisian cases of CL more than four-fold, and should help to elucidate the geographical distribution and epidemiology of the various forms of the disease.