The recent emergence of Leishmania tropica in Jericho (A’riha) and its environs, a classical focus of L. major

Between 1997 and 2002, 49 strains of Leishmania were isolated from the cutaneous lesions of Palestinians
living in and around Jericho. A polymerase chain reaction (PCR) amplifying the ribosomal internal
transcribed spacer 1 (ITS1-PCR) was applied to their cultured promastigotes and to 207 individuals’ skin
scrapings spotted on filter-papers, 107 of which proved positive for leishmanialDNA.Species identification
was performed by restricting the ITS1-PCR amplification products from the cultured promastigotes and
the amastigotes in the scrapings with the endonuclease HaeIII. Of the 49 cultures, 28 (57%) were L. major
and 21 (43%) were L. tropica. Of the 107 dermal samples tested directly, 53 (49.5%) were infected with
L. major, 52 (48.5%) with L. tropica and two remained unidentified. This is the first time L. tropica has
been exposed in the population of the Jericho area and on such a large scale. The itinerant behaviour of
some of this population precludes categorically declaring that L. tropica has recently become established
in this classical focus of L. major. For this and although 88.2% of the cases of L. tropica claimed not to
have travelled out of the vicinity of Jericho, local infected sand fly vectors of L. tropica must be caught,
identified and, if possible, shown to harbour infections, and, if one exists, an animal reservoir host should
also be exposed to endorse whether the cases caused by L. tropica were imported or autochthonous.