Search

Cutaneous leishmaniasis (ZCL) is a protozoan disease well documented not only in Egypt, but in nearly all the East Mediterranean Countries. Sinai Peninsula was a sparsely populated area where sporadic cases of ZCL were reported with the reconstruction of Sinai and people coming in and out, it was indicated to study the status of ZCL in North Sinai Governorate, the reservoir host(s) and insect vector(s) in Sinai. In the present study, the six species of rodents were trapped from areas or nearby areas where human ZCL cases were detected. Rodents (50) were Mus musculus (10), Rattus r. alexandrinus (18), R. norvegicus (2), Gerbillus gerbillus (4), G. pyramidum (12) and Jaculus jaculus (4). The rodents were examined clinically for any skin lesion or even nodule, particularly in head and tail. One G. pyramidumn had natural infection with L. major as indicated by smears and culture, but typing was not done. The spot light surveys for Phlebotomus were carried out by the sticky paper traps and the CDC light traps in four main centers; Al Hassanah, Nakhil, Al Arish, and Bir Al-Abd. A total of 1320 sandflies were identified. They were P. papatasi (1150) and P. sergenti (170) in a ratio of 7:1. A total of three isolates of zymodeme London 70 undistinguished from the formerly obtained human and rodent isolates were enzymatically identified in P. papatasi.

Polymerase Chain Reaction (PCR) had been used to amplify the mini-exon gene repeat from 30 clinically and parasitologically positively cases of zoonotic cutaneous leishmaniasis. It revealed that they possess 440-460 bp mini-exon gene that belongs to Old world Leishmania. Hybridization of the PCR-amplified mini-exon repeats was performed. A single pair of PCR primers within a conserved region of the mini-exon repeat was used to amplify the repeats of the 30 cases. Oligonucleotide hybridization probes for the detection and identification of the PCR-amplified repeats were constructed from alignment of mini-exon intron and intergenic sequences. The probes of Leishmania major and Leishmania tropic, which are supposed to be present in the research area, were used to identify the causative species. They revealed that the all collected samples are belonging to L. major.

Generally speaking, there are at least few endemic zoonotic cutaneous leishmaniasis (ZCL) in the Sinai and the Suez Canal Governorates. A spotlight survey for new cases of human ZCL among out-patients with skin complaints revealed sixteen out of 100 (16%) individuals examined. But, none ZCL infection was found among 50 normal individuals. The typing of three human isolates proved to be Leishmania major Zymodeme London 70. Trapping and examination of the rodent reservoirs and sand-fly vector(s) were carried out as well, but will be published later on.

Zoonotic cutaneous leishmaniasis is endemic in Sinai Peninsula. Human cases were recorded from the northern Sinai, however little was known about the disease in southern Sinai. During entomological surveys conducted southern Sinai in summers of 1997-1999, a clinically confirmed ZCL case was encountered for the first time in Sheikh Atiya village in June 1999. The parasite was isolated and identified as L. major using cellulose acetate electrophoresis. A total of 784 phlebotomine sand flies were collected. Sand fly species composition at Sheikh Atiya village showed that P. papatasi and P. alexandri were the most abundant species in the area and each comprises about 47 % of the flies collected. P. sergenti and P. kazeruni occurred in very low numbers. All the female flies dissected (N = 304) were negative for any Leishmania-like flagellates. When the identified isolate was inoculated in the footpads of a clean laboratory colonized Acomys cahirinus dimidiatus, a lesion was developed on the site of inoculation 9 months post injection. The role of P. alexandri and A. c. dimidiatus in transmission of leishmaniasis in southern Sinai remains questionable. Environmental factors contributed to the appearance of ZCL in the area are discussed.

The restriction fragment length polymorphism (PCR-RFLP) of 18S rDNA amplified fragments, was conducted to recognize between an unidentified Leishmania isolated from Egyptian patient infected in Saudi Arabia and two L. major reference strains causing cutaneous lesions. The strains were maintained both in vivo & in vitro. Additional requirement as morphological characterization on basis of the light microscope & scanning electron microscopy and behaviour in experimental Swiss albino mice regarding development of lesions were performed. The results showed that, PCR-RFLP analysis of the 18S rDNA amplified PCR fragments was highly successful to put the unidentified Leishmania strain in the category of L. major. There was no significant differences regarding the cutaneous lesions development. In spite of the significant variations of the morphometric measurements of the three strains were observed.

A leishmanial isolate was obtained from the ear of one red fox or Nile fox (Vulpes v. aegyptiaca) out of eight from North Sinai Governorate. The isolate was typed by the enzymatic variant profiles of the four enzymes, GPI, G6PD. 6PGD and PGM against the three Old World reference strains, L. major, L. tropica and L. donovani and proved to be Leishmania major. This is the second time that L. major has been shown to occur in canine hosts. The list of the mammalian hosts of L. major was reviewed and discussed.

Rabbit monospecific antibody Leishmania major surface glycoprotein (gp63) was used in an indirect immunofluorescence assay (IFA) to identify promastigotes and amastigotes from sandflies and lesion fluid aspirates, respectively. Anti-gp63 fluoresced the entire periphery and flagella of promastigotes of different Leishmania species at dilutions to 1:50. Promastigotes were distinctively demonstrated in whole infected sandfly homogenate for 17 days post-infection. Amastigotes from lesion aspirates of infected BALB/c mice and from a human cutaneous leishmaniasis case were also fluoresced by the antibody. This technique could prove to be especially useful in arthropod vector surveillance efforts in which detection of the pathogen is as important as speciation of the sand fly vector.

Diffuse cutaneous leishmaniasis (DCL) is an unusual form of cutaneous leishmaniasis mainly caused by infection with Leishmania aethiopica in the Old World. In this paper, diffuse cutaneous leishmaniasis was reported for the first time, in an Egyptian patient from Sinai Peninsula resulting from infection with L. major zymodeme LOND-1 as proved by enzymatic characterization, using seven enzymes.

Bone-marrow aspiration and biopsy material samples obtained from two patients, one diagnosed as visceral and other as cutaneous leishmaniasis, were inoculated in Novy, McNeal, Nicolle (NNN) medium and nutrient broth (NB), containing fetal calf serum (FCS), penicillin and streptomycine. Both media were incubated at 27 degrees C for 10 days and observed daily for L. infantum and L. major promastigotes. Promastigotes were observed in nutrient broth after the first day, while in NNN media after the second or third day of incubation, indicating the effectiveness of nutrient broth in early diagnosis of both forms of leishmaniasis.

Leishmaniasis (cutaneous, CL. and visceral, VL.) is an increasing public health problem in the Mediterranean Region. From a practical point of view, ZCL is the most important and distributed form in Egypt. Consequently, it was aimed to study the status of ZCL among a group of temporary workers in North Sinai Governorate. The results showed that (i) rodent populations are more or less common in Al Arish City (Rattus rattus and R. norvegicus), Bir Lehfan (Gerbillus pyramidum) and Abo Oegela (G. pyramidum. Meriones crassus and Jaculus jaculus). (ii) Phlebotomus papatasi the main vector of ZCL is common in nearly all areas in North Sinai. (iii) ZCL. was identified (smear and/or culture as well as IHAT) among five workers out of 30 (16.7%). (iv) isolates recovered from P. papatasi trapped in Sad Al Rawafei and G. pyramidum trapped in Abo Oegela proved biochemically (isoenzyme cellulose acetate electrophoresis) to be Leishmania major indistinguish from each other. Discussion and recommendations were given.