[Epidemiology of Cutaneous Leishmaniasis in Algeria through Molecular Characterization]

Human Cutaneous Leishmaniasis in North Africa and Its Threats to Public Health: A Statistical Study Focused on Djelfa (Algeria)

Cutaneous leishmaniasis, the most common form of leishmaniasis, causes long-term skin lesions on exposed areas of the skin. It is caused by a protozoan parasite belonging to the genus Leishmania and is transmitted via infected phlebotomine sand flies. In North Africa, particularly Algeria, the disease represents a major public health problem. This retrospective study, which focuses on the agropastoral region of Djelfa (central Algeria) during a period of 16 years, from 2006 to 2021, is part of the surveillance of cutaneous leishmaniasis to identify the key factors favouring its probable spread. The analyzed data reveal that this disease is more prevalent in male patients (53.60%) and is highly widespread in this vast area of 66,415 km2 with a total of 3864 CL cases, reaching a peak of 1407 cases in 2006. Statistically, the Pearson correlation validated by the p-value shows, in an original and sometimes unexpected way, that certain factors, such as temperature linked to climate change, are playing a significant role in the probable spread of the disease in Djelfa and its surrounding regions. The concentration of the population in some specific rural areas with limited or nonexistent access to public health services is another potential factor in disease transmission. The results were highlighted by a significant correlation coefficient (r=0.66) with a p-value less than 0.01. While there is currently no vaccine or prophylactic drug available, our research represents a preliminary approach that addresses various epidemiological aspects of the disease. This paves the way for a proactive preventive strategy involving the control of vector-borne diseases.

Clinical and immunological spectra of human cutaneous leishmaniasis in North Africa and French Guiana

Cutaneous leishmaniasis (CL) caused by infection with the parasite Leishmania exhibits a large spectrum of clinical manifestations ranging from single healing to severe chronic lesions with the manifestation of resistance or not to treatment. Depending on the specie and multiple environmental parameters, the evolution of lesions is determined by a complex interaction between parasite factors and the early immune responses triggered, including innate and adaptive mechanisms. Moreover, lesion resolution requires parasite control as well as modulation of the pathologic local inflammation responses and the initiation of wound healing responses. Here, we have summarized recent advances in understanding the in situ immune response to cutaneous leishmaniasis: i) in North Africa caused by Leishmania (L.) major, L. tropica, and L. infantum, which caused in most cases localized autoresolutives forms, and ii) in French Guiana resulting from L. guyanensis and L. braziliensis, two of the most prevalent strains that may induce potentially mucosal forms of the disease. This review will allow a better understanding of local immune parameters, including cellular and cytokines release in the lesion, that controls infection and/or protect against the pathogenesis in new world compared to old world CL.

Epidemiological situation analysis of cutaneous leishmaniasis in Batna (northeast): An important focus in Algeria

Cutaneous leishmaniasis (CL) is a parasitic infection which poses a real public health problem in various countries, including Algeria. We aimed in this study to investigate the current epidemiological situation of CL in the wilaya of Batna (northeastern Algeria) during 2010-2020 and to discuss some control measures used to combat the disease in the most endemic foci. Data on CL cases and control measures were obtained from the "Direction de la Santé et de la Population (DSP) of Batna" and the "Etablissement Public de la Santé de Proximité (EPSP) of Barika". Data were analyzed and mapped using Microsoft Office Excel 2007, SPSS.21, and ArcGIS 10.3. A total of 9259 cases were notified, with a peak incidence of 1924 cases in 2010. The annual evolution of the disease showed decreasing and increasing trends during the study period. Cases were detected year-round, with a peak notification in November (1957 cases) and January (1663 cases). CL affects both genders and all age groups with predominance for males (58.6%) and infants less than 9 years old (54.4%). Most cases have occurred in western areas of the wilaya especially in the commune of Barika with 2979 cases (32.17%), followed by Abdelkader Azil (13.37%), Bitam (12.32%), Djezzar (8.67%), Ouled Ammar (7.07%), and Amdoukal (4.36%) communes. Spatiotemporal analysis showed that the highest frequencies of CL were exclusively reported in the western regions. There was no evidence of a possible relationship between Deltamethrin house spraying and leishmaniasis incidence. This study revealed that CL is highly endemic in the western areas of Batna, especially in Barika, with children less than 9 years old as the most age group at risk. The development of control measures and the selection of appropriate strategies are necessary to prevent, control, and eradicate the disease.

Updates on Geographical Dispersion of Leishmania Parasites Causing Cutaneous Affections in Algeria

Leishmaniases are neglected tropical diseases of public health concern in Algeria. To update the geographical distribution of Leishmania spp. causing cutaneous affection, we examined a set of Giemsa-stained smears prepared from skin lesions of the patients suspected to have cutaneous leishmaniasis (CL) in various geographical areas in Algeria. The identification of Leishmania parasites was performed using microscopy, conventional PCR, and PCR-RFLP (PCR-Restriction Fragment Length Polymorphism) targeting ITS1-rDNA. Among 32 smears provided from 27 suspected patients with cutaneous lesions, no trace of parasites was observed in the smear of three patients using microscopy and molecular approaches. Furthermore, four patients presented at least two lesions. PCR-RFLP confirmed the presence of Leishmania in 29 smears prepared from 24 patients. Two biopsies, negative after microscopic examination, were found positive by PCR. Of these 29 PCR positive smears (24 patients), 20 were identified using RFLP-PCR as L. major, two as L. tropica, and two as L. infantum. We found L. major infected patients from Ain skhouna, Biskra, El M'hir, Ghardaïa, M'Sila, and Saida, in agreement with previously reported cases. Furthermore, we highlighted for the first time, the identification of L. major in the patients from Bourkika, Bou Kremissa, Bou Saada Clef, Hajout, Maghnia, Médéa, Menaceur, Messad, Mostaghanem, Nador, Oran, and Sidi Okba. A phylogenetic reconstruction performed with sequences collected from the PCR products confirmed these identifications. Our data provide additional information on the geographical extension of CL caused by L. tropica and L. infantum in Algeria.