Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 21 2 2026 07 12 265 274 Nazim Messaoudi Department of Veterinary Sciences, Faculty of Life and Nature Sciences, Chadli Bendjedid El-Tarf University, Laboratory on Biodiversity and Ecosys-tem’s Pollution, Eltarf, Algeria Samir Djemai Institute of Veterinary Sciences-El Khroub, University of Constantine 1, Constantine, Algeria Fayçal Zeroual Department of Veterinary Sciences, Faculty of Life and Nature Sciences, Chadli Bendjedid El-Tarf University, Laboratory on Biodiversity and Ecosys-tem’s Pollution, Eltarf, Algeria Noureddine Zeghilet Institute of Veterinary Sciences-El Khroub, University of Constantine 1, Constantine, Algeria Abdelfateh Beghriche Department of Mathematics, Faculty of Exact Sciences, University the Brothers Mentouri Constantine 1, Algeria Latifa Boultif Laboratoire de Recherche de Pathologie Animale Développement Des Elevages Et Surveillance de La Chaine Alimentaire Des Denrées Animales Ou d’origine Animale (PADESCA laboratory), Institute of Veterinary Sciences, University of Constantine1, Constantine, Algeria Adam B Bessou Department of Veterinary Sciences, Faculty of Life and Nature Sciences, Chadli Bendjedid El-Tarf University, Laboratory on Biodiversity and Ecosys-tem’s Pollution, Eltarf, Algeria 2025 11 29 2026 07 12 Background: In Algeria, leishmaniasis is characterized by an endemic nature, which appears in humans in the two known forms: visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). This study aimed to determine the seroprevalence of canine leishmaniasis within a group of dogs and the incidence of human leishmaniasis. Methods: We performed a serological survey of canine leishmaniasis (CanL) in 84 asymptomatic dogs in Constantine wilaya (north-west of Algeria). The collected dog sera were tested by the indirect ELISA method. The study considered multiple risk factors, including the breed, sex, age, and location of the dogs. The dogs whose blood samples were taken during this survey came from the following municipalities in Constantine: El-Khroub, Ali Mendjeli, Zighoud Youcef, Aïn Smara, Hamma Bouziane, Didouche Mourad, and Constantine. In parallel, an epidemiological study of human leishmaniasis in the Constantine region was conducted. We collected retrospective data on the two forms of human leishmaniasis from Constantine's Department of Public Health between 2016 and 2024. Results: The incidence of CanL observed in the study was 8.33% (with 7 dogs testing positive. During the nine-year study period, 136 cases of CL and VL were recorded. The predominance of CL (with 124 cases, 91.18%) over VL (12 cases, 8.82%) was statistically significant (χ²=92.24; P<0.001) throughout the study duration. Conclusion: The high seroprevalence of leishmaniasis in asymptomatic owned dogs, along with the significant frequency of human cases of CL and VL in the Constantine region, indicated that leishmaniasis remained a major public health problem in Algeria. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/4829 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/4829/1501