Symptoms of Canine Leishmaniosis in Tunisian Dogs.

Canine leishmaniosis (CanL) is a fatal disease caused by Leishmania infantum which is a zoonotic protozoan transmitted to humans from dogs through sandflies. In Tunisia, there is a lack of knowledge on CanL risk and protective factors that limits the possibilities to design control strategies. In this study, 269 dogs suffering from CanL that were presented by their owners to the clinic of the National School of Veterinary Medicine of Sidi Thabet (Tunisia), were examined. Male dogs were more infected than female dogs (sex-ratio = 1.53). The age distribution in dogs has a normal distribution; mostly animals less than 4 years old (48.7%) gets affected by this disease. The majority of the animals were German Shepherded (14.4%) followed by Staffordshire (12.6%) and Rottweiler (9.6%). Most of the dogs live outdoor (87%), did not receive any acaricidal treatment (88.5%) and were not dewormed (70.3%). Poor body condition (73.2%), depilation (69.1%), lymph node enlargement (67.3%) and lethargy (60.2%) were the most frequent symptoms. Further studies need to be carried out to establish the presence of a relation between the zymodems and the clinical typology of CanL. It is also important to know if these disparities were due to differences in the canine population under study, to inherent differences in susceptibility to the disease or to a genetic diversity of the parasite.

La leishmaniose viscérale canine est une maladie fatale due à Leishmania infantum qui est un protozoaire zoonotique transmis aux humains par les chiens par l'intermédiaire de phlébotomes. En Tunisie, il y a un manque d'informations sur la leishmaniose viscérale canine, les facteurs de risque et de protection, limitant les possibilités de développement de stratégies de contrôle. Les auteurs ont examiné 269 chiens présentés par leurs propriétaires en consultation à la clinique de l'École nationale de médecine vétérinaire de Sidi Thabet (Tunisie), présentant une leishmaniose viscérale canine en Tunisie. Les chiens mâles étaient plus infectés que les chiens femelles (sex-ratio = 1,53). La distribution de l'âge des chiens est en cloche, la maladie a concerné principalement les animaux âgés de moins de 4 ans (48,7 %). La majorité des animaux étaient de race berger allemand (14,4 %), suivis par les Staffordshire bull-terrier (12,6 %) et les rottweilers (9,6 %). La majorité des chiens vivaient à l'extérieur (87 %), ne recevaient pas de traitements acaricides (88,5 %) et n'étaient pas vermifugés (70,3 %). Le mauvais état général (73,2 %), la dépilation (69,1 %), l'hypertrophie des nœuds lymphatiques (67,3 %) et la léthargie (60,2 %) étaient les symptômes les plus fréquents. Des études ultérieures sont nécessaires pour établir une relation entre les zymodèmes et la typologie clinique de la leishmaniose viscérale du chien. Il serait intéressant également de savoir si ces disparités étaient dues à une différence de la population canine étudiée, à une différence de la sensibilité des chiens ou à une diversité génétique du parasite.

Leishmaniosis (Leishmania infantum infection) in dogs.

The authors present an overview of canine leishmaniosis due to Leishmania infantum. This protozoan is transmitted by sandflies and the disease is frequently characterised by chronic evolution. Cutaneous and visceral clinical signs appear as the infection progresses. Lymph node enlargement, emaciation and skin lesions are the main signs observed in the classical forms of the disease. Control is difficult since infected dogs remain carriers for years and may relapse at any time. The mass screening of infected animals and their treatment or euthanasia represent the best way to reduce the prevalence of this disease in endemic regions. Further research is needed to improve the efficiency of the vaccines available to protect dogs against infection. This disease is zoonotic; in humans, clinical cases are reported mainly in elderly people, the young and those whose immune systems have been compromised.

Molecular and morphological systematics of the sandfly Sergentomyia (Sintonius) clydei Sinton, 1928 and questions about its record in the Seychelles.

In the Phlebotomine sandflies, a few molecular studies related on the genus Sergentomyia have been published. The present study explored the genetic variability within Sergentomyia (Sintonius) clydei (Diptera, Psychodidae). The sampling included 15 populations originating from 12 countries. A morphological approach was coupled to the sequencing of two molecular markers (cytochrome b mtDNA and cacophony nuclear DNA). The most variable morphological characters resided in the cibarium of the females, especially (i) the pigment patch pattern and (ii) the number of cibarial teeth and denticles in the armature. However this morphological approach was unable to individualize any population within S. clydei. The NJ trees based on both molecular markers individualized the specimens from the Aldabra group of islands in the Seychelles. Surprisingly, cyt b variability was not compatible with the known data about the complete submersion of Aldabra occurring relatively recently some 125,000 years ago. The settlement of these islands by S. clydei from continental Africa, the Middle East or Asia, and the value of mtDNA markers are discussed.

Usefulness of a PCR-based method in the detection and species identification of Leishmania from clinical samples.

The aim of this study is to assess the usefulness of a simple, low-cost method for the detection and species identification of Leishmania isolated by in vitro culture or detected directly from clinical samples. A total of 110 samples were used in this study. Among these, 21 were human and canine peripheral bloods, 63 skin lesion material samples, eight reference strains and 18 Leishmania culture. Detection of Leishmania DNA with PCR using primers designed to amplify the internal transcribed spacer 1 (ITS1) region of the rRNA gene proved sufficiently sensitive at the level of 0.1 parasites per PCR reaction. Furthermore, followed by single-strand conformational polymorphism (SSCP), the PCR-ITS1 allowed the species identification of Leishmania. The inter-specific polymorphism of Leishmania was first validated on reference strains, and then this method was applied on clinical samples and culture. Typing identified all human and canine visceral leishmaniasis samples (21 samples) as L. infantum, 95.23% of the cutaneous leishmaniasis samples as L. major and 3.17% as L. killicki and 1.58% as L. infantum. A scheme of the PCR diagnosis procedure for the detection and identification of Leishmania parasites is proposed in this study.