Blood meal analysis of culicoides (Diptera: ceratopogonidae) in central Tunisia.

To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females' midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia

Infection of dogs with [i]Echinococcus granulosus[/i]: causes and consequences in an hyperendemic area

Tunisia is a hyper endemic country for human echinococcosis. The infection is transmitted via the eggs of Echinococcus granulosus which are passed in the faeces of the definitive canid host.METHODS: This study evaluated the contamination rate of the dog faeces in different climatic conditions at eight different geographic regions throughout Tunisia. Dog faecal samples were collected from the soil and the Echinococcus eggs were identified using microscopic and molecular (Eg1121/1122 PCR, Egss1 PCR and Nad1 PCR-RFLP) tools.RESULTS: The contamination index of dog faeces by E. granulosus eggs ranged from 8.3% to 41.3% depending on the region. Comparisons of the dog faecal contamination rate against human incidence found them to be independent. Neither human prevalence nor dog contamination index appeared to be related to climatic conditions or geographic characteristics. The genetic variability of E. granulosus samples was different within each region but was not related to geographic distance which is indicative of local divergent evolutions rather than isolation by distance.CONCLUSIONS:A high environmental dog contamination index does not necessarily correspond to high prevalence in humans as transmission is strongly linked to human behavior and hygiene

Gastrointestinal parasites of canids, a latent risk to human health in Tunisia

Abstract Background Although data on the parasite environmental contamination are crucial to implement strategies for control and treatment, information about zoonotic helminths is very limited in Tunisia. Contamination of areas with canid faeces harboring infective parasite elements represents a relevant health-risk impact for humans. The aim of this study was to assess the environmental contamination with eggs and oocysts of gastrointestinal parasites of dogs and wild canids in Tunisia with special attention to those that can be transmitted to humans. Results One thousand two hundred and seventy faecal samples from stray dogs and 104 from wild canids (red foxes and golden jackals) were collected from different geographical regions throughout Tunisia. The helminth eggs and protozoan oocysts were concentrated by sucrose flotation and identified by microscopic examination. The most frequently observed parasites in dog samples were Toxocara spp. (27.2%), E. granulosus (25.8%), and Coccidia (13.1%). For wild canid faeces, the most commonly encountered parasites were Toxocara spp. (16.3%) followed by Capillaria spp. (9.6%). The parasite contamination of dog faeces varied significantly from one region to another in function of the climate. Conclusion To our knowledge, the study highlights for the first time in Tunisia a serious environmental contamination by numerous parasitic stages infective to humans. Efforts should be made to increase the awareness of the contamination risk of such parasites in the environment and implement a targeted educational program

Total number of biting midges captured with light traps in Central Tunisia.

<p>Total number of biting midges captured with light traps in Central Tunisia.</p

Localization of farms in Central Tunisia.

<p><u>Farm A</u> is located in Khniss and reprented by a black circle with blue border. <u>Farm B, C, D</u> are located in Bir zira and showed by a black triangle with orange border. <u>Farm E and F are</u> identified by a black triangle with orange border also. <u>Farm G i</u>s located in Jemmel and signified by a black square with a blue border. <u>Farm H</u> is showed by a lozenge with a yellow border. <u>Farm N</u> is situated in Mahdia and showed by a white circle with black border.</p

Analytical sensitivity of cyt <i>b</i> gene PCR amplification (359 bp) (A). Analytical sensitivity of <i>PNOC</i> gene PCR amplification (333 bp) (B).

<p>Lanes 1–10, 9-fold dilutions of human genomic DNA; Lane 11, negative control. MW, Molecular Weight marker (100-bp DNA ladder)</p

In vitro scolicidal activity of Thymus capitatus Hoff. et Link. essential oil on Echinococcus granulosus protoscoleces

Cystic echinococcosis remains a serious public health problem worldwide. Surgery is considered as the first option of treatment. Various investigations were carried out to find a convenient scolicidal agent for reducing the risk of post-surgical recurrence of the disease but most of them are associated with adverse side effects. The present study aimed to evaluate the in vitro scolicidal activity of Thymus capitatus Hoff. et Link. essential oil against Echinococcus granulosus protosco- leces. Three concentrations of essential oil (1, 2 and 3 mg/mL) were tested for 1 to 10 min on E. granulosus protosoleces and their viability was assessed by eosin staining test. The essential oil concentrated at 2 and 3 mg/mL killed 100% protoscoleces after 5 and 1 min, respectively. Furthermore, GC/MS and GC-FID analyzes indicated that carvacrol (82.4%) was the major compo- nent of the essential oil. The current investigation showed the potent scolicidal effect of T. capitatus essential oil in vitr

Genetic relationship between the [i]Echinococcus granulosus[/i] sensu stricto cysts located in lung and liver of hosts

G1 genotype of Echinococcus granulosus sensu stricto is the major cause of hydatidosis in Northern Africa, Tunisia included. The genetic relationship between lung and liver localization were studied in ovine, bovine and human hydatid cysts in Tunisia. Allozyme variation and single strand conformation polymorphism were used for genetic differentiation. The first cause of genetic differentiation was the host species and the second was the localization (lung or liver). The reticulated genetic relationship between the liver or the lung human isolates and isolates from bovine lung, is indicative of recombination (sexual reproduction) or lateral genetic transfer. The idea of two specialized populations (one for the lung one for the liver) that are more or less successful according to host susceptibility is thus proposed

Seroprevalence of Toxoplasma gondii among healthy blood donors in two locations in Tunisia and associated risk factors

International audienceToxoplasma gondii is a protozoan parasite that can be transmitted to humans through a variety of routes including blood transfusion. This study aimed to investigate the seroprevalence of T . gondii infection and associated risk factors in healthy blood donors in Tunisia. A total of 800 healthy blood donors from two blood centers in south and coastal Tunisia were analyzed for anti- T. gondii IgG and IgM antibodies by indirect immunofluorescence assay (IFA) and enzyme-linked immunoassays (ELISA), respectively. Structured questionnaires were used to gather information on risk factors for T . gondii infection during collection. The overall seroprevalence was 44.4% of which 352 (44%) and 3 (0.4%) were positive for IgG and both IgG and IgM anti- T. gondii antibodies, respectively. Multivariate analysis showed that T. gondii seropositivity was significantly associated with the birth place (adjusted odds ratio [OR] = 2.72; 95% confidence interval [CI]: 1.49–4.94) and the age of the donors (adjusted OR = 4.98; 95% CI: 1.50–16.58) which are independent risk factors. In addition, the variables of hand washing before eating (adjusted OR = 0.52; 95% CI: 0.37–0.74) and living in an urban environment (adjusted OR = 0.30; 95% CI: 0.13–0.71) are two protective factors. This study provided the first data on the seroprevalence and epidemiology of T. gondii infection in healthy blood donors in Tunisia.Toxoplasma gondii est un parasite protozoaire qui peut être transmis à l’homme par diverses voies, dont la transfusion sanguine. Cette étude vise à étudier la séroprévalence de l’infection à T. gondii et les facteurs de risque associés chez les donneurs de sang sains en Tunisie. Au total, huit cents donneurs de sang sains de deux centres de transfusion sanguine du sud et de la côte tunisienne ont été analysés respectivement pour la recherche des anticorps IgG et IgM anti- T. gondii par immunofluorescence indirecte (IFA) et par dosage immuno-enzymatique (ELISA). Des questionnaires structurés ont été utilisés pour recueillir des informations sur les facteurs de risque d’infection à T. gondii pendant la collecte. La séroprévalence globale était de 44,4 % dont 352 (44 %) et 3 (0,4 %) étaient respectivement positifs pour les anticorps IgG et IgG/IgM anti- T. gondii . Une analyse multivariée a montré que la séropositivité à T. gondii était significativement associée au lieu de naissance (rapport de côtes ajusté [OR] = 2,72 ; intervalle de confiance à 95 % [IC] : 1,49–4,94) et à l’âge des donneurs (OR ajusté = 4,98 ; IC 95 % : 1,50–16,58) qui sont des facteurs de risque indépendants. De plus, le lavage des mains avant de manger (OR ajusté = 0,52 ; IC 95 % : 0,37–0,74) et vivre dans un milieu urbain (OR ajusté = 0,30 ; IC 95 % : 0,13–0,71) sont deux facteurs de protection. Cette étude a fourni les premières données sur la séroprévalence et l’épidémiologie de l’infection à T. gondii chez les donneurs de sang sains en Tunisie