Sero-epidemological survey on canine visceral leishmaniasis and the distribution of sandfly vectors in northwestern Turkey: prevention strategies for childhood visceral leishmaniasis.
ABSTRACT Visceral leishmaniasis (VL) caused by Leishmania infantum, is an endemic disease in Aegean and Mediterranean Regions among humans and dogs. In this study, a sero-epidemiological survey for VL and cutaneous leishmaniasis (CL), which both are sporadically reported in the region, were carried out in the villages of Eskisehir, Afyon, and Bilecik cities. The study was designed according to the location of the sporadic cases of VL and CL, and blood samples of 111 dogs were randomly collected. Lymph node aspiration samples were taken from dogs that have popliteal lymphadenopathy. Sand flies were also collected using CDC light traps in the several localities. The sera samples were screened using IFAT, ELISA, rk39 ELISA and dip-stick tests for anti-Leishmania antibodies. A total of 15 (13.51 per cent) dogs out of 111 were found to be seropositive by at least one of the tests. The seropositivity ratios among dogs were found to be 27.5 per cent (8/29), 9.09 per cent (4/44) and 7.8 per cent (3/38) in Afyon, Bilecik and Eskisehir cities respectively. Leishmania amastigotes were detected in 4 of the 14 lymph node aspiration samples (eight seronegative, six seropositive), and all of them were seropositive dogs. One year later, two of the dogs were found to be dead and the other two were severely ill. Among the 179 collected Phlebotomus specimens from, Phlebotomus major was found to be abundant (35.7 per cent) and the other species were P. simici (28.5 per cent), P. similis (34.7 per cent) and P. alexandri (1.1 per cent). In the study area, canine VL is more spread than human VL. Because dogs are playing an important role for VL in Mediterranean Basin, and development of appropriate control measures will be necessary for childhood VL.
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ABSTRACT: BACKGROUND: Dogs are the main reservoir hosts of , the agent of human zoonotic visceral leishmaniosis. This study investigated the efficacy of a polymer matrix collar containing a combination of 10% imidacloprid and 4.5% flumethrin as a novel prophylactic measure to prevent infections in young dogs from a hyper-endemic area of southern Italy, with a view towards enhancing current control strategies against both human and canine leishmaniosis. METHODOLOGYPRINCIPAL FINDINGS: The study was carried out on 124 young dogs, of which 63 were collared (Group A) while 61 were left untreated (Group B), from March-April 2011 until March 2012. Blood and skin samples were collected at baseline (April 2011) and at the first, second, third and fourth follow-up time points (July, September 2011 and November 2011, and March 2012, respectively). Bone marrow and conjunctiva were sampled at baseline and at the fourth follow-up. Serological, cytological and molecular tests were performed to detect the presence of in the different tissues collected. At the end of the trial, no dog from Group A proved positive for at any follow-up, whereas 22 dogs from Group B were infected (incidence density rate = 45.1%); therefore, the combination of 10% imidacloprid and 4.5% flumethrin was 100% efficacious for the prevention of infection in young dogs prior to their first exposure to the parasite in a hyper-endemic area for CanL. CONCLUSIONS: The use of collars containing 10% imidacloprid and 4.5% flumethrin conferred long-term protection against infection by to dogs located in a hyper-endemic area, thus representing a reliable and sustainable strategy to decrease the frequency and spread of this disease among the canine population which will ultimately result in the reduction of associated risks to human health.PLoS ONE 01/2013; 8(2):e56374. · 3.73 Impact Factor
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ABSTRACT: There is a need for sensitive and specific rapid diagnostic tests (RDT) for canine visceral leishmaniasis. The aims of this study were to evaluate the diagnostic performance of immunochromatographic dipstick RDTs using rK39 antigen for canine visceral leishmaniasis by (i) investigating the sensitivity of RDTs to detect infection, disease and infectiousness in a longitudinal cohort study of natural infection in Brazil, and (ii) using meta-analysis to estimate the sensitivity and specificity of RDTs from published studies. We used a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios) to test sera collected from 54 sentinel dogs exposed to natural infection in an endemic area of Brazil. Dogs were sampled bimonthly for up to 27 months, and rK39 results compared to those of crude antigen ELISA, PCR, clinical status and infectiousness to sandflies. We then searched MEDLINE and Web of Knowledge (1993-2011) for original studies evaluating the performance of rK39 RDTs in dogs. Meta-analysis of sensitivity and specificity was performed using bivariate mixed effects models. The sensitivity of the rK39 RDT in Brazil to detect infection, disease and infectiousness was 46%, 77% and 78% respectively. Sensitivity increased with time since infection, antibody titre, parasite load, clinical score and infectiousness. Sixteen studies met the inclusion criteria for meta-analysis. The combined sensitivity of rK39 RDTs was 86.7% (95% CI: 76.9-92.8%) to detect clinical disease and 59.3% (37.9-77.6%) to detect infection. Combined specificity was 98.7% (89.5-99.9%). Both sensitivity and specificity varied considerably between studies. The diagnostic performance of rK39 RDTs is reasonable for confirmation of infection in suspected clinical cases, but the sensitivity to detect infected dogs is too low for large-scale epidemiological studies and operational control programmes.PLoS Neglected Tropical Diseases 01/2013; 7(1):e1992. · 4.57 Impact Factor
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ABSTRACT: Our aim was to establish the influence on the prevalence of canine leishmaniasis (CanL) of the following: (1) the use of different diagnostic techniques; (2) different positivity thresholds; (3) selection of animals either at random from a population or focused on symptomatic individuals, (4) the function which the dog performs; and (5) scenarios with differing epidemiological characteristic. Three groups of dogs were analysed (416 sampled at random from an endemic area, 71 with symptomatology compatible with CanL and 15 from a non-endemic area) using three serological techniques (indirect fluorescence antibody test (IFAT), Kalazar Detect(TM) and Q Letitest ELISA) and a PCR-ELISA. The diagnostic technique had a considerable influence on the CanL prevalence value obtained. Uncertain antibody titres were more representative in dogs sampled at random and with the IFAT technique. Although employing different capture antigens, correlation of results was higher between the two commercial techniques in the group of dogs with symptomatology compatible with CanL. The sensitivity and specificity values of the different diagnostic techniques were affected by the epidemiological characteristic of the area under study, the presence of clinical signs and the function which the dog performs. This must be taken into account when comparing endemicity in different geographical areas, such as in studies carried out for the construction of risk maps. Using more than one technique, and adopting the criterion of considering an animal to be positive only when it has been diagnosed as such by more than one technique, considerably raises the prevalence values but maintains the differences between areas with different characteristics.Parasitology Research 01/2012; 111(1):155-64. · 2.85 Impact Factor