Seropositive dog for L. (L.) infantum overlapping spatial distribution of cutaneous disease (original) (raw)
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PLoS ONE, 2014
The techniques used for diagnosis of canine visceral leishmaniasis (CVL) in Brazil ELISA and IFAT have been extensively questioned because of the accuracy of these tests. A recent change in the diagnosis protocol excluded IFAT and included the Dual-Path Platform (DPP) . We evaluated the prevalence and incidence rates of Leishmania spp. before and after the change in the protocol. In addition, based on our results, we propose a new alternative that is less expensive for the screening and confirmation of CVL. Plasma samples were obtained from a serobank from dogs evaluated in a cross-sectional study (1,226 dogs) and in a cohort study of susceptible animals (n = 447), followed for 26 months. Serology testing was performed using ELISA, IFAT, and DPP. The incidence and prevalence of CVL were determined by using the protocol of the Visceral Leishmaniasis Control and Surveillance Program until 2012 (ELISA and IFAT using filter paper) and the protocol used after 2012 (DPP and ELISA using plasma). The prevalence was 6.2% and the incidence was 2.8 per 1,000 dog-months for the protocol used until 2012. For the new diagnosis protocol for CVL resulted in an incidence of 5.4 per 1,000 dog-months and a prevalence of 8.1%. Our results showed that the prevalence and incidence of infection were far greater than suggested by the previously used protocol and that the magnitude of infection in endemic areas has been underestimated. As tests are performed sequentially and euthanasia of dogs is carried out when the serological results are positive in both tests, the sequence does not affect the number of animals to be eliminated by the Control Program. Then we suggest to municipalities with a large demand of exams to use ELISA for screening and DPP for confirmation, since this allows easier performance and reduced cost.
We investigated the performance of the DPP®canine visceral leishmaniasis (CVL) rapidtest, a novel immunochromatographic assay launched by BioManguinhos (Brazil), whichwas recently included in the new Brazilian protocol for screening CVL in serological surveys.The present study compared the DPP®with the ELISA and IFA produced by BioManguinhos(Brazil) both with L. major-like antigens and with in-house tests using Leishmania infantumchagasi (in-house ELISA and in-house IFA). We analyzed the sera from clinically symp-tomatic (n = 47) and asymptomatic (n = 38) infected dogs from an endemic area of CVL, aswell as from healthy (n = 18) dogs, in addition to the sera of dogs (n = 81) infected withother pathogens. The DPP®and the in-house ELISA showed a sensitivity of 90.6% and 94.1%,respectively, and specificity of 95.1% and 97.5%, respectively, and both presented cross-reactivity only with the sera of dogs with babesiosis, 44% for the DPP®and 22% for thein-house ELISA. The clinical groups were detected equally by the two assays. The ELISABioManguinhos, IFA BioManguinhos, and in house-IFA showed a good sensitivity, 90.6%,96.5% and 89.4%, respectively, but very low specificity, 77.8%, 69.1% and 65.8%, respec-tively, due to the high cross-reactivity with the sera from the animals harboring otherpathogens. The in-house ELISA provided the highest accuracy (95.8%), followed by theDPP®(92.7%), ELISA BioManguinhos (84.3%), IFA BioManguinhos (83.1%), and in-house IFA(78.0%). The simultaneous use of the DPP®and ELISA BioManguinhos reached a sensitiv-ity of 99.1% and 82.1% when used sequentially. In conclusion, the DPP®performed well asserological test for CVL, and detected both asymptomatic and symptomatic dogs in equalproportions. Although its sensitivity is not ideal yet, discarding the IFA and including theDPP®improved the accuracy of the new Brazilian CVL diagnostic protocol, particularly ofdetecting truly infected dogs. Moreover, considering the higher specificity of DPP®(95.1%vs 77.8%), positive predictive value (95.1% vs 81.1%) and positive likelihood value (18.3% vs4.1%) in comparison with the ELISA BioManguinhos, the use of DPP®as a confirmatory testinstead of a screening test is suggested.
Memórias do Instituto Oswaldo Cruz, 2018
BACKGROUND Visceral leishmaniasis is a major public health challenge in South America, and dogs are its main urban reservoir. OBJECTIVE Validation of the canine Dual-path Platform immunoassay for canine visceral leishmaniasis (DPP ® CVL) for a sample set composed of 1446 dogs from different Brazilian endemic areas. METHODS A well-defined reference standard by means of parasitological culture, immunohistochemistry, and histopathology was used. Animals were classified as asymptomatic, oligosymptomatic, or symptomatic. Sensitivity and specificity were assessed as a single set and in clinical groups. A reproducibility assessment of the tests was conducted using the Kappa (κ) index at three different laboratories (A, B, and C). FINDINGS Overall, 89% sensitivity and 70% specificity were obtained for the entire sample set. Analysis of the clinical groups showed a gradual decrease in the sensitivity and an increase in the specificity with the reduction of clinical signs in the dogs that were assessed, reaching a sensitivity of 75% (42.8-94.5%) among asymptomatic dogs and lower specificity of 56% (46.2-66.3%) among symptomatic dogs. Inter-laboratory agreement was substantial (κ AB = 0.778; κ AC = 0.645; κ CB = 0.711). MAIN CONCLUSIONS The test performance is somewhat dependent on canine symptomatology, but such influence was less evident than in previous studies. Favourable results for sensitivity and specificity can be obtained even in asymptomatic animals; however, caution is needed in these evaluations, and the results suggest that the immunochromatographic test may be further improved for better investigation in asymptomatic dogs. The results obtained confirm the usefulness of DPP ® CVL for application in serological surveys.
Ciência Rural
ABSTRACT: Leishmaniosis is a great public health problem affecting both humans and animals. The disease is caused by the protozoan Leishmania spp., which has a complex cycle involving a phlebotomine vector. The ELISA test (Enzyme-Linked Immunosorbent Assay) along with a chromatographic immunoassay was defined by the Brazil Health Ministry as the confirmatory screening protocol in 2011. Uruguaiana city is 630 km away from Porto Alegre, which makes it difficult to send samples and diagnose leishmaniasis, as well as receive quick results. In view of this, the present study evaluated an in-house indirect ELISA method compared to indirect immunofluorescence assay (IFA) and dual-path platform chromatographic immunoassay (DPP-BioManguinhos®) for the detection of an immune response to Leishmania spp. in canine species. The serological evaluation included 48 canines from the western border of Brazil (Uruguaiana and Barra do Quaraí city). Among the 48 canine samples tested, 18 were positive w...
Revista Da Sociedade Brasileira De Medicina Tropical, 2014
Introduction: Dogs play a primary role in the zoonotic cycle of visceral leishmaniasis (VL). Therefore, the accurate diagnosis of infected dogs, primarily asymptomatic dogs, is crucial to the effi ciency of VL control programs. Methods: We investigated the agreement of four diagnostic tests for canine visceral leishmaniasis (CVL): parasite detection, either after myeloculture or by direct microscopic examination of tissue imprints; kinetoplast-deoxyribonucleic acid-polymerase chain reaction (kDNA-PCR); and an immunochromatographic test (ICT). An enzyme-linked immunosorbent assay (ELISA) and an indirect immunofl uorescence test (IFAT), both of which were adopted as part of the screening-culling program in Brazil, were used as reference tests. Our sample set consisted of 44 seropositive dogs, 25 of which were clinically asymptomatic and 19 were symptomatic for CVL according to ELISA-IFAT. Results: The highest and lowest test co-positivities were observed for ICT (77.3%) and myeloculture (58.1%), respectively. When analyzed together, the overall percentage of co-positive tests was signifi cantly higher for the symptomatic group compared to the asymptomatic group. However, only ICT was signifi cantly different based on the results of a separate analysis per test for each group of dogs. The majority (93.8%) of animals exhibited at least one positive test result, with an average of 2.66 positive tests per dog. Half of the symptomatic dogs tested positive for all four tests administered. Conclusions: The variability between test results reinforces the need for more effi cient and reliable methods to accurately diagnose canine VL, particularly in asymptomatic animals.
Pathogens
Canine Vector-Borne Diseases (CVBDs) are widespread in Europe and enzootic in many other countries. Though severe illnesses may occur, dogs living in enzootic areas often show vague or no clinical signs of CVBDs. Undiagnosed infections/co-infections in subclinically infected animals favor the spread of CVBDs and increase the risk of transmission to other animals and, in some cases, humans. This study has evaluated the exposure of dogs living in key enzootic countries, i.e., Italy and Greece, to major CVBDs via the use of in-clinic diagnostic kits. Overall, 300 privately owned dogs without/with single mild clinical signs living in different regions of Italy (n. 150) and Greece (n. 150) were included in the study. As part of a clinical examination, a blood sample was collected from each dog and subjected to two serological rapid tests, i.e., the SNAP® 4Dx®Plus (IDEXX Laboratories Inc.) for the detection of antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi s.l. an...
Veterinary research communications, 2015
Visceral leishmaniasis (VL) is a serious chronic disease with a lethality rate of up to 10 % in humans. In urban areas of Brazil, dogs are the main reservoirs of the etiological agent (Leishmania infantum) of VL, and the Brazilian Ministry of Health recommends the euthanasia of animals that are seropositive in both the immunochromatographic dual path platform rapid test (DPP(®); Bio-Manguinhos) and the enzyme-linked immunosorbent assay (ELISA) with an L. major-like antigen (Bio-Manguinhos). Vaccination is an additional tool in the control of canine VL, but the use of Leishmune(®) (Zoetis Indústria de Produtos Veterinários, São Paulo, SP, Brazil), which contains the fucose mannose ligand (FML) isolated from L. donovani, is not currently recommended by the Brazilian Ministry of Health because vaccinated animals may exhibit positive serology and there are reservations regarding the efficacy of the vaccine. The aims of the present study were: (i) to verify the abilities of the fast aggl...
Revista do Instituto de Medicina Tropical de Sao Paulo, 2017
Dogs are considered the main reservoir of Leishmania infantum. This protozoan causes visceral leishmaniasis (VL), an uncontrolled urban zoonosis in Brazil. Serological tests and polymerase chain reaction (PCR) on peripheral blood were performed to identify infected dogs in scenarios of higher and lower prevalence of the disease (Teresina and Vitória). One-hundred infected and 57 non-infected animals from Teresina and 100 non-infected animals from Vitória were studied. Animal selection was not dependent on previous serology. The sensitivity (Teresina) and specificity (Teresina and Vitória) were as follows: indirect antibody fluorescence (IFAT) cut-off of 1:40 (IFAT 1:40): 96%, 18%, and 76%; IFAT 1:80: 90%, 33%, and 93%; direct agglutination test (DAT): 96%, 33%, and 98%; fast agglutination screening test (FAST): 93%, 68%, and 100%; immunochromatographic assay with a recombinant rK39 antigen (rK39): 88%, 74%, and 98%; enzyme linked immunosorbent assay (ELISA): 91%, 79%, and 98%; rapid...