Canine visceral leishmaniasis (CVL) is caused by the protozoan Leishmania infantum, which infects dogs and humans in many regions of Brazil. The present study involved an indirect fluorescent antibody test (IFAT) to analyze L. infantum, Ehrlichia spp., Babesia canis, Toxoplasma gondii and Neospora caninum infection rates in serum samples from 93 dogs in a rural settlement in Ilha Solteira, SP, Brazil. The seroprevalence rates of anti-L. infantum, anti-Ehrlichia, anti-B. canis, anti-T. gondii and anti-N. caninum antibodies were 37.6%, 75.3%, 72%, 47.3% and 6.4%, respectively. In addition to IFAT, direct microscopic examination of popliteal lymph node aspirates revealed 26.9% of CVL positive dogs. Serological tests revealed that 17.2% of the dogs were seropositive for a single parasite, 29% for two parasites, 33% for three, 16.1% for four, and 1.1% for five parasites, while 3.2% were seronegative for five parasites. The presence of antibodies against these parasites in serum samples from dogs confirmed their exposure to these parasites in this rural area. Because of the potential zoonotic risk of these diseases, mainly leishmaniasis, ehrlichiosis and toxoplasmosis, special attention should focus on programs for the improvement of diagnostic assays and control measures against these parasites.
The purpose of the present work was a comparative study of diagnostic methods for Canine Visceral Leishmaniasis (CVL) using serological methods, enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFAT), histochemical (HE) and immunohistochemical (IMHC) tests using spleen, lymph node and liver canine tissues. In addition, Polymerase Chain Reaction (PCR) was done in blood and in tissues in order to compare and confirm no conclusive and negative diagnosis by the methods above. For this study, 34 dogs were divided according to clinical signs in asymptomatic, oligosymptomatic and polisymptomatic Leishmania-infected dogs euthanized by Zoonotic Disease Control Center (CCZ) from Ilha Solteira, SP, Brazil. The positivism indexes of ELISA, IMHC, IFAT and HE were 65.0, 62.0, 56.0 and 56.0%, respectively with the highest numbers of positive dogs in polisymptomatic (92.0%) followed by oligosymptomatic (57.0%) and asymptomatic dogs (12.5%). Furthermore, PCR confirmed the positive results and detected DNA in tissues from 100% of negative dogs and 89.0% suspects raising the animal positivism index up to 97.0%. In conclusion, PCR was the most sensitive and a valuable method for a definitive CVL diagnosis.
ResumoO objetivo da presente pesquisa foi avaliar comparativamente os métodos diagnósticos da Leishmaniose Visceral Canina (LVC), utilizando-se o ensaio imunoenzimático indireto (ELISA), a reação de imunofluorescência indireta (RIFI), a histoquímica (HE) e a imunoistoquímica (IMIQ) em tecidos de órgãos, como o baço, linfonodo e fígado. Além disso, a Reação em Cadeia pela Polimerase (PCR) das amostras de sangue e dos tecidos foi utilizada para comparar e confirmar os diagnósticos negativos e não conclusivos pelos métodos acima. Para esse estudo, foram utilizados 34 cães com diferentes sintomas da LVC, classificados em polissintomáticos, oligossintomáticos e assintomáticos e eutanasiados no Centro de Controle de Zoonoses (CCZ) de Ilha Solteira, SP. Os índices de positividade para os testes ELISA, IMIQ, RIFI e HE foram de 65,0, 62,0, 56,0 e 56,0%, respectivamente, sendo a maior positividade detectada nos cães polissintomáticos (92,0%), seguida pelos oligossintomáticos (57,0%) e assintomáticos (12,5%). A PCR confirmou os resultados positivos pelas outras técnicas e ainda detectou DNA do parasita nos tecidos de 100% dos cães negativos e em 89,0% dos suspeitos, elevando para 97,0% a positividade. Em conclusão, a PCR demonstrou ser o método mais sensível e preciso para o diagnóstico definitivo da LVC.Palavras-chave: Leishmania (L.) chagasi, imunoistoquímica, ELISA, RIFI, PCR. AbstractThe purpose of the present work was a comparative study of diagnostic methods for Canine Visceral Leishmaniasis (CVL) using serological methods, enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFAT), histochemical (HE) and immunohistochemical (IMHC) tests using spleen, lymph node and liver canine tissues. In addition, Polymerase Chain Reaction (PCR) was done in blood and in tissues in order to compare and confirm no conclusive and negative diagnosis by the methods above. For this study, 34 dogs were divided according to clinical signs in asymptomatic, oligosymptomatic and polisymptomatic Leishmania-infected dogs euthanized by Zoonotic Disease Control Center (CCZ) from Ilha Solteira, SP, Brazil. The positivism indexes of ELISA, IMHC, IFAT and HE were 65.0, 62.0, 56.0 and 56.0%, respectively with the highest numbers of positive dogs in polisymptomatic (92.0%) followed by oligosymptomatic (57.0%) and asymptomatic dogs (12.5%). Furthermore, PCR confirmed the positive results and detected DNA in tissues from 100% of negative dogs and 89.0% suspects raising the animal positivism index up to 97.0%. In conclusion, PCR was the most sensitive and a valuable method for a definitive CVL diagnosis.
ResumoO propósito do presente trabalho foi o estudo da Leishmaniose Visceral Canina -LVC por meio de métodos parasitológicos e imunoistoquímicos para a detecção de formas amastigotas de Leishmania (L.) chagasi em baço, além de descrever a histopatologia das lesões esplênicas em 34 cães, com diferentes manifestações clínicas da LVC, eutanasiados pelo Centro de Controle de Zoonoses de Ilha Solteira, SP. Esses animais foram examinados clinicamente antes da eutánásia e de acordo com os sinais clínicos da LVC, foram classificados em três grupos: assintomáticos (8 cães), oligossintomáticos (17 cães) e sintomáticos (9 cães). Após a realização desses exames, dos 34 cães, 22 (64,7%) estavam positivos e 12 (35,3%) negativos. Desses cães positivos, 1/22 (4,5%) era assintomático, 12/22 (54,5%) eram oligossintomáticos e 9/22 (40,1%) sintomáticos. Pela histopatologia, os cães, especialmente os sintomáticos apresentavam o baço com inflamação crônica e espessamento na região capsular e trabecular, além de extensa alteração morfológica na polpa vermelha e branca pela presença de grande quantidade de macrófagos repletos de amastigotas, pela reação granulomatosa inflamatória e pelas áreas hemorrágicas. Os exames histopatológicos e a detecção microscópica direta da L. (L.) chagasi revelaram que o baço é um órgão útil para auxiliar no diagnóstico da LVC. A coloração imunoistoquímica foi a que detectou o maior número de tecidos esplênicos positivos com amastigotas, além de elucidar os casos suspeitos pelos exames parasitológicos, principalmente, nos animais assintomáticos ou oligossintomáticos.Palavras-chave: Leishmania (L.) chagasi, Leishmaniose Visceral, cães, baço, imunoistoquímica. AbstractThe purpose of this work was a Canine Visceral Leishmaniasis -CVL study by parasitological direct examination of Leishmania (L.) chagasi (imprinting and histological), immunohistochemical test and histopathological analysis using spleen tissues from 34 dogs euthanized by the Zoonotic Disease Control Centre from Ilha Solteira, SP, Brazil. According to the clinical signs, the dogs were divided in three groups: asymptomatics (8 dogs), oligosymptomatics (17 dogs) and symptomatics (9 dogs). After the accomplishment of all diagnostic tests, 22 dogs were considered positives (64.7%) and 12 (35.3%) were negatives to CVL. From these positive dogs, 1/22 (4.5%) was asymptomatic, 12/22 (54.5%) were oligosymptomatics and 8/22 (40.1%) were symptomatics. The histopathological study in spleen tissues from positive, especially symptomatic dogs, showed a diffuse chronic inflammation with thickness of capsular and trabecular regions and there was extense morphologic alteration of the red and white pulp by the presence of abundant macrophages full with amastigotes, the granulomatous inflammatory reaction and haemorragic areas. The data of this work from histopathologic examination and direct microcopic visualization of L. (L.) chagasi showed that the spleen was an useful organ to collect sample tissues for CVL diagnosis. The immunostaining detected the highest num...
Mosquitoes can act as vectors of important diseases such as malaria, dengue, Zika virus, yellow fever, Chikungunya and Mayaro fever, in addition to filariasis. The use of insecticides, larvicides, bed nets and repellents, besides the use of drugs as chemoprevention and the treatment of the sick are currently the pillars of the control of these vectors. We studied the biological control against of Anopheles darlingi, Aedes aegypti and Culex quinquefasciatus larvae using shrimps of the species M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii. Larvae of mosquitoes were collected from the breeding environment and placed in a 500 and 1000 l tank containing 60 shrimps/m2. The predatory activity was evaluated for 30 days and, in all groups it was observed that 100% of the larvae were consumed in few minutes. In the environment, these same species of crustaceans were released in water bodies with the presence of larvae of these insects. In just 72 h there was a marked reduction of the larvae in the release sites of shrimps. Similarly, there was a reduction in the number of adult mosquitoes caught near the breeding sites, allowing to infer that, in places where the crustaceans were released, the predatory activity on the larvae of mosquitoes was sufficient to reduce the number of adult mosquitoes p ≤ 0,05. This is the first description of the predatory activity of M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii on An. darlingi, A. aegypti and C. quinquefasciatus larvae, constituting an important tool of biological control of these parasites-vectors.
Introduction: We sought to determine risk factors (RFs) associated with the presence of antibodies against Leishmania in dogs from a rural area of Ilha Solteira, SP, Brazil. Methods: Serum samples were collected from 250 dogs and tested using indirect enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence antibody tests (IFATs). Data concerning dogs, their environment, and their owners' knowledge of leishmaniasis were collected using a questionnaire. To determine RFs for contact with the parasite, univariate statistical analysis based on chi-squared and Fisher's exact tests, followed by logistic regression, was used. Results: It was found that 79/250 (31.6%) of the dogs were positive by IFAT, and 72/250 (28.8%) by ELISA. A total of 82/250 dogs (32.8%) were positive in at least one test. The RFs associated with occurrences of Leishmania exposure were large body size (OR = 2.25; 95% CI = 1.26-4.04; p = 0.003), presence of chickens (OR = 1.94; 95% CI = 1.05-3.65; p = 0.023), and lack of knowledge about Leishmania among dog owners (OR = 1.74; 95% CI = 0.96-3.21; p = 0.049). After multivariate analysis, the RFs for occurrence of Leishmania exposure in dogs that remained significantly associated were the dog's size (large dogs) (OR = 1.2; 95% CI = 1.06-1.35; p = 0.003) and presence of chickens on the properties (small farms) (OR = 1.15; 95% CI = 1.02-1.30; p = 0.023). Conclusions: These results may be useful for improving preventive practices to reduce the incidence of Leishmania exposure among dogs in rural areas.
The prevalence study of Leishmania spp. in hematophagous insects captured from the environment in bat roosts and pigeon nests, or feeding their hosts (cattle, pigs, horses, dogs and humans) in urban, peri-urban and rural areas, between 2012 and 2014. For this study, the amastigotes present in these insects were detected by histochemical and PCR techniques. Positive gene amplification for Leishmania was found in two horseflies of the species Tabanus importunus collected in the environment, and amastigote forms of Leishmania spp., as well as erythrocytes and leukocytes, were histochemically detected in one of that insect. The other analyzed insects were not positive by PCR our by direct parasitological examination. Only horseflies captured in urban and peri-urban areas were positive. During the collection, no phlebotomine sand flies were captured in rural areas far from the city limits. It can be concluded that the discovery of horseflies positive for Leishmania spp. in urban and peri-urban areas indicates the likelihood that urban areas and their surroundings provide vector parasites with an environment suitable for the spread and consequent perpetuation of the biological cycle of this protozoan.
RESUMO Diversos trabalhos foram realizados ao longo da história do Brasil com o intuito de se controlar e erradicar os bichos barbeiros do ambiente habitado por seres humanos, incluindo a realização de controle químico com hexaclorociclohexanos. O objetivo desta pesquisa foi avaliar a eficácia da acaricidas e inseticidas no controle de triatomíneos em municípios da região noroeste do Estado de São Paulo, Brasil. Foram capturados 94 triatomíneos com 81,91% (77/94) da espécie T. sordida e 18,08% (17/94) P. megistus. Os produtos a base de piretróides e imiprotrina associada a permetrina promoveram a morte 100% dos insetos em até 60 segundos. Observou-se que os produtos com maior taxa de letalidade também foram os que tiveram maior ação repelente. Os produtos a base de piretróide e citronela, imiprotrina associada a permetrina e a cipermetrina associada ao clorpirifós e citronelal repeliram os insetos por até 16 dias nos locais de aplicação. O amitraz demonstrou eficácia reduzida no controle destas duas espécies de parasitos. Pode-se concluir com estes resultados que diferentes produtos químicos foram eficazes no controle de triatomíneos em áreas rurais da região noroeste do estado de São Paulo, sendo estes produtos, em sua maioria, apresentados comercialmente como carrapaticidas e inseticidas.
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