Epidemiology of canine visceral leishmaniasis in a vulnerable region in Brazil.

Visceral leishmaniasis (VL) is a neglected and endemic zoonosis that occurs throughout Brazil; nevertheless, few studies have focused on the early detection of the disease. The municipality of Ourinhos is a non-receptive, silent and vulnerable area for VL, where the seroprevalence of this disease has so far not been investigated. The present study aimed to determine the seroprevalence of canine VL in Ourinhos-SP, and to identify the presence of risk factors. Blood samples were obtained from 604 dogs during a rabies vaccination campaign together with application of a socioeconomic questionnaire, environmental and animal characteristics and tutor's knowledge about the disease. The samples were subjected to indirect ELISA and new samples were collected from reactive and suspect animals, including whole blood and lymph node aspiration evaluated by parasitological method, complete blood count and PCR. No animal was diagnosed as positive based on the combination of direct and indirect tests and the tutors' answers indicated little knowledge about leishmaniasis, being often confused with other diseases transmitted by arthropods; hence, according to the proposed methods, the presence of canine leishmaniasis in the city of Ourinhos was not confirmed and health education campaigns about the disease should be carried out.

Effect of uterine ozone therapy and anticoagulant sampling on oxidative stress parameters in mares.

With the purpose of assessing the effects of uterine ozone therapy and anticoagulant sampling on oxidative stress (OS) parameters in mares, ten mares underwent three consecutive days of uterine ozone therapy by flushing the uterus with ozonated lactated Ringer's solution followed by insufflation with ozone­oxygen gas. Serum samples were obtained at baseline and days 3, 6, 10 and 17 to determine the effect of ozone therapy on OS markers. Plasma obtained with anticoagulants citrate, ethylenediaminetetraacetic acid (EDTA) and heparin were at baseline and 6 days following therapy to determine the effect of anticoagulant on OS parameters. Antioxidants albumin and uric acid, total antioxidant capacity (TAC) using four different methods, total oxidant capacity (TOC) and lipid peroxidation were determined through photocolorimetry. Statistical analyses comprised repeated measures ANOVA followed by Dunnett's test or Friedman followed by Dunn's post-hoc test. Differences were considered significant when p < 0.05. Uterine ozone therapy significantly decreased uric acid, TAC in all four different methods, concomitantly with an increase on TOC at days 3 and 6 following therapy. No changes were observed on albumin and lipid peroxidation levels. Anticoagulants prevented the detection of oxidative stress induced by uterine ozone therapy depending on the method of analysis. In conclusion, uterine ozone therapy causes systemic oxidative stress in mares and the choice of anticoagulant sampling interferes with laboratory tests.

Postprandial lipemia causes oxidative stress in dogs.

Oxidative stress (OS) has been strongly associated with postprandial lipemia (PPL) in humans, and still requires further investigation in dogs. However, since lipemia interferes with spectrophotometric determinations such as those used to assess OS, the present study investigated the effect of PPL on OS parameters of healthy dogs. Twenty dogs had lipemic postprandial samples compared to the average of two non-lipemic moments. Subsequently, PPL was simulated in vitro using a commercial lipid emulsion and twelve pools of non-lipemic serum of these dogs were used to simulate the minimum, median and maximum concentrations of triglycerides obtained during the lipemic state. Serum OS parameters were assessed using the antioxidants uric acid, albumin and total bilirubin; total antioxidant capacity (TAC); total oxidant capacity (TOC); and lipid peroxidation. In vivo PPL caused an increase in albumin, TAC-CUPRAC, TAC-FRAP, uric acid (p < 0.0001), TOC (p = 0.0012) and total bilirubin (p = 0.0245); reduction of TAC-ABTS (p = 0.0008); and did not alter the lipid peroxidation (p = 0.8983). In vitro, levels of albumin increased at the three lipemic concentrations (p < 0.0001), uric acid increased in the median and maximum levels (p < 0.0001), and total bilirubin concentration increased only at the maximum lipemic level (p = 0.0012). All lipemic levels tested increased TAC-ABTS (p = 0.0011) and TAC-FRAP (p < 0.0001). TAC-CUPRAC (p = 0.5002), TOC (p = 0.5938) and lipid peroxidation (p = 0.4235) were not affected by in vitro lipemia. In conclusion, both the in vivo postprandial state and in vitro simulated lipemia affect oxidative stress markers in dogs depending on the oxidative stress marker, and thus the postprandial state and/or lipemic samples should be avoided.

Epidemiology of canine visceral leishmaniasis in a vulnerable region in Brazil / Soroepidemiologia da leishmaniose visceral canina em uma região vulnerável do Brasil

Abstract Visceral leishmaniasis (VL) is a neglected and endemic zoonosis that occurs throughout Brazil; nevertheless, few studies have focused on the early detection of the disease. The municipality of Ourinhos is a non-receptive, silent and vulnerable area for VL, where the seroprevalence of this disease has so far not been investigated. The present study aimed to determine the seroprevalence of canine VL in Ourinhos-SP, and to identify the presence of risk factors. Blood samples were obtained from 604 dogs during a rabies vaccination campaign together with application of a socioeconomic questionnaire, environmental and animal characteristics and tutor's knowledge about the disease. The samples were subjected to indirect ELISA and new samples were collected from reactive and suspect animals, including whole blood and lymph node aspiration evaluated by parasitological method, complete blood count and PCR. No animal was diagnosed as positive based on the combination of direct and indirect tests and the tutors' answers indicated little knowledge about leishmaniasis, being often confused with other diseases transmitted by arthropods; hence, according to the proposed methods, the presence of canine leishmaniasis in the city of Ourinhos was not confirmed and health education campaigns about the disease should be carried out.

Resumo A leishmaniose visceral (LV) é uma zoonose negligenciada e endêmica presente em todas as regiões do Brasil, mas mesmo assim poucos estudos têm objetivado a detecção inicial da doença. O município de Ourinhos - SP é uma área não receptiva, silenciosa e vulnerável à LV, não havendo até o momento estudos que tenham investigado a soroprevalência no município. Nesse sentido, o presente estudo objetivou determinar a soroprevalência da LV canina em Ourinhos-SP, bem como associar a presença de fatores de risco. Amostras sanguíneas de 604 cães foram obtidas juntamente com a aplicação de questionário socioeconômico, características ambientais e dos animais e conhecimento sobre a doença. As amostras foram submetidas à sorologia por ELISA e novas amostras coletadas de cães reagentes ou suspeitos foram analisadas por método parasitológico direto, hemograma e PCR. Nenhum animal foi considerado positivo na combinação de testes direto e indireto, e as respostas dos tutores indicaram pouco conhecimento sobre a leishmaniose, sendo muitas vezes confundida com outras doenças transmitidas por artrópodes. Dessa forma, de acordo com os métodos propostos, a presença de leishmaniose canina, na cidade de Ourinhos, não foi confirmada. Por isso campanhas de educação em saúde sobre a doença deveriam ser realizadas.

Systemic oxidative stress in Suffolk and Santa Ines sheep experimentally infected with Haemonchus contortus.

The mechanisms responsible for the imbalance between oxidants and antioxidants in sheep infected with Haemonchus contortus are not well established. This study aimed to prove the hypothesis that oxidative stress occurring during infection by H. contortus varies according to breed, and that the parasite burden correlates with hypoalbuminaemia and anaemia. Thus, after deworming and confirming the absence of infection, two different sheep breeds, Suffolk (n = 15) and Santa Ines (n = 22), were orally inoculated with a single dose of 5,000 L3 of H. contortus. The egg counts per gram of faeces (EPG), packed cell volume (PCV) and concentrations of several plasma markers of oxidative stress (lipid peroxidation, albumin, uric acid, total bilirubin, total antioxidant capacity [TAC], total oxidant concentration [TOC] and the oxidative stress index [OSI]) were quantified before (control group) and during the experimental infection (28, 34 and 42 days post-inoculation). In both breeds, TOC increased at 28 days and TAC increased at 42 days. In Suffolk sheep, there was a positive correlation of EPG with oxidant components (28 days) and a negative correlation of EPG with PCV (42 days). In Santa Ines sheep, there was a positive correlation of EPG with bilirubin (r = 0.492; p = 0.020). H. contortus infection caused oxidative stress, which varied according to the breed. Parasite burden was not associated with hypoalbuminaemia, whereas there was a negative correlation with PCV. This research provides the first evidence that the antioxidant status contributes more to the resilience to H. contortus in Santa Ines sheep compared to Suffolk sheep.

The effects of increased heme oxygenase-1 on the lymphoproliferative response in dogs with visceral leishmaniasis.

Canine visceral leishmaniasis (CVL) is known to affect the cellular immunity of infected dogs, through impairing lymphoproliferation and microbicidal mechanisms. This study examined heme oxygenase-1 (HO-1) and its metabolites, oxidative stress and IL-10 levels in CVL and investigated correlations between these parameters. Additionally, the effects of HO-1 inhibition on the lymphoproliferative response and cytokine production in lymph node cells (LNCs) from infected dogs were evaluated. Forty-four dogs, 24 controls and 20 dogs with CVL were selected. Plasma and splenic levels of HO-1, haptoglobin, soluble CD163 receptor, ferritin and IL-10 were determined using capture ELISA. The HO-1 levels and relative gene expression in peripheral blood and bone marrow mononuclear cells were also determined. LNCs proliferation was evaluated with an HO-1 activator and with an HO-1 inhibitor, in the presence of the Leishmania infantum soluble antigen (SAgL), using flow cytometry. HO-1, IL-2, IFN-gamma and IL-10 were also determined in these cultures using capture ELISA. Infected dogs presented oxidative stress and increased HO-1 levels and relative gene expression, with correlation between oxidative stress and HO-1. The substances from heme metabolism and IL-10 were also elevated in the plasma and spleens of infected dogs. IL-10 and HO-1 levels were positively correlated with one another. Inhibition of HO-1 increased LNCs proliferation and decreased IL-10 and IL-2 production in the presence of SAgL. The increased HO-1 metabolism observed in CVL is probably associated with oxidative stress and increased IL-10, which could be one of the mechanisms responsible for inhibition of the lymphoproliferative response in sick dogs.

Hypertension and its correlation with renal lesions in dogs with leishmaniosis / Hipertensão e sua correlação com lesões renais em cães com leishmaniose

To evaluate the prevalence of hypertension and its correlation with the severity of renal injury and proteinuria in dogs with leishmaniosis, sixty-six dogs were divided into two groups. Group 1 (G1) was composed of 54 dogs included in stage 1 of chronic kidney disease (CKD), and group 2 (G2) of twelve dogs in stages 2 and 3 of CKD. Prevalence of hypertension was 28.8%, comprising 22.2% of the dogs from G1 and 58.3% from G2 (P=0.011). The mean arterial blood pressure (BP) of dogs from G1 (135.7 ± 20.5) was lower than from G2 (170.0 ± 26.3) (P <0.001). Urine protein-creatinine ratio (UP/C) revealed values above 0.5 in 75.7% of the dogs, with 34% presenting hypertension. All dogs with hypertension had histopathological and laboratory evidence of glomerular disease. Although there was no statistically significant correlation between elevated BP and the severity of glomerular lesions (P=0.408), there was a statistically significant correlation between elevated BP and increased UP/C in the studied population (P=0.002). Thus, dogs with leishmaniosis and renal disease must be screened for the presence of hypertension so that treatment may be instituted as early as possible, in countries where treatment is allowed, to prevent the progression of renal damage.

Para avaliar a prevalência de hipertensão arterial e sua correlação com a severidade da lesão renal e proteinúria em cães com leishmaniose, 66 cães foram divididos em dois grupos. O grupo 1 (G1), composto por 54 cães em estágio 1 de doença renal crônica (DRC), e o grupo 2 (G2) por 12 cães em estágios 2 e 3 de DRC. A prevalência de hipertensão foi de 28,8%, compreendendo 22,2% dos cães de G1 e 58,3% dos cães de G2 (p = 0,011). A pressão arterial média (PA) de G1 (135,7 ± 20,5) foi inferior a de G2 (170,0 ± 26,3) (P <0,001). A relação proteína creatinina urinária (P/C U) foi maior que 0,5 em 75,7% dos cães, dos quais 34% possuíam hipertensão. Todos os cães com hipertensão apresentavam doença glomerular. Embora não tenha sido observada correlação estatisticamente significativa entre elevação da PA e severidade das lesões glomerulares (P =0,408), houve uma correlação significativa entre PA elevada e aumento da UP/C (P = 0,002). Portanto, cães com leishmaniose e doença renal devem ser pesquisados ​​quanto à presença de hipertensão, para que o tratamento possa ser instituído o mais precocemente possível em países onde ele é permitido, para evitar a progressão da lesão renal.