Abstract INTRODUCTION: Visceral leishmaniasis is a disease that affects humans, wildlife, and domestic species. Since dogs play a key role in urban Leishmania spp. transmission, the Brazilian government maintains the Monitoring and Control Program of Visceral Leishmaniasis (VLMCP) in endemic regions, which promotes awareness campaigns aiming to enhance the control of the infection. The VLMCP recommends the Dual Path Platform (DPP®) canine visceral leishmaniasis test (Bio-Manguinhos, Brazil) for screening and enzyme-linked immunosorbent assay to confirm the infection. The DPP® test is produced and distributed by the Health Ministry to the Municipal Health Centers responsible for the local VLMCP. The test is not available to all the clinics, forcing some veterinarians to use other rapid tests for screening and diagnosis of this disease in their daily routine. METHODS: The present study was conducted to compare the performance of the DPP® and SNAP® tests using sera from the dogs with confirmed infections of L. infantum and from the dogs with no previous testing, residing in areas with a low Leishmania infection. RESULTS: There was 97.0% agreement between the two tests. Sensitivity and specificity of the SNAP® test were 96.3% and 100%, respectively. Agreement between both the antibody tests and the parasitological detection methods was 96.8%. The DPP® test had 95.8% sensitivity and 100% specificity. CONCLUSIONS: The SNAP® and the DPP® tests were virtually equivalent in terms of detection of canine antibodies against L. infantum, and both the tests demonstrated high and similar levels of sensitivity and specificity.

Abstract INTRODUCTION: Chagas disease is caused by the protozoa Trypanosoma cruzi. Its main reservoir is the domestic dog, especially in rural areas with favorable characteristics for vector establishment and proliferation. The aims of this study were to collect data, survey and map the fauna, and identify T. cruzi infection in triatomines, as well as to assess the presence of anti-T. cruzi antibodies in dogs in rural areas of the municipality of Mossoró, Brazil. METHODS: An active entomologic research was conducted to identify adult specimens through an external morphology dichotomous key. The analysis of natural infection by T. cruzi in the insects was performed by isolation in culture and polymerase chain reaction. The antibody testing for T. cruzi in dogs was performed by enzyme-linked immunosorbent assay and indirect immunofluorescence assay. RESULTS: A total of 68 triatomines were captured, predominantly the Triatoma brasiliensis brasiliensis (Neiva 1911) species. The vector mapping displayed areas with greater risk for parasite transmission. Of the examined triatomines (51 specimens), 41.2% (21/51) were positive on polymerase chain reaction, and all were negative on culture. In the serum testing, 11% (25/218) of dogs were seropositive, but no association was found between the serologic results and the presence and infection by T. cruzi in triatomines. CONCLUSIONS: This study demonstrated the movement of T. cruzi in the studied area, by the presence of vectors and naturally infected domestic reservoirs. The mapping of the studied rural area demonstrates the risk of disease transmission.

RESUMO: O estudo teve como objetivo verificar a infecção por Leishmania em uma população de cães (n=92 animais) de uma área de turismo de pesca no município de Bonito e avaliar comparativamente os métodos sorológicos utilizados, ensaio imunoenzimático (ELISA), reação de imunofluorescência indireta (RIFI) e teste rápido de plataforma dupla (DPP®). Testes parasitológicos também foram realizados, como o isolamento do parasita em meio de cultura Neal, Novy, Nicolle, técnica de Woo, esfregaços em lâminas coradas com Giemsa e identificação específica pela reação em cadeia da polimerase (PCR). A RIFI revelou sorologia positiva de 56/92, ELISA 8/92 e DPP®41/92. Quanto à concordância entre os testes sorológicos pelo índice Kappa, houve um ligeiro acordo entre ELISA/RIFI e ELISA/DPP®, e uma concordância razoável entre RIFI/DPP®. A cultura NNN foi positiva em três cães, e identificada por PCR como Leishmania infantum chagasi. Nenhuma amostra foi positiva pela técnica de Woo. Nossos resultados mostraram baixas concordâncias entre os testes sorológicos recomendados pelo Ministério da Saúde, sendo necessário associar a outras técnicas de diagnóstico, como testes parasitológicos e PCR, para aumentar a sensibilidade ao diagnóstico de leishmaniose visceral canina, principalmente, com relação aos cães assintomáticos em áreas endêmicas.

ABSTRACT: The study aimed to investigate Leishmania infection in a population of dogs (92 animals) in a fishing area of Bonito Municipality, and evaluate comparatively the serological methods used, immunoenzymatic assay (ELISA), indirect immunofluorescence antibody test (IFAT), and rapid Dual Path-Platform test (DPP®). Blood and aspirate of bone marrow samples were used and parasitological investigation was also performed, such as parasite isolation in Neal, Novy, Nicolle (NNN) medium culture, Woo technique, Giemsa stained smears and specific identification by polymerase chain reaction (PCR). IFAT revealed 56/92 seropositive, the ELISA 8/92 and the DPP®41/92. Regarding the agreement between the serological tests by the Kappa index, there was a slight agreement between ELISA/IFAT and ELISA/DPP®, and fair agreement in IFAT/DPP®. The NNN culture was positive in three out of 21 dogs, and identified by PCR as Leishmania infantum chagasi. No samples were positive by the Woo technique. Our results showed low agreements between the serological tests recommended by the Brazilian Ministry of Heath, and it is necessary to associate other diagnostic techniques, such as parasitological tests and PCR, to increase the sensitivity for canine visceral leishmaniosis diagnosis, mainly regarding asymptomatic dogs in endemic areas.

BACKGROUND Leishmaniasis is a parasitosis caused by several species of the genus Leishmania. These parasites present high resistance against oxidative stress generated by inflammatory cells. OBJECTIVES To investigate oxidative stress and molecular inflammatory markers in BALB/c mice infected with L. amazonensis and the effect of antioxidant treatment on these parameters. METHODS Four months after infection, oxidative and inflammatory parameters of liver, kidneys, spleen, heart and lungs from BALB/c mice were assessed. FINDINGS In liver, L. amazonensis caused thiol oxidation and nitrotyrosine formation; SOD activity and SOD2 protein content were increased while SOD1 protein content decreased. The content of the cytokines IL-1β, IL-6, TNF-α, and the receptor of advanced glycation endproducts (RAGE) increased in liver. Treatment with the antioxidant N-acetyl-cysteine (20 mg/kg b.w) for five days inhibited oxidative stress parameters. MAIN CONCLUSIONS L. amazonensis induces significant alterations in the redox status of liver but not in other organs. Acute antioxidant treatment alleviates oxidative stress in liver, but it had no effect on pro-inflammatory markers. These results indicate that the pathobiology of leishmaniasis is not restricted to the cutaneous manifestations and open perspectives for the development of new therapeutic approaches to the disease, especially for liver function.

IntroductionAn awareness of visceral leishmaniasis (VL) is necessary to encourage the population to participate in prevention and control in collaboration with more efficient, centrally organized health programs. The aim of this study was to evaluate the awareness of the riverside population regarding VL and the association between awareness and the prevalence of canine visceral leishmaniasis (CVL).MethodsIn total, 71 people living in riverside areas in the City of Mossoró in State of Rio Grande do Norte participated of the study, and 71 dogs were tested for CVL by polymerase chain reaction (PCR). Association analysis of several variables related to knowledge of the riverside population regarding CVL positivity was performed, yielding odds ratios (OR) and 95% confidence intervals (CI), and significance was determined using chi-square (χ2) and Fisher's exact tests.ResultsAmong individuals whose dogs tested positive for CVL, 60% did not know the cure for CVL, and these subjects were three times more likely to have a dog test positive for CVL than those who were aware the cure for CVL. Knowledge of CVL cure was the only variable that remained in the logistic model after the successive removal of variables, with an adjusted OR of 3.11 (95%CI: 1.1-8,799; p=0.032).ConclusionsInsufficient awareness regarding VL in riverside areas with CVL-positive dogs was associated with increased rates of canine infection, which suggests that changes in habits and the adoption of attitudes and preventive practices may contribute to the control and prevention of this disease. This study reinforces the need to invest in better health education programs regarding VL.

A resposta de pacientes com leishmaniose ao tratamento antimonial pode variar em função de fatores como a cepa do parasito envolvido, estado imunológico do paciente e a forma clínica da doença. Os esquemas terapêuticos com antimônio pentavalente (Sb5+) têm sido frequentemente modificados quanto à dose e duração da terapia. Os efeitos colaterais observados com o uso de 20 mg/kg/dia de Sb5+ durante quatro semanas (dose recomendada para o tratamento da forma mucosa) são mais acentuados em pacientes idosos, os mais afetados pela forma mucosa (espundia) da doença. Nossa experiência demonstra que a forma cutânea ocorrendo no Rio de Janeiro responde muito bem ao tratamento com a dose de 5 mg/kg/dia de Sb5+ durante 30 ou 45 dias. Neste estudo foi obtida elevada eficácia (91,4%) com o mesmo regime terapêutico em 36 pacientes com espundia (que evoluem, contudo, com lesão crônica menos destrutiva do que o observado em outras áreas endêmicas) procedentes desta região. Os efeitos colaterais foram reduzidos, não havendo também qualquer resistência ao emprego de doses maiores nos casos que não responderam ao tratamento inicial.

Response to treatment with antimonial drugs varies considerably depending on the parasite strain involved, immune status of the patient and clinical form of the disease. Therapeutic regimens with this first line drug have been frequently modified both, in dose and duration of therapy. A regimen of 20 mg/kg/day of pentavalent antimony (Sb5+) during four weeks without an upper limit on the daily dose is currently recommended for mucosal disease ("espundia"). Side-effects with this dose are more marked in elderly patients, more commonly affected by this form of leishmaniasis. According to our experience, leishmaniasis in Rio de Janeiro responds well to antimony and, in cutaneous disease, high cure rates are obtained with 5 mg/kg/day of Sb5+ during 30 to 45-days. In this study a high rate of cure (91.4%) employing this dose was achieved in 36 patients with mild disease in this same geographic region. Side-effects were reduced and no antimony refractoriness was noted with subsequent use of larger dose in patients that failed to respond to initial schedule.