ABSTRACT Background: Microscopy and enzyme-linked immunosorbent assay (ELISA) are routinely used for Cryptosporidium diagnosis, without differentiating the parasite species. Methods: Children’s feces were analyzed by modified Ziehl-Neelsen (mZN) and ELISA for Cryptosporidium diagnosis and by polymerase chain reaction-restriction fragment length polymorphism for species identification. Results: Cryptosporidium frequency was 2.6%. The sensitivity and specificity of ELISA were 85.7% and 99.7%, respectively, with excellent concordance with mZN (kappa=0.854). Parasite species were characterized as Cryptosporidium hominis (78.3%), Cryptosporidium felis (17.4%), and Cryptosporidium parvum (4.3%). Conclusions: Coproantigen ELISA is as efficient as mZN for Cryptosporidium diagnosis. Cryptosporidium genotyping suggests anthroponotic and zoonotic transmission to children.

Os parasitos são responsáveis por prejuízos econômicos na estrutiocultura, visto reduzirem a produção. Para determinar a frequência de nematoides gastrintestinais e de Cryptosporidium sp., em avestruzes, bem como os fatores associados a transmissão, foram colhidas amostras de fezes de 342 avestruzes, dos quais 188 eram adultos e 154 jovens, criados em sete plantéis no Polo Regional do Paraguaçu, para a contagem de ovos por grama de fezes, identificação de larvas de terceiro estádio de nematoides e de oocistos de Cryptosporidium sp. Os dados relacionados aos animais e ao ambiente foram obtidos por meio de visita às propriedades e entrevistas com os produtores. A associação entre a carga parasitária e às variáveis de manejo dos animais foi analisada pelo teste Qui-quadrado e por Razão de Odds, com intervalo de confiança de 95%. Em todos os plantéis, foram encontradas aves infectadas. Em 88,3% das amostras de fezes, foram detectados ovos de nematoides gastrointestinal, e, em 18,8%, oocistos de Cryptosporidium sp. Larvas de Libyostrongylus dentatus (98%), L.douglassii (2%) e Codiostomum sp. (2%) foram identificadas nas coproculturas. Fatores ambientais e de manejo estão associados com risco de enteroparasitos em criações de avestruz. As aves mantidas em piquetes de topografia acidentada, na ausência de outros animais ou que recebiam água procedente de poços ou cisternas, apresentavam menores chances de infecção por nematoides, enquanto para o gênero Cryptosporidium, as criações em áreas planas, com presença de outros animais nos piquetes e o fornecimento da água do rio aumentam as chances (2,7 vezes) de infecção.

The parasites are responsible for economic losses in the ostrich, by reducing the production and productivity. To determine the frequency and the factors associated with transmission of gastrointestinal nematodes and Cryptosporidium sp. in ostriches, 342 faecal samples were collected from 188 adults and 154 young ostriches raised in seven herds in the Regional Pole of Paraguaçu. Samples were evaluated for fecal eggs count, nematodes third-stage larvae and Cryptosporidium sp oocysts frequency. The data related to animals and their environments have been obtained by visiting the properties and interviews with producers. The association between parasite burden and the variables of management of the animals was analyzed by chi-square and "Odds ratio", with an interval of 95%. In all flocks were found infected birds. In 88.3% of stool samples were detected eggs of gastrointestinal nematodes, and 18.8% Cryptosporidium sp oocysts. Libyostrongylus dentatus (98%), L.douglassii (2%) and Codiostomum sp (2%) larvae were identified in faecal cultures. Environmental and management factors were associated with risk enteric parasites in ostrich farms. It was found that the ostriches kept in paddocks of irregular topography, in the absence of other animals or receiving water coming from wells or cisterns had lower chances of infection by nematodes. As for the Cryptosporidium genus, the creation in flat areas, with the presence of other animals in the paddocks and the supply of river water increases the chances (2.7 times) of infection.

Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs) to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.