Prevalence of Giardia duodenalis and Cryptosporidium spp. in dogs from different living conditions in Uberlândia, Brazil

Infection rates with Giardia duodenalis and Cryptosporidium spp. were compared among dogs living under different conditions. Stool samples (n = 433) collected from dogs of different ages, gender, living conditions and origin were analyzed using three techniques, i.e., centrifugal flotation in zinc sulfate solution, centrifugal flotation in sucrose solution, and methylene blue gram safranin staining. Eighty-nine of the samples were from stay dogs living in shelters run by animal protection societies, 199 were from kennels and 122 from households. A total of 119 (29.0%) had G. duodenalis cysts and six (1.4%) were positive for Cryptosporidium spp. oocysts. Dogs from kennels were most frequently affected by G. duodenalis (49.7%) while those from shelters showed a higher prevalence of Cryptosporidium spp. (2.2%). A significant difference (p < or = 0.05) was observed between immature dogs and adults only with respect to Giardia infection. There was no significant difference between the gender with regard to the presence of either protozoan.     

Evaluation of Toxoplasma gondii and Neospora caninum infections in sheep from Uberlândia, Minas Gerais State, Brazil, by different serological methods

Toxoplasmosis and neosporosis have been recognized as economically important diseases with considerable impact on the livestock industry. Considering the scarce information on the occurrence of Toxoplasma gondii and Neospora caninum infections in sheep from Uberlandia, Minas Gerais State, Brazil, this study aimed to investigate the frequency of antibodies against these parasites in sheep sera from this region by using different serological methods. A total of 155 sheep serum samples were analyzed by the indirect fluorescence antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) for the detection of IgG against T. gondii and N. caninum. Seroreactivity by IFAT showed 80% of samples with titers between 512 and 2048 for T. gondii (cutoff ≥ 64) and 78% presenting titers between 50 and 200 for N. caninum (cutoff ≥ 50). Seroreactivity by ELISA showed 75% of samples with ELISA index (EI) between 2.0 and 3.0 for T. gondii (cutoff ≥ 1.3) and 54% presenting EI between 1.3 and 2.0 for N. caninum (cut off ≥ 1.3). Discordant results by both tests were analyzed by immunoblot, resulting in a total seropositivity of 61% for T. gondii and 23% for N. caninum, with 41% to T. gondii only, 3% to N. caninum only, and 20% to both parasites. There was a significant positive association between seropositivity to T. gondii and age over one year (P<0.001), but such association was not found for N. caninum infection. In conclusion, as T. gondii and N. caninum infections are simultaneously present in sheep flocks of this region, it should be emphasized the importance to carry out a regular monitoring of Toxoplasma infection due to its high prevalence, its zoonotic potential and induction of reproductive disorders leading to economic losses. For neosporosis, sheep farmers should be instructed about the presence of the parasite in the flock, its risk factors and potential abortifacient role in sheep. Differential flock management could be valuable tool to establish the association of serological positivity and reproductive disease induced by N. caninum in sheep.     

Prevalence of anti-Neospora caninum antibodies in dogs from urban, periurban and rural areas of the city of Uberlândia, Minas Gerais--Brazil

In Brazil there are few reports on the prevalence of anti-Neospora caninum antibodies in dogs from urban, periurban and rural areas. Serum samples from 450 dogs, 300 from urban, 58 from periurban and 92 from rural areas, were tested for the detection of anti-N. caninum IgG antibodies using IFAT: indirect fluorescent antibody test (IFAT, > or =50). Antibodies were observed in 63 (14%) of the 450 serum samples analyzed, with 32 (10.7%) in dogs coming from the urban area, 11 (18.9%) from the periurban area and 20 (21.7%) from the rural area. Statistical differences were seen between the occurrences in animals from the urban area and those of the rural area (P = 0.01). The antibody titers found were: 1:50 in 20 dogs, 1:100-1:800 in 41 dogs, and 1:3200 in two dogs. In the female dogs, a smaller prevalence of dogs with antibodies was observed in those from the urban area (7.5%) in comparison with those of the rural (21.0%) (P = 0.05) and periurban (23.3%) (P = 0.01) areas. There were growing levels of antibody prevalence with the increase in age of the dogs in all three areas studied. Although this increase was not significant, it indicates a tendency towards more infections with age, suggesting post-natal exposure to N. caninum. However, a significant difference (P = 0.05) was observed in the occurrence of anti-N. caninum antibodies in dogs with ages = 2 years in urban (13.1% urban) versus rural environments (27.1% rural). Among the other age brackets studied the difference was not significant. The results confirm the presence of N. caninum in the region and reveal the important role of dogs in the parasite's epidemiology.     

Cryptic Leishmaniosis by Leishmania infantum, a feature of canines only? A study of natural infection in wild rabbits, humans and dogs in southeastern Spain

An epidemiological study was carried out to investigate asymptomatic Leishmania infantum infection by PCR and ELISA in wild rabbits, humans and domestic dogs in southeastern Spain. Seroprevalence was 0% (0/36) in rabbits, 2% (13/657) in humans and 7% (14/208) in dogs. The prevalence of PCR-positives was 0.6% (1/162) in rabbits tested in a wide range of tissue samples, 2% (8/392) in humans analysed in blood samples and 10% (20/193) and 67% (29/43) in dogs analysed in blood and lymphoid tissue samples, respectively. Results suggest that wild rabbits have a very low risk of becoming chronically infected with L. infantum, and provide further evidence that cryptic L. infantum infection is widespread in the domestic dog population and is also present in a comparatively smaller proportion of healthy humans. The epidemiological and clinical implications of these findings are discussed.