SUMMARYCryptosporidium isolates identified in fourteen stool samples, collected from five HIV-infected patients and nine immunocompetent children, living in the Sate of São Paulo, Brazil, were submitted to a molecular analysis using a nested PCR followed of restriction fragment length polymorphism (RFLP), for genetic characterization. The analysis was based on digestion with RsaI restriction enzyme of a DNA fragment amplified from the Cryptosporidium oocyst wall protein (COWP) gene. Based on this analysis, four samples were identified as Cryptosporidium parvum, eight as Cryptosporidium hominis and two presented a profile that corresponded to Cryptosporidium meleagridis when compared to the standards used in the analysis. The use of molecular methods can be helpful to identify source of infections and risk factors related to Cryptosporidium infection in our communities.

Neospora caninum is an apicomplexan protozoan parasite that is one of the most important infectious causes of abortion in both dairy and beef cattle in many countries. The objectives of this longitudinal study were to determine the prevalence, rates of vertical and horizontal transmission of N. caninum and hazard for culling of N. caninum-seropositive animals in three Brazilian dairy herds. Blood samples from all animals were collected nine times at each of the three farms over a two-year period. Serum was tested for antibodies against N. caninum using the indirect fluorescent antibody test with a cutoff value of 1:100. The percentage of N. caninum-positive samples at each sampling time ranged at Farm I from 3.32% to 11.71%, at Farm II from 3.90% to 22.06% and at Farm III from 3.90% to 22.06%. The number of positive serological reactions varied in relation to the number of repeated samples taken from individual animals at each farm. In all herds, there was a high degree (P<0.05) of association between the N. caninum serological status of dams and daughters. The seropositive conversion rate was estimated as 0.37%, 3.00% and 6.94% per 100 cow-years at Farms I, II and III, respectively. The seronegative conversion rate was estimated as 31.58% and 11.11% per 100 cow-years at Farms I and III, respectively. In all herds, there was no difference (P>0.05) in the culling rate between the cattle that were seropositive cattle and seronegative for N. caninum infection. The results from this study confirm the importance of vertical transmission in the epidemiology of N. caninum. Although a few positive seroconversions indicated horizontal transmission, it does not appear to be the major route of infection for N. caninum.

The aims of this study were to investigate the occurrence of infection b Cryptosporidium spp in children living in Taubaté, São Paulo, Brazil, and to realiz the molecular characterization of the parasite isolates. Thirteen day-care cente were selected and 4-72 months old children were involved in prospective study detect diarrhea, during the 2002 year. In four of these day-care centers, transversal study was performed in the beginning of the study to know th prevalence of intestinal parasites of children's community. A total of 483 sto samples were examined by the modified formalin-etil acetate concentration metho and the acid-fast Kinyoun stain was used to visualize oocysts. In the prospectiv study Cryptosporidium spp were detect in 11.1 % (3/27) of stool samples and n other parasites were found. In the transversal study oocysts were detected in 0.2 (1/456) of the samples and the frequency of infection by other parasites was 30.5 (139/456). In the genotyping study, 14 stool samples from humans and one samp from bovine and another from dog were analyzed. Among the human isolates, fo were from children of Taubaté, five were from children living in a slum of São Pau city and the other five from HIV-positive patients of Sorocaba, São Paulo. Th animal samples were collected in Taubaté region. A DNA fragment of 553 pb of th Cryptosporidium oocyst wall protein (COWP) gene was amplified from sto samples by Nested-PCR, and Restriction Fragment Length Polymorphism analys identified three species: Cryptosporidium hominis in eight samples, Cryptosporidiu parvum in four samples and Cryptosporidium meleagridis in two samples. Amon samples from Taubaté, two were positive for C. hominis and two for C. parvum. Th bovine and dog samples were positive for C. parvum. The findings from Tauba were confirmed by sequence analysis of the 553bp amplicons and comparison the COWP gene available in the GenBank.

Neosporosis is one of the most important causes of abortion in both dairy and beef cattle in many countries. The objective of this study was to quantify the effect of Neospora caninum seropositivity on reproductive parameters in three dairy herds and the dynamics of anti-N. caninum antibodies during gestation in naturally infected cows. Blood samples from all animals were collected nine times on each of the three farms over a two-year period. Serum was tested for antibodies against N. caninum using the indirect fluorescent antibody test (IFAT) with a cutoff value of 1:100. The relative risk of abortion between N. caninum-seropositive and seronegative cows varied between samplings at all farms, but there was only a statistically significant difference (P<0.05) on Farm III in samplings 4, 7 and 8, with positive animals presenting higher risk of abortion. No significant differences (P>0.05) were found regarding gestational age at abortion, repeated abortion, number of inseminations for conception and calving intervals, between seropositive and seronegative cows on all the farms. ResumoNeosporose é uma das causas mais importantes de abortamento em bovinos leiteiro e de corte em muitos países. O objetivo desse estudo foi quantificar o efeito da soropositividade para Neospora caninum nos parâmetros reprodutivos em três rebanhos leiteiros e a dinâmica dos anticorpos anti-N. caninum durante a gestação em vacas infectadas naturalmente. Amostras de sangue de todos os animais foram colhidas nove vezes em cada uma das três fazendas dentro do período de dois anos. O soro foi testado para anticorpos contra N. caninum usando o teste de reação imunofluorescência indireta (RIFI) com valor de corte de 1:100. O risco relativo de abortamento entre vacas N. caninum-soropositivas e soronegativas variou entre as amostragens em todas as fazendas, mas, houve somente diferença estatisticamente significativa (P<0,05) na Fazenda III na amostragem 4, 7 e 8, com os animais soropositivos apresentando maiores risco de abortamento. Nenhuma diferença significativa (P>0,05) foi encontrada em consideração a idade gestacional no abortamento, abortamentos repetidos, número de inseminações por concepção e intervalo entre partos entre vacas soropositivas e soronegativas em todas as fazendas.Palavras-chave: Neospora caninum. Risco de abortamento. Abortamentos repetidos. Parâmetros reprodutivos.