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Neospora caninum ranges among the major causes of infectious abortion in cattle worldwide. The present study was designed to improve the serodiagnostic tools by complementing a conventional ELISA with a highly sensitive and species-specific N. caninum immunoblot. To evaluate this test combination, sera from several groups of cows were tested. The first group, consisting of experimentally infected calves, showed that immunoblot antibody reactivities were detectable 1 to 3days earlier than those found in ELISA. The first immunodominant bands that appeared were a 29-kDa (NcSAG1) and a 36-kDa (NcSRS2) antigen. Other groups, based upon naturally infected cattle, were used to compare the diagnostic sensitivity of ELISA and immunoblotting. Overall, N. caninum immunoblotting exhibited a higher sensitivity (98%) than ELISA (87%). Conversely, immunoblotting also confirm in two other cases, true transient negativation in some animals. In general, banding patterns and band staining intensity correlated to the semiquantitative ELISA findings. On the other hand, the banding pattern could not be used to discriminate between sera from animals with a recent abortion and those of cows with latent N. caninum infection. We also addressed putative cross-reactions due to infection with Toxoplasma gondii. Sera from animals with a serologically proven T. gondii infection were either clearly negative by Neospora immunoblotting or they yielded a specific immunoblot antibody profile indicating a double infection with N. caninum. Sera from animals with positive findings in both Toxoplasma and Neospora ELISA thus provided dichotomic results in the immunoblot by allowing to confirm or to rule out the specificity of the antibody reaction in Neospora ELISA. Altogether, our findings demonstrate that N. caninum immunoblotting is a very sensitive and specific complementary tool to improve the serology for N. caninum infections in cattle

The present study was designed to exploratively determine (a) how many healthy calves, born from seropositive mothers, were also precolostrally seropositive; (b) how many precolostrally negative calves became postcolostrally positive; and (c) in these calves, how the IgG1/IgG2 situation developed pre- and postcolostrally. All calves were born from mothers that were determined to be seropositive in a conventional Neospora caninum-ELISA and by immunoblotting. When the diagnostic performance of the conventional ELISA was compared with that of immunoblotting and an IgG1/IgG2-ELISA in the calves, the latter two exhibited a higher sensitivity: From a total of 15 precolostral calf sera, 7 were positive in the conventional ELISA (diagnostic sensitivity 47%) compared to 15 that were positive by immunoblotting (diagnostic sensitivity 100%) and 12 that were positive by the IgG1/IgG2-ELISA (diagnostic sensitivity 80%). With regard to IgG1/IgG2 findings in the dams, IgG2 appeared as the dominant subclass in the humoral immune response of adult cattle, while in calves, IgG1 appeared as the main prenatally/precolostrally reactive antibody isotype. Provided that precolostral seropositivity reflects postnatal persistent infection with N. caninum, we then postulate that, basically, all of our study calves born form N. caninum-seropositive mothers were prenatally infected with the parasite, and may, thus, all become members of the next transmitting generation

In a Swiss dairy farm (canton of Geneva) consisting of 73 animals 8 abortions were observed within 2 weeks. Serological and molecular biological analyses (PCR) on aborting dams, and abortion materials, respectively, revealed that the protozoan parasite Neospora caninum was the causative agent. Besides the 8 aborting animals, 12 other non-aborting heifers were found to be serologically positive for this parasite. All positive sera were further tested in an avidity-ELISA to elucidate the recency of infection. All seropositive animals but one showed low avidities at the time the abortion storm started. This indicated at a recent N. caninum-infection within the herd. Thus, the animals most probably were exposed to N. caninum-oocysts (e.g. by dog feces-contaminated forage) and the resulting abortion storm was due to an exogenous (formerly known as "horizontal") parasite transmission into a naive herd. This is the first documented record of such an event in Switzerland.

Alveolar echinococcosis (AE) is a rare, but potentially severe zoonotic disease caused by Echinococcus (E.) multilocularis. Recent findings indicated an increasing importance of AE for non-human primates living in regions endemic for E. multilocularis. The death of five cynomolgus monkeys (Macaca fascicularis) and a lowland gorilla (Gorilla g. gorilla) due to AE raised concern about the incidence of this parasite in the Basle Zoo. Consequently, a project was initiated to investigate the prevalence amongst an affected group of cynomolgus monkeys, as well as in foxes and mice. Three out of 46 monkeys were seropositive for E. multilocularis antigen. In two of these monkeys and in another three animals, which were seronegative, structures compatible with metacestodal cysts were observed using ultrasonography. Seven out of 35 free roaming foxes caught at the zoo were positive for an intestinal E. multilocularis copro-antigen ELISA, four of them shed taeniid eggs simultaneously. No lesions compatible with AE were present in 50 necropsied mice from the zoo area. These results indicate that the fox population is a potential source to introduce E. multilocularis and may thus represent a risk for the zoo animals.