ABSTRACT
In the German state of Rhineland-Palatinate, herds were identified that were likely to have a Neospora caninum sero-prevalence > or = 10% by using a bulk milk ELISA. Individual herd data were obtained by a questionnaire. Univariate logistic regression showed that bulk milk positive farms had a significantly higher chance to report an increased abortion rate than negative farms (P(Wald)<0.1). The chance to have a bulk milk positive herd increased with the minimum number of years a farm had reported an increased abortion rate (P(Wald)<0.1). Questionnaire data, population and dog density as well as climatic data specific for the farm localization were used to identify potential risk factors for a herd to have acquired N. caninum infections. Within an optimized multiple logistic regression model 'Number of farm dogs', 'Herd size', and factors related to the municipality the farm was localized, i.e. 'Mean temperature in July', and 'Dog density' were significant risk factors (P(Wald)<0.1). The present study underlines the role farm dogs have in the epidemiology of neosporosis. In addition, it suggests that the risk a herd has to acquire N. caninum infections is also associated with factors related to the farm location, i.e. factors that are largely out of the control of farmers.
Subject(s)
Cattle Diseases/parasitology , Coccidiosis/veterinary , Milk/parasitology , Neospora/growth & development , Abortion, Veterinary/epidemiology , Abortion, Veterinary/parasitology , Animal Husbandry , Animals , Cattle , Cattle Diseases/epidemiology , Coccidiosis/epidemiology , Coccidiosis/parasitology , Dogs , Female , Germany/epidemiology , Logistic Models , Rain , Risk Factors , Surveys and Questionnaires , TemperatureABSTRACT
To obtain a rapid overview over the distribution of bovine Neospora caninum-infections in the German state of Rhineland-Palatinate, an ELISA to determine specific bovine antibodies against a p38 surface antigen of N. caninum tachyzoites was modified to examine bulk milk samples from cattle herds. Experimental bulk milk samples were used to demonstrate that the seroprevalence in a group of animals can be estimated with this ELISA. A cut-off was selected for the specific detection of herds having a seroprevalence > or =10%. About 90% of the dairy herds located in Rhineland-Palatinate were examined. An overall prevalence of bulk milk-positive herds of 7.9% (95% confidence interval 7.0-8.9%), respectively, was determined. Major regional differences in the distribution of bulk milk-positive herds were observed. Prevalences were higher in regions with an increased degree of urbanisation. Logistic regression was applied to model the prevalence of bulk milk-positive herds on a district and city level. Variables describing the dog density, mean temperature in July, mean temperature in January and the total yearly precipitation in districts and cities were able to explain most of the observed variability in the regional prevalences. Our results provide evidence that in addition to risk factors related to individual farms also risk factors related to the farm location such as dog density in the surrounding and climate factors are important in the epidemiology of bovine neosporosis.
