Construction of standardized surveillance indicators for bovine cysticercosis.

Bovine cysticercosis is a zoonotic parasitic disease due to Cysticercus bovis. This study aimed to identify factors that could have an impact on the prevalence of cysticercosis and to use them to build standardized indicators of prevalence. Multivariate logistic regression analyses were performed on data from 4,564,065 cattle (91.3% of the cattle population slaughtered in France in 2010) among which 6491 cattle (0.14%) were found to harbor at least one lesion of cysticercosis (including 611 cattle harboring viable cysts, 0.01%). Two multivariate logistic models were fit to the data using as outcome variables either the presence or absence of viable cysts and the presence or absence of cysts whatever their level of development. Age and sex were identified as the main factors influencing bovine cysticercosis prevalence and were used for the construction of standardized prevalence and standardized cysticercosis rate. To illustrate the use of such indicators, they were calculated for the first and second semester of 2010 and for two different areas in France. The differences between raw prevalence and standardized prevalence highlight the use of standardized indicators for comparisons of prevalence between different areas and time periods as the structure of the slaughtered populations differ considerably from one to another.

Factors associated with offal, partial and whole carcass condemnation in ten French cattle slaughterhouses.

The proportion of cattle with offal, partial or whole carcass condemnation could be a useful indicator for animal health syndromic surveillance purposes. It requires first highlighting the factors associated with condemnation in order to include them in a modeling process. This study aims to identify and quantify these factors. It was based on data from ten French cattle slaughterhouses from 2006 to 2010 (n=1,439,868 cattle). Multivariable multinomial logistic regression analyses were performed. Sex, age and slaughterhouse were the main effects for offal, partial and whole carcass condemnation and have to be taken into account when implementing syndromic surveillance systems based on meat inspection data. The presence of an error in cattle identification was identified as a potential indicator for a higher risk of condemnation and should be explored as a potential factor for risk-based meat inspection.

High-resolution typing of Leptospira interrogans strains by multispacer sequence typing.

Leptospirosis is a worldwide zoonosis which is responsible for the typical form of Weil's disease. The epidemiological surveillance of the Leptospira species agent is important for host prevalence control. Although the genotyping methods have progressed, the identification of some serovars remains ambiguous. We investigated the multispacer sequence typing (MST) method for genotyping strains belonging to the species Leptospira interrogans, which is the main agent of leptospirosis worldwide. A total of 33 DNA samples isolated from the reference strains of L. interrogans serogroups Icterohaemorrhagiae, Australis, Canicola, and Grippotyphosa, which are the most prevalent serogroups in France, were analyzed by both the variable-number tandem-repeat (VNTR) and MST methods. An MST database has been constructed from the DNA of these reference strains to define the MST profiles. The MST profiles corroborated with the VNTR results. Moreover, the MST analysis allowed the identification at the serovar level or potentially to the isolate level for strains belonging to L. interrogans serovar Icterohaemorrhagiae, which then results in a higher resolution than VNTR (Hunter-Gaston index of 0.94 versus 0.68). Regarding L. interrogans serogroups Australis, Canicola, and Grippotyphosa, the MST and VNTR methods similarly identified the genotype. The MST method enabled the acquisition of simple and robust results that were based on the nucleotide sequences. The MST identified clinical isolates in correlation with the reference serovar profiles, thus permitting an epidemiological surveillance of circulating L. interrogans strains, especially for the Icterohaemorrhagiae serogroup, which includes the most prevalent strains of public health interest.

Prevalence of the Leptospira serovars bratislava, grippotyphosa, mozdok and pomona in French dogs.

Although most French dogs are correctly vaccinated against leptospirosis with inactivated strains of canicola and icterohaemorrhagiae, the disease is still very prevalent in France raising the question of whether the vaccines used require updating. The aim of the present study was to provide serological data regarding circulation of the Leptospira serovars: grippotyphosa, bratislava, pomona and mozdok, which are contained in vaccines available in other parts of the world and which could be rapidly adapted for France. Results indicated that the epidemiology was consistent with the circulation of Leptospira belonging to the serogroups Australis and Grippotyphosa and that the case to support the inclusion of either pomona or mozdok in a dog vaccine for France was weak.