Cross-sectional serosurvey of Coxiella burnetii in healthy cattle and sheep from extensive grazing system in central Italy

A cross-sectional survey was carried out to estimate the seroprevalence of Coxiella burnetii in extensively grazed cattle and sheep from central Italy and to identify the related risk factors. Data on notified human Q fever cases in the area were also collected and described. A two-stage cluster sampling was performed. A total of 5083 animals (2210 cattle; 2873 sheep) belonging to 186 farms (92 herds; 94 flocks) were tested for the presence of antibodies against C. burnetii using a commercial enzyme-linked immunosorbent assay kit. The prevalence at the animal-level resulted three times higher in sheep compared to cattle (37.8% vs. 12.0%; χ2 = 270.10, P < 0.001). The prevalence at the herd-level was also higher in sheep than in cattle (87.2% vs. 68.5%; χ2 = 9.52, P < 0.01). The multivariate analysis showed a higher risk of seropositivity for cattle aged 67-107 months (OR 2.79, 95% CI 1.86-4.18), cattle >107 months of age (OR 2.07, 95% CI 1.36-3.14) and mixed breed cattle (OR 1.74, 95% CI 1.11-2.72). A herd size >92 animals was recognized as herd-level risk factor in cattle (OR 6.88, 95% CI 1.67-28.37). The risk of being seropositive was double in sheep belonging to flocks >600 animals (odds ratio (OR) 2.04, 95% CI 1.63-2.56). Sheep were confirmed to be the most exposed species. Nevertheless, the prevalence observed in cattle also suggests the potential involvement of this species in the circulation of the pathogen in the area. Seven confirmed human Q fever cases were reported. In five out of seven cases there was at least one exposed herd within a 5 km buffer. Even though the source of the infection was not identified, the possibility of C. burnetii circulating in the livestock and human population in the study area cannot be overlooked. The integration between veterinary and human surveillance will be crucial to understand the spread of this zoonosis and to support the adoption of appropriate control measures.

Biotic and abiotic factors influencing distribution and abundance of Culicoides obsoletus group (Diptera: Ceratopogonidae) in central Italy

In the framework of a bluetongue surveillance program including clinical, serological, and entomological activities, Culicoides biting midges were light trapped weekly in two regions of central Italy, Lazio and Tuscany. In the period January 2002 through December 2005, 3,944 collections were carried out in 189 trap sites distributed in all the provinces of the two regions. Abundance data of C. obsoletus group were analyzed in relation to trap site altitude, distance from the sea, land use, and number of farmed animals. Species seasonality and overall temporal trend were also described. C. obsoletus was distributed over the whole study area, almost in all trapping sites and with high abundances. The species group was dominant among all captured Culicoides, with higher abundances recorded inland and in areas where land cover was partially or completely natural-wooded. Adults on the wing were caught all year round, with peaks in May-June and middle October. The observed trend through years recorded a peak during autumn 2002, in concomitance with a local epidemic of bluetongue.

Ehrlichia infection in Italy

Immunoglobulin M seroconversion to Ehrlichia chaffeensis was documented in U.S. citizens bitten by ticks in Sardinia. Seven cases of suspected ehrlichiosis in local residents were not confirmed by laboratory tests. In Alpine areas antibodies to E. phagocytophila were detected in persons at high risk, i.e., foresters (8.6%) and hunters (5.5%), and in controls (1.5%). Of 153 persons bitten by ticks, only one was Ehrlichia antibody-positive after 6 months.