Serological evidence of Coxiella burnetii, Leptospira interrogans Hardjo, Neospora caninum and bovine pestivirus infections in a dairy cattle herd from the United Arab Emirates

The serostatus of five abortigenic agents and the association between abortion history and Coxiella burnetii seropositivity were assessed in 350 dairy cattle from Al Ain, UAE. The bovine sera were ELISA-screened for C. burnetii, Leptospira Hardjo, Neospora caninum, and Brucella abortus antibodies, plus bovine pestivirus (BVDV) antigen. The serology data were collated and the level of significance between the proportions of C. burnetii-seropositive cattle with and without abortion history assessed by the Z test of two proportions. Of the 350 cattle, 41.4%, 1.7%, 1.4%, 0.3%, and 0.0% were seropositive to the above pathogens, respectively. Besides, 61.9%, 2.9%, 1.0%, 0.0%, and 0.0% of the 105 cattle with history of abortion and 32.7%, 1.2%, 1.6%, 0.0% and 0.0% of the 245 seropositive cattle with no history of abortion were also seropositive for the above pathogens respectively. Moreover, the proportion of C. burnetii-seropositive cattle with history of abortion were significantly higher than the C. burnetii-seropositive ones without abortion history (p-value < 0.01). Apparent C. burnetii infections were relatively higher than the other four pathogens suggesting this bacterium contributed to abortion in the herd. Additional research on the public and bovine health implications of C. burnetii and Leptospira in the UAE are urgently needed.

Herd-level risk factors associated with Leptospira Hardjo infection in dairy herds in the southern Tohoku, Japan

A cross-sectional study was designed to generate information on the herd level prevalence and the risk factors for Leptospira serovar Hardjo (L. Hardjo) in Yamagata, the southern Tohoku, Japan. Bulk tank milk samples from 109 dairy herds were used to test the herd level sero-prevalence of L. Hardjo using a commercial ELISA kit, which detects both L. interrogans serovar Hardjo and L. borgpetersenii serovar Hardjo. A questionnaire survey was conducted at the sampled farms, and univariable and multivariable analyses were performed. Spatial clustering of L. Hardjo at the herd level was examined using spatial scan statistics. Seventy-one herds were found to be positive for L. Hardjo, and the apparent herd prevalence was 65.1% (95% CI: 56.2-74.1%). The risk factors for sero-positivity were larger herd size (p=0.004) and cows with a history of staying in Hokkaido (p <0.001). The spatial scan statistic detected a most likely cluster (relative risk=1.87, log likelihood ratio=9.93, radius=13.70km, p<0.01) in the southern part of the study area where there are large herd sizes and farm density is high. This study revealed that L. Hardjo is prevalent throughout Yamagata, and large scale herd owners introducing cows from Hokkaido in particular should be aware of the risk of infection.