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Background: Information on the prevalence of infectious agents in dairy farms forms the basis for formulating a suitable control strategy; especially in endemic situations. Aims: A cross-sectional study was undertaken to determine the prevalence of six economically important bovine diseases, causing reproductive disorders including bovine abortion in organized dairy herds in India. Methods: A total of 1,075 animals (cattle and buffaloes) from 09 dairy farms were screened by ELISA tests. Results: Bovine viral diarrhoea (BVD) was the most prevalent (56.5%) disease followed by infectious bovine rhinotracheitis (IBR) (45.4%). Prevalence of Q-fever (5.4%) and neosporosis (6.1%) were less on the farms. Although 16.3% of the samples turned positive for brucellosis, the contribution of calf-hood vaccination (B. abortus S19 vaccine) to the prevalence of antibodies cannot be ruled out. The overall prevalence of bovine anaplasmosis, known to cause sporadic abortions in dairy herds, was 34.1% in the 9 farms with a prevalence of less than 20% in 5 farms. Infection of multiple abortifacient (seroprevalence to more than two pathogens) was recorded in 56.8% of animals. A very strong association was observed between BVD and brucellosis (Odds ratio 14.2; P<0.001). Further, a positive association was also seen between seroprevalence of IBR and anaplasmosis, and neosporosis and Q fever (P<0.05). Conclusion: Viral diseases were found to be more common in the dairy herds than bacterial and protozoan diseases. Increased susceptibility of IBR seropositive cows to other bacterial and viral infections was observed. [ABSTRACT FROM AUTHOR]

The use of liposome as an adjuvant and a vaccine carrier has been cited previously in the literature. It has also been shown to be effective in enhancing the immunogenicity of vaccine candidates. BALB/c mice immunized subcutaneously with outer membrane protein (OMP) of Brucella abortus S19 vaccine strain entrapped in a commercial cationic liposome (S19-OMP-liposome) for vaccine delivery, showed enhanced protection (P<0.05) compared to groups of mice inoculated with S19 OMP alone, S19 live B. abortus vaccine and liposome alone, when challenged intra-peritoneally with virulent B. abortus strain 544 at 30 days post-immunization (DPI). The S19-OMP-liposome preparation was found to be safer compared to the live B. abortus S19 vaccine at 15 days post challenge (DPC), as evidenced by the significant difference in spleen weight between S19-OMP-liposome, S19 OMP and S19 live as well as the liposome control groups (P<0.01). Antibody isotype response profiles of the experimental groups indicated that the immune response was Th1 cell mediated. The protective advantage conferred to mice immunized with S19-OMP entrapped in liposome over those immunized with the live B. abortus S19 version, could probably be related to the significantly different response of IgG2b at 30 DPI (P<0.01), IgG2a (P<0.01), IgG2b (P<0.01) and IgG3 (P<0.05) at the DPC stages, respectively. [ABSTRACT FROM AUTHOR]