The study was a combination of two investigations into active outbreaks of lumpy skin disease (LSD) in cattle in central Ethiopia and a retrospective analysis of outbreak reports between January 2007 and December 2011 covering the entire country. Active outbreaks were investigated in four districts of central Ethiopia: Adama, Wenji, Mojo and Welenchiti. A semi-structured questionnaire was used to acquire data at individual and herd levels, and tissue samples were collected for viral isolation and characterisation. The retrospective analyses showed that, during the five-year period, a total of 1,675 outbreaks were reported, with 62,176 cases and 4,372 deaths. The highest number of outbreaks was reported in Oromia (1,066), followed by Amhara (365) and the Southern Nations, Nationalities and People's Region (123). Outbreaks were more frequently observed between September and December and the highest number of outbreaks was reported in 2010. During the period studied, a total of 2,174 local zebu cattle were clinically examined and morbidity and mortality rates of 13.61% (296) and 4.97% (108) were recorded, respectively. Analysis of the active outbreaks revealed a relatively consistent morbidity rate, with the highest observed in Adama (15.38%), followed by Wenji (10.26%). The highest mortality rates were also observed in Adama (5.89%) and Wenji (3.42%). The LSD virus was isolated from 22 samples and all tested positive in polymerase chain reaction analysis. The disease was observed in the cattle regardless of previous vaccination with Kenyan sheep-and goatpox vaccine; thus, vaccine efficacy was assessed under field conditions and the authors' findings, together with a possible remedy, are presented in this paper.
To evaluate the safety and immunogenicity of combined hemorrhagic septicemia (HS) and blackleg (BL) vaccine, combined vaccine was produced in two different formulations (group one, G1 and group two, G2) and compared with safety and immunogenicity of monovalent Hs and BL vaccines in different doses. G1 combined vaccine was vaccinated in 4 and 2 ml in to five calves each while G2 combined vaccine, the monovalent HS and blackleg vaccines were vaccinated in 2 and 1 ml amount into to five calves each leaving ten non-vaccinated calves managed similarly as vaccinated ones. The safety test was made by giving single and double doses of experimental vaccines and double doses of monovalent vaccines in each case using two calves per dose group. The immunogenicity of BL vaccine component in the combined vaccine was evaluated by using 10 guinea pigs per group for six different doses of combined and monovalent blackleg vaccine, leaving 10 non-vaccinated controls. The study indicated that the protection against virulent challenges for animals vaccinated with G1 combined vaccine at 2 ml, G2 vaccine at 1 ml, monovalent HS and BL vaccine vaccinated at 1 ml doses was by far less than 90%. On the other hand, protection against experimental challenge for G1 vaccine vaccinated in 4 ml amount was 100% against both HS and blackleg virulent challenges while the protection against experimental challenge for G2 vaccine vaccinated in 2 ml amount was 66.67% against the HS virulent challenge and 90% against BL virulent challenge. So G1 combined vaccine vaccinated in 4 ml was found to be the best candidate vaccine according to this experiment which needs to be confirmed at field test before use for mass vaccination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.