Contagious bovine pleuro-pneumonia （CBPP） is one of the endemic and life-threatening livestock diseases in the arid and semi-arid land areas （ASALs） of Kenya, which justify the case for the control of livestock di...Contagious bovine pleuro-pneumonia （CBPP） is one of the endemic and life-threatening livestock diseases in the arid and semi-arid land areas （ASALs） of Kenya, which justify the case for the control of livestock diseases to avoid the spread of such diseases from the ASALs to the rest of the country, and a CBPP control quarantine line （CQL） that to help prevent the spread of CBPP from the ASALs of North-eastern Kenya to the rest of the country has been in existence since the colonial （pre-1963） times in Kenya. However, the livestock keepers in the ASALs view the CQL as an impediment to their main source of livelihoods because it entails livestock movement restrictions, thus constraining unfettered livestock marketing. Available literature shows that there is a dearth of information on the economics of livestock diseases control in Kenya in terms of its impacts on social welfare. Employing the CQL as a case study, this study shows that an application of analytic techniques that combine disease risk analysis and conventional cost-benefit modelling that incorporates some aspects that are specific to livestock diseases and their control strategies can generate indices of economic impacts of livestock diseases control on social welfare. The study finds that the livestock keepers and traders in Kenya do not consider CBPP a major problem to warrant livestock movement restrictions, yet the official records of the veterinary authorities indicate that CBPP is a major threat to the cattle industry in Kenya. Annually, the government spends substantial resources on the CQL operation and maintenance and also on CBPP surveillance and monitoring to contain the CBPP menace in Kenya. This study shows that such expenditures are economically and socially justifiable. Nevertheless, the study finds some operational inefficiencies in the enforcement of the CQL requirements. The authors, therefore, undertake an evaluation of alternative CBPP control strategies and conclude that it would be more cost effective to shift the CQL from its current location to the international borders of the arid districts, provided that this action is preceded by adequate CBPP control preparatory measures, as described in the paper.展开更多
Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain an...Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.展开更多
文摘Contagious bovine pleuro-pneumonia （CBPP） is one of the endemic and life-threatening livestock diseases in the arid and semi-arid land areas （ASALs） of Kenya, which justify the case for the control of livestock diseases to avoid the spread of such diseases from the ASALs to the rest of the country, and a CBPP control quarantine line （CQL） that to help prevent the spread of CBPP from the ASALs of North-eastern Kenya to the rest of the country has been in existence since the colonial （pre-1963） times in Kenya. However, the livestock keepers in the ASALs view the CQL as an impediment to their main source of livelihoods because it entails livestock movement restrictions, thus constraining unfettered livestock marketing. Available literature shows that there is a dearth of information on the economics of livestock diseases control in Kenya in terms of its impacts on social welfare. Employing the CQL as a case study, this study shows that an application of analytic techniques that combine disease risk analysis and conventional cost-benefit modelling that incorporates some aspects that are specific to livestock diseases and their control strategies can generate indices of economic impacts of livestock diseases control on social welfare. The study finds that the livestock keepers and traders in Kenya do not consider CBPP a major problem to warrant livestock movement restrictions, yet the official records of the veterinary authorities indicate that CBPP is a major threat to the cattle industry in Kenya. Annually, the government spends substantial resources on the CQL operation and maintenance and also on CBPP surveillance and monitoring to contain the CBPP menace in Kenya. This study shows that such expenditures are economically and socially justifiable. Nevertheless, the study finds some operational inefficiencies in the enforcement of the CQL requirements. The authors, therefore, undertake an evaluation of alternative CBPP control strategies and conclude that it would be more cost effective to shift the CQL from its current location to the international borders of the arid districts, provided that this action is preceded by adequate CBPP control preparatory measures, as described in the paper.
文摘Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.
