Evaluation of new generation macrolides for the treatment and metaphylaxis of contagious bovine pleuropneumonia (CBPP) in cattle experimentally infected with Mycoplasma mycoides subspecies mycoides

Sero-prevalence of contagious bovine pleuropneumonia in dryland of Borana, southern Oromia, Ethiopia

Ethiopia is one of the largest African countries where livestock farming represent a relevant resource for the economy and the livelihood of the population. Contagious bovine pleuropneumonia (CBPP) is among the transboundaries animal disease that is hindering cattle farming in Ethiopia. Due to the limited resources of veterinary services, disease control and surveillance is discontinuous and occasional field investigations of target areas contribute to depict disease spreading in the country. The study was conducted to determine the seroprevalence, at herd and animal level, and identify the risk factors involved in CBPP diffusion and persistence in the Borana pastoral zone. A total of 498 serum samples were collected from 120 cattle herds and tested using competitive Enzyme-Linked Immunosorbent Assay (c-ELISA). Of 120 herds sampled, 37 (30.83%; (95% CI = 22.73-39.91%) were tested positive to CBPP antibody. Out of 498 sera samples tested 46 (9.24%; 95% CI = 6.84-12.13%) were positive. The highest prevalence was observed in Teltele (12/95; 12.90%; 95% CI = 6.7-21%) followed by Yabello (12/104; 11.54%; 95% CI = 6.1-19.3%) and Arero (10/91; 10.99%; 95% CI = 95% CI = 5.4-19.3%), whereas the lowest prevalence was observed in Gomole (5/101; 6.42%; 95% CI = 1.6-11.2%) and Dubluk (7/109; 4.95%; 95% CI = 2.6-12.8%) districts and statistically not significant (p > 0.05). Results of multivariate logistic regression analysis revealed that, age, herd movement and herd size of the animals had statistically significant effect on sero-positivity to CBPP (p < 0.05). Sex, season and body condition were not significantly (p > 0.05) associated with the occurrence of CBPP. The study confirms that CBPP is persistent in the territory and remain as a major problem that affects health and productivity of cattle. Therefore, awareness creation to the pastoralists in the study area about the effect of CBPP and designing appropriate control methods has a paramount importance to improve the health and productivity of cattle production in the area.

Effectiveness and profitability of preventive veterinary interventions in controlling infectious diseases of ruminant livestock in sub-Saharan Africa: a scoping review

Agriculture in general, and livestock production in particular, serve as a livelihood source for many people in sub-Saharan Africa (SSA). In many settings, lack of control of infectious diseases hampers livestock productivity, undermining the livelihood of rural populations. This scoping review sought to identify veterinary interventions previously evaluated as well as their relative effectiveness in controlling infectious livestock diseases. To be included, papers had to be written in English, German or French, and had to describe the effectiveness and/or profitability of preventive veterinary intervention(s) against anthrax, blackleg, bovine tuberculosis, brucellosis, contagious bovine pleuropneumonia, contagious caprine pleuropneumonia, foot-and-mouth disease, goat pox, lumpy skin disease, pasteurellosis, peste des petits ruminants, and/or sheep pox in any SSA country. Of the 2748 publications initially screened, 84 met our inclusion criteria and were analyzed. Most of the studies (n = 73, 87%) evaluated the effectiveness and/or profitability of vaccination, applied exclusively, applied jointly with, or compared to strategies like deworming, antimicrobial treatment, surveillance, feed supplementation, culling and dipping in reducing morbidity and/or mortality to livestock diseases. The effectiveness and/or profitability of antimicrobial treatment (n = 5), test and slaughter (n = 5), and use of lay animal health workers (n = 1) applied exclusively, were evaluated in the other studies. Vaccination was largely found to be both effective and with positive return on investment. Ineffective vaccination was mainly due to loss of vaccine potency under unfavorable field conditions like adverse weather events, cold chain failure, and mismatch of circulating pathogen strain and the vaccines in use.

In summary, vaccination is the most effective and profitable means of controlling infectious livestock diseases in SSA. However, to achieve effective control of these diseases, its implementation must integrate pathogen surveillance, and optimal vaccine delivery tools, to overcome the reported field challenges.

Contagious Bovine Pleuropneumonia: Challenges and Prospects Regarding Diagnosis and Control Strategies in Africa

Contagious bovine pleuropneumonia (CBPP) is an infectious and contagious respiratory disease of cattle, caused by Mycoplasma mycoides subsp. mycoides (Mmm). In this review, basic epidemiological features of CBPP, complicated by existing different strains of Mycoplasmas with similar biochemical characteristics, with preference to Sub-Saharan Africa are discussed. Many sub-Saharan African countries are challenged by variable gaps that include diagnostic tools and control strategies. Science-based issues on diagnostic procedures, vaccination, treatment, and other control strategies are discussed. Participatory epidemiology (PE), a diagnostic technique used in the identification and solving of animal health problems in rural communities, was also discussed. PE application, in conjunction with conventional diagnostic tools, will improve CBPP identification in pastoral rural communities and promote control of the disease in Africa. Furthermore, adequate CBPP control can be achieved through stronger political commitments from governments by prioritizing the disease among major diseases of high economic importance to the livestock industry for surveillance and control. Investment in CBPP control in endemic African countries will assure food security, livelihoods and the general well-being of people, and international trade.

Baseline analysis of Mycoplasma mycoides subsp. mycoides antigens as targets for a DIVA assay for use with a subunit vaccine for contagious bovine pleuropneumonia

BACKGROUND

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia in cattle. A prototype subunit vaccine is being developed, however, there is currently no diagnostic test that can differentiate between infected cattle and those vaccinated with the prototype subunit vaccine. This study characterized Mmm proteins to identify potential antigens for use in differentiating infected from vaccinated animals.

RESULTS

Ten Mmm antigens expressed as recombinant proteins were tested in an indirect ELISA using experimental sera from control groups, infected, and vaccinated animals. Data were imported into R software for analysis and drawing of the box and scatter plots while Cohen's Kappa assessed the level of agreement between the Mmm antigens. Two vaccine antigens (MSC_0499 and MSC_0776) were superior in detecting antibodies in sera of animals vaccinated with the subunit vaccines while two non-vaccine antigens (MSC_0636 and LppB) detected antibodies in sera of infected animals showing all clinical stages of the disease. Sensitivity and specificity of above 87.5% were achieved when the MSC_0499 and MSC_0636 antigens were tested on sera from vaccinated and infected animals.

CONCLUSIONS

The MSC_0499 and MSC_0776 antigens were the most promising for detecting vaccinated animals, while MSC_0636 and LppB were the best targets to identify infected animals. Further testing of sera from vaccinated and infected animals collected at different time intervals in the field should help establish how useful a diagnostic test based on a cocktail of these proteins would be.

Contagious Bovine Pleuropneumonia: A Comprehensive Overview

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle that is listed as notifiable by the World Organization for Animal Health. It is endemic in sub-Saharan Africa and causes important productivity losses due to the high mortality and morbidity rates. CBPP is caused by Mycoplasma mycoides subsp. mycoides (Mmm) and is characterized by severe fibrinous bronchopneumonia and pleural effusion during the acute to subacute stages and by pulmonary sequestra in chronic cases. Additional lesions can be detected in the kidneys and in the carpal and tarsal joints of calves. Mmm infection occurs through the inhalation of infected aerosol droplets. After the colonization of bronchioles and alveoli, Mmm invades blood and lymphatic vessels and causes vasculitis. Moreover, Mmm can be occasionally demonstrated in blood and in a variety of other tissues. In the lung, Mmm antigen is commonly detected on bronchiolar and alveolar epithelial cells, in lung phagocytic cells, within the wall of blood and lymphatic vessels, inside necrotic areas, and within tertiary lymphoid follicles. Mmm antigen can also be present in the cytoplasm of macrophages within lymph node sinuses, in the germinal center of lymphoid follicles, in glomerular endothelial cells, and in renal tubules. A complete pathological examination is of great value for a rapid presumptive diagnosis, but laboratory investigations are mandatory for definitive diagnosis. The purpose of this review is to describe the main features of CBPP including the causative agent, history, geographic distribution, epidemiology, clinical course, diagnosis, and control. A special focus is placed on gross and microscopic lesions in order to familiarize veterinarians with the pathology and pathogenesis of CBPP.