Seroprevalence and Risk Factors of Contagious Bovine Pleuropneumonia in Selected Districts of North Gondar Zone, Ethiopia

Contagious bovine pleuropneumonia (CBPP) is an infectious and highly contagious respiratory disease of cattle and water buffalo, which is caused by the Mycoplasma mycoides subspecies mycoides small colony. It induces significant economic losses and leads to a serious food security problem, negatively influencing peoples' livelihoods in affected countries. The disease has been reported in different parts of Ethiopia with prevalence ranging from 1.78 to 96%. However, there is not enough epidemiological information about CBPP in the northwestern part of the country, particularly in North Gondar Administrative Zone. This cross-sectional study, therefore, was conducted in four selected districts (Metema, Alefa, Quara, and Dembia) of North Gondar Administrative Zone to detect the incursion and estimate the seroprevalence of CBPP and to identify the potential predisposing factors associated with the spread and occurrence of CBPP in the area. A total of 751 serum samples were collected from 41 herds (villages) having no history of CBPP vaccination. Information like age, sex, breed, herd size, and management were collected during blood sample collection. Data related to agro-climatic zone, trade trekking route from or through CBPP endemic/epidemic zone, transhumance grazing route, vehicle route, and bordering with CBPP epidemic/endemic zone were obtained from district agricultural offices. The serum was screened for CBPP using competitive enzyme-linked immunosorbent assay (c-ELISA) test. The animal level and herd level apparent seroprevalences were 12.92% (95% CI: 10.70-15.52) and 65.85% (95% CI: 49.57-79.10), respectively. The true animal level and herd level prevalences were estimated at 20.13% (95% CI: 16.64-24.21) and 65.22% (95% CI: 48.64-78.72%), respectively. At the animal level, trekking route from or through CBPP endemic/epidemic zone to the study area [OR = 4.77 (95% CI: 1.92-11.84) compared to without trekking route] was identified as the most important risk factor for CBPP spread and seropositivity. In general, epidemiological evidence of the present study indicates that CBPP is a prevalent disease, and animal trekking is an important risk factor for spread of the disease in the study area. This needs due attention from the government and other concerned bodies for its prevention and control to mitigate its economic impact.

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.

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.

Pro-Inflammatory Response of Bovine Polymorphonuclear Cells Induced by Mycoplasma mycoides subsp. mycoides

Mycoplasma mycoides subsp. mycoides (Mmm) is the etiological agent of contagious bovine pleuropneumonia (CBPP), one of the major diseases affecting cattle in sub-Saharan Africa. Some evidences suggest that the immune system of the host (cattle) plays an important role in the pathogenic mechanism of CBPP, but the factors involved in the process remain largely unknown. The present study aimed to investigate the cell response of bovine polymorphonuclear neutrophils (PMNs) after Mmm in vitro exposure using one step RT-qPCR and Western blotting. Data obtained indicate that gene and protein expression levels of some pro-inflammatory factors already change upon 30 min of PMNs exposure to Mmm. Of note, mRNA expression level in Mmm exposed PMNs increased in a time-dependent manner and for all time points investigated; targets expression was also detected by Western blotting in Mmm exposed PMNs only. These data demonstrate that when bovine PMN cells are triggered by Mmm, they undergo molecular changes, upregulating mRNA and protein expression of specific pro-inflammatory factors. These results provide additional information on host-pathogen interaction during CBPP infection.

Serological Prevalence of Contagious Bovine Pleuropneumonia in Niger in 2017

Contagious bovine pleuropneumonia (CBPP) is a highly contagious disease of cattle caused by Mycoplasma mycoides subsp. mycoides Biotype Small Colony (MmmSC). The disease currently occurs in most of sub-Saharan Africa and where it is endemic and a major constraint for improving pastoral productivity. Following the persistence of this scourge, and in order to control this disease, a serological survey was conducted to determine the prevalence of CBPP in Niger. In fact, 1,590 sera were collected following a stratified sampling plan based on the risk factor of dissemination of CBPP. The analysis were performed at the Central Livestock Laboratory using the c-Elisa test. The results obtained show a wide distribution of the disease with an overall prevalence of 4.15% at individual level. The highest prevalences were recorded in the South-East regions [Zinder (7.5%), Diffa (7.5%)] and the West part [Tahoua (6.9%)]. The prevalence at the commune level was about 36.55%, which was relatively high. The prevalence at strata level was 36.55% (95% PI 0.2428-0.4882). The expected prevalences did not match those found. The results of this serological survey are considered the reference situation (T0) of CBPP in Niger with the PRAPS project, and allowed to the country to redefine control policies for better control of the disease at national and sub-regional level.

Methodological aspects of serosurveillance in resource-poor settings

Animal production is important for the agricultural economy in low-income countries, but is threatened by infectious diseases. Serosurveys are conducted for different reasons such as disease detection, risk factor studies, disease monitoring and establishing disease-free status. Most reports on such serosurveys include some discussion about methodological constraints but still, by necessity, rely on serological results for case definition. This study uses a cross-sectional serosurvey for foot-and-mouth disease (FMD), Rift Valley fever (RVF) and contagious bovine pleuropneumonia (CBPP) in cattle in three districts in Western Uganda to illustrate the limitations of this approach, addressing the questions of what flaws can be expected in sampling and diagnostics and how these influence the results. The target was to collect blood samples from 60 cattle herds per district. To reflect the recent infection history of the herd, young animals (two to five years) were prioritised. The farmers were interviewed about management, cattle trade, cattle health and vaccination. Commercial ELISAs were used for serological analyses: for CBPP the IDEXX CBPP Mycoplasma mycoides subspecies mycoides antibody test kit, for RVF the ID Screen Rift Valley Fever competitive ELISA, and for FMD the PrioCHECK FMDV NS. Apparent prevalence, true prevalence and associations with herd characteristics were assessed. The sampling plans could not be entirely fulfilled, nor the number of tests run in the laboratory. There were reactors to all three diseases with an apparent prevalence of approximately 30 per cent for CBPP, 6 per cent for RVF and 7 per cent for FMD. Calculation of true prevalence based on test sensitivity and specificity resulted in a slightly higher prevalence figure for CBPP and lower figures for RVF and FMD. The study illustrates the importance of considering diagnostic test performance when interpreting results from serosurveys, and the challenge of representative sampling and laboratory work in low-income countries.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): contagious bovine pleuropneumonia

Contagious bovine pleuropneumonia has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of contagious bovine pleuropneumonia to be listed, Article 9 for the categorisation of contagious bovine pleuropneumonia according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to contagious bovine pleuropneumonia. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, contagious bovine pleuropneumonia can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria as in Sections 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (d) and (e) of Article 9(1). The animal species to be listed for contagious bovine pleuropneumonia according to Article 8(3) criteria are species of the family Bovidae as susceptible.

Seroprevalence and Distribution of Contagious Bovine Pleuropneumonia in Ethiopia: Update and Critical Analysis of 20 Years (1996-2016) Reports

Contagious bovine pleuropneumonia (CBPP), infectious and highly contagious diseases of cattle in Africa, is the only bacterial disease in the OIE list A diseases. This severe respiratory disease of cattle is the second most important transboundary animal disease in Africa after rinderpest. CBPP is caused by Mycoplasma mycoides subsp. mycoides SC (small colony bovine biotype) and it is endemic disease in many African countries including Ethiopia. This paper systematically reviews prevalence report at herd and individual animal level for the last 20 years (1996-2016) with main aim of making comprehensive document regarding the seroprevalence and distribution of CBPP in Ethiopia. The paper is therefore helpful in knowing the past and current disease status and also to forecast the future and possible prevention option in the country. So far, the seroprevalence that ranges from 0.4 to 96% was reported from different export quarantine centers and production areas in Ethiopia. The reported seroprevalence is significantly associated with different agro-ecology of the country and the highest was reported from lowland in which 40% of livestock population was kept. The recent seroprevalence studies report from different areas of the country also indicated as CBPP is posing a major threat to cattle production in many parts of the country, thereby causing considerable economic losses through morbidity and mortality. This disease also causes restriction on the trade of animals and animal products internationally and accounts for a loss of over 8.96 million US dollars per year in Ethiopian situation. Thus, a great attention should be given both at production areas and the quarantine stations as its occurrence may affect the export earnings of the country, thereby threatening the livelihood of pastoralists and national economy of the country.

mycoides, the causative agent of contagious bovine pleuropneumonia

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm) is a severe cattle disease, present in many countries in sub-Saharan Africa. The development of improved diagnostic tests and vaccines for CBPP control remains a research priority. Polyacrylamide gel electrophoresis and mass spectrometry were used to characterize the Triton X-114 soluble proteome of nine Mmm strains isolated from Europe or Africa. Of a total of 250 proteins detected, 67 were present in all strains investigated. Of these, 44 were predicted to be lipoproteins or cytoplasmic membrane-associated proteins and are thus likely to be members of the core in vitro surface membrane-associated proteome of Mmm. Moreover, the presence of all identified proteins in other ruminant Mycoplasma pathogens were investigated. Two proteins of the core proteome were identified only in other cattle pathogens of the genus Mycoplasma pointing towards a role in host-pathogen interactions. The data generated will facilitate the identification and prioritization of candidate Mycoplasma antigens for improved control measures, as it is likely that surface-exposed membrane proteins will include those that are involved in host-pathogen interactions.