Private sector involvement in the control of contagious bovine pleuropneumonia (CBPP) in the Kazungula district of Zambia benefitted the community and the control strategy

Assessment of the control measures for category A diseases of Animal Health Law: Contagious Bovine Pleuropneumonia

EFSA received a mandate from the European Commission to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases ('Animal Health Law'). This opinion belongs to a series of opinions where these control measures will be assessed, with this opinion covering the assessment of control measures for Contagious Bovine Pleuropneumonia (CBPP). In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period, (iii) the minimum radius of the protection and surveillance zones, and (iv) the minimum length of time the measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere. Several scenarios for which these control measures had to be assessed were designed and agreed prior to the start of the assessment. Different clinical and laboratory sampling procedures are proposed depending on the scenarios considered. The monitoring period of 45 days was assessed as not effective and at least 90 days (3 months) is recommended in affected areas where high awareness is expected; when the index case occurs in an area where the awareness is low the monitoring period should be at least 180 days (6 months). Since transmission kernels do not exist and data to estimate transmission kernels are not available, the effectiveness of surveillance and protection zones for CBPP was based on expert knowledge. A surveillance zone of 3 km was considered effective, while a protection zone including establishments adjacent to affected ones is recommended. Recommendations, provided for each of the scenarios assessed, aim to support the European Commission in the drafting of further pieces of legislation, as well as for plausible ad hoc requests in relation to CBPP.

Host-Pathogen Interactions of Mycoplasma mycoides in Caprine and Bovine Precision-Cut Lung Slices (PCLS) Models

Respiratory infections caused by mycoplasma species in ruminants lead to considerable economic losses. Two important ruminant pathogens are Mycoplasma mycoides subsp. Mycoides (Mmm), the aetiological agent of contagious bovine pleuropneumonia and Mycoplasma mycoides subsp. capri (Mmc), which causes pneumonia, mastitis, arthritis, keratitis, and septicemia in goats. We established precision cut lung slices (PCLS) infection model for Mmm and Mmc to study host-pathogen interactions. We monitored infection over time using immunohistological analysis and electron microscopy. Moreover, infection burden was monitored by plating and quantitative real-time PCR. Results were compared with lungs from experimentally infected goats and cattle. Lungs from healthy goats and cattle were also included as controls. PCLS remained viable for up to two weeks. Both subspecies adhered to ciliated cells. However, the titer of Mmm in caprine PCLS decreased over time, indicating species specificity of Mmm. Mmc showed higher tropism to sub-bronchiolar tissue in caprine PCLS, which increased in a time-dependent manner. Moreover, Mmc was abundantly observed on pulmonary endothelial cells, indicating partially, how it causes systemic disease. Tissue destruction upon prolonged infection of slices was comparable to the in vivo samples. Therefore, PCLS represents a novel ex vivo model to study host-pathogen interaction in livestock mycoplasma.

Perceptions, circumstances and motivators affecting the implementation of contagious bovine pleuropneumonia control programmes in Nigerian Fulani pastoral herds

Contagious bovine pleuropneumonia (CBPP) is an infectious disease of cattle which substantially contributes to poor productivity of the sub-Saharan pastoral livestock sector. In Nigeria and most of the West African countries, limited public funding for CBPP control have necessitated farmers to bear a bigger burden of managing the disease. Understanding the factors influencing decision of farmers to implement disease control programmes is therefore a key element in informing future policies aimed at improving CBPP management. This study explored perceptions of Nigerian Fulani pastoral herdsmen on the responsibility for cattle healthcare, and identified their circumstances and motivations in implementing CBPP management programmes. Field data were collected from 191 pastoral farmers using a semi-structured, interviewer-administered questionnaire. The results indicated that younger farmers were more likely than their older counterpart to accept the responsibility for CBPP management (p<0.01). This may signal future prospects for improved CBPP management where upcoming farmers could be encouraged to implement CBPP control programmes and uphold the costs. 13.6% of the farmers had no intention of implementing any CBPP control programme on farm, while 81.2% either had a positive intention or implemented at least one programme aimed at controlling CBPP. Intention to implement CBPP control programmes was significantly associated with educational attainment of farmers (p<0.01) and their access to CBPP control services offered by trained veterinarians (p<0.01). Farmers with negative attitudes towards implementing CBPP control programmes could be motivated to change their perspectives by advice from trusted sources and improved access to veterinary services. Conversely, farmers with positive attitudes towards implementing CBPP control programmes were more likely to be motivated by affordable veterinary services and advocacy on specific CBPP control programmes. As such, the former group of farmers will be more likely to benefit from programmes which focus on providing credible information from trusted sources, such as extension agents, veterinarians or successful peers. On the contrary, interventions targeting the latter group of farmers should prioritize cost-effective delivery of improved CBPP control technologies.

Capsular polysaccharide from Mycoplasma mycoides subsp. mycoides shows potential for protection against contagious bovine pleuropneumonia

Contagious Bovine Pleuropneumonia (CBPP) is a severe respiratory disease caused by Mycoplasma mycoides subsp. mycoides (Mmm) which is widespread in Africa. The capsule polysaccharide (CPS) of Mmm is one of the few identified virulence determinants. In a previous study, immunization of mice against CPS generated antibodies, but they were not able to prevent multiplication of Mmm in this model animal. However, mice cannot be considered as a suitable animal model, as Mmm does not induce pathology in this species. Our aim was to induce antibody responses to CPS in cattle, and challenge them when they had specific CPS antibody titres similar or higher than those from cattle vaccinated with the live vaccine. The CPS was linked to the carrier protein ovalbumin via a carbodiimide-mediated condensation with 1-ethyl-3(3-imethylaminopropyl) carbodiimide (EDC). Ten animals were immunized twice and challenged three weeks after the booster inoculation, and compared to a group of challenged non-immunized cattle. When administered subcutaneously to adult cattle, the vaccine elicited CPS-specific antibody responses with the same or a higher titre than animals vaccinated with the live vaccine. Pathology in the group of immunized animals was significantly reduced (57%) after challenge with Mmm strain Afadé compared to the non-immunized group, a figure in the range of the protection provided by the live vaccine.