Risk of foot and mouth disease spread through cattle movements in Uganda.

Foot and mouth disease (FMD) is endemic in Uganda, where livestock movements through porous borders and beyond play a key role in the spread of transboundary animal diseases. Data from published and unpublished sources were used to conduct a qualitative risk assessment based on the World Organisation for Animal Health framework to assess the risk of foot and mouth disease virus spread in Uganda through pastoral and trade-related cattle movements from the country's southern border districts. A scenario tree was developed as a conceptual framework, and the risk was assessed by considering factors including the cattle population, proportion of vaccinated cattle, number of live cattle legally moved from districts along the Ugandan-Tanzanian border, the production system in the destination districts and the purpose of the movement. Factors associated with higher risk included live cattle movements for pastoral/grazing and breeding purposes, particularly those towards agro-pastoral (AP) areas, which have the potential to lead to outbreaks on several farms in the destination district and other districts countrywide. Prophylactic vaccination should therefore prioritise districts from which movements of large volumes of cattle to other areas originate and the AP destination districts. Specific awareness campaigns should be conducted in destination districts to improve preventative measures and farm biosecurity levels. This study will inform the revision of the risk-based strategic plan, aimed at reducing FMD impacts in Uganda, as the country progresses along the progressive control pathway for FMD.

La fièvre aphteuse est présente à l'état endémique en Ouganda, pays où les mouvements de bétail à travers et au-delà des frontières poreuses jouent un rôle déterminant dans la propagation des maladies animales transfrontalières. Une évaluation qualitative des risques basée sur le cadre de l'Organisation mondiale de la santé animale a été réalisée, en utilisant des données provenant aussi bien de sources publiées que non publiées, afin d'évaluer les risques de propagation du virus de la fièvre aphteuse en Ouganda par le biais des mouvements pastoraux et commerciaux de bétail en provenance des districts frontaliers du sud du pays. Un arbre de scénarios a été élaboré en tant que cadre conceptuel. Les risques ont été évalués en tenant compte de facteurs tels que les effectifs du cheptel bovin, la proportion de bovins vaccinés, le nombre de bovins vivants déplacés légalement depuis les districts situés le long de la frontière entre l'Ouganda et la Tanzanie, le système de production pratiqué dans les districts de destination et la finalité des déplacements du bétail. Les principaux facteurs associés à un risque accru étaient les mouvements de bovins vivants liés à l'élevage pastoral/ la mise en pâturage ou à des fins de reproduction, et plus particulièrement les déplacements vers les zones agro-pastorales, en raison du potentiel épidémique qu'ils peuvent avoir dans les fermes du district de destination et d'autres districts à l'échelle du pays. La vaccination prophylactique devrait donc être conduite en priorité dans les districts de provenance des bovins déplacés en grand nombre vers d'autres zones, ainsi que dans les districts de destination lorsqu'ils sont à dominante agro-pastorale. Des campagnes spécifiques d'information et de sensibilisation devraient être menées dans les districts de destination afin d'améliorer les mesures de prévention et le niveau de biosécurité des élevages. Les résultats de cette étude étayeront la mise à jour du plan stratégique fondé sur les risques, qui vise à réduire l'impact de la fièvre aphteuse en Ouganda parallèlement aux avancées du pays sur la voie de l'approche progressive de la lutte contre la fièvre aphteuse.

La fiebre aftosa es endémica en Uganda, país donde los desplazamientos de ganado a través y más allá de sus porosas fronteras son un factor decisivo en la propagación de enfermedades animales transfronterizas. Los autores exponen una evaluación cualitativa del riesgo realizada a partir de datos publicados e inéditos con empleo del marco de la Organización Mundial de Sanidad Animal. Se trataba de evaluar así el riesgo de propagación del virus de la fiebre aftosa en Uganda a resultas de los desplazamientos de ganado desde los distritos fronterizos meridionales con fines de pastoreo o de comercio. Tras elaborar como marco teórico un árbol de hipótesis, se determinó el riesgo teniendo en cuenta, como principales factores, la cabaña bovina, la proporción de ejemplares vacunados, el número de animales vivos transportados legalmente desde los distritos que bordean la frontera entre Uganda y Tanzania, el sistema productivo en los distritos de destino y la finalidad de cada desplazamiento. Entre los factores ligados a un aumento del riesgo destacaba el desplazamiento de animales vivos con fines de pastoreo y de reproducción, en particular con destino a zonas agropastorales, pues ello puede provocar brotes en múltiples explotaciones no solo del distrito de destino, sino también de otros distritos de todo el país. En las actividades de vacunación profiláctica, por lo tanto, conviene otorgar prioridad a los distritos de los que parten grandes contingentes de ganado hacia otras zonas y también a los distritos de destino agropastorales. También habría que implantar campañas específicas de sensibilización en los distritos de destino para mejorar en ellos las medidas de prevención y los niveles de seguridad biológica de las explotaciones. Este estudio servirá de base para la revisión del plan estratégico basado en los riesgos, encaminado a reducir las repercusiones de la fiebre aftosa en Uganda, a la par que el país va cubriendo etapas en la senda progresiva de control de la fiebre aftosa.

Epidemiological analysis of an outbreak of foot-and-mouth disease (serotype SAT2) on a large dairy farm in Kenya using regular vaccination.

During August-September 2012, an outbreak of Foot-and-mouth Disease (FMD) due to serotype Southern African Territories-2 (SAT2) occurred on a large, extensively grazed dairy farm in Nakuru County, Kenya. Over 29 days, 400/644 (62.1%) cattle were recorded as displaying clinical signs consistent with FMD. Out of the 18 management groups present, 17 had clinical cases (weighted mean incidence rate 3.5 per 100 cattle-days, 95% CI 2.4, 5.1; range 0.064-10.9). Transmission may have been encouraged when an infected group was moved to a designated isolation paddock. A four to five day minimum incubation period was apparent in five groups for which a point source exposure was evident. Further transmission was associated with the movement of individual animals incubating infection, use of a common dip and milking parlour, and grazing of susceptible groups in paddocks neighbouring to infectious cases. Animals over 18 months old appeared to be at highest risk of disease possibly due to milder clinical signs seen among younger animals resulting in reduced transmission or cases not being recorded. Cows with a breeding pedigree containing a greater proportion of zebu appeared to be at lower risk of disease. The outbreak occurred despite regular vaccination (three times per year) last performed approximately three months before the index case. Incidence risk by the lifetime number of doses received indicated limited or no vaccine effectiveness against clinical disease. Reasons for poor vaccine effectiveness are discussed with antigenic diversity of the SAT2 serotype and poor match between the field and vaccine strain as a likely explanation. Detailed field-derived epidemiological data based on individual animals are rarely presented in the literature for FMD, particularly in East-Africa and with the SAT2 serotype. This study provides a detailed account and therefore provides a greater understanding of FMD outbreaks in this setting. Additionally, this is the first study to provide field-derived evidence of poor vaccine effectiveness using a SAT2 vaccine. Further field-based measures of vaccine effectiveness in line with evaluation of human vaccines are needed to inform FMD control policy which has previously relied heavily upon experimental data and anecdotal experience.

Naked mole-rats: behavioural phenotyping and comparison with C57BL/6 mice.

Naked mole-rats (NMR) live underground in large eusocial colonies in East Africa. They are extremely long-lived, some individuals having a lifespan of over 30 years. This has attracted research into longevity and possibly neurodegenerative disorders. However, very little is known about their basic behaviour, particularly in tests commonly used to characterise the behaviour of the laboratory rat and mouse, for which there is an enormous database. Recently the authors carried out comprehensive behavioural phenotyping on NMRs, comparing them on most tasks directly with C57BL/6 mice, the strain for which there is the largest behavioural database. The NMR colony had been obtained from the wild originally, but housed in an animal facility for about two years. Large inter-species differences in behaviour were seen between the mice and the NMRs. The latter had generally poor sensorimotor function, including cutaneous sensation, strength and even grasp reflexes. They were often reluctant to enter or head-dip into small holes that mice readily entered. Their vision (generally considered to be very poor) was sufficient to distinguish the two zones of a light-dark box. Although, as expected, the NMRs were capable of burrowing and digging, when individually housed they did not shred cotton material to make nests. Shredding was seen in a colony cage containing a queen, but no nests were made there even when a nesting box was provided. In cognitive testing, although, unlike mice and rats, they did not spontaneously alternate in a T-maze, they learnt rewarded alternation and a cued position task well. This study demonstrates how behaviour uniquely reflects the natural environment in which these unusual animals have evolved and live, and provides baseline data for future work.