Assessing the extent and use of risk analysis methodologies in Africa, using data derived from the Performance of Veterinary Services (PVS) Pathway.

African countries that wish to export are increasingly faced with import risk assessments from importing countries concerned about the sources of their imported goods. Other risk analysis methodologies and approaches are also employed, which focus on animal and human health within countries and communities. Based on an analysis of evaluations conducted by the World Organisation for Animal Health (OIE), using the Performance of Veterinary Services Tool, the authors attempt to define current practice in Africa and degrees of compliance with the World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures ('SPS Agreement') and OIE standards. To assist in this task, the authors also make use of a review of selected risk assessment reports. Results point to a lack of technical capacity and capability to conduct risk assessments in compliance with OIE standards (except in the case of three countries), ranging from an outright absence of any form of (documented) risk assessment and consecutive risk management decisions (level of advancement 1) to shortcomings in one or several aspects of the risk assessment process. This is confirmed by a number of case studies, half of which have been produced by international consultants. The major recommendations of this paper are i) to strengthen the human resources pool for conducting risk assessments and ii) to establish dedicated risk assessment units, with clear terms of reference, job descriptions and policies, procedures and protocols.

Les pays africains souhaitant accéder aux marchés d'exportation sont confrontés à la réalisation de plus en plus fréquente d'appréciations du risque à l'importation par les pays importateurs, qui cherchent à vérifier les sources d'approvisionnement des marchandises qu'ils importent. D'autres méthodologies d'analyse du risque sont également pratiquées, axées sur la santé animale et la santé humaine au niveau des pays et des communautés. À partir d'une analyse des évaluations réalisées par l'Organisation mondiale de la santé animale (OIE) au moyen de l'Outil d'évaluation des performances des Services vétérinaires, les auteurs tentent de définir les pratiques actuelles en Afrique ainsi que le niveau de conformité des pays à l'Accord sur l'application des mesures sanitaires et phytosanitaires de l'Organisation mondiale du commerce (« Accord SPS ¼) et aux normes de l'OIE. Pour ce faire, les auteurs s'appuient également sur l'analyse d'une sélection de rapports d'appréciation du risque. Les résultats laissent apparaître l'inadéquation des capacités et des compétences techniques dédiées à l'appréciation du risque par rapport aux normes de l'OIE (à l'exception du cas de trois pays), depuis l'absence totale d'appréciation du risque à partir d'éléments documentés et de décisions relevant de la gestion de ce risque (niveau d'avancement 1), jusqu'à des insuffisances concernant un ou plusieurs aspects du processus d'appréciation du risque. Cette analyse est confirmée par une série d'études de cas, dont la moitié a été produite par des consultants internationaux. Les auteurs recommandent principalement de renforcer les ressources humaines dédiées aux appréciation du risque et de mettre en place des unités dédiées, en déterminant clairement leur mandat, leur fonction, ainsi que les politiques à mener, les procédures applicables et les protocoles à suivre.

Cada vez más, los países africanos que desean exportar son sometidos a determinaciones del riesgo de importación por parte de los países importadores, preocupados por la procedencia de las mercancías que importan. A veces también se emplean otros métodos y planteamientos de análisis del riesgo, centrados en determinados aspectos zoosanitarios y sanitarios de los países o comunidades de origen. Basándose en un análisis de las evaluaciones realizadas por la Organización Mundial de Sanidad Animal (OIE) con la Herramienta PVS, los autores tratan de aprehender los usos actualmente vigentes en África, así como los niveles de cumplimiento del Acuerdo sobre la Aplicación de Medidas Sanitarias y Fitosanitarias (Acuerdo MSF) de la Organización Mundial del Comercio (OMC) y las normas de la OIE, ayudándose también para ello del estudio de una serie de informes de determinación de riesgos. Los resultados ponen de relieve la falta de competencias y capacidades técnicas para llevar a cabo determinaciones de riesgos con arreglo a las normas de la OIE (salvo en el caso de tres países), con situaciones que van desde la ausencia absoluta de toda forma de determinación (documentada) de los riesgos y, a partir de ahí, de toda decisión para gestionarlos (nivel de progreso 1), hasta la existencia de uno o varios aspectos defectuosos en el proceso de determinación de riesgos, observación que confirman una serie de estudios monográficos, la mitad de ellos obra de consultores internacionales. Las principales recomendaciones de los autores apuntan a fortalecer la dotación de recursos humanos para efectuar determinaciones de riesgos y a establecer unidades dedicadas específicamente a esta labor, habiendo definido con toda claridad su mandato, los perfiles que deben integrarlas y sus políticas, procedimientos y protocolos de trabajo.

The area-wide epidemiology of bovine trypanosomosis and its impact on mixed farming in subhumid West Africa; a case study in Togo.

This paper reports on an area wide study of all major variables determining the expression of trypanosomosis in cattle in the subhumid eco-zone of West Africa, taking Togo as an example. To enable systematic area-wide sampling, the country was divided in 311 grid-squares of 0.125 x 0.125 sides. Cross-sectional surveys were then conducted to generate maps or digital layers on cattle density, herd structure, ownership and breed. These data layers, except for the breed data, were subjected to a cluster analysis in order to define spatial patterns in animal husbandry systems. This analysis revealed two main systems: one is oriented towards integration with crop-agriculture and a second towards investment in cattle. These two systems could be further characterised by incorporating breed data. Zebu cattle and their crossbreeds are more favoured in the second system. The breed distribution map shows the actual situation but also serves to predict the outcome of progressive crossbreeding. An area wide trypanosomosis survey allowed the production of prevalence maps for Trypanosoma congolense, T. vivax and the associated packed cell volume (PCV) values. A simple curvi-linear relationship was established between vector density and disease prevalence. The regression between disease prevalence and PCV for taurine and zebu plus crossbreeds separately, revealed that taurine cattle maintain a comparatively high PCV level particularly in high prevalence scenarios. The relationship between the average herd PCV and cattle density suggests that herd PCV value may provide a mirror for the number of animals not kept because of the prevailing risk. The regression between agricultural intensity and cattle density subsequently in areas with decreasing herd PCV values reveals that the level of integration of cattle in crop production decreases with a decreasing PCV. Thus, despite the presence of taurine animals in Togo, the omnipresence of tsetse in particular Glossina tachinoides, remains a major obstacle to cattle raising and indirectly mixed farming development and intensification. It is argued that only with the present type of wide scale, spatial studies it becomes possible to clarify all the major variables influencing the expression of trypanosomosis. Spatial epidemiological studies at a macro level may form the basis for area wide trypanosomosis control in West Africa.

Can remotely sensed meteorological data significantly contribute to reduce costs of tsetse surveys?

A 0.125 degree raster or grid-based Geographic Information System with data on tsetse, trypanosomiasis animal production, agriculturerkina> and land use has recently been developed in Togo. This paper addresses the problem of generating tsetse distribution and abundance maps from remotely sensed data, using a restricted amount of field data. A discriminant analysis model is tested using contemporary tsetse data and remotely sensed, low resolution data acquired from the National Oceanographic and Atmospheric Administration and Meteosat platforms. A split sample technique is adopted where a randomly selected part of the field measured data (training set) serves to predict the other part (predicted set). The obtained results are then compared with field measured data per corresponding grid-square. Depending on the size of the training set the percentage of concording predictions varies from 80 to 95 for distribution figures and from 63 to 74 for abundance. These results confirm the potential of satellite data application and multivariate analysis for the prediction, not only of the tsetse distribution, but more importantly of their abundance. This opens up new avenues because satellite predictions and field data may be combined to strengthen or substitute one another and thus reduce costs of field surveys.

Pharmacokinetics and anthelmintic efficacy of febantel in the racing pigeon (Columba livia).

This paper reports on the pharmacokinetics and the efficacy of febantel against Capillaria obsignata and Ascaridia columbae in the racing pigeon. Febantel was rapidly cleared from the circulation and highly metabolized. The efficacy of febantel against Capillaria and Ascaridia was studied on lightly and heavily infected pigeons. The efficacy against Ascaridia was 100% for the faecal egg count reduction (FECR) as well as for the worm reduction in all treated pigeons. After two treatments with febantel against Capillaria in heavily infected pigeons the FECR amounted to 96.7% and worm reduction was 95%. In order to effectively remove both parasites from the host, repeated treatments with febantel at a short interval could be the treatment of choice.

The presence of an early L4 larvae population in relation to the immune response of calves against Ostertagia ostertagi.

The influence of different levels of infection with Ostertagia ostertagi on the development of a protective immune response in calves was investigated. Four groups of calves were infected with either 5000 (Group A), 10,000 (Group B), 20,000 (Group C) or 40,000 (Group D) infective larvae (O. ostertagi L3) weekly until treatment began. Group E functioned as controls. All animals were treated with oxfendazole (9 mg ml-1) at Week 17 (Groups A, B and E) or Week 18 (Groups C and D). Sixteen days post-treatment all calves received a challenge infection of 150,000 O. ostertagi L3 spread over 10 consecutive days. Faeces and blood were collected weekly for egg counts and to assess levels of pepsinogen, gastrin and IgG1 and IgG2 Ostertagia antibodies. All calves were necropsied 31 days post-challenge for worm counts. Egg counts and pepsinogen levels were proportional to the infection level during the first few weeks of the experiment. Only in the high-dosed Group D was a gastrin response evoked. Ostertagia IgG1 antibodies increased between Day 25 and Day 95, and in the non-infected control group an antibody rise was observed from Day 67 onwards. All measured parameters except Ostertagia antibodies showed a gradual decrease from Day 70 until the day of treatment. At necropsy there was no significant difference between the groups in the total worm populations. Only the composition of the worm populations differed, with 35% early L4 (EL4) larvae in the previously infected Groups A, B, C and D and only 5% in the control Group E. The results indicate a slow immune response against O. ostertagi in cattle and question the possible role of the EL4 stage in developing immunity.