Highly Pathogenic Avian Influenza Virus Subtype H5N1 in Africa: A Comprehensive Phylogenetic Analysis and Molecular Characterization of Isolates

Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level

Sequential Application of Lambda-Cyhalothrin on Cattle with the Electrodyn^TM Method. Results Obtained in Togo in the Context of the African Animal Trypanosomosis Control

Smallholders’ access to pour-on-type products was rendered difficult after the price increase of imported products, a consequence of the 1994 devaluation of the CFA franc. They thus turned to less reliable methods for the control not only of ticks, but also of African animal trypanosomoses (AAT) transmitted by tsetse flies or glossinae. To address this problem, the Animal Trypanomosis Control Project in Togo investigated the use of a new application method that combined pour-on method advantages and a lower cost: ElectrodynTM (Zeneca). This method is based on the electrodynamic spraying of an insecticide formulation (Karate 2.5 ED®) containing 1% lambda-cyhalothrin. The trial was conducted on 170 head of cattle in the village of Skriback in the north of Togo (304 head at the end of the trial). All the animals were treated between March 1996 and March 1997, and only half of them were treated between July 1997 and July 1998. Before starting the first treatment, preliminary surveys were carried over a one-year period (from February 1995 to February 1996) to obtain precise data on the area tsetse challenge, for before-and-after-treatment comparisons. Results showed that the system was very efficient within the study set-up. It helped reduce tsetse fly densities by 99.55%, and reduce AAT prevalence from 17 to 2% when used in combination with a trypanocide treatment. It also helped improve the herd mean packed cell volume from 27 to 32.5%, when used in combination with a regular anthelmintic treatment. The Electrodyn method is also cost-effective, its cost being a third of the traditional pour-on method. Furthermore, huge additional advantages can be obtained through the joint use of equipment in areas of intensive phytosanitary control. Handling of the applicator (fixed length) and the relatively high cost of batteries are the constraints that may affect acceptability of the technique

Adoption d\'une nouvelle technique de contrôle de la mouche tsésé par des éleveurs du nord du Togo: considérations socio-économiques

ACQUISITION OF A NEW TSETSE FLY CONTROL TECHNIQUE BY FARMERS OF THE NORTH OF TOGO: SOCIO-ECONOMIC ASPECTS Summary This document comments on an approach of integrated AAT control through vector-control (tsetse), a technique which requires concerted action and cooperation of the farmers. The results recorded between 1997 and 1999 show that the method was never 100% assimilated (between 3% and 67%). The organisation of livestock owners in time (synchronisation) and space (adherence) was problematic. Cattle numbers, as well as economic constraints, forced stockholders to adapt the technology in terms of lower frequency of treatment, a weaker synchronisation and /or a smaller coverage of the herd. Factors such as the importance of animal traction, the relationships between stockholders, their knowledge of the disease, of the insecticides available and the importance they attach to tick-control and the health status of their animals were determinant in accepting the control-method. General veterinary expenses decreased by 43%, cattle numbers increased by 28%. The latter was a result of increased trading and influx of cattle herds into the controlled areas. This campaign has hardly been an overall success, but offers nevertheless an interesting insight into socio-cultural and economic mechanisms which contribute to the farmers' decision to accept or reject a new technology. Key words: Pour-on, glossina, trypanosoma, cattle, Togo. Résumé Ce document décrit une approche de contrôle intégré de la TAA sous forme de lutte anti-vectorielle (tsétsé) à l'aide d'insecticides topiques, une technique qui nécessite une action concertée et la coopération des éleveurs. Les résultats obtenus entre 1997 et 1999 montrent que le taux d'adoption de la technologie n'a jamais été de 100% (entre 3% et 67%). L'organisation des éleveurs dans le temps (synchronisation) et dans l'espace (adhésion) pose problème. Les effectifs ainsi que des considérations économiques forcent à l'adaptation de la technologie : diminution de la fréquence, faible synchronisation et/ou moindre couverture des animaux. L'importance accordée à la culture attelée, mais aussi l'entente qui règne entre les éleveurs, leur connaissance des maladies et des insecticides, l'importance qu'ils accordent aux tiques et l'état de santé de leurs animaux sont déterminants. Les dépenses vétérinaires globales ont diminué de 43%. L'effectif de l'ensemble des zones a connu une augmentation de 28%; ceci s'explique par une politique d'achat et l'introduction de troupeaux dans les zones assainies. La campagne n'a donc pas été un succès généralisé, mais offrait plutôt un aperçu de toutes les considérations socioculturelles et économiques qui interviennent dans la décision de l'éleveur d'adopter ou de rejeter une nouvelle technologie. Mots-clés: Insecticide, glossine, trypanosome, bétail, Togo. Bull Anim. Hlth. Prod. Afr. Vol.52(3) 2004: 142-15

Evaluation de la campagne de lutte contre la peste des petits ruminants au Togo: Evaluation of the vaccination campaign against peste des petits ruminants in Togo

Le Togo compte plus de 4,5 millions de petits ruminants (ovins et caprins) élevés par près de 80 % de ménages agricoles. Malgré son importance économique, cet élevage est confronté à de nombreuses contraintes dont les pathologies parmi lesquelles la Peste des Petits Ruminants (PPR) qui est une pathologique majeure. Plus de 50 foyers de PPR étaient notifiés chaque année avant 2010 en raison d’une faible couverture vaccinale. Pour lutter contre ce fléau, un programme de vaccination a été initié et débuté en 2011 dans le cadre de la mise en oeuvre du programme national d’investissement agricole et de sécurité alimentaire (PNIASA). Le programme a consisté en une vaccination systématique des petits ruminants, accompagnée d’un déparasitage à l’albendazole sur toute l’étendue du territoire. Cette étude fait l’évaluation de ce programme de vaccination 5 ans après sa mise en oeuvre. Des prélèvements de sang sur les petits ruminants ont été réalisés avant le début du programme pour déterminer la situation de référence et après chaque campagne de vaccination pour estimer le taux de séroconversion d’une part et d’autre part la séroprévalence résiduelle. Sur les 5 campagnes de vaccination menées (période 2011- 2012 à 2015-2016), un effectif cumulé de 2 300 000 petits ruminants sur 4 506 489 petits ruminants recensés ont été vaccinés pour une prévision à vacciner de 2 500 000. La séroconversion a évolué durant les 5 campagnes de 70 % à plus de 90%. Aucune différence significative n’a été notée entre les taux de séroconversion chez les ovins et les caprins. La séroprévalence initiale qui était de 28,23% + 0,18 en début de campagne en 2011-2012 a baissé jusqu’à 5,7% à la campagne de 2015-2016. La diminution de l’incidence de la maladie sur le terrain démontre de l’efficacité de la stratégie mise en place pour le contrôle de la PPR. Une stratégie nationale a permis au Togo de disposer d’un fonds de roulement pour pérenniser ces actions et contrôler cette maladie. De même, le Togo s’est inscrit en 2015 dans le programme mondial d’éradication de la PPR (PMEPPR) suivant un processus de contrôle et d’éradication de la PPR à l’horizon 2030.ABSTRACT:Togo has more than 4.5 million small ruminants (sheep and goats), which are farmed by almost 80% of agricultural households. Despite its economic importance, this livestock is confronted with many constraints including pathologies. Peste des Petits Ruminants (PPR) is one of the major pathological constraints. More than 50 outbreaks of PPR were reported annually before 2010 due to low immunization coverage. To fight this disease, a vaccination program was initiated and started in 2011 as part of the implementation of the National Agricultural Investment and Food Security Program (PNIASA). The vaccination program consists of a routine vaccination of small ruminants surveyed throughout the territory, accompanied by deworming with albendazole. This study evaluates this program after 5 years’ implementation. Blood samples from small ruminants were taken before the beginning of the program to determine the reference situation and after each vaccination campaign to estimate the seroconversion rate on the one hand and the residual seroprevalence on the other hand. Of the 5 vaccination campaigns carried out (from 2011-2012 to 2015-2016), a cumulative total of 2,300,000 small ruminants out of 4,506,489 identified small ruminants in 2015 were vaccinated for a vaccination forecast of 2,500,000. Seroconversion was evolved during the 5 campaigns from 70% to over 90%. No significant difference was noted between seroconversion rates in sheep and goats. The initial seroprevalence, which was 28.23% + 0.18 at the beginning of the campaign in 2011-2012, decreased to 5.7% in the 2015-2016 campaign. The decrease in the incidence of the disease demonstrates the effectiveness of the strategy put in place for its control. A national strategy has enabled Togo to have revolving fund to sustain these actions and control the disease. However, since 2015, Togo has been in the process of monitoring and eradicating PPR by 2030 within the framework of the global PPR eradication program (GEP-PPR)

Parasitisme des petits ruminants dans la zone périurbaine de Sokodé, Togo. I. Ovins

The cross-section parasitological analysis of 359 samples taken from sheep in the suburban area of Sokode (central area of Togo) allowed the diagnosis of coccidiosis (33% prevalence) and gastrointestinal nematodes (88%) such as Trichostrongylus sp., Cooperia sp., Oesophagostomum sp. and Haemonchus sp. Furthermore, lungworms (Protostrongylus rufescens) were found (16%) as well as the cestode Monieza sp. (8%). Trematodes were represented by Paramphistomum sp. (15%), Fasciola sp. (1%) and Schistosoma sp. (only one positive sample). All three major scabies parasites were confirmed (Sarcoptes sp., Psoroptes sp. and Chorioptes sp.). Ticks were represented by Amblyomma sp. and Boophilus sp. Serological analyses showed animals positive for Toxoplasma gondii (22%) and for Oestrus ovis (79%), although no larvae were found (exploration of the nasal cavity). When combining the effects on PCV of several classes of infection with trypanosomosis, gastrointestinal nematodes and their mixed infections, it appeared that trypanosomosis (13%) remained the parasitosis with the highest impact on health parameters. Several statistical analyses that took into account environmental, management and breed-related factors allowed better understanding of host-environment interactions

Les bovins trypanotolerants de l’Afrique de l’ouest

L’amélioration de la productivité des races animales et le maintien de la diversité génétique animale sont utiles aux éleveurs. Ceci leur permet de sélectionner les animaux ou de créer de nouvelles races afin de faire face aux modifications de l’environnement, à l’émergence de nouvelles maladies et aux besoins de la société. Tout programme de sélection ou d’amélioration nécessite au préalable un inventaire détaillé des races animales disponibles. Ce travail s’est intéressé à l’inventaire des différentes races bovines trypanotolérantes existantes dans la zone du CIRDES. Cette zone couvre sept pays de l’Afrique de l’ouest à savoir le Bénin, le Burkina Faso, la Côte-d’Ivoire, le Ghana, le Mali, le Niger et le Togo. La collecte des données a été réalisée grâce à une étude bibliographique, complétée par des enquêtes dans les pays concernés. Quinze races bovines locales ont été inventoriées parmi lesquelles cinq sont qualifiées de trypanotolérantes : N’dama, Baoulé/Somba, Lagunaire, métis Zébu X N’dama et métis Zébu X Taurins à courtes cornes. Les résultats obtenus ont permis de réaliser une cartographie des bovins en indiquant, pour chaque pays, les zones de fortes concentrations du bétail, les races les plus importantes et les aires de distribution. L’étude a révélé que la race Pabli du Bénin a disparu, que les races Lagunaire et Kouri sont menacées d’extinction, que le groupe Baoulé-Somba est soumis à une absorption par les races Borgou et zébu. Le pourcentage des taurins par rapport à l’effectif total du cheptel diminue au fil des années. Par contre celui des races Borgou et Zébu augmente considérablement dans les zones à risque trypanosomien élevé. Aussi est-il urgent de mettre en place un programme régional visant la conservation des races aux effectifs réduits afin de maintenir la diversité biologique.Mot clés : Inventaire, races bovines trypanotolérantes, taurins, zébus, métis locaux, caractères ethniques, Cartographie