The Strategic Advisory Group of Experts (SAGE) Working Group on rabies vaccines and immunoglobulins was established in 2016 to develop practical and feasible recommendations for prevention of human rabies. To support the SAGE agenda we developed models to compare the relative costs and potential benefits of rabies prevention strategies.
Transmission of rabies from animals to people continues despite availability of good vaccines for both human and animal use. The only effective strategy to achieve elimination of dog rabies and the related human exposure is to immunize dogs at high coverage levels. We present the analysis of two consecutive parenteral dog mass vaccination campaigns conducted in N'Djamena in 2012 and 2013 to advocate the feasibility and effectiveness for rabies control through proof of concept. The overall coverage reached by the intervention was >70% in both years. Monthly reported rabies cases in dogs decreased by more than 90% within one year. Key points were a cooperative collaboration between the three partner institutions involved in the control program, sufficient information and communication strategy to access local leaders and the public, careful planning of the practical implementation phase and the effective motivation of staff. The dynamic and semi to non-restricted nature of dog populations in most rabies endemic areas is often considered to be a major obstacle to achieve sufficient vaccination coverage. However, we show that feasibility of dog mass vaccination is highly dependent on human determinants of dog population accessibility and the disease awareness of dog owners. Consequently, prior evaluation of the human cultural and socio-economic context is an important prerequisite for planning dog rabies vaccination campaigns.
La rage est une zoonose virale grave. Elle constitue autant de menace pour la Sante Publique que les autres infections. Elle est causee par un virus du genre Lyssavirus et de la famille rhabdoviridae. Pour l’execution de la campagne antirabique 2012, 30 agents vaccinateurs et 3 superviseurs ont ete recrutes, vaccines contre la rage et formes sur les techniques de vaccination. Aussi, 50.000 doses du vaccin antirabique, des seringues, des carnets de vaccination et des aiguilles ainsi que des glacieres (10 de 5 litres et 3 de 50 litres) ont ete achetees. Les seances de vaccination des chiens et autres animaux de compagnie se sont deroulees uniquement pendant les week-ends (vendredi, samedi et dimanche) et se sont realisees aux endroits (postes) fixes predetermines en commun accord avec les Delegues des quartiers. Pour mener a bien la campagne de vaccination, des seances de sensibilisation de la population de la ville de N’djamena ont ete organisees. Elles consistaient en l’affichage des posters dans les lieux publics (les hopitaux, les centres de sante, les etablissements scolaires, les bureaux des arrondissements, etc.), la distribution des depliants dans les hopitaux et les centres de sante et l’organisation d’un atelier d’information a l’intention des Delegues de differents quartiers de Ndjamena. La campagne de vaccination antirabique edition 2012 a ete lancee officiellement lors de la manifestation de la journee mondiale de lutte contre la rage le 28 Septembre a l’Ecole Nationale des Techniques d’Elevage (ENATE). La campagne de vaccination de masse a dure au total 13 semaines. Selon la methode developpee par Thomas Bayes au 18eme siecle citee par Goodman (1999), la population canine dans la ville de Ndjamena a ete estimee a 24.989 tetes. Au total 17.701 chiens avec proprietaires ont ete vaccines lors de cette campagne soit une couverture vaccinale de 70,83%. Hormis les chiens, 1.484 chats et 104 singes ont aussi ete vaccines. Malgre les difficultes rencontrees durant la campagne de vaccination antirabique 2012, les resultats de la campagne antirabique de 2012 peuvent etre consideres comme succes car plus de 70,% de taux de couverture vaccinale est obtenue, ce qui est legerement au dessus du seuil preconise par l’Organisation mondiale de la sante animale qui est de 70%. Pour la prochaine campagne, il est recommande d’impliquer suffisamment les maires d’arrondissements afin d’amener les delegues des quartiers et les chefs des carres a mieux sensibiliser leurs populations respectives. Mots cles : Rage, vaccin, vaccination, chiens, Ndjamena, Tchad
Better surveillance is desperately needed to guide rabies prevention and control to achieve the goal of zero dogmediated human rabies by 2030, defined by the World Health Organization (WHO) and partners in 2015.With the help of funding from the Vaccine Alliance (GAVI) learning agenda, we implemented animal rabies surveillance based on One Health communication, improved accessibility of diagnostic testing and facilitated sample transport to increase case detection in three regions of Chad.Through the project, rabies surveillance, previously only available in N'Djaména, was extended to selected provincial rural and urban areas.Nine decentralized diagnostic units (DDU) were established, hosted by veterinary district agencies (VDA) in four different administrative regions.Four additional VDAs in the study area were reinforced with facilitation of sample collection and transport.Staff from all these 13 veterinary facilities were trained in sample collection and diagnostics.DDUs performed Rapid Immunodiagnostic Tests (RIDT) providing a preliminary result before samples were sent to the central laboratory in N'Djamena for confirmation with the standard Florescent Antibody Test (FAT).Within the project period from June 2016 to March 2018, 115 samples were reported by veterinary facilities in the study areas compared to 63 samples received from outside the study area, the vast majority of them originating from the capital city N'Djaména (N=61).Eighty nine percent of all 178 samples reported to IRED during the project period tested positive.Most of the samples originated from dogs (92%).Other confirmed rabies positive animals observed were cats, a donkey and a pig.Although surveillance of animal rabies was the focus, four human saliva samples were also submitted for diagnosis.We observed high differences in reporting rates between the four study regions.This could be attributable to differences in rabies epidemiology but are also influenced by the distance to the central laboratory in N'Djaména, the cultural background and the level of public awareness.The possibility for local testing through RIDT was very welcomed by local veterinary staff and preliminary insights suggest a positive influence on One Health communication and PEP initiation.However, these aspects as well as the relative impact of local testing on sample collection in comparison to reinforcement of sample collection and transport alone, need to be further investigated.Challenges encountered related to poor infrastructure (buildings, appliances, materials) and low logistic capacity (lacking means and material for transport and communication) of veterinary services in Chad.In addition, veterinary personnel lack experience in data management.Together with staff turnover, this leads to a need for repeated training.Major shortcoming of the approach was the high cost per sample and limited sustainability beyond the project timeframe.
