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Freuling CM, Busch F, Shikongo MB, Silume N, van der Westhuizen J, Khaiseb S, Shilongo A, Müller T. Emergency response using oral rabies vaccination of dogs -field data from Namibia demonstrate high efficiency. One Health 2023; 16:100562. [PMID: 37363208 PMCID: PMC10288086 DOI: 10.1016/j.onehlt.2023.100562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 06/28/2023] Open
Abstract
Dog-mediated rabies is responsible for tens of thousands of human deaths annually, and in resource-constrained settings, vaccinating dogs to control the disease at source remains challenging for various reasons. Currently, rabies elimination efforts rely on mass dog vaccination by the parenteral route. While oral rabies vaccination (ORV) of dogs is primarily considered a tool to increase herd immunity, particularly by targeting free-roaming and stray dogs, here, we are showcasing an ORV-only approach as an emergency response model. Using a third-generation vaccine and a standardized egg-flavored bait, we assessed the effectiveness and vaccination under field conditions in the Zambezi region of Namibia. During this trial, with four teams and within four working days, 3097 dogs were offered a bait, of which 88,0% were considered vaccinated. Teams managed to vaccinate, on average, over 20 dogs/h, despite using a door-to-door vaccination approach. The favorable results both in terms of bait acceptance and successful vaccination as well as field applicability and effectiveness further support the great potential of ORV in dog rabies control programmes.
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Affiliation(s)
- Conrad M. Freuling
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut (FLI), WHO Collaborating Centre for Rabies Surveillance and Research, OIE Reference Laboratory for Rabies, 17493 Greifswald-Insel Riems, Germany
| | - Frank Busch
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut (FLI), 17493 Greifswald-Insel Riems, Germany
| | - Mainelo Beatrice Shikongo
- Animal Disease Control, Zambezi Region, Ministry of Agriculture, Water & Land Reform, Directorate of Veterinary Services, State Veterinary Office, Katima Mulilo, Namibia
| | - Nzwana Silume
- Animal Disease Control, Zambezi Region, Ministry of Agriculture, Water & Land Reform, Directorate of Veterinary Services, State Veterinary Office, Katima Mulilo, Namibia
| | - Jolandie van der Westhuizen
- Central Veterinary Laboratory, Directorate of Veterinary Services (DVS), Ministry of Agriculture Water and Land Reform, Windhoek, Namibia
| | - Siegfried Khaiseb
- Central Veterinary Laboratory, Directorate of Veterinary Services (DVS), Ministry of Agriculture Water and Land Reform, Windhoek, Namibia
| | - Albertina Shilongo
- Directorate of Veterinary Services (DVS), Ministry of Agriculture Water and Land Reform, Windhoek, Namibia
| | - Thomas Müller
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut (FLI), WHO Collaborating Centre for Rabies Surveillance and Research, OIE Reference Laboratory for Rabies, 17493 Greifswald-Insel Riems, Germany
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Samkange A, van der Westhuizen J, Voigts AS, Chitate F, Kaatura I, Khaiseb S, Hikufe EH, Kabajani J, Bishi AS, Mbiri P, Hawanga NN, Mushonga B. Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018. Trop Anim Health Prod 2022; 54:346. [PMID: 36242679 DOI: 10.1007/s11250-022-03342-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 10/04/2022] [Indexed: 11/28/2022]
Abstract
This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X2 (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X2 (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.
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Affiliation(s)
- Alaster Samkange
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia.
| | | | | | - Frank Chitate
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
| | - Israel Kaatura
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
| | - Siegfried Khaiseb
- Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia
| | - Emmanuel H Hikufe
- Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia
| | - Juliet Kabajani
- Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia
| | - Alec S Bishi
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
| | - Pricilla Mbiri
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
| | - Ndahafa N Hawanga
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
| | - Borden Mushonga
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia
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Freuling CM, Busch F, Vos A, Ortmann S, Lohr F, Hedimbi N, Peter J, Nelson HA, Shoombe K, Shilongo A, Gorejena B, Kaholongo L, Khaiseb S, van der Westhuizen J, Dietze K, Geurtse G, Müller T. Oral rabies vaccination of dogs—Experiences from a field trial in Namibia. PLoS Negl Trop Dis 2022; 16:e0010422. [PMID: 35994498 PMCID: PMC9436088 DOI: 10.1371/journal.pntd.0010422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/01/2022] [Accepted: 06/24/2022] [Indexed: 11/29/2022] Open
Abstract
Dog-mediated rabies is responsible for tens of thousands of human deaths annually, and in resource-constrained settings, vaccinating dogs to control the disease at source remains challenging. Currently, rabies elimination efforts rely on mass dog vaccination by the parenteral route. To increase the herd immunity, free-roaming and stray dogs need to be specifically addressed in the vaccination campaigns, with oral rabies vaccination (ORV) of dogs being a possible solution. Using a third-generation vaccine and a standardized egg-flavoured bait, bait uptake and vaccination was assessed under field conditions in Namibia. During this trial, both veterinary staff as well as dog owners expressed their appreciation to this approach of vaccination. Of 1,115 dogs offered a bait, 90% (n = 1,006, 95%CI:91–94) consumed the bait and 72.9% (n = 813, 95%CI:70.2–75.4) of dogs were assessed as being vaccinated by direct observation, while for 11.7% (n = 130, 95%CI:9.9–17.7) the status was recorded as “unkown” and 15.4% (n = 172, 95%CI: 13.4–17.7) were considered as being not vaccinated. Smaller dogs and dogs offered a bait with multiple other dogs had significantly higher vaccination rates, while other factors, e.g. sex, confinement status and time had no influence. The favorable results of this first large-scale field trial further support the strategic integration of ORV into dog rabies control programmes. Given the acceptance of the egg-flavored bait under various settings worldwide, ORV of dogs could become a game-changer in countries, where control strategies using parenteral vaccination alone failed to reach sufficient vaccination coverage in the dog population. Rabies in dogs can be prevented by vaccination, and this approach has become a cornerstone in the control and eventual elimination of the disease. However, vaccinating hard-to-reach often free-roaming dogs are a challenge and represents one of the challenges to reach sufficient herd-immunity. A potential solution would be to vaccinate these dogs using oral baits filled with a vaccine. In this study we have assessed the acceptability of oral rabies vaccination (ORV) in Namibian dogs under field conditions. The results demonstrate that the method is acceptable both for the owners and the dogs, with a very high uptake of the egg-flavored bait. This supports the potential of ORV to contribute to vaccination programs where parenteral vaccination alone failed to reach sufficient vaccination coverage in the dog population.
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Affiliation(s)
- Conrad Martin Freuling
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut (FLI), WHO Collaborating Centre for Rabies Surveillance and Research, WOAH Reference Laboratory for Rabies, Greifswald-Insel Riems, Germany
- * E-mail:
| | - Frank Busch
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut (FLI), Greifswald-Insel Riems, Germany
| | - Adriaan Vos
- Ceva Innovation Center GmbH, Dessau–Rosslau, Germany
| | | | | | - Nehemia Hedimbi
- Animal Disease Control, Kunene, Ministry of Agriculture, Water & Land Reform, Directorate of Veterinary Services, State Veterinary Office, Opuwo, Namibia
| | - Josephat Peter
- Directorate of Veterinary Services, State Veterinary Office, Omusati, Namibia
| | | | - Kenneth Shoombe
- Deputy Chief Veterinary Officer, Animal Disease Control, North, Ministry of Agriculture, Water & Land Reform, Directorate of Veterinary Services, State Veterinary Office, Ongwediva, Namibia
| | - Albertina Shilongo
- Chief Veterinary Officer, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | - Brighton Gorejena
- Faculty of Agriculture and Natural Resources, Ogongo Campus, University of Namibia, Wnindhoek, Namibia
| | - Lukas Kaholongo
- Faculty of Agriculture and Natural Resources, Ogongo Campus, University of Namibia, Wnindhoek, Namibia
| | - Siegfried Khaiseb
- Central Veterinary Laboratory, Directorate of Veterinary Services (DVS), Ministry of Agriculture Water and Land Reform, Windhoek, Namibia
| | - Jolandie van der Westhuizen
- Central Veterinary Laboratory, Directorate of Veterinary Services (DVS), Ministry of Agriculture Water and Land Reform, Windhoek, Namibia
| | - Klaas Dietze
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut (FLI), Greifswald-Insel Riems, Germany
| | | | - Thomas Müller
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut (FLI), WHO Collaborating Centre for Rabies Surveillance and Research, WOAH Reference Laboratory for Rabies, Greifswald-Insel Riems, Germany
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Müller T, Hassel R, Jago M, Khaiseb S, van der Westhuizen J, Vos A, Calvelage S, Fischer S, Marston DA, Fooks AR, Höper D, Freuling CM. Rabies in kudu: Revisited. Adv Virus Res 2022; 112:115-173. [DOI: 10.1016/bs.aivir.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hassel R, Vos A, Clausen P, Moore S, van der Westhuizen J, Khaiseb S, Kabajani J, Pfaff F, Höper D, Hundt B, Jago M, Bruwer F, Lindeque P, Finke S, Freuling CM, Müller T. Experimental screening studies on rabies virus transmission and oral rabies vaccination of the Greater Kudu (Tragelaphus strepsiceros). Sci Rep 2018; 8:16599. [PMID: 30413745 PMCID: PMC6226427 DOI: 10.1038/s41598-018-34985-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/26/2018] [Indexed: 11/25/2022] Open
Abstract
Rabies in the Greater Kudu (Tragelaphus strepsiceros) in Namibia is unique and found in such magnitude as has not been reported elsewhere in southern Africa. Reasons as to why Kudus appear to be exceptionally susceptible to rabies still remain speculative at best. Because the current severe rabies endemic in Kudus continues to have an enormous negative impact on the Namibian agricultural sector, we set out to question existing dogmas regarding the epidemiology of the disease in a unique experimental setting. In addition, we explored effective measures to protect these antelopes. Although we were able to confirm high susceptibly of kudus for rabies and sporadic horizontal rabies virus transmission to contact animals, we contend that these observations cannot plausibly explain the rapid spread of the disease in Kudus over large territories. Since parenteral vaccination of free-roaming Kudus is virtually impossible, oral rabies vaccination using modified life virus vaccines with a high safety profile would be the ultimate solution to the problem. In a proof-of-concept study using a 3rd generation oral rabies virus vaccine construct (SPBN GASGAS) we found evidence that Kudus can be vaccinated by the oral route and protected against a subsequent rabies infection. In a second phase, more targeted studies need to be initiated by focusing on optimizing oral vaccine uptake and delivery.
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Grants
- The project was funded by kind donations from Namibian farmers associations and individual farmers, the Conservancies Association of Namibia (CANAM) and individual conservancies, the Namibia Professional Hunting Association (NAPHA), Environmental Investment Fund (EIF), Game Products Trust Fund (GPF), Small Grant Program, First National Bank of Foundation, Agribank of Namibia, Paratus Telecom, B 2 Gold, Blaser Jagdwaffen, Dallas Safari Club, Global Supplies, Feedmaster, Afrivet, AGRA Ltd, Safari Den and Voermol Feeds
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Affiliation(s)
- Rainer Hassel
- School of Veterinary Medicine, University of Namibia, Private Bag 13301, Windhoek, Namibia
- ProVision at Agra Ltd., Private Bag 12011, Windhoek, Namibia
| | - Ad Vos
- IDT Biologika GmbH, Am Pharmapark, 06861, Dessau-Rosslau, Germany
| | - Peter Clausen
- Okosongoro Safari Ranch, P.O. Box 324, Omaruru, Namibia
| | - Susan Moore
- Kansas State University, Veterinary Diagnostic Laboratory, Rabies Laboratory, Manhattan, KS, 66502, USA
| | | | | | - Juliet Kabajani
- Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia
| | - Florian Pfaff
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, Südufer 10, 17493, Greifswald - Insel Riems, Germany
| | - Dirk Höper
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, Südufer 10, 17493, Greifswald - Insel Riems, Germany
| | - Boris Hundt
- IDT Biologika GmbH, Am Pharmapark, 06861, Dessau-Rosslau, Germany
| | - Mark Jago
- School of Veterinary Medicine, University of Namibia, Private Bag 13301, Windhoek, Namibia
| | - Floris Bruwer
- ProVision at Agra Ltd., Private Bag 12011, Windhoek, Namibia
| | | | - Stefan Finke
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institute, Südufer 10, 17493, Greifswald - Insel Riems, Germany
| | - Conrad M Freuling
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institute, Südufer 10, 17493, Greifswald - Insel Riems, Germany
| | - Thomas Müller
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institute, Südufer 10, 17493, Greifswald - Insel Riems, Germany.
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