Dr. Darryn Knobel

About

Dr. Knobel’s research encompasses the epidemiology, impact and control of infectious diseases in populations at interfaces. Engaging a One Health approach, he studies the epidemiology of multi-host pathogens that affect animal and human populations. His specific topic of interest is the epidemiology and control of rabies in domestic dog and wild canid populations in Africa. His current research explores the question of non-specific effects of rabies vaccine and other vaccines in dogs. Non-specific effects are unanticipated effects of vaccines that may manifest as a general increase or decrease in rates of illness or death in host populations that cannot be explained by the specific protective effect induced by the vaccine. To address this topic, Dr. Knobel employs a skillset as a quantitative epidemiologist that encompasses randomized controlled trials, analysis of time-to-event data (survival analysis), analysis of mediation and effect modification, and sensitivity analysis. 

As the Director for the Center for Conservation Medicine and Ecosystem Health at Ross University School of Veterinary Medicine (RUSVM), Dr. Knobel also oversees the center's focus on the role of wildlife and the broader ecosystem in the emergence of disease, and conversely, on the impact of infectious diseases from humans or domestic animals on wildlife. Conservation medicine and ecosystem health are emerging fields in the study of diseases in populations. They apply the principle of One Health–the recognition that the health of humans, animals, and the ecosystems in which they live, are inextricably linked. Infectious diseases in particular can no longer be studied in isolation, as these diseases often affect multiple species, including humans, domestic animals and wildlife. 

Publications

  1. Anderson, A., Kotzé, J., Shwiff, S.A., Hatch, B., Slootmaker, C., Conan, A., Knobel, D.L. & Nel, L.H. (2019) A bioeconomic model for the optimization of local canine rabies control. PLoS Neglected Tropical Diseases 13(5): e0007377. doi: 10.1371/journal.pntd.0007377 
  2. Berrian, A.M., Martínez-López, B., Quan, V., Conrad, P.A., van Rooyen, J., Simpson, G.J.G., Frean, J., Weyer, J., Rossouw, J., Knobel, D.L. & Blumberg, L.H. (2019) Risk factors for bacterial zoonotic pathogens in acutely febrile patients in Mpumalanga Province, South Africa. Zoonoses and Public Health 66(5): 458-469. doi: 10.1111/zph.12577 
  3. Stewart, K.M., Norton, T.M., Mitchell, M.A. & Knobel, D.L. (2018) Sea turtle education program development, implementation, and outcome assessment in St. Kitts, West Indies. Chelonian Conservation and Biology 17(2): 216-226. 
  4. Conan, A., Meyer, A., Reininghaus, B., van Rooyen, J. & Knobel, D.L. (2018) A live weight-heart girth relationship in Nguni-type and Brahman-type cattle as a tool for small-scale farmers in South Africa. Applied Animal Husbandry and Rural Development 11: 46-52. 
  5. Grover, M., Bessell, P., Conan, A., Polak, P., Sabeta, C.T., Reininghaus, B. & Knobel, D.L. (2018) Spatiotemporal epidemiology of rabies virus at an interface between domestic dogs and wildlife in South Africa. Scientific Reports 8: 10864. doi: 10.1038/s41598-018-29045-x 
  6. Simpson, G.J.G., Quan, V., Frean, J., Knobel, D.L., Rossouw, J., Weyer, J., Marcotty, T., Godfroid, J. & Blumberg, L.H. (2018) Prevalence of selected zoonotic diseases and risk factors at a human-wildlife-livestock interface in Mpumalanga Province, South Africa. Vector-Borne and Zoonotic Diseases 18(6): 303-310. doi: 10.1089/vbz.2017.2158 
  7. Byaruhanga, C., Collins, N.E., Knobel, D.L., Khumalo, Z.T.H., Chaisi, M.E. & Oosthuizen, M.C. (2018) Molecular detection and phylogenetic analysis of Anaplasma marginale and Anaplasma centrale amongst transhumant cattle in north-eastern Uganda. Ticks and Tick-Borne Diseases 9: 580-588. doi: 10.1016/j.ttbdis.2018.01.012 
  8. Conan, A., Napier, P., Shell, L., Knobel, D.L., Dundas, J, Scorpio, D. & Ketzis, J. (2017) Heterogeneous distribution of Dirofilaria immitis in dogs in St Kitts, West Indies, 2014-2015. Veterinary Parasitology: Regional Studies and Reports 10: 139-142. doi: 10.1016/j.vprsr.2017.10.006 
  9. Conan, A., Geerdes, J.A.C., Reininghaus, B., Akerele, O.A., Simpson, G.J.G. & Knobel, D.L. (2017) Census and rabies vaccination coverage of owned dog populations in four resource-limited rural communities, Mpumalanga Province, South Africa. Journal of the South African Veterinary Association  88(0): a1529. doi: 10.4102/jsava.v88i0.1529 
  10. Conan, A., O’Reilly, C., Ogola, E., Ochieng, J.B., Blackstock, A.J., Omore, R., Ochieng, L., Moke, F., Parsons, M.B., Xiao, L., Roellig, D., Farag, T.H., Nataro, J.P., Kotloff, K.L., Levine, M.M., Mintz, E.D., Breiman, R.F., Cleaveland, S. & Knobel, D.L. (2017) Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: a matched case-control study. PLoS Neglected Tropical Diseases 11(8): e0005795. doi: 10.1371/journal.pntd.0005795 
  11. Knobel, D.L, Arega, S.M., Reininghaus, B., Simpson, G.J.G., Gessner, B.D., Stryhn, H. &. Conan, A. (2017) Rabies vaccine is associated with decreased all-cause mortality in dogs. Vaccine 35: 3844-3849. doi: 10.1016/j.vaccine.2017.05.095 
  12. Hiby, E., Nattras Attema, K., Brimley, R., Hammond-Seaman, A., Jones, M., Rowan, A., Fogelberg, E., Kennedy, M., Balaram, D., Nel, L., Cleaveland, S., Hampson, K., Townsend, S., Lembo, T., Rooney, N., Whay, H.R., Pritchard, J, Murray, J., van Dijk, L., Waran, N., Bacon, H., Knobel, D.L., Tasker, L., Baker, C. & Hiby, L. (2017) Scoping review of indicators and methods used to evaluate the impact of dog population management interventions. BMC Veterinary Research 13:143. doi: 10.1186/s12917-017-1051-2 
  13. Artemiou, E., Conan, A., Knobel, D.L., Thompson, R., Spackman, C. & Kelly, P.J. (2017) Children’s attitudes towards cats on St. Kitts, West Indies. Anthrozoös 30(2): 263-271. doi:10.1080/08927936.2017.1311030 
  14. Gessner, B., Knobel, D.L., Conan, A. & Finn, A. (2017) Could the RTS,S/AS01 meningitis safety signal really be a protective effect of rabies vaccine? Vaccine 35(5): 716-721. doi:10.1016/j.vaccine.2016.12.067 
  15. Berrian, A.M., van Rooyen, J., Martínez-López, B., Knobel, D.L., Simpson, G., Wilkes, M.S. & Conrad, P.A. (2016) One Health profile of a community at the wildlife-domestic animal interface, Mpumalanga, South Africa. Preventive Veterinary Medicine 130: 119-128. doi:10.1016/j.prevetmed.2016.06.007 
  16. Barongo, M.B., Bishop, R.P., Fèvre, E.M., Knobel, D.L. & Ssematimba, A. (2016) A mathematical model that simulates control options for African swine fever virus. PLoS ONE 11(7): e0158658. doi: 10.1371/journal.pone.0158658 
  17. Byaruhanga, C., Collins, N.E., Knobel, D.L., Chaisi, M.E., Vorster, I., Steyn, H.C. & Oosthuizen, M.C. (2016) Molecular investigation of tick-borne haemoparasite infections among transhumant zebu cattle in Karamoja Region, Uganda. Veterinary Parasitology: Regional Studies and Reports 3-4: 27-35. doi: 10.1016/j.vprsr.2016.06.004 
  18. Keehner, J.R., Cruz-Martinez, L. & Knobel, D.L. (2016) Conservation value, history and legal status of non-native white-tailed deer (Odocoileus virginianus) on the Caribbean island of St. Kitts. Tropical Conservation Science 9(2): 758-775.  
  19. van Schalkwyk, O.L., De Clercq, E.M., De Pus, C., Hendrickx, G. & Knobel, D.L. (2016) Heterogeneity in a communal cattle farming system in a zone endemic for foot and mouth disease in South Africa. Geospatial Health 11(2): 338. doi: 10.4081/gh.2016.338 
  20. Kolo, A.O., Sibeko-Matjila, K.P., Maina, A.N., Richards, A.L., Knobel, D.L. & Matjila, P.T. (2016) Molecular detection of zoonotic rickettsiae and Anaplasma spp. in domestic dogs and their ectoparasites in Bushbuckridge, South Africa. Vector-Borne and Zoonotic Diseases 16(4): 245-252. doi: 10.1089/vbz.2015.1849 
  21. van Schalkwyk, O.L., Knobel, D.L., De Clercq, E.M., De Pus, C., Hendrickx, G. & Van den Bossche, P. (2016) Description of events where African buffaloes (Syncerus caffer) strayed from the endemic foot-and-mouth disease zone in South Africa, 1998-2008. Transboundary and Emerging Diseases 63(3): 333-347 doi: 10.1111/tbed.12280
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