Yrjö Gröhn

Faculty member

Department of Population Medicine and Diagnostic Sciences

James Law Professor of Epidemiology

Yrjo Grohn's Lab

Department of Population Medicine and Diagnostic Sciences
Cornell University College of Veterinary Medicine
Ithaca, NY 14853

Office: 607.253.4394
Lab: 607.253.3571
Fax: 607.253.3907
Email: ytg1@cornell.edu

Research Interest

My research interests have evolved from studies of basic metabolism in ruminants and genetics to veterinary epidemiology, economic modeling and food safety. The two main areas of investigations currently ongoing in my laboratory are: 1) mathematical modeling of zoonotic infectious diseases, and 2) optimizing health and management decisions. Both of these areas of research offer opportunities for training in epidemiological and mathematical modeling, genetic analysis, and economic methods.


  • 1973 B.V.M., College of Vet. Med., Helsinki, Finland
  • 1977 L.V.M.,(equiv DVM) College of Vet. Med., Helsinki, Finland
  • 1980 Food Hygienist, College of Vet Med, Helsinki, Finland
  • 1982 M.P.V.M., in Epidemiology, University of California, Davis
  • 1983 M.S., in Genetics, University of California, Davis
  • 1985 D.V.M. (equiv Ph.D.), in Vet. Med., College of Vet. Med., Helsinki
  • 2002 Diplomate ECVPH (European College of Vet. Public Health)

Biography/Professional Experience

  • 2001-2002 Acting Chair and 2002-2012 Chair, Dept. of Population Medicine and Diagnostic Sciences, Cornell University
  • 1998 -2001 Assoc. Chair, Dept. of Population Medicine and Diagnostic Sciences, Cornell University
  • 1993 – 1994 and 1995 - 2001 Chief, Section of Epidemiology, Cornell University, Ithaca, NY
  • 1994 - 1995 Visiting Professor, F.C. Donders Chair, University of Utrecht, Utrecht, The Netherlands
  • 1988 - Present Assistant, Associate, Full, and James Law Professor of Epidemiology, CVM, Cornell University
  • 1993 - Present Docent of Epidemiology, University of Helsinki, Finland
  • 1988 - 1991 Associate Professor, Dept. of Animal Hygiene, CVM, Helsinki, Finland
  • 1986 - 1988 Post doc, Visiting Assistant Professor, Dept. of Clinical Sciences, CVM, Cornell University


PubMed: http://www.ncbi.nlm.nih.gov/pubmed/?term=grohn+Y
Google Scholar: https://scholar.google.com/citations?user=kh950kkAAAAJ&hl=en


  1. Evans, T.S., et al.: Synergistic China-US ecological research is essential for global emerging infectious disease preparedness. EcoHealth.  https://doi.org/10.1007/s10393-020-01471-2

  2. Søgaard Jørgensen, P. et al.: Co-evolutionary governance of antibiotic and pesticide resistance. Trends in Ecology and Evolution. https://doi.org/10.1016/j.tree.2020.01.011 

  3. Lhermie, G., et al.: Global resistance to antimicrobials and their sustainable use in agriculture. The Lancet Planetary Health

  4. Søgaard Jørgensen, P., et al.: Promoting antibiotic and pesticide susceptibility to preserve an Anthropocene operating space. Nature Sustainability 2018; 1: 632–641  https://doi.org/10.1038/s41893-018-0164-3

  5. Gröhn, Y.T.et al.: A proposed analytic framework for determining the impact of an antimicrobial resistance intervention at the national level. Animal Health Res Rev. 2017;18(1):1-25.  https://pubmed.ncbi.nlm.nih.gov/28506325/

  6. Gröhn, Y.T.: Progression to multi-scale models and the application to food system intervention strategies. Prev. Vet. Med. 2015, 118: 238-246. https://www.sciencedirect.com/science/article/pii/S0167587714002657?via%3Dihub

  7. Lanzas, C., et al.: Model or meal? Animal agriculture systems as models for infectious diseases of humans. Nature Reviews, Microbiology. 2010, 8: 139-148. https://www.nature.com/articles/nrmicro2268

Mathematical Modeling

  1. Stapleton, S, Casey CL, Grohn, Y.T.: Modeling the Effect of Tylosin on Macrolide-Resistant Enterococci in Feedlots and Reducing Resistance Transmission. Foodborne Pathogen and Disease 2 Oct 2020 https://doi.org/10.1089/fpd.2020.2835
  2. Cazer, C. L., M. A. Al-Mamun, K. Kaniyamattam, W. J. Love, J. G. Booth, C. L. Lanzas, and Y. T. Gröhn: Shared multidrug resistance patterns in chicken-associated Escherichia coli identified by association rule mining. Front. Microbiol., Section Antimicrobials, Resistance and Chemotherapy.12 April 2019. https://doi.org/10.3389/fmicb.2019.00687 
  3. Al-Mamun, M.A., Smith, R.L., and Schukken, Y.H., Nigsch, A., Grohn, Y.T.: A data-driven individual-based model of infectious disease in livestock operation: A validation study for Paratuberculosis. PloS One 2018 13(12): e0203177. https://doi.org/10.1371/journal.pone.0203177
  4. Zoellner, C., Abdullah Al-Mamun, M., Gröhn, Y.T., Jackson, P., Worobo R.W.: Post-harvest supply chain with microbial travelers: a farm-to-retail microbial simulation and visualization framework. Applied and Environmental Microbiology. 2018 Jun 29. DOI: https://aem.asm.org/content/aem/84/17/e00813-18.full.pdf
  5. Cazer CL, Volkova VV, and Gröhn, Y.T.:  Expanding behavior pattern sensitivity analysis with model selection and survival analysis. Cazer et al. BMC Veterinary Research 2018 14:355  https://doi.org/10.1186/s12917-018-0174-y 
  6. Verteramo Chiu, L.J., Tauer, L.W., Al-Mamun, M. A., Kaniyamattam, K., Smith, R.L., Grohn, Y.T.: An agent-based model evaluation of economic control strategies for paratuberculosis in a dairy herd. J. Dairy Sci., 2018, 101(7):6443-6454. DOI: 10.3168/jds.2017-13175
  7. Al-Mamun, M.A., Smith, R.L., Schukken, Y.H., Gröhn, Y.T.: Use of an individual-based model to control transmission pathways of Mycobacterium avium Subsp. paratuberculosis infection in cattle herds. Scientific reports. 2017; 7(1):11845. DOI: 10.1038/s41598-017-12078-z 
  8. Cazer, C.L., Ducrot, L., Volkova, V.V., Gröhn, Y.T.: Monte Carlo simulations suggest current chlortetracycline drug-residue based withdrawal periods would not control antimicrobial resistance dissemination from feedlot to slaughterhouse. Frontiers in microbiology, 2017, 8:1753. DOI: 10.3389/fmicb.2017.01753
  9. Volkova VV, Cazer CL, Grohn, Y.T.: Models of antimicrobial pressure on intestinal bacteria of the treated host populations. Epidemiol Infect., 2017, 145(10):2081-2094. DOI: 10.1017/S095026881700084X
  10. Smith, R.L., Al-Mamun, M.A., Gröhn, Y.T.: Economic consequences of paratuberculosis control in dairy cattle: a stochastic modeling study Prev. Vet. Med. 2017, 138: 17-27. doi: 10.1016/j.prevetmed.2017.01.007
  11. Al-Mamun, M.A., Smith, R.L., Schukken, Y.H., Gröhn, Y.T.: Modeling of Mycobacterium avium subsp. paratuberculosis dynamics in a dairy Herd: an individual based approach. Journal of Theoretical Biology 2016 Nov 7; 408:105-17. doi: 10.1016/j.jtbi.2016.08.014. Epub 2016 Aug 10.
  12. Love, W. J., Zawack, K.A., Booth J.G., Gröhn, Y.T., Lanzas C.: Markov networks of collateral antibiotic resistance: National Antimicrobial Resistance Monitoring System surveillance results from E. coli isolates, 2004-2013. PLoS Comput Biol 12(11): e1005160.doi:10.1371/journal. pcbi.1005160 
  13. Smith, R.L., Gröhn, Y.T., Pradhan, A.K., Whitlock, R.H., Van Kessel, J.S., Smith, J.M., Wolfgang, D.R., Schukken, Y.H.: The effects of progressing and nonprogressing Mycobacterium avium ssp. paratuberculosis infection on milk production in dairy cows. J Dairy Sci., 2016, 99(2):1383-1390. DOI: 10.3168/jds.2015-9822
  14. Smith, R.L., Schukken, Y.H., Gröhn, Y.T.: A new compartmental model of Mycobacterium avium subsp. paratuberculosis infection dynamics in cattle. Prev Vet Med., 2015, 122(3):298-305. DOI: 10.1016/j.prevetmed.2015.10.008
  15. Smith, R.L., Gröhn, Y.T.: Use of approximate Bayesian computation to assess and fit models of Mycobacterium leprae to predict outcomes of the Brazilian control program. PLoS One., 2015, 10(6):e0129535. DOI: 10.1371/journal.pone.0129535
  16. Cazer, C.L., Volkova, V.V., Gröhn, Y.T.: Use of pharmacokinetic modeling to assess antimicrobial pressure on enteric bacteria of beef cattle fed chlortetracycline for growth promotion, disease control, or treatment. Foodborne Pathog Dis., 2014, 11(5):403-411. DOI: 10.1089/fpd.2013.1677

Optimizing Health and Management

  1. Lhermie G, Sauvage. P., Tauers, L.W., Verteramo Chiu, L., Kanyiamattam, K., Raboisson, D., Ferchiou, A., Scott, H. M, Smith, D.R., Grohn, Y.T.:  Economic effects of policy options restricting antimicrobial use for high risk cattle placed in U.S. feedlots. PLOS ONE https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239135
  2. K. Kaniyamattam, J. A. Hertl, G. Lhermie, U. Tasch, R. Dyer, and Gröhn, Y.T.:  Cost benefit analysis of automatic lameness detection systems in dairy herds: A dynamic programming approach. Pre. Vet. Med.  178:104993  10.1016/j.prevetmed.2020.104993 
  3. Verteramo Chiu, L.J., Tauer, L.W., Gröhn, Y.T., and Smith, R. L.: Ranking disease control strategies with stochastic outcomes. Pre. Vet. Med. 2020, 176, 104906 (Editor's Choice February 2020) https://doi.org/10.1016/j.prevetmed.2020.104906 
  4. Lhermie, G., Grohn, Y.T., Serrand, T., Sans, P., Raboisson, D.: How do veterinarians influence sales of antimicrobials? A spatial-temporal analysis of the French prescribing-delivery complex in cattle. The Zoonoses and Public Health.  ZPH December 23, 2019 DOI: 10.1111/zph.12678 PMID: 31868302 
  5. Verteramo Chiu L.J., Tauer L.W., Gröhn Y.T., Smith R.L. (2019). Mastitis risk effect on the economic consequences of paratuberculosis control in dairy cattle: A stochastic modeling study. PLOS ONE 14(9): e0217888. https://doi.org/10.1371/journal.pone.0217888 
  6. Kaniyamattam, K., A. De Vries, L. W. Tauer, and Gröhn, Y.T.: Economics of reducing antibiotic usage for clinical mastitis and metritis through genetic selection. J. Dairy Sci. 2020 Jan;103(1):473-491. doi: 10.3168/jds.2018-15817
  7. Salvador L.C.M., O’Brien D.J., Cosgrove M.K., Stuber T. P., Schooley A., Crispell J., Church S., Grohn Y.T., Robbe-Austerman S., Kao R.R.: Disease management at the wildlife-livestock interface: using whole-genome sequencing to study the role of elk in Mycobacterium bovis transmission in Michigan, USA. Mol Ecol. 2019; 28: 2192– 2205. https://doi.org/10.1111/mec.15061
  8. Lhermie, G., Wernlii, D., Søgaard Jørgensen, P., Kenkel, D., Lin Lawell, C.-Y. C., Tauer, L.W., Gröhn, Y.T.: Tradeoffs between resistance to antimicrobials in public health and their use in agriculture: moving towards sustainability assessment. Ecological Economics. https://doi.org/10.1016/j.ecolecon.2019.106427
  9. Lhermie. G., Verteramo, L.C., Kaniyamattam, K., Tauer L.W., Scott, H.M., Gröhn, Y.T.: Antibiotic policies in United States beef production: choosing the right instruments to reduce antimicrobial resistance under structural and market constraints.  Front. Vet. Sci., 19 July 2019 https://doi.org/10.3389/fvets.2019.00245 
  10. Verteramo Chiu, L.J., Tauer, L.W., Smith, R.L., Gröhn Y.T.: Assessment of the bovine tuberculosis elimination protocol in the United States. J. Dairy Sci. 2019, 102:1-17. https://doi.org/10.3168/jds.2018-14990
  11. Lhermie, G., L.W. Tauer, Grohn, Y.T.: An assessment of the economic costs to the U.S. dairy market of antimicrobial use restrictions. Preventive Veterinary Medicine 2018. Volume 160, Pages 63-67. https://doi.org/10.1016/j.prevetmed.2018.09.028
  12. Lhermie, G., Tauer, L.W., Gröhn, Y.T.: The farm cost of decreasing antimicrobials use in dairy production.  PLoS ONE, 2018, 13(3): e0194832. DOI: 10.1371/journal.pone.0194832
  13. Troendle, J.A., Tauer, L.W., Gröhn, Y.T.: Optimally achieving milk bulk tank somatic cell count thresholds, Journal of Dairy Science. 2017. 100: 731-738. https://doi.org/10.3168/jds.2016-11578
  14. Lhermie, G., Gröhn, Y.T., Raboisson, D.: Addressing antimicrobial resistance: an overview of priority actions to prevent suboptimal antimicrobial use in food-animal production. Front. Microbiol., 06 January 2017 | https://doi.org/10.3389/fmicb.2016.02114
  15. Cha, E., Smith, R.L., Kristensen, A.R., Hertl, J.A., Schukken, Y.H., Tauer, L.W., Welcome, F.L., Gröhn, Y.T.: The value of pathogen information in treating clinical mastitis. Journal of Dairy Research. 2016, 83 (4):456-463. PMID: 27845019
  16. Zoellner, C., Venegas, F., J. Churey, J.J., Dávila-Aviña, J., Gröhn, Y.T., García, S., Heredia, N., Worob. R.W..: Microbial dynamics of indicator microorganims on fresh tomatoes in the supply chain from Mexico to the USA. International Journal of Food Microbiology 2016 Dec 5; 238:202-207. doi: 10.1016/j.ijfoodmicro.2016.09.013.

Mathematical modeling of infectious diseases with application to COVID-19.

Three virtual lectures by the Epidemiology Faculty at College of Veterinary Medicine, Cornell University, April 2020.

Session 1 recording: Modeling basics: SIR, R0 and Herd Immunity, some example models including COVID-19. (Yrjo Grohn);

Session 2 recording:  Why are all COVID-19 models wrong but some are useful? (Renata Ivanek); “Covid Act Now” (Renata Ivanek); Early dynamics of transmission and control of COVID-19: a mathematical modelling study (Wendy Beauvais);

Session 3 recording:  Prediction of hospital demand from the COVID-19 death curve: IHME Model (Casey Cazer); Molecular epidemiology of SARS-Cov-2: what viral genomes can tell us about transmission? (Kristina Ceres).


Awards and Honors

  • 1981-1982 Kellogg Fellow
  • Phi Zeta, Veterinary Medicine
  • Sigma Xi, American Research Association
  • Gamma Sigma Delta, The Honor Society of Agriculture
  • 1994-1995 F.C.Donders Chair, University of Utrecht, August, 1994 - July, 1995
  • 1999 Samuel F. Scheidy Memorial Award
  • 2007 The Gareth Davies lecture
  • 2013 The Calvin Schwabe Award for Lifetime Achievement
  • 2014 UC Davis School of Veterinary Medicine Alumni Achievement Award
  • 2014 James Law Professor; Cornell Institute for Food Systems Fellow; Atkinson Center for a Sustainable Future Faculty Fellow
  • The American Veterinary Epidemiology Society Honorary Diplomate, 2019

Professional/Academic Affiliations

  • American Dairy Science Association
  • American Veterinary Medical Association
  • Association of Teachers of Veterinary Public Health and Preventive Medicine
  • Finnish Veterinary Medical Association
  • New York State Veterinary Medical Society
  • Nordic Association of Veterinary Epidemiology
  • System Dynamics Society