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


  1. Lanzas, C., Ayscue, P., Ivanek, R., Gröhn, Y.T.: Model or meal? Animal agriculture systems as models for infectious diseases of humans. Nature Reviews, Microbiology. 2010, 8: 139-148.
  2. Gröhn, Y.T.: Progression to multi-scale models and the application to food system intervention strategies. Prev. Vet. Med. 2015, 118: 238-246.
  3. Gröhn, Y.T., Carson C., Lanzas C. Pullum L., Stanhope M., Volkova V.: A proposed analytic framework for determining the impact of an antimicrobial resistance intervention at the national level. Animal Health Res Rev. 2017, May 16, 1-25.

Mathematical Modeling

  1. Lanzas, C., Dubberke, E.R., Lu, Z., Reske, K.A., Gröhn, Y.T.: Epidemiological model for Clostridium difficile transmission in healthcare settings. Infection Control and Hospital Epidemiology, 2011, 32: 553-561.
  2. Teose, M., Ahmadizadeh, K., O’Mahony, E., Smith, R.L., Ju. Z., Ellner, S.P., Gomes, C., Gröhn, Y.T.: Embedding system dynamics in agent based models for complex adaptive systems. Int. Joint Conf. Artificial Intelligence. AAAI Press Proceedings, 7, 19-22, 2011.
  3. Pradhan, A., Ivanek, R., Gröhn, Y.T., Bukowski, R., Wiedmann, M.: Comparison of public health impact of Listeria monocytogenes product-to-product and environmental-to-product contamination of deli meats at retail. Journal of Food Protection, 2011, 74: 1860-1868.
  4. Volkova, V., Lanzas, C., Lu, Z., Gröhn Y.T.: Mathematical model of plasmid-mediated resistance to ceftiofur in commensal enteric Escherichia coli of cattle. PLoS ONE 2012, 7(5): e36738. doi:10.1371/journal.pone.0036738
  5. Reksen, O., Gröhn Y.T., Barlow, J.W., and Schukken, Y.H.: Transmission dynamics of intramammary infections with coagulase-negative staphylococci. J. Dairy Sci., 2012, 95: 4899-4910.
  6. Lu, Z., Schukken, Y.H., Smith, R.L., R. M. Mitchell, Gröhn, Y.T.: Impact of imperfect Mycobacterium avium subsp. paratuberculosis vaccines in dairy herds: A mathematical modeling approach. Prev Vet Med. 2012, 148-158.
  7. Lu, Z., Schukken YH, Smith RL, and Gröhn YT: Using vaccination to prevent the invasion of Mycobacterium avium subsp. paratuberculosis (MAP) in dairy herds: A stochastic simulation study. Prev Vet Med. (2013). http://dx.doi.org/10.1016/j.prevetmed.2013.01.006
  8. Lu, Z., Mitchell, R.M., Smith, R.L., Karns, J.S., Wolfgang, D.R., Schukken, Y.H., Gröhn, Y.T.: Invasion and transmission of Salmonella Kentucky in an adult dairy herd using approximate Bayesian computation. BMC Vet. Res. 2013, 9:245.
  9. Lu, Z., Gröhn, Y.T., Smith, R.L., Karns, J.S., Hovingh, E., Schukken, Y.H.: Stochastic modeling of imperfect Salmonella vaccines in an adult dairy herd. Bulletin of Mathematical Biology. 2014, 76: 541-565.
  10. Volkova, V., Lu, Z., Lanzas, C., Gröhn Y.T.: Evaluating targets for control of plasmid-mediated antimicrobial resistance in enteric commensals of beef cattle: a modelling approach. Epidemiol. Infect., 2013 Jan 23:1-19.
  11. Smith, R.L., Tauer, L.W., Schukken, Y.H, Lu, Z., Mitchell, R.M., Gröhn, Y.T.: Minimizing of bovine tuberculosis control costs in US dairy herds. Prev Vet Med. 2013 Aug 14. doi:pii: S0167-5877(13)00240-7.10.1016/j.prevetmed.2013.07.014.
  12. Volkova, V., Lu, Z., Lanzas, C., Scott, H.M., Gröhn Y.T.: Modeling dynamics of plasmid-gene mediated antimicrobial resistance in enteric bacteria using stochastic differential equations. Nature Scientific Reports. In press.
  13. Volkova, V., Lu, Z., Besser, T. Lanzas, C., Gröhn Y.T.: Modeling infection dynamics of enteric coliphages: Estimating the contribution of transduction to antimicrobial gene dissemination. Appl. Environ. Microbiology. 2014, 80(14):4350-62.
  14. Smith, R.L., Tauer, L.W., Sanderson, M.W, Gröhn, Y.T.: Minimizing cost to control bovine tuberculosis control in cow-calf herds. Prev Vet Med. 2014, 115(1-2):18-28.
  15. Awosanya, E., Olugasa, B., Ogundipe, G., Gröhn Y.T.: Sero-prevalence and risk factors associated with African swine fever on pig farms in southwest Nigeria. BMC Veterinary Research 2015: 11:133. DOI 10.1186/s12917-015-0444-3.
  16. 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
  17. Weller, D., Shiwakoti, S., Bergholz, P., Grohn, Y.T., Wiedmann, M., Strawn, L.: Validation of a previously developed geospatial model that predicts Listeria monocytogenes prevalence for New York State produce fields. Appl. Environ. Microbiology. 11/2015; DOI:10.1128/AEM.03088-15.
  18. 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 non-progressing Mycobacterium avium ssp. paratuberculosis infection on milk production in dairy cows. Journal of Dairy Science. 2016, 99: 1383-1390.
  19. 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 Dec 1;122(3):298-305. doi: 10.1016/j.prevetmed.2015.10.008. Epub 2015 Oct 21.
  20. Zawack, K.A., Li, M., Booth J.G., Love, W.J., Lanzas C., Gröhn, Y.T.: Monitoring antimicrobial resistance in the food supply chain and its implications for FDA policy initiatives. Antimicrobial Agents and Chemotherapy. 201606/2016; DOI:10.1128/AAC.00688-16
  21. 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.
  22. 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
  23. Volkova, V.V., Cazer, C.L., Gröhn Y.T.: Models of antimicrobial pressure on intestinal bacteria of the treated host populations. Epidemiol Infect. 2017, 145, (10):2081-2094.
  24. 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.

Optimizing Health and Management

  1. Wang, C., Turnbull, B.W., Nielsen, S.S., Gröhn, Y.T.: Bayesian analysis of longitudinal Johne’s disease diagnostic data without a gold standard test. Journal of Dairy Science, 2011, 94: 2320-2328.
  2. Cha, E., Bar, D., Hertl, J.A., Tauer, L.W., Bennett, G., González, R.N., Schukken, Y.H., Welcome, F.L., Gröhn, Y.T.: The cost and management of different types of clinical mastitis in dairy cows estimated by dynamic programming. Journal of Dairy Science, 2011, 94: 4476-4487.
  3. Hertl, J.A., Schukken, Y.H, Bar, D., Bennett, G.J., Gonzalez, R.N., Rauch, B.J., Welcome, F.L., Tauer, L.W., Gröhn, Y.T.: The effect of recurrent episodes of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on mortality and culling in Holstein dairy cows. Journal of Dairy Science, 2011, 94: 4863-4877.
  4. Smith, R.L., Schukken, Y.H., Pradhan, A.K., Smith, J.M., Whitlock, R.H., Van Kessel, J.S., Wolfgang, D.R., Gröhn, Y.T.: Environmental contamination with Mycobacterium avium subsp. paratuberculosis in endemically infected dairy herds. Preventive Veterinary Medicine 2011 Oct 1; 102(1): 1-9.
  5. Cho, J., Tauer, L.W., Schukken, Y.H., Gomez, M.I., Smith, R.L., Zhao, L. and Gröhn, Y.T.: Economic analysis of Mycobacterium avium subsp. paratuberculosis vaccines in dairy herds. Journal of Dairy Science, 2012, 95: 1855-1872.
  6. Cho, J., Tauer, L.W., Schukken, Y.H., Smith, R.L., Zhao, L. and Gröhn, Y.T.: Cost-effective control strategies for Johne’s Disease in dairy herds. The Canadian J. of Ag. Econ. 00 (2012) 1–26 DOI: 10.1111/j.1744-7976.2012.01270.x.
  7. Cha, E., Kristensen, A.R., Hertl, J.A., Schukken, Y.H., Tauer, L.W., Welcome, F.L., Gröhn, Y.T.: Optimal insemination and replacement decisions to minimize the cost of pathogen-specific clinical mastitis in dairy cows. J Dairy Sci 2014,97:1-17http://dx.doi.org/10.3168/jds.2013-7067
  8. Beaver, A., Cazer, C.L., Ruegg, P., Gröhn Y.T., Schukken Y.H.: Implications of the PCR/ELISA relationship on the routes of bulk-tank contamination with Mycobacterium avium subsp. Paratuberculosis. Journal of Dairy Science. J Dairy Sci. 2015, 99: 1391-1405. Dec 10. pii: S0022-0302(15)00882-6. doi: 10.3168/jds.2015-9855.
  9. Cha, E., Hertl, J.A., Schukken, Y.H., Welcome, F.L., Gröhn, Y.T.: Evidence of no protection for a recurrent case of pathogen specific clinical mastitis from a previous case. Journal of Dairy Research. 2016, 83, 72-80.
  10. Kessels, J.A., Cha, E., Johnson, S.K., Welcome, F.L., Kristensen, A.R., Gröhn, Y.T.: Economic comparison of common treatment protocols and J5 vaccination for clinical mastitis in dairy herds using dynamic programming. Journal of Dairy Science 2016, 99: 3838-3847. http://dx.doi.org/10.3168/jds.2015-10385 
  11. 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 Nov; 83 (4):456-463. PMID: 27845019
  12. Beaver, A., Ruegg, P.L., Gröhn Y.T., Schukken Y.H.: Comparative risk assessment for new bovine MAP infections between 3 dairy production types: organic, conventional, and conventional-grazing systems. Journal of Dairy Sci. 2016 Sep 28. pii: S0022-0302(16)30656-7. doi: 10.3168/jds.2016-11360.
  13. 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.
  14. 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.
  15. 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 | ttps://doi.org/10.3389/fmicb.2016.02114

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

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