Karim Khader

Karim Khader, PhD, MStat, MS

Languages spoken: English

Academic Information

Departments Primary - Internal Medicine , Adjunct - Population Health Sciences

Divisions: Epidemiology

Karim Khader's research areas of interest are the advancing of statistical methodology and the use of mathematical models and computer simulations to understand the behavior of complex systems. These two general interests are complementary to one another; mathematical modeling and computer simulation represent a data-generating process which can be analyzed through the use of various statistical methodologies, while advances in statistical methodologies are needed to inform and parameterize computer simulations as the data-generating processes become increasingly complex. He has pursued these interests across multiple domains of study with a particular focus on transmission and infection due to antimicrobial resistant organisms in healthcare facilities, particularly with respect to understanding how to improve patient outcomes by reducing rates of healthcare-associated infections and gaining deeper insights into the key factors that result in infection.

Education History

Postdoctoral Fellowship Division of Epidemiology, University of Utah
 Postdoctoral Fellow
Doctoral Training University of Utah
 PhD
Graduate Training University of Utah
 MStat
Graduate Training University of Rhode Island
 MS
Undergraduate University of Utah
 BS

Selected Publications

Journal Article

  1. Thomas A, Khader K, Hersh A, Samore M (2026). Calculating the Probability that a Previously Susceptible Individual is Infected as a Function of Time Following Exposure to SARS-CoV-2. Infect Dis Ther, 15(7), 1977-1993.
  2. Britt NS, Khader K, He T, Prinzi AM, Hommel B, Timbrook TT, Potter EM, Lodise TP (2026). Clinical Impact of the BIOFIRE® FILMARRAY® Pneumonia Panel in the Veterans Affairs Healthcare System: A Difference-in-Differences Study. Clin Infect Dis.
  3. De-la-Rosa-Martinez D, Porco TC, Hazel A, Liu X, Khader K, Blumberg S (2026). Clostridioides difficile colonization amplification despite limited in-hospital transmission: A modeling study. PLoS Med, 23(4), e1004712.
  4. Khader K, Haroldsen C, Stevens V, Visnovsky L, Evans M, Simbartl L, McCauley B, Samore M, Rubin M (2026). Estimating changes in facility MRSA infection rates due to changes in MRSA precaution policy. Clin Infect Dis.
  5. Mosleh T, Weil A, Beard D, Clements A, Radloff C, Nolen LD, Khader K, Stevenson E, Cheever S, Rigby S (2026). Outpatient antibiotic prescribing among Utah Medicaid recipients: A 4-year population-based analysis. Am J Infect Control.
  6. OHara LM, Pineles L, Newman M, Bahr-Robertson M, Baracco GJ, Goetz MB, Ikuta KS, Crnich CJ, Bradley SF, Linder KA, Rubin MA, Khader K, Nelson RE, Johnson JK, Perencevich EN, Evans ME, Harris AD (2025). Factors associated with healthcare personnel glove or gown contamination with MRSA: a cohort study of VA hospitals in 5 states. Infect Control Hosp Epidemiol, 46(11), 1105-1109.
  7. Toth DJA, Khader K, Mitchell C, Samore MH (2025). Transmission thresholds for the spread of infections in healthcare facilities. PLoS Comput Biol, 21(10), e1013577.
  8. Keegan LT, Tanner W, Orleans B, Slayton RB, Jernigan JA, McDonald LC, Noble-Wang J, Leecaster M, Haroldsen C, Khader K, Toth DJA, OSullivan T, Samore MH, Brazelton W, Rubin M (2025). Environmental and Health Care Personnel Sampling and Unobserved Clostridium difficile Transmission in ICU. JAMA Netw Open, 8(4), e252787.
  9. Pham TM, Zhang Y, Nevers M, Li H, Khader K, Grad YH, Lipsitch M, Samore M (2024). Trends in infection incidence and antimicrobial resistance in the US Veterans Affairs Healthcare System: a nationwide retrospective cohort study (2007-22). Lancet Infect Dis, 24(12), 1333-1346.
  10. Hutcherson C, Luke B, Khader K, Dhaher YY (2024). Unraveling the complex interplay of sex, endocrinology, and inflammation in post-Injury articular cartilage breakdown through in silico modeling. Sci Rep, 14(1), 28654.
  11. Mitchell C, Keegan LT, Le TTT, Khader K, Beams A, Samore MH, Toth DJA (2024). Importance of underlying mechanisms for interpreting relative risk of Clostridioides difficile infection among antibiotic-exposed patients in healthcare facilities. PLoS One, 19(8), e0306622.
  12. Duong KNC, Nguyen DT, Kategeaw W, Liang X, Khaing W, Visnovsky LD, Veettil SK, McFarland MM, Nelson RE, Jones BE, Pavia AT, Coates E, Khader K, Love J, Vega Yon GG, Zhang Y, Willson T, Dorsan E, Toth DJA, Jones MM, Samore MH, Chaiyakunapruk N (2024). Incorporating social determinants of health into transmission modeling of COVID-19 vaccine in the US: a scoping review. Lancet Reg Health Am, 35, 100806.
  13. Smith M, Crnich C, Donskey C, Evans CT, Evans M, Goto M, Guerrero B, Gupta K, Harris A, Hicks N, Khader K, Kralovic S, McKinley L, Rubin M, Safdar N, Schweizer ML, Tovar S, Wilson G, Zabarsky T, Perencevich EN (2024). Research agenda for transmission prevention within the Veterans Health Administration, 2024-2028. Infect Control Hosp Epidemiol, 45(8), 1-10.
  14. Nelson Chang NC, Leecaster M, Fridkin S, Dube W, Katz M, Polgreen P, Roghmann MC, Khader K, Li L, Dumyati G, Tsay R, Lynfield R, Mahoehney JP, Nadle J, Hutson J, Pierce R, Zhang A, Wilson C, Haroldsen C, Mulvey D, Reddy SC, Stone ND, Slayton RB, Thompson ND, Stratford K, Samore M, Visnovsky LD (2023). Assessing Pathogen Transmission Opportunities: Variation in Nursing Home Staff-Resident Interactions. J Am Med Dir Assoc, 24(5), 735.e1-735.e9.
  15. Britt NS, Khader K, He T, Willson TM, Effiong A, Timbrook TT, Potter EM, Lodise TP (2022). Examining the clinical impact of rapid multiplex polymerase chain reaction-based diagnostic testing for bloodstream infections in a national cohort of the Veterans Health Administration. Pharmacotherapy, 43(1), 24-34.
  16. Jones M, Khader K, Branch-Elliman W (2022). Estimated Impact of the US COVID-19 Vaccination Campaign-Getting to 94% of Deaths Prevented. JAMA Netw Open, 5(7), e2220391.
  17. Khader K, Thomas A, Stevens V, Visnovsky L, Nevers M, Toth D, Keegan LT, Jones M, Rubin M, Samore MH (2021). Association Between Contact Precautions And Transmission of Methicillin-Resistant Staphylococcus Aureus in Veterans Affairs Hospitals . JAMA Netw Open.
  18. Khader K, Munoz-Price LS, Hanson R, Stevens V, Keegan LT, Thomas A, Pezzin LE, Nattinger A, Singh S, Samore MH (2021). Transmission Dynamics of Clostridioides difficile in 2 High-Acuity Hospital Units. Clin Infect Dis.
  19. Khader K, Thomas A, Huskins WC, Stevens V, Keegan LT, Visnovsky L, Samore MH (2021). Effectiveness of Contact Precautions to Prevent Transmission of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci in Intensive Care Units. Clin Infect Dis.
  20. Toth DJA, Khader K (2021). Efficient SARS-CoV-2 surveillance strategies to prevent deadly outbreaks in vulnerable populations. BMC Med, 19(25).
  21. Sutton JD, Stevens VW, Chang NN, Khader K, Timbrook TT, Spivak ES (2020). Oral β-Lactam Antibiotics vs Fluoroquinolones or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Enterobacterales Bacteremia From a Urine Source. . JAMA Netw Open, 3(10).
  22. Toth DJA, Keegan LT, Samore MH, Khader K, OHagan JJ, Yu H, Quintana A, Swerdlow DL (2020). Modeling the potential impact of administering vaccines against Clostridioides difficile infection to individuals in healthcare facilities. Vaccine, 18;38(37), 5927-5932.
  23. Stevens VW, Khader K, Echevarria K, Nelson RE, Zhang Y, Jones M, Timbrook TT, Samore MH, Rubin MA (2020). Use of Oral Vancomycin for Clostridioides difficile Infection and the Risk of Vancomycin-Resistant Enterococci. Clin Infect Dis, 71(3), 645-651.
  24. Stevens VW, Shoemaker H, Jones M, Jones BE, Nelson RE, Khader K, Samore MH, Rubin MA (2020). Validation of the SHEA/IDSA severity criteria to predict poor outcomes among inpatients and outpatients with Clostridioides difficile infection. Infect Control Hosp Epidemiol.
  25. Marra AR, Perencevich EN, Nelson RE, Samore M, Khader K, Chiang HY, Chorazy ML, Herwaldt LA, Diekema DJ, Kuxhausen MF, Blevins A, Ward MA, McDanel JS, Nair R, Balkenende E, Schweizer ML (2020). Incidence and Outcomes Associated With Clostridium difficile Infections: A Systematic Review and Meta-analysis. JAMA Netw Open, 3(1).
  26. Lynch KE, Viernes B, Khader K, DuVall SL, Schroeck FR (2019). Sex and the diagnostic pathway to bladder cancer among Veterans: no evidence of disparity. Womens Health Issues.
  27. Khader K, Thomas A, Jones M, Toth D, Stevens V, Samore MH (2019). Variation and trends in transmission dynamics of Methicillin-resistant Staphylococcus aureus in veterans affairs hospitals and nursing homes. Epidemics.
  28. Toth DJA, Khader K, Beams A, Samore MH (2019). Model-based Assessment of the Effect of Contact Precautions Applied to Surveillance-detected Carriers of Carbapenemase-producing Enterobacteriaceae in Long-term Acute Care Hospitals. Clin Infect Dis.
  29. Stevens VW, Khader K, Echevaria K, Nelson RE, Zhang Y, Jones M, Timbrook TT, Samore MH, Rubin MA (2019). Use of oral vancomycin for Clostridioides difficile Infection (CDI) and the risk of vancomycin-resistant Enterococci (VRE). Clin Infect Dis.
  30. Livorsi DJ, Chorazy ML, Schweizer ML, Balkenende EC, Blevins A, Nair R, Samore M, Nelson RE, Khader K, Perencevich EN (2018). A systematic review of the epidemiology of carbapenem-resistant Enterobacteriaceae in the United States. Antimicrob Resist Infect Control, 7(1).
  31. Nelson RE, Stevens VW, Jones M, Khader K, Schweizer ML, Perencevich EN, Rubin MA, Samore MH (2018). Attributable Cost and Length of Stay Associated with Nosocomial Gram-Negative Bacterial Cultures. Antimicrob Agents Chemother, 62(11).
  32. Thomas A, Khader K, Redd A, Leecaster M, Zhang Y, Jones M, Greene T, Samore M (2018). Extended models for nosocomial infection: parameter estimation and model selection. Math Med Biol, 35(suppl_1), 29-49.
  33. Perencevich EN, Harris AD, Pfeiffer CD, Rubin MA, Hill JN, Baracco GJ, Evans ME, Klutts JS, Streit JA, Nelson RE, Khader K, Reisinger HS (2018). Establishing a Research Agenda for Preventing Transmission of Multidrug-Resistant Organisms in Acute-Care Settings in the Veterans Health Administration. Infect Control Hosp Epidemiol, 39(2), 189-195.
  34. McDanel J, Schweizer M, Crabb V, Nelson R, Samore M, Khader K, Blevins AE, Diekema D, Chiang HY, Nair R, Perencevich E (2017). Incidence of Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli and Klebsiella Infections in the United States: A Systematic Literature Review. Infect Control Hosp Epidemiol, 38(10), 1209-1215.
  35. Nelson RE, Slayton RB, Stevens V, Jones M, Khader K, Rubin MA, Jernigan JA, Samore M (2017). Attributable Mortality of Healthcare-Associated Infections Due to Multidrug-Resistant Gram-Negative Bacteria and Methicillin-Resistant Staphylococcus Aureus. Infect Control Hosp Epidemiol, 38(07), 1-9.
  36. Toth DJA, Khader K, Slayton RB, Kallen AJ, Gundlapalli AV, OHagan JJ, Fiore AE, Rubin MA, Jernigan JA, Samore MH (2017). The potential for interventions in a long-term acute care hospital to reduce transmission of carbapenem-resistant enterobacteriaceae in affiliated healthcare facilities. Clin Infect Dis.
  37. Stevens VW, Nelson RE, Schwab-Daugherty EM, Khader K, Jones MM, Brown KA, Greene T, Croft LD, Neuhauser M, Glassman P, Goetz MB, Samore MH, Rubin MA (2017). Comparative effectiveness of vancomycin and metronidazole for the prevention of recurrence and death in patients with clostridium difficile infection. JAMA Intern Med.
  38. Nelson R, Deka R, Khader K, Stevens V, Schweizer M, Rubin M (2017). Dynamic transmission models for economic analysis applied to healthcare associated infections: A review of the literature. Am J Infect Control.
  39. Khader K, Thomas A, Huskins WC, Leecaster M, Zhang Y, Greene T, Redd A, Samore MH (2017). A dynamic transmission model to evaluate the effectiveness of infection control strategies. Open Forum Infect Dis.
  40. Chiang HY, Perencevich EN, Nair R, Nelson RE, Samore M, Khdaer K, Chorazy ML, Herwaldt LA, Blevins A, Ward MA, Schweizer ML (2017). Incidence and outcomes associated with infections caused by vancomycin-resistant enterococci in the united states: systematic literature review and meta-analysis. Infect Control Hosp Epidemiol.
  41. Beams AB, Toth DJA, Khader K, Adler FR (2016). Harnessing Intra-Host Strain Competition to Limit Antibiotic Resistance: Mathematical Model Results. Bull Math Biol.
  42. Nelson R, Schweizer M, Perencevich E, Nelson S, Khader K, Chiang H, Chorazy M, Blevins A, Ward M, Samore M (2016). Costs and mortality associated with healthcare-associated multi-drug resistant Acinetobacter infections. Infect Control Hosp Epidemiol.
  43. Toth D, Tanner W, Khader K, Gundlapalli A (2016). Estimates of the risk of a large or long-lasting outbreak of Middle East respiratory syndrome (MERS) after an importation outside the Arabian Peninsula. Epidemics.
  44. Nelson RE, Jones M, Leecaster M, Samore MH, Ray W, Huttner A, Huttner B, Khader K, Stevens VW, Gerding D, Schweizer ML, Rubin MA (2016). An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model. PLoS One.
  45. Nelson RE, Samore MH, Khader K, Jones M, Stevens V, Evans ME, Schweizer ML, Perencevich EL, Rubin MA (2016). Economic analysis of Veterans Affairs initiative to prevent methicillin-resistant Staphylococcus aureus infections. Am J Prev Med.
  46. Slayton R, Toth D, Lee B, Tanner W, Bartsch S, Khader K, Wong K, Brown K, McKinnell J, Ray W, Miller L, Rubin M, Kim D, Adler F, Cao C, Avery L, Stone N, Kallen A, Samore M, Huang S, Fridkin S, Jernigan J (2015). Vital Signs: Estimated effects of a coordinated approach for action to reduce antibiotic-resistant infections in health care facilities — United States. MMWR Morb Mortal Wkly Rep.
  47. Toth D, Gudlapalli A, Khader K, Pettey W, Rubin M, Adler F, Samore M (2015). Estimates of outbreak risk from new introductions of Ebola with immediate and delayed transmission control. Emerg Infect Dis.
  48. Nelson R, Nelson S, Khader K, Perencevich E, Schweizer M, Rubin M, Graves N, Harbarth S, Stevens V, Samore M (2015). The magnitude of time-dependent bias in the estimation of excess length of stay attributable to healthcare-associated infections. Infect Control Hosp Epidemiol.
  49. Stevens V, Khader K, Nelson R, Jones M, Rubin M, Brown K, Evans M, Greene T, Slade E, Samore M (2015). Excess length of stay attributable to clostridium difficile infection (CDI) in the acute care setting: A multistate model. Infect Control Hosp Epidemiol.
  50. Thomas A, Redd A, Khader K, Leecaster M, Greene T, Samore M (2015). Efficient parameter estimation for models of healthcare-associated pathogen transmission in discrete and continuous time. Math Med Biol, 32(1), 79-98.
  51. Khader K, Leecaster M, Greene T, Samore M, Thomas A (2014). Improved hidden Markov model for nosocomial infections. Math Med Biol, 31(4), 338-52.
  52. Jones M, Nielson C, Gupta K, Khader K, Evans M (2014). Collateral benefit of screening patients for methicillin-resistant Staphylococcus aureus at hospital admission: Isolation of patients with multidrug-resistant gram-negative bacteria. Am J Infect Control.
  53. Fridkin S, Baggs J, Fagan R, Magill S, Pollack L, Malpiedi P, Slayton R, Khader K, Rubin M, Jones M, Samore M, Dumyati G, Dodds-Ashley E, Meek J, Yousey-Hindes K, Jernigan J, Shehab N, Herrera R, McDonald C, Schneider A, Srinivasan A (2014). Vital Signs: Improving antibiotic use among hospitalized patients. MMWR Morb Mortal Wkly Rep.
  54. Rubin MA, Jones M, Leecaster M, Khader K, Ray W, Huttner A, Huttner B, Toth D, Sablay T, Borotkanics RJ, Gerding DN, Samore MH (2013). A simulation-based assessment of strategies to control Clostridium difficile transmission and infection. PLoS One, 8(11), e80671.

Video/Film/CD/Web/Podcast

  1. Slayton R, Toth D, Lee B, Tanner W, Bartsch S, Khader K, Wong K, Brown K, McKinnell J, Ray W, Miller L, Rubin M, Kim D, Adler F, Cao C, Avery L, Stone N, Kallen A, Samore M, Huang S, Fridkin S, Jernigan J (2015). CDC Vital Signs: Stop the Spread of Antibiotic Resistance [Web]. Available: https://www.youtube.com/watch?v=2INGuNAvAOE.