Irving Nachamkin, DrPH, MPH, D(ABMM), FAAM, FIDSA

Professor of Pathology and Laboratory Medicine at the Hospital of the University of Pennsylvania (Emeritus)
University of Pennsylvania Perelman School of Medicine

Contact InformationDepartment of Pathology and Laboratory Medicine
Hospital of the University of Pennsylvania
3400 Spruce Street
Philadelphia, PA 19104-4283


Specialty Division

Laboratory Medicine

Research Expertise

I am a co-investigator in the CDC Prevention Epicenter at Penn and our lab is involved in several collaborative studies examining risk factors for development of antimicrobial resistant infections in hospitalized patients and in the community. I also have a special interest in Campylobacter and other gastrointestinal infections, with a focus on diagnostics, antibiotic resistance, and association of Campylobacter with Guillain-Barre Syndrome. Other areas of interest include diagnostic microbiology, molecular diagnostic microbiology, cost-effectiveness of laboratory testing.

Clinical Expertise

I am currently Director of the Division of Laboratory Medicine at the Hospital of the University of Pennsylvania. I also am Associate Director of the Clinical Microbiology Laboratory. My areas of expertise include most areas of clinical microbiology. I have particular interests in the diagnosis of gastrointestinal infections.


B.Sc. (Medical Laboratory Science), University of Bridgeport, Bridgeport, CT, 1975
M.P.H. (Public Health Laboratory Practice), University of North Carolina at Chapel Hill, Chapel Hill, NC, 1978
Dr.P.H. (Public Health Microbiology), University of North Carolina at Chapel Hill, Chapel Hill, NC, 1980

Specialty Certification

MT (ASCP), American Society of Clinical Pathologists, 1975
Diplomate, American Board of Medical Microbiology, 1987

Postgraduate Training

Fellow, Medical and Public Health Laboratory Microbiology, Dept. of Pathology, Medical College of Virginia, Virginia Commonwealth University, Richmond, 1980-1982
Penn Medicine Clinical Leadership Academy, Penn Medicine, 2010-2011

Awards and Honors

Becton Dickinson Pre-Doctoral Fellowship, University of North Carolina at Chapel Hill, 1977-1980
Professor (Hon.), Department of Neurology, Second Affiliated Hospital, Shijiazhuang, P.R. China, 1993
President's Award, New Jersey Public Health Association, 1995
Professor (Hon.) of Medical Sciences, Hebei Medical College, Shijiazhuang, P.R. China, 1995
Fellow, Infectious Diseases Society of America, 2000
Fellow, American Academy of Microbiology, 2000
Foundation for Microbiology Lecturer, American Society for Microbiology, Washington, DC, 2000-2002
Fellow, College of Physicians of Philadelphia, 2003
Elected Member, Council Policy Committee, American Society for Microbiology, 2005-2008
UPHS Quality Award, "Building a Culture of High-Value Care: Reducing Unnecessary Ordering of Inpatient Laboratory Tests", Sedrak MS, Murray D, Ziemba J, Myers J, Dine J, Tsypenyuk B, Nachamkin I, Mincarelli M, Danoski D, Brennan PJ, Hanson B, Berns J, 2015

Memberships and Professional Organizations

American Society of Clinical Pathologists, 1975 - Present
Eastern Pennsylvania Branch, American Society for Microbiology, 1982 - Present
American Society for Microbiology, 1982 - Present
Infectious Diseases Society of America, 1995 - Present
Food and Drug Administration, Microbiological Devices Review Panel, 1999 - 2016
American Academy of Microbiology, 2000 - Present
College of Physicians of Philadelphia, 2003 - Present
Clinical Laboratory Standards Institute, 2004 - 2004
The Society for Healthcare Epidemiology of America, 2009 - 2020
American Association for Clinical Chemistry, 2010 - 2019
Association for Molecular Pathology, 2011 - 2019
Voting Member, Council on Microbial Sciences, American Society for Microbiology, 2019 - 2021
American Academy of Microbiology (AAM), 2020 - 2023

Web Links

Selected Publications

Risk factors for antimicrobial resistance among Staphylococcus isolated from pets living with a patient diagnosed with methicillin-resistant Staphylococcus aureus infection

Ferradas C, Cotter C, Shahbazian JH, Iverson SA, Baron P, Misic AM, Brazil AM, Rankin SC, Nachamkin I, Ferguson JM, Peng RD, Bilker WB, Lautenbach E, Morris DO, Lescano AG, Davis MF, Zoonosis Public Health, 2022

Phylogenetic analysis reveals source attribution patterns for Campylobacter spp in Tennessee and Pennsylvania

Hudson LK, Andershock WE, Yan R, Golwalkar M, M’ikanatha NM, Nachamkin I, Thomas LS, Moore C, Qian X, Steece R, Garman KN, Dunn JR, Kovac J, Denes TG., Microorganisms 9(11): 2900, 2021

Reduction in sporadic Norovirus infections following the start of the COVID-19 pandemic, 2019-2020, Philadelphia

Nachamkin I, Richard-Greenblatt M, Yu M, Bui H., Infectious Diseases and Therapy 10(3): 1793-1798, 2021

Reducing Blood Culture Contamination Rates: Experiences of Four Hospital Systems

Halstead DC, Sautter RL, Snyder JW, Crist Jr AE, Nachamkin I, Infectious Diseases and Therapy 9(2): 389-401, 2020

Combined Biomarkers Predict Acute Mortality Among Critically Ill Patients with Suspected Sepsis

Kelly BJ, Lautenbach E, Nachamkin I, Coffin SE, Gerber JS, Fuchs BD, Garrigan C, Han X, Bilker WB, Wise J, Tolomeo P, Han JH., Critical Care Med, 2018

The Potential Economic Value of Sputum Culture Use in Patients with Community-Acquired Pneumonia and Healthcare-Associated Pneumonia

Asti, L., Bartsch, S., Umsheid, C., Hamilton, K., Nachamkin, I., Lee, B., Clin Microbiol Infect 25(8): 1038.e1-1038.e9, 2019, PMID:30590113

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Gut microbiome alteration in MORDOR I: a community-randomized trial of mass azithromycin distribution

Doan, T., A. Hinterwirth, L. Worden, A.M. Arzika, R. Maliki, A. Abdou, S. Kane, L. Zhong, S.L. Cummings, S. Sakar, C. Chen, C. Cook, E. Lebas, E.D. Chow, I. Nachamkin, T.C. Porco, J.D. Keenan, T.M. Lietman, Nat Medicine 25(): 1370-76, 2019

Blood culture utilization at an academic hospital: addressing a gap in benchmarking

Chen A, Bilker W, Hamilton K, O'Donnell J, Nachamkin I, Infect Control Hosp Epidemiol 39(11): 1353-59, 2018, PMID:30261936

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A laboratory medicine best practices systematic review and meta-analysis of nucleic acid amplification tests (NAAT) and algorithms including NAAT for the diagnosis of Clostridioides (Clostridium) difficile in adults

Kraft C, Parrott J, Cornish N, Rubinstein M, Weissfeld A, McNult P, Nachamkin I, Humphries R, Kirn T, Dien Bard J, Lutgring J, Gullett J, Bittencourt C, Benson S, Bobenchik A, Sautter R, Baselski V, Atlas M, Marlowe B, Miller N, Fischer M, Richter S, Gilligan P, Snyder J, Clin Microbiol Rev, 2019

Factors associated with persistent colonisation with methicillin-resistant Staphylococcus aureus

Cluzet VC, Gerber JS, Nachamkin I, Coffin SE, Davis MF, Julian KG, Zaoutis TE, Metlay JP, Linkin DR, Tolomeo P, Wise JA, Bilder WB, Hu B, Lautenbach E, Epidemiology and Infection 145(): 1409-17, 2017

Isolation of Campylobacter species from stool samples using a filtration method: assessment from a U.S. based population

Nachamkin I, Nguyen P., J Clin Microbiol 55(): 2204-7, 2017

Effect of a Price Transparency Intervention in the Electronic Health Record on Clinician Ordering of Inpatient Laboratory Tests: The PRICE Randomized Clinical Trial

Sedrak MS, Myers JS, Small DS, Nachamkin I, Ziemba JB, Murray D, Kurtzman GW, Zhu J, Wang W, Mincarelli D, Danoski D, Wells BP, Berns JS, Brennan PJ, Hanson CW, Dine CJ, Patel MS, JAMA Intern Med 177(7): 939-945, 2017, PMID:28430829

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Assessing Clinical Microbiology Practice Guidelines: American Society for Microbiology ad hoc Committee on Evidence-Based Laboratory Medicine Practice Guidelines Assessment

Nachamkin, I., Kirn, T., Westblade, L., Humphries, R., J. Clin. Microbiol. 55(): 3194-3200, 2017

The Effect of Total Household Decolonization on Clearance of Colonization with Methicillin-Resistant Staphylococcus aureus

Cluzet VC, Gerber JS, Metlay JP, Nachamkin I, Zaoutis TE, Davis MF, Julian KG, Linkin DR, Coffin SE, Margolis DJ, Hollander JE, Biler WB, Han X, Mistry RD, Gavin LJ, Tolomeo P, Wise JA, Wheeler MK, Hu B, Fishman NO, Royer D, Lautenbach E., Infect Cont Hosp Epidemiol, 2016

Evaluation of a research use only luminex based assay for measurement of procalcitonin in serum samples

Garrigan C, Han J, Tolomeo P, Johnson KJ, Master SR, Lautenbach E and Nachamkin I, Am J Translation Research 8(): 4362-69, 2016

Multicenter evaluation of clinical diagnostic methods for detection and isolation of Campylobacter spp. from stool.

Fitzgerald C, Patrick M, Gonzalez A, Akin J, Polage C, Wymore K, Gillim-Ross L, Xavier K, Sadlowski J, Monahan J, Hurd S, Dahlberg S, Jerris R, Watson R, Santovenia M, Mitchell D, Harrison C, Tobin-D'Angelo M, DeMartino M, Pentella M, Leonard C, Razaq J, Jung C, Achong-Bowe R, Evans Y, Jain D, Juni B, Leano F, Robinson R, Smith S, Gittelman R, Garrigan C, Nachamkin I and Campylobacter Diagnostics Study Working Group, J Clin Microbiol 54(): 1209-1215, 2016

Gastrointestinal Infections

Alby K., Nachamkin I., Microbiology Spectrum 4(3): doi:10.1128 /microbiolspec.DMIH2-0005-2015, 2016, PMID:27337464

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Comparing the economic and health benefits of different approaches to diagnosing Clostridium difficile infection

Bartsch SM, Umsheid CA, Nachamkin I, Hamilton K, Lee BY., Clin Microbiol Infect 21(1): 77.e1-9, 2015, PMID:25636938

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Distribution of Campylobacter jejuni capsular types, 2007-2012, Philadelphia, PA

Garrigan C, Attela A, Poly F, Guerry P, Nachamkin I, Diag Microbiol Infect Dis 80(): 204-206, 2014

Use of a combination biomarker algorithm to identify medical intensive care unit patients with suspected sepsis at very low likelihood of bacterial infection

Han J., Nachamkin I., Coffin S., Gerber J., Fuchs B., Garrigan C., Han X., Bilker W., Wise J., Tolomeo P., Lautenbach E., Antimicrobial Agents Chemother 59(10): 6494-6500, 2015, PMID:26239984

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Appropriateness of Expectorated Sputum Cultures in the Hospital Setting

Sloan CE, Bernard S, Nachamkin I., Diag Microbiol Infect Dis 83(1): 74-6, 2015, PMID:26032431

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The shared microbiota of humans and companion animals as evaluated from Staphylococcus carriage sites

Misic A., David MF., Tyldsley AS, Hodkinson BP, Tolomeo P, Hu B., Nachamkin I, Lautenbach E, Morris DO., Grice EA., Microbiome 3(2): doi: 10.1186/s40168-014-0052-7, 2015

Duration of Colonization and Determinants of Earlier Clearance of Colonization with Methicillin-Resistant Staphylococcus aureus

Cluzet VC, Gerber JS, Nachamkin I, Metlay JP, Zaoutis TE, Davis MF, Julian KG, Royer D, Linkin DR, Coffin SE, Margolis DJ, Hollander JE, Mistry RD, Gavin LJ, Tolomeo P, Wise JA, Wheeler MK, Bilker WB, Han X, Hu B, Fishman NO, Lautenbach E., Clin Infect Dis 60(10): 1489-96, 2015

Patterns of Guillain-Barre syndrome in children: results from a Mexican population

Nachamkin, I., Arzarte Barbosa, P., Ung, H., Lobato, C., Gonzalez Rivera, A., Rodriguez, P., Garcia Briseno, A., Maria Cordero, L., Garcia Perea, L., Carlos Perez, J., Ribera, P. Chico Aldama, G. Davila Gutierrez, L. Flores Sarnat, M. ruiz Garcia, M., Veitch, J., Fitzgerald, C., Cornblath, D., Pinto, M.R., Griffin, J.W., Willison, H.J., Asbury, A.K, McKhann, G.M., Neurology 69(): 1665-1671, 2007, PMID:17898327

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Campylobacter, 3rd edition

Nachamkin, I., Szymanski, C., Blaser, M.J. (eds), ASM Press, 2008

Increasing fluoroquinolone resistance in Campylobacter jejuni, Pennsylvania, 1982-2001

Nachamkin, I., Ung, H., Li, M., Emerg Infect Dis 8(): 1501-1503, 2002

Anti-GD1a antibody distinguishes axonal from demyelinating forms of Guillain-Barre Syndrome.

Ho, T.W., Willison, H.J., Nachamkin, I., Veitch, J., Li, C.Y., Cornblath, D.R., Asbury, A.K., Griffin, J.W., McKhann, G.M., Ann. Neurol. 45(): 168-173, 1999

Campylobacter jejuni lipopolysaccharides in Guillain-Barre syndrome: molecular mimicry and host susceptibility/determinants of outcome after Campylobacter jejuni infection.

Sheikh, K.A., Nachamkin, I., Ho, T.W., Willison, H.J., Veitch, J., Li, C.Y., Cornblath, D.R., Asbury, A.K., McKhann, G.M., Griffin, J.W., Neurology 51(): 371-378, 1998

Quinolone and macrolides resistance in Campylobacter jejuni and Campylobacter coli: A review of mechanisms and trends over time of resistance profiles in human isolates.

Engberg, J., Aarestrup, F.M., Taylor, D.E., Gerner-Smidt, P., Nachamkin, I., Emerg Infect Dis 7(): 724-734, 2001

Motor nerve terminal degeneration provides a potential mechanism for rapid recovery in Acute Motor Axonal Neuropathy after Campylobacter infection.

Ho, T.W., Hsieh, S.-T., Nachamkin, I., Willison, H.J., Sheikh, K., Kiehlbauch, J., Flanigan, K., McArthur, J.C., Cornblath, D.R., McKhann, G.M., Griffin, J.W., Neurology 48(): 717-724, 1997

Inappropriate utilization of microbiologic tests for the diagnosis of diarrheal disease in hospitalized patients

Siegel, D., Edelstein, P.H., Nachamkin, I., J.A.M.A. 263(): 979-982, 1990

Campylobacter and Guillain Barre Syndrome

Nachamkin, I., Mishu, B., Ho., T., Clin. Microbiol. Rev. 11(): 555-567, 1998

Flagellin gene typing of Campylobacter jejuni by restriction fragment length polymorphism analysis

Nachamkin, I., Bohachick, K., Patton, C.M., J. Clin. Microbiol. 31(): 1531-1536, 1993, PMID:8100241

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