Pablo C. Okhuysen, M.D., FACP, FIDSA
Department of Infectious Diseases, Infection Control, and Employee Health, Division of Internal Medicine
About Dr. Okhuysen
I have over 30 years’ experience in the study of enteric infectious diseases. I trained as a physician-scientist in Infectious Diseases at The University of Texas Medical School. I am a past Director of the NIH NCRR funded General Clinical Research Center at UT Health/Memorial Hermann Hospital and co-lead the joint UT Houston Medical School NIH CTSA-funded Center for Clinical and Translational Sciences.
I have conducted clinical and translational research in subjects with norovirus infection, travelers’ diarrhea, cryptosporidiosis and HIV and received the Oswald Avery Award for Early Accomplishment from the Infectious Diseases Society of America in 2007. I have gained extensive laboratory research experience in the characterization of bacterial agents of diarrhea, host immune response and genetic susceptibility to enteric infection, as well as with clinical trials with antibiotic and antiviral agents, human experimental challenge studies with enteropathogens and studied naturally acquired intestinal infections in US travelers to developing countries. In 2013, I joined MD Anderson Cancer Center and have established a laboratory dedicated to the study of enteropathogens in patients with cancer. I participate in the NIH funded U19 Genomic Centers for Infectious Diseases Program carrying out studies on enteric pathogens the microbiome in patients with cancer. I also participate in an NIH funded U19 Novel, Alternative Model Systems for Enteric Diseases Program examining host-enteropathogen interactions using human intestinal stem cell derived organoids. I am an active member of the NIH funded Texas Medical Center Digestive Diseases Center.
I am Director for the Onco-Transplant Infectious Diseases Fellowship Program at MDACC and site Program Director for the UT McGovern Medical School /MDACC and the Baylor College of Medicine Infectious Diseases Fellowship Programs.
Present Title & Affiliation
Primary Appointment
Professor, Department of Infectious Diseases, Infection Control and Employee Health, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX
Dual/Joint/Adjunct Appointment
Professor, Division of Infectious Diseases, The University of Texas Medical School, Houston, TX
Adjunct Professor, Department of Epidemiology, Human Genetics and Environmental Health, The University of Texas School of Public Health, Houston, TX
Adjunct Professor of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX
Research Interests
Education & Training
Degree-Granting Education
| 1988 | Universidad Autonoma de Guadalajara, Guadalajara, MEX, MD, Medicine |
Postgraduate Training
| 1991-1994 | Clinical Fellowship, Infectious Diseases, The University of Texas Medical School at Houston, Houston, TX |
| 1989-1991 | Clinical Residency, Internal Medicine, The University of Texas Medical School at Houston, Houston, TX |
| 1988-1989 | Clinical Internship, Internal Medicine, Cook County Hospital, Chicago, IL |
Board Certifications
| 1994 | American Board of Internal Medicine - Infectious Diseases |
| 1994 | American Board of Internal Medicine |
Experience & Service
Academic Appointments
Associate Faculty, UT Health and MD Anderson Cancer Center, Graduate School of Biological Sciences, Houston, TX, 2010 - 2015
Administrative Appointments/Responsibilities
Program Director Onco-Transplant Infectious Diseases Fellowship, Department of Infectious Diseases, The University of Texas MD Anderson Cancer Center, Houston, TX, 2019 - Present
Site Program Director - Infectious Diseases, Baylor College of Medicine, Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, TX, 2017 - Present
Co-Program Director, Clinical and Translational Research Center (NIH Clinical and Translational Sciences Award-CTSA), The University of Texas Health Science Center, Houston, TX, 2006 - 2009
Program Director, University Clinical Research Center (NIH General Clinical Research Center-GCRC), The University of Texas Medical School at Houston, Houston, TX, 2002 - 2010
Program Director, Infectious Diseases Fellowship Program, The University of Texas Medical School at Houston, Houston, TX, 2002 - 2009
Associate Program Director, Infectious Diseases Fellowship Program, The University of Texas Medical School at Houston, Houston, TX, 1999 - 2002
Minority Clinical Associate Physician, The University of Texas Medical School at Houston, Houston, TX, 1994 - 1997
Other Appointments/Responsibilities
Member - Internal Medicine Education Committee, UT MD Anderson Cancer Center, Houston, 2020 - Present
Institutional Committee Activities
Member, Academic Review Committee, The University of Texas MD Anderson Cancer Center, 2022 - Present
Honors & Awards
| 2015 | Teacher of the Year Award, Infectious Diseases Fellows MDACC/BCM |
| 2013 | Teacher of the Year Award, Infectious Diseases Fellows MDACC/BCM |
| 2012 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 2011 | Teacher of the Year Award, UTHSC/MDACC ID Fellows |
| 2009 | America's Top Physicians, Guide to America’s Top Physicians |
| 2007 | AOA Honors Medical Society, Delta Chapter |
| 2007 | Oswald Avery Award, Infectious Diseases Society of America |
| 2003 | Honors in International and National Research, The University of Texas Health Science Center at Houston |
| 2001 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 1999 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 1998 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 1996 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 1995 | Dean's Excellence Award, The University of Texas Medical School at Houston |
| 1989 | Honors Mention for Clinical Excellence, Cook County Hospital, Chicago IL |
Selected Publications
Peer-Reviewed Articles
- Chappell CL, Okhuysen PC, Langer-Curry RC, Lupo PJ, Widmer G, Tzipori S. Cryptosporidium muris: Infectivity and Illness in Healthy Adult Volunteers. Am J Trop Med Hyg, 2014.
- Mahale P, Okhuysen PC, Torres HA. Does chemotherapy cause viral relapse in cancer patients with hepatitis C infection successfully treated with antivirals?. Clin Gastroenterol Hepatol 12(6):1051-4, 2014.
- Nordell AD, McKenna M, Borges ÁH, Duprez D, Neuhaus J, Neaton JD; INSIGHT SMART, ESPRIT Study Groups; SILCAAT Scientific Committee. Severity of cardiovascular disease outcomes among patients with HIV is related to markers of inflammation and coagulation. J Am Heart Assoc 3(3), 2014. PMID: 24870935.
- Borges AH, O'Connor JL, Phillips AN, Baker JV, Vjecha MJ, Losso MH, Klinker H, Lopardo G, Williams I, Lundgren JD; INSIGHT SMART Study Group; ESPRIT Study Group; SILCAAT Scientific Committee. Factors associated with D-dimer levels in HIV-infected individuals. PLoS One 9(3), 2014. PMID: 24626096.
- Nair P, Okhuysen PC, Jiang ZD, Carlin LG, Belkind-Gerson J, Flores J, Paredes M, DuPont HL. Persistent abdominal symptoms in US adults after short-term stay in Mexico. J Travel Med 21(3):153-8, 2014. PMID: 24621006.
- Ajami NJ, Kavanagh OV, Ramani S, Crawford SE, Atmar RL, Jiang ZD, Okhuysen PC, Estes MK, DuPont HL. Seroepidemiology of norovirus-associated travelers' diarrhea. J Travel Med 21(1):6-11, 2014. PMID: 24383649.
- McGrath DM, Barbu EM, Driessen WH, Lasco TM, Tarrand JJ, Okhuysen PC, Kontoyiannis DP, Sidman RL, Pasqualini R, Arap W. Mechanism of action and initial evaluation of a membrane active all-D-enantiomer antimicrobial peptidomimetic. Proc Natl Acad Sci U S A 110(9):3477-82, 2013. e-Pub 2013. PMID: 23345420.
- Leder K, Torresi J, Libman MD, Cramer JP, Castelli F, Schlagenhauf P, Wilder-Smith A, Wilson ME, Keystone JE, Schwartz E, Barnett ED, von Sonnenburg F, Brownstein JS, Cheng AC, Sotir MJ, Esposito DH, Freedman, DO. GeoSentinel Surveillance of Illness in Returned Travelers, 2007-2011. Ann Intern Med 158(6):456-468, 2013. PMID: 23552375.
- Bjerk SM, Baker JV, Emery S, Neuhaus J, Angus B, Gordin FM, Pett SL, Stephan C, Kunisaki KM; INSIGHT SMART Study Group. Biomarkers and bacterial pneumonia risk in patients with treated HIV infection: a case-control study. PLoS One 8(2):e56249, 2013. PMID: 23457535.
- Matteelli A, Schlagenhauf P, Carvalho AC, Weld L, Davis XM, Wilder-Smith A, Barnett ED, Parola P, Pandey P, Han P, Castelli F; GeoSentinel Surveillance Network. Travel-associated sexually transmitted infections: an observational cross-sectional study of the GeoSentinel surveillance database. Lancet Infect Dis(13):205-213, 2013. PMID: 23182931.
- Gautret P, Gaudart J, Leder K, Schwartz E, Castelli F, Lim PL, Murphy H, Keystone J, Cramer J, Shaw M, Boddaert J, von Sonnenburg F, Parola P; GeoSentinel Surveillance Network. Travel-associated illness in older adults (>60 y). J Travel Med 19(3):169-177, 2012. PMID: 22530824.
- Flores-Figueroa J, Okhuysen PC, von Sonnenburg F, DuPont HL, Libman MD, Keystone JS, Hale DC, Burchard G, Han PV, Wilder-Smith A, Freedman DO, GeoSentinel Surveillance Network. Patterns of illness in travelers visiting Mexico and Central America: the GeoSentinel experience. Clin Infect Dis 53(6):523-31, 2011. e-Pub 2011. PMID: 21832261.
- Flores J, Dupont HL, Jiang ZD, Okhuysen PC, Melendez-Romero JH, Gonzalez-Estrada A, Carrillo I, Paredes M. A randomized, double-blind, pilot study of rifaximin 550 mg versus placebo in the prevention of travelers' diarrhea in Mexico during the dry season. J Travel Med 18(5):333-6, 2011. e-Pub 2011. PMID: 21896097.
- Chappell CL, Okhuysen PC, Langer-Curry RC, Akiyoshi DE, Widmer G, Tzipori S. Cryptosporidium meleagridis: infectivity in healthy adult volunteers. Am J Trop Med Hyg 85(2):238-42, 2011. PMID: 21813841.
- Cozzi-Lepri A, French MA, Baxter J, Okhuysen P, Plana M, Neuhaus J, Landay A, INSIGHT SMART study group. Resumption of HIV replication is associated with monocyte/macrophage derived cytokine and chemokine changes: results from a large international clinical trial. AIDS 25(9):1207-17, 2011. PMID: 21505304.
- Mohamed JA, DuPont HL, Flores J, Palur H, Nair P, Jiang ZD, Guo D, Belkind-Gerson J, Okhuysen PC. Single nucleotide polymorphisms in the promoter of the gene encoding the lipopolysaccharide receptor CD14 are associated with bacterial diarrhea in US and Canadian travelers to Mexico. Clin Infect Dis 52(11):1332-41, 2011. PMID: 21596674.
- Paredes-Paredes M, Okhuysen PC, Flores J, Mohamed JA, Padda RS, Gonzalez-Estrada A, Haley CA, Carlin LG, Nair P, DuPont HL. Seasonality of diarrheagenic Escherichia coli pathotypes in the US students acquiring diarrhea in Mexico. J Travel Med 18(2):121-5, 2011. e-Pub 2011. PMID: 21366796.
- Villa NA, Okhuysen PC, Flores-Figueroa J, Jiang ZD, Belkind-Gerson J, Paredes M, Mohamed JA, Nair P, Carlin L, DuPont HL. Campylobacter jejuni is not an important pathogen as a cause of diarrhea in US travelers to Mexico. J Travel Med 18(1):56-8, 2011. e-Pub 2010. PMID: 21199144.
- Ouyang-Latimer J, Ajami NJ, Jiang ZD, Okhuysen PC, Paredes M, Flores J, Dupont HL. Biochemical and genetic diversity of enterotoxigenic Escherichia coli associated with diarrhea in United States students in Cuernavaca and Guadalajara, Mexico, 2004-2007. J Infect Dis 201(12):1831-8, 2010. PMID: 20443738.
- Flores J, DuPont HL, Paredes-Paredes M, Aguirre-Garcia MM, Rojas A, Gonzalez A, Okhuysen PC. Pilot study of whole-blood gamma interferon response to the Vibrio cholerae toxin B subunit and resistance to enterotoxigenic Escherichia coli-associated diarrhea. Clin Vaccine Immunol 17(5):879-81, 2010. e-Pub 2010. PMID: 20219880.
- Koo HL, Ajami NJ, Jiang ZD, Neill FH, Atmar RL, Ericsson CD, Okhuysen PC, Taylor DN, Bourgeois AL, Steffen R, DuPont HL. Noroviruses as a cause of diarrhea in travelers to Guatemala, India, and Mexico. J Clin Microbiol 48(5):1673-6, 2010. e-Pub 2010. PMID: 20305012.
- Martinez-Sandoval F, Ericsson CD, Jiang ZD, Okhuysen PC, Romero JH, Hernandez N, Forbes WP, Shaw A, Bortey E, DuPont HL. Prevention of travelers' diarrhea with rifaximin in US travelers to Mexico. J Travel Med 17(2):111-7, 2010. PMID: 20412178.
- Ajami N, Koo H, Darkoh C, Atmar RL, Okhuysen PC, Jiang ZD, Flores J, Dupont HL. Characterization of norovirus-associated traveler's diarrhea. Clin Infect Dis 51(2):123-130, 2010. PMID: 20540620.
- INSIGHT-SMART Study Group. Martinez E, Visnegarwala F, Grund B, Thomas A, Gibert C, Shlay J, Drummond F, Pearce D, Edwards S, Reiss P, El-Sadr W, Carr A. The effects of intermittent, CD4-guided antiretroviral therapy on body composition and metabolic parameters. AIDS 24(3):353-363, 2010.
- Flores J, Okhuysen PC. Genetics of susceptibility to infection with enteric pathogens. Curr Opin Infect Dis 22(5):471-6, 2009. PMID: 19633551.
- INSIGHT-ESPRIT Study Group. Abrams D, Levy Y, Losso MH, Babiker A, Collins G, Cooper DA, Darbyshire J, Emery S, Fox L, Gordin F, Lane HC, Lundgren JD, Mitsuyasu R, Neaton JD, Phillips A, Routy JP, Tambussi G, Wentworth D. Interleukin-2 therapy in patients with HIV infection. N Engl J Med 361(16):1548-1559, 2009.
- INSIGHT-SMART Study Group. Rodger AJ, Fox Z, Lundgren JD, Kuller LH, Boesecke C, Gey D, Skoutelis A, Goetz MB, Phillips AN. Activation and coagulation biomarkers are independent predictors of the development of opportunistic disease in patients with HIV infection. J Infect Dis 200(6):973-983, 2009.
- INSIGHT-SMART Study Group. Grund B, Peng G, Gibert CL, Hoy JF, Isaksson RL, Shlay JC, Martinez E, Reiss P, Visnegarwala F, Carr AD. Continuous antiretroviral therapy decreases bone mineral density. AIDS 23(12):1519-1529, 2009.
- Mohamed JA, DuPont HL, Jiang ZD, Flores J, Carlin LG, Belkind-Gerson J, Martinez-Sandoval FG, Guo D, White AC, Okhuysen PC. A single-nucleotide polymorphism in the gene encoding osteoprotegerin, an anti-inflammatory protein produced in response to infection with diarrheagenic Escherichia coli, is associated with an increased risk of nonsecretory bacterial diarrhea in North American travelers to Mexico. J Infect Dis 199(4):477-85, 2009. PMID: 19128145.
- Flores J, Okhuysen PC. Enteroaggregative Escherichia coli infection. Curr Opin Gastroenterol 25(1):8-11, 2009. PMID: 19114769.
- INSIGHT-SMART Study Group. Mocroft A, Wyatt C, Szczech L, Neuhaus J, El-Sadr W, Tracy R, Kuller L, Shlipak M, Angus B, Klinker H, Ross M. Interruption of antiretroviral therapy is associated with increased plasma cystatin C. AIDS 23(1):71-82, 2009.
- Nallapareddy SR, Singh KV, Okhuysen PC, Murray BE. A functional collagen adhesin gene, acm, in clinical isolates of Enterococcus faecium correlates with the recent success of this emerging nosocomial pathogen. Infect Immun 76(9):4110-9, 2008. e-Pub 2008. PMID: 18591238.
- Flores J, DuPont HL, Lee SA, Belkind-Gerson J, Paredes M, Mohamed JA, Armitige LY, Guo DC, Okhuysen PC. Influence of host interleukin-10 polymorphisms on development of traveler's diarrhea due to heat-labile enterotoxin-producing Escherichia coli in travelers from the United States who are visiting Mexico. Clin Vaccine Immunol 15(8):1194-8, 2008. e-Pub 2008. PMID: 18579697.
- Nair P, Mohamed JA, DuPont HL, Figueroa JF, Carlin LG, Jiang ZD, Belkind-Gerson J, Martinez-Sandoval FG, Okhuysen PC. Epidemiology of cryptosporidiosis in North American travelers to Mexico. Am J Trop Med Hyg 79(2):210-4, 2008. PMID: 18689626.
- Grimes KA, Mohamed JA, Dupont HL, Padda RS, Jiang ZD, Flores J, Belkind-Gerson J, Martinez-Sandoval FG, Okhuysen PC. PCR-based assay using occult blood detection cards for detection of diarrheagenic Escherichia coli in specimens from U.S. travelers to Mexico with acute diarrhea. J Clin Microbiol 46(7):2227-30, 2008. e-Pub 2008. PMID: 18480224.
- Lupo PJ, Langer-Curry RC, Robinson M, Okhuysen PC, Chappell CL. Cryptosporidium muris in a Texas canine population. Am J Trop Med Hyg 78(6):917-21, 2008. PMID: 18541769.
- Frech SA, Dupont HL, Bourgeois AL, McKenzie R, Belkind-Gerson J, Figueroa JF, Okhuysen PC, Guerrero NH, Martinez-Sandoval FG, Meléndez-Romero JH, Jiang ZD, Asturias EJ, Halpern J, Torres OR, Hoffman AS, Villar CP, Kassem RN, Flyer DC, Andersen BH, Kazempour K, Breisch SA, Glenn GM. Use of a patch containing heat-labile toxin from Escherichia coli against travellers' diarrhoea: a phase II, randomised, double-blind, placebo-controlled field trial. Lancet 371(9629):2019-25, 2008. PMID: 18554712.
- Flores J, DuPont HL, Jiang ZD, Belkind-Gerson J, Mohamed JA, Carlin LG, Padda RS, Paredes M, Martinez-Sandoval JF, Villa NA, Okhuysen PC. Enterotoxigenic Escherichia coli heat-labile toxin seroconversion in US travelers to Mexico. J Travel Med 15(3):156-61, 2008. PMID: 18494692.
- Huang DB, Brown EL, DuPont HL, Cerf J, Carlin L, Flores J, Belkind-Gerson J, Nataro JP, Okhuysen PC. Seroprevalence of the enteroaggregative Escherichia coli virulence factor dispersin among USA travellers to Cuernavaca, Mexico: a pilot study. J Med Microbiol 57(Pt 4):476-9, 2008. PMID: 18349368.
- Carr A, Grund B, Neuhaus J, El-Sadr WM, Grandits G, Gibert C, Prineas RJ and SMART study Investigators. Asymptomatic myocardial ischaemia in HIV-infected adults. AIDS(22):257-267, 2008.
- Strategies for Management of Antiretroviral Therapy Study Group. Emery S, Neuhaus JA, Phillips AN, Babiker A, Cohen CJ, Gatell JM, Girard PM, Grund B, Law M, Losso MH, Palfreeman A, Wood R. Major clinical outcomes in antiretroviral therapy (ART)-naive participants and in those not receiving ART at baseline in the SMART study. J Infect Dis(197):1133-1144, 2008.
- SMART Study Group. El-Sadr WM, Grund B, Neuhaus J, Babiker A, Cohen CJ, Darbshire J, Emery S, Lundgren JD, Philips A, Neaton JD. Risk of Opportunistic Disease and Death after Re-initiating Continous Antiretroviral Therapy in Patients with HIV Previously Receiving Episodic therapy: A randomized Trial. Ann Intern Med(149):289-299, 2008.
- SMART Study Group. A, Cohen C, Neuhaus J, Baxter J, Emery S, Hirschel B, Hullsiek KH, Stephan C, Lundgren J Fox Z, Phillips. Viral resuppression and detection of drug resistance following interruption of a suppressive non-nucleoside reverse transcriptase inhibitor-based regimen. AIDS 12(22):2279-2289, 2008.
- Planque S, Mitsuda Y, Taguchi H, Salas M, Morris MK, Nishiyama Y, Kyle R, Okhuysen P, Escobar M, Hunter R, Sheppard HW, Hanson C, Paul S. Characterization of gp120 hydrolysis by IgA antibodies from humans without HIV infection. AIDS Res Hum Retroviruses 23(12):1541-54, 2007. PMID: 18160012.
- Huang DB, Mohamed JA, Nataro JP, DuPont HL, Jiang ZD, Okhuysen PC. Virulence characteristics and the molecular epidemiology of enteroaggregative Escherichia coli isolates from travellers to developing countries. J Med Microbiol 56(Pt 10):1386-92, 2007. PMID: 17893178.
- Ericsson CD, DuPont HL, Okhuysen PC, Jiang ZD, DuPont MW. Loperamide plus azithromycin more effectively treats travelers' diarrhea in Mexico than azithromycin alone. J Travel Med 14(5):312-9, 2007. PMID: 17883462.
- Jiang ZD, Garey KW, Price M, Graham G, Okhuysen P, Dao-Tran T, LaRocco M, DuPont HL. Association of interleukin-8 polymorphism and immunoglobulin G anti-toxin A in patients with Clostridium difficile-associated diarrhea. Clin Gastroenterol Hepatol 5(8):964-8, 2007. e-Pub 2007. PMID: 17618838.
- Aguirre-García MM, Okhuysen PC. Cryptosporidium parvum: identification and characterization of an acid phosphatase. Parasitol Res 101(1):85-9, 2007. e-Pub 2007. PMID: 17252269.
- Dupont HL, Jiang ZD, Belkind-Gerson J, Okhuysen PC, Ericsson CD, Ke S, Huang DB, Dupont MW, Adachi JA, De La Cabada FJ, Taylor DN, Jaini S, Martinez Sandoval F. Treatment of travelers' diarrhea: randomized trial comparing rifaximin, rifaximin plus loperamide, and loperamide alone. Clin Gastroenterol Hepatol 5(4):451-6, 2007. e-Pub 2007. PMID: 17382603.
- The ESPRIT Research Group. Predictors of CD4 count change over 8 months of follow up in HIV-1-infected patients with a CD4 count>/=300 cells/muL who were assigned to 7.5 MIU interleukin-2. HIV Med(8):112-123, 2007.
- Okhuysen PC, Flores F, DuPont HL, Flores-Lopez JJ, Mathewson JJ, Perez-Castell F. A Comparative Study of Furazolidone and Placebo in Addition to Oral Rehydration Therapy in the Treatment of Infantile Gastroenteritis. Scan J Gastroentrol(24s):39-46, 1989.
Book Chapters
- Okhuysen PC, Lee SA, Guerrant RL. Genetic Susceptibility to Enteric Infections; Implications for Endemic and Travelers’ Diarrhea. In: Travelers’ Diarrhea Textbook, 2nd Edition. 2nd. Becker: Lewinston NY, 153-158, 2007.