O'Connell Research Group

The Clinical Parasitology Unit is an interdisciplinary group of clinically trained LPD staff members who oversee the clinical research portfolio and provide clinical care, consultations, and training in tropical medicine and parasitology. The overriding goals of this program are:

  • To gain insight into the clinical syndromes associated with parasitic infections
  • To understand and help define the pathogenesis underlying clinical disease
  • To identify better ways of treating individual infections and to prevent secondary consequences of treatment
  • To develop better diagnostic tools for the species-specific diagnosis of active parasitic infection

Although the Clinical Parasitology Unit has protocols to see patients with any parasitic infection, the overwhelming majority of patients have neurocysticercosis, filarial infections (lymphatic filariasis, onchocerciasis, loiasis, mansonellosis), strongyloidiasis, Chagas disease, hookworm infections, ascaraisis, giardiasis, echinococcosis, and leishmaniasis. We occasionally see patients with gnathostomiasis, African trypanosomiasis, and malaria, among others.
 

Clinical Parasitology Unit, June 2022

Clinical Parasitology Unit, June 2022: Front Row (left to right): Nicole Holland, R.N. (former member); Perla Adames Castillo, R.N.; Amy Klion, M.D.; Paneez Khoury, M.D., MHSc; JeanAnne Ware, M.P.H., C.R.N.P.; Elise O’Connell, M.D., Senior Investigator; Celeste Nelson, M.S., C.R.N.P. Back Row (left to right): Gregory Constantine, M.D.; Thomas Nutman, M.D.; William Sears, M.P.H., M.D. (former member); Lauren Wetzler, MHS, PA-C; Thomas Brown, R.N.; Ejiofor Ezekwe, M.D., Ph.D.

Credit: NIAID

Elise M. O’Connell, M.D.

Chief, Clinical Parasitology Unit
Associate Research Physician

Specialty(s): Infectious Disease, Internal Medicine
Provides direct clinical care to patients at NIH Clinical Center

Education:

M.D., Loyola University Chicago

Dr. O’Connell received her medical degree from Loyola University of Chicago. She is a board-certified physician in Internal Medicine and Infectious Diseases and completed residency at Indiana University and fellowship at the National Institute for Allergy and Infectious Diseases (NIAID/NIH).

Learn more about Elise M. O’Connell, M.D.

Elise M. O’Connell, M.D.

Jessica Bass, D.O.

Infectious Disease Clinical Fellow

Education:

D.O., Kansas City University of Medicine and Biosciences
Residency, NCH Healthcare System Internal Medicine Residency
Chief Resident, NCH Healthcare System Internal Medicine Residency
Fellowship, NIH Infectious Disease Fellowship

Languages Spoken: Spanish

My research projects include identifying Helicobacter pylori (H. pylori) antibiotic resistance genes, diagnosis of H. pylori utilizing an entero-string test, and clinical outcomes of H. pylori resistance-guided treatment in patients who have failed prior therapies. My clinical interests include tropical medicine and parasitology.

Learn more about Jessica Bass, D.O.

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Thomas Brown, R.N.

Nurse Specialist, CCRP

Thomas is the study coordinator for the following protocols: Natron, Pilot Study of Mepolizumab in Episodic Angioedema with Eosinophilia, Collection of blood, body fluid and tissue specimens from healthy donors for use in in vitro research, An Open-Label, Proof-of-Concept Study to Evaluate the Safety and Efficacy of Dexpramipexole (KNS-760704) in Subjects with Hypereosinophilic Syndrome, A Phase 2...

Learn more about Thomas Brown, R.N.

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Perla Adames Castillo, R.N.

Nurse Research Specialist

Languages Spoken: Spanish

Perla is study coordinator for the Cysticercosis, Leishmaniasis, and Chagas arm of the Parasite Screening protocols.

Learn more about Perla Adames Castillo, R.N.

Gregory M. Constantine, M.D.

Assistant Research Physician, Human Eosinophil Section (HES), Laboratory of Parasitic Diseases (LPD)

Specialty(s): Allergy and Immunology, Internal Medicine
Provides direct clinical care to patients at NIH Clinical Center

Education:

M.D., University of Texas Long School of Medicine, San Antonio, TX

Residency, Internal Medicine, Baylor College of Medicine, Houston, TX

Chief Residency, Internal Medicine, Baylor College of Medicine, Houston, TX

Fellowship, Allergy and Immunology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, MD

Gregory Constantine, M.D., is an Assistant Research Physician Clinician at NIAID. He has been involved in translational research in eosinophilic disorders since joining the Human Eosinophil Section in 2020. He received his M.D. from the University of Texas Long School of Medicine, followed by a residency in internal medicine at Baylor College of Medicine (BCM). He was then selected and served as...

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Gustavo Cuevas

Clinical Research Coordinator

Languages Spoken: Spanish

Harris Richard Droghini, M.D.

Allergy and Immunology Fellow

Education:

BMus, Vanderbilt University 
M.D., Medical University of South Carolina

I am interested in the modulation of the immune system and allergic responses by helminth infections, in particular, the human whipworm (Trichuris trichiura) in a Phase 1 clinical trial (NCT05706116). I am also working on developing a novel approach to characterize the human gut microbiome.

Learn more about Harris Richard Droghini, M.D.

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Ejiofor Ezekwe, M.D., Ph.D.

Allergy and Immunology Clinical Fellow

Education:

Pediatrics Residency, University of North Carolina
Ph.D., University of North Carolina
Medical School, University of North Carolina

Janitzio Guzman, M.D.

Infectious Diseases Fellow

Education:

Internal Medicine/Pediatrics Residency, University of Oklahoma School of Community Medicine, Tulsa, OK
Doctor of Medicine, University of Texas School of Medicine at San Antonio, San Antonio, TX
Bachelor of Science, The Ohio State University, Columbus, OH

Languages Spoken: Spanish

Janitzio is a combined adult/pediatric infectious diseases fellow with an interest in the immunopathogenesis of helminthic infections. He is working in Elise O’Connell’s group to study the immune response to subarachnoid neurocysticercosis, including the role of autoantibody formation in disease. His clinical interests include parasitic infection, neglected tropical diseases, and infections...

Learn more about Janitzio Guzman, M.D.

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Paneez Khoury, M.D., M.H.Sc., FAAAAI

Senior Clinician; Director, Allergy & Immunology Fellowship Training Program, Laboratory of Allergic Diseases (LAD)
Head, Eosinophil Clinical Research Unit, Human Eosinophil Section, Laboratory of Parasitic Diseases (LPD)

Specialty(s): Allergy and Immunology, Internal Medicine
Provides direct clinical care to patients at NIH Clinical Center

Education:

M.D., University of Illinois College of Medicine, Chicago, IL

M.H.Sc., Duke University, Durham, NC

Paneez Khoury, M.D. is Senior Clinician in NIAID. She has been involved in translational research in eosinophilic disorders since joining the Human Eosinophil Section in 2012. She is the head of the Eosinophil Clinical Research Unit in the Human Eosinophil Section where she leads clinical investigative trials and studies in a variety of eosinophilic disorders. She received her M.D. from University...

Learn more about Paneez Khoury, M.D., M.H.Sc., FAAAAI

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Amy Klion, M.D.

Co-Deputy Chief, Laboratory of Parasitic Diseases
Chief, Human Eosinophil Section

Education:

B.A., Princeton University

M.D., New York University School of Medicine

Dr. Klion earned her B.A. from Princeton University and her M.D. from New York University School of Medicine. After completing a residency in internal medicine at Johns Hopkins University, she was a postdoctoral fellow in the Laboratory of Parasitic Diseases from 1989 to 1991. She completed her fellowship in infectious diseases at the University of Iowa Hospitals and Clinics in Iowa City, Iowa, where she was appointed an assistant professor in the division of infectious diseases prior to returning to the Laboratory of Parasitic Diseases in 1997 as a staff clinician. She became a tenure-track clinical investigator in the Laboratory of Parasitic Diseases in 2009 and a senior clinical investigator in 2014.

Learn more about Amy Klion, M.D.

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Michelle M. Luera, M.S.N.

Registered Nurse

Education:

M.S.N., Nursing Informatics, Nova Southeastern University, Fort Lauderdale, FL
B.S., Nursing, Florida International University, Miami, FL

Michelle is a certified pediatric nurse with experience in hematology/oncology, bone marrow transplant, and clinical research. She is also a study coordinator on the LPD screen, and she has experience in Chagas disease and the Hypereosinophilia protocol.

Learn more about Michelle M. Luera, M.S.N.

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Emily E. Miltenberger, B.S.

Postbaccalaureate IRTA Fellow

Education:

B.S., 2021, University of Southern California, Los Angeles, CA

Languages Spoken: French, Korean

Emily’s project is focused on characterizing the inflammatory cascade observed in the central nervous system of patients with subarachnoid neurocysticercosis. She also runs and optimizes diagnostic assays for the disease.

Learn more about Emily E. Miltenberger, B.S.

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Celeste Gerise Nelson M.S., C.R.N.P.

Advanced Practice Nurse (C.R.N.P.)

Celeste is a family nurse practitioner with the Laboratory of Allergic Diseases since 2008 working on multiple protocols for allergic disorders including urticaria, atopic dermatitis, capillary leak and genetic disorders of allergic inflammation.

Learn more about Celeste Gerise Nelson M.S., C.R.N.P.

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Thomas Nutman, M.D.

Lab Chief, Laboratory of Parasitic Diseases
Chief, Helminth Immunology Section

Provides direct clinical care to patients at NIH Clinical Center

Education:

A.B., Brown University, Providence, RI

M.D., University of Cincinnati College of Medicine, Cincinnati, OH

Dr. Nutman received his A.B. from Brown University and his M.D. from the University of Cincinnati College of Medicine. He did an internal medicine residency at New York University (Bellevue) and postdoctoral training in the Laboratory of Parasitic Diseases (LPD). He is board certified in internal medicine and allergy and immunology. He also holds a diploma/certificate in tropical medicine and...

Learn more about Thomas Nutman, M.D.

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Adrienne Showler, M.D.

Attending Physician 

Education:

Medical School, University of Ottawa
Residency, University of Toronto Faculty of Medicine
Fellowship, University of Toronto Hospital

Languages Spoken: French

Dr. Adrienne Showler is an infectious disease and clinical tropical medicine physician focused on diagnosis and treatment of neglected tropical diseases in travelers and foreign-born populations.

Learn more about Adrienne Showler, M.D.

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JeanAnne M. Ware, M.P.H., C.R.N.P.

Nurse Practitioner, C.R.N.P., FNP-BC

Education:

BSN, Johns Hopkins University
MSN, University of California San Francisco Family Nurse Practitioner Program
M.P.H., Johns Hopkins Bloomberg School of Public Health

Languages Spoken: Spanish

Clinician and Associate Investigator on clinical trials for parasitology including leishmaniasis, neurocysticercosis, filarial diseases and Chagas disease, and hypereosinophilic disorders.

Learn more about JeanAnne M. Ware, M.P.H., C.R.N.P.

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Lauren Wetzler, MHS, PA-C

Physician Assistant

Education:

MHS, Physician Assistant, Drexel University
BS, Biology, University of Maryland, College Park

Lauren began her career in 2011, initially specializing in neurosurgery and trauma. She transitioned to clinical research at NIH in 2014, serving as an associate investigator on multiple natural history and investigational drug studies spanning a range of parasitic infections and hypereosinophilic syndromes.

Learn more about Lauren Wetzler, MHS, PA-C

Former Research Group Members

  • Nina Lei Tang, BS, Postbaccalaureate IRTA Fellow; Education: BA, Barnard College; Languages spoken (other than English): French
  • Nina studied the immunopathology of neurocysticercosis with a particular focus on the local immune environment of subarachnoid neurocysticercosis and the persistence of seropositivity following cure of active disease. After NIAID: M.D./Ph.D. program at Baylor College of Medicine
  • Aissatou Bah, BS. After NIAID: M.D. program at University of Minnesota
  • Madelyn Corda, BS. After NIAID: Campbell University School of Osteopathic Medicine
  • Lauren Thumm, R.N. After NIAID: Merck
  • Nicole Holland, R.N. After NIAID:  HRSA
  • Jiana L. Blaha, MHS
  • William J. Sears, M.D., MHS
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