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: Front Row (left to right): Nicole Holland, RN; Perla Adames Castillo, RN; Amy Klion, M.D.; Paneez Khoury, M.D., MHSc; JeanAnne Ware, MPH, CRNP, Elise O’Connell, M.D.; Celeste Nelson, MS, CRNP Back Row (left to right): Gregory Constantine, M.D.; Thomas Nutman, M.D.; William Sears, MPH, M.D.; Lauren Wetzler, MHS, PA-C, Thomas Brown, RN; Ejiofor Ezekwe, M.D., Ph.D.
Elise M. O’Connell, M.D. (She/Her/Hers)
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

Jiana L. Blaha, MHS (She/Her/Hers)
NIH/NIAID Postbac IRTA
Education:
MHS., 2021, Johns Hopkins University
B.S., 2020, American University
Languages Spoken: Spanish
Thomas Brown, RN (He/Him/His)
Nurse Specialist, CCRP

Perla Adames Castillo, RN (She/Her/Hers)
Nurse Research Specialist
Languages Spoken: Spanish
Gregory M. Constantine, M.D. (He/Him/His)
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

Gustavo Cuevas
Clinical Research Coordinator
Languages Spoken: Spanish
Ejiofor Ezekwe, M.D., Ph.D. (He/Him/His)
Allergy and Immunology Clinical Fellow
Education:
Pediatrics Residency, University of North Carolina
Ph.D., University of North Carolina
Medical School, University of North Carolina
Janitizio 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

Paneez Khoury, M.D., M.H.Sc., FAAAAI (She/Her/Hers)
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

Amy Klion, M.D.
Chief, Human Eosinophil Section
Education:
B.A., Princeton University
M.D., New York University School of Medicine

Celeste Gerise Nelson M.S., C.R.N.P. (She/Her/Hers)
Advanced Practice Nurse (CRNP)

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

William J. Sears, M.D., MHS (He/Him/His)
Infectious Disease Fellow
Education:
Med/Peds Residency, Indiana University
M.D., University of Louisville School of Medicine
MHS, Johns Hopkins School of Public Health
Languages Spoken: Spanish
Adrienne Showler, M.D. (She/Her/Hers)
Attending Physician
Education:
Medical School, University of Ottawa
Residency, University of Toronto Faculty of Medicine
Fellowship, University of Toronto Hospital
Languages Spoken: French

JeanAnne M. Ware, MPH, CRNP (She/Her/Hers)
Nurse Practitioner, CRNP, FNP-BC
Education:
BSN, Johns Hopkins University
MSN, University of California San Francisco Family Nurse Practitioner Program
MPH, Johns Hopkins Bloomberg School of Public Health.
Languages Spoken: Spanish

Lauren Wetzler, MHS, PA-C (She/Her/Hers)
Physician Assistant
Education:
MHS, Physician Assistant, Drexel University
BS, Biology, University of Maryland, College Park
Former Research Group Members
Nina Lei Tang, BS (She/Her/Hers), 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, RN. After NIAID: Merck
Nicole Holland, RN. After NIAID: HRSA