eMedicine Specialties > Pediatrics: General Medicine > Parasitology

Hookworm Infection: Differential Diagnoses & Workup

Author: Christopher M Watson, MD, Pediatric Critical Care Fellow, Johns Hopkins Hospital; Assistant Professor of Pediatrics, Uniformed Services University of the Health Sciences
Coauthor(s): Patrick W Hickey, MD, FAAP, Assistant Professor of Pediatrics, Uniformed Services University of the Health Sciences; Consulting Staff, Department of Pediatrics, Division of Pediatric Infectious Disease, Walter Reed Army Medical Center
Contributor Information and Disclosures

Updated: Oct 7, 2008

Differential Diagnoses

Amebiasis
Growth Failure
Anemia, Acute
Loffler Syndrome
Anemia, Chronic
Pneumonia
Ascariasis
Protein-Losing Enteropathy
Asthma
Schistosomiasis
Bronchiolitis
Strongyloidiasis
Cognitive Deficits
Contact Dermatitis
Gastroenteritis

Workup

Laboratory Studies

  • Anemia is confirmed by evaluating the CBC count, and microscopy reveals hypochromic, microcytic RBCs.
  • Eosinophilia may also be present during the initial phases of infection, peaking at 30-65 days.4
  • The diagnosis is confirmed with microscopic analysis of fecal samples to verify the presence of hookworm eggs. The specimen is fixed in formalin and prepared as a wet mount.4,5
    • During the initial stages of infection, results of stool studies may be normal.
    • In rare cases, the worm or larvae may be present in the fecal sample.
    • Although hookworm eggs are easily distinguished from the eggs of other helminth, rhabditiform larvae are occasionally seen in old stool specimens. Differentiating hookworm larvae from those of Strongyloides organisms requires attention to the unique morphologic features, particularly the relatively short buccal cavity and prominent genital primordium of Strongyloides larvae.
    • Under basic light microscopy, the eggs of N americanus and A duodenale appear morphologically similar. During clinical evaluation, this distinction is not necessary because the management remains the same for both.
    • The worm burden may be estimated by counting the number of eggs per gram of stool, by multiplying by the daily stool weight, and by dividing the result by 25,000. A worm burden of less than 25 is generally subclinical. However, more than 500 worms is clinically significant.

More on Hookworm Infection

Overview: Hookworm Infection
Differential Diagnoses & Workup: Hookworm Infection
Treatment & Medication: Hookworm Infection
Follow-up: Hookworm Infection
Multimedia: Hookworm Infection
References
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References

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  2. World Health Organization. Parasitic Diseases. WHO. Available at http://www.who.int/vaccine_research/diseases/soa_parasitic/en/index2.html. Accessed September 6, 2008.

  3. Capello M, Hotez PJ. Chapter 276: Intestinal Nematodes. In: Long SS, ed-in-chief; Pickering LK, Prober CG, eds. Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia, PA: Churchill Livingstone, an imprint of Elsevier Science; 2008:1298-1300.

  4. Gilles HM. Soil-transmitted Helminths (Geohelminths). In: Cook GC, Zumla AI, eds. Manson's Tropical Diseases. 2003. ed. Philadelphia, PA: WB Saunders; 1538-60.

  5. Centers for Disease Control and Prevention. Hookworm. CDC DPDx: Laboratory Identification of Parasites of Public Health Concern. Available at http://www.dpd.cdc.gov/DPDx/HTML/Hookworm.htm. Accessed September 6, 2008.

  6. Centers for Disease Control and Prevention. Hookworm Infection. CDC. Available at http://www.cdc.gov/ncidod/dpd/parasites/hookworm. Accessed September 6, 2008.

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  15. Stoltzfus RJ, Chway HM, Montresor A, et al. Low dose daily iron supplementation improves iron status and appetite but not anemia, whereas quarterly anthelminthic treatment improves growth, appetite and anemia in Zanzibari preschool children. J Nutr. Feb 2004;134(2):348-56. [Medline].

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Further Reading

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Keywords

hookworm infection, Ancylostomatidae, ancylostomiasis, Necator americanus, N americanus, A duodenale, Ancylostoma duodenale, ground itch, anemia, malnutrition, eosinophilic enteritis, hypoproteinemia, pruritic dermatitis, Wakana syndrome, Loeffler syndrome, pulmonary infection, pica, syncope

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Contributor Information and Disclosures

Author

Christopher M Watson, MD, Pediatric Critical Care Fellow, Johns Hopkins Hospital; Assistant Professor of Pediatrics, Uniformed Services University of the Health Sciences
Christopher M Watson, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, and American Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

Patrick W Hickey, MD, FAAP, Assistant Professor of Pediatrics, Uniformed Services University of the Health Sciences; Consulting Staff, Department of Pediatrics, Division of Pediatric Infectious Disease, Walter Reed Army Medical Center
Patrick W Hickey, MD, FAAP is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, and Pediatric Infectious Diseases Society
Disclosure: Nothing to disclose.

Medical Editor

Ashir Kumar, MBBS, MD, FAAP, Professor, Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University; Consulting Staff, Department of Pediatrics, EW Sparrow Hospital
Ashir Kumar, MBBS, MD, FAAP is a member of the following medical societies: American Academy of Pediatrics, American Association of Physicians of Indian Origin, American Federation for Clinical Research, American Society for Microbiology, Infectious Diseases Society of America, and Pediatric Infectious Diseases Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

Martin Weisse, MD, Program Director, Associate Professor, Department of Pediatrics, West Virginia University
Martin Weisse, MD is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Pediatric Infectious Diseases Society
Disclosure: Nothing to disclose.

CME Editor

Robert W Tolan Jr, MD, Chief, Division of Allergy, Immunology and Infectious Diseases, The Children's Hospital at Saint Peter's University Hospital; Clinical Associate Professor of Pediatrics, Drexel University College of Medicine
Robert W Tolan Jr, MD is a member of the following medical societies: American Academy of Pediatrics, American Medical Association, American Society for Microbiology, American Society of Tropical Medicine and Hygiene, Infectious Diseases Society of America, Pediatric Infectious Diseases Society, Phi Beta Kappa, and Physicians for Social Responsibility
Disclosure: GlaxoSmithKline Honoraria Speaking and teaching; MedImmune Honoraria Consulting; MedImmune Honoraria Speaking and teaching; Merck Honoraria Speaking and teaching; Novartis Honoraria Speaking and teaching; sanofi pasteur Grant/research funds Unrestricted research grant; sanofi pasteur  Consulting; sanofi pasteur Honoraria Speaking and teaching; Tap Honoraria Speaking and teaching

Chief Editor

Russell W Steele, MD, Head, Division of Pediatric Infectious Diseases, Ochsner Children's Health Center; Clinical Professor, Department of Pediatrics, Tulane University School of Medicine
Russell W Steele, MD is a member of the following medical societies: American Academy of Pediatrics, American Association of Immunologists, American Pediatric Society, American Society for Microbiology, Infectious Diseases Society of America, Louisiana State Medical Society, Pediatric Infectious Diseases Society, Society for Pediatric Research, and Southern Medical Association
Disclosure: None None None

 
 
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