Diagnostic Considerations

Once iron-deficiency anemia from blood loss is diagnosed, it is important to remember that rare causes of intestinal blood loss (eg, polyps and Meckel diverticulum) are far less common in developing countries than is hookworm disease.

Respiratory symptoms with peripheral eosinophilia suggest a parasitic etiology.

Differentials

Acute Anemia
Amebiasis
Ascariasis
Asthma
Bacterial Gastroenteritis
Bacterial Pneumonia
Bronchiolitis
Chronic Anemia
Cognitive Deficits
Contact Dermatitis
Cutaneous Larva Migrans (zoonotic hookworm)
Eosinophilia
Gastroenteritis
Growth Failure
Hemolytic Anemia
Hypersensitivity Pneumonitis
Iron-Deficiency Anemia
Löffler Syndrome
Plummer-Vinson Syndrome
Pneumonia
Protein-Losing Enteropathy
Scabies
Schistosomiasis
Strongyloidiasis
Tinea
Trichuriasis

Workup

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Media Gallery

Adult hookworm attached to duodenal mucosa.
Hookworm filariform larva. Courtesy of Division of Parasitic Diseases, Centers for Disease Control and Prevention (CDC).
Adult Ancylostoma duodenale worm. Anterior end with mouth parts visible. Courtesy of Patrick W Hickey, MD.
Adult Necator americanus worm. Anterior end with mouth parts visible. Courtesy of Patrick W Hickey, MD.
Hookworm eggs examined on wet mount. Eggs of Ancylostoma duodenale and Necator americanus cannot be distinguished morphologically. Courtesy of Division of Parasitic Diseases, Centers for Disease Control and Prevention (CDC).
Hookworm rhabditiform larva (wet preparation). Courtesy of Division of Parasitic Diseases, Centers for Disease Control and Prevention (CDC).
Life cycle of hookworm. Courtesy of the Centers for Disease Control and Prevention (CDC) [https://www.cdc.gov/parasites/hookworm/biology.html].
Hookworm egg in an unstained wet mount at 400x magnification. Courtesy of the Centers for Disease Control and Prevention (CDC) [https://www.cdc.gov/dpdx/hookworm/].
Hookworm rhabditiform larva. Courtesy of the Centers for Disease Control and Prevention (CDC) [https://www.cdc.gov/dpdx/hookworm/].
Side-by-side image of the mouth parts of each species of human-infecting hookworm. Courtesy of the Centers for Disease Control and Prevention (CDC) [https://www.cdc.gov/parasites/hookworm/biology.html].
Cutaneous larva migrans. Courtesy of Wikipedia [WeisSagung, https://en.wikipedia.org/wiki/Cutaneous_larva_migrans].

of 11

Table 1: WHO intensity classifications

Intensity	Eggs per gram of feces
Mild	< 1,999
Moderate	2,000-3,999
Heavy	>4,000

Table 2: WHO and CDC treatment recommendations

Drug	Adults	Children (>24 months)
Albendazole (preferred)*	400mg daily for 3 days OR Single 400mg dose	Single 400mg dose (CDC) OR Single 200mg dose (WHO)
Mebendazole	Single 500mg dose OR 100mg orally twice daily for 3 days	100mg orally twice daily for 3 days
Pyrantel pamoate	11mg/kg orally daily for 3 days (up to maximum of 1g)	11mg/kg orally daily for 3 days
Thiabendazole	Applied topically to areas of migrating larvae	Applied topically to areas of migrating larvae

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Author

Darvin Scott Smith, MD, MSc, DTM&H, FIDSA Chief of Infectious Diseases and Geographic Medicine, Department of Internal Medicine, Kaiser Permanente Medical Group

Darvin Scott Smith, MD, MSc, DTM&H, FIDSA is a member of the following medical societies: American Medical Association, American Society of Tropical Medicine and Hygiene, Infectious Diseases Society of America, International Society of Travel Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Jade Chee Riopelle, BS

Disclosure: Nothing to disclose.

Chief Editor

Pranatharthi Haran Chandrasekar, MBBS, MD Professor, Chief of Infectious Disease, Department of Internal Medicine, Wayne State University School of Medicine

Pranatharthi Haran Chandrasekar, MBBS, MD is a member of the following medical societies: American College of Physicians, American Society for Microbiology, International Immunocompromised Host Society, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

David R Haburchak, MD, FACP Key Faculty, Wellstar Kennestone Internal Medicine Residency Program, Wellstar Health System

David R Haburchak, MD, FACP is a member of the following medical societies: American College of Physicians, American Osler Society, American Society for Microbiology, Christian Medical and Dental Associations, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Vinod K Dhawan, MD, FACP, FRCPC, FIDSA Clinical Professor, Department of Clinical Medicine, University of California, Los Angeles, David Geffen School of Medicine; Clinical Professor, Department of Clinical Medicine, Charles R Drew University of Medicine and Science

Vinod K Dhawan, MD, FACP, FRCPC, FIDSA is a member of the following medical societies: American College of Physicians, American Medical Association, American Society for Microbiology, Infectious Diseases Society of America, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Christopher M Watson, MD, MPH Professor, Department of Pediatrics, Medical College of Georgia at Augusta University

Christopher M Watson, MD, MPH is a member of the following medical societies: American Academy of Pediatrics, Society of Critical Care Medicine

Disclosure: Nothing to disclose.

Acknowledgements

Jeffrey L Arnold, MD, FACEP Chairman, Department of Emergency Medicine, Santa Clara Valley Medical Center

Jeffrey L Arnold, MD, FACEP is a member of the following medical societies: American Academy of Emergency Medicine and American College of Physicians