Hookworm Infection Does NOT Cause Neutrophilia
A neutrophil count of 45% (assuming this is a percentage, not an absolute count) is within normal range and is not caused by hookworm infection. Hookworm characteristically causes eosinophilia, not neutrophilia, and the primary hematologic manifestation is iron-deficiency anemia from chronic blood loss. 1, 2
Expected Hematologic Findings in Hookworm Infection
Eosinophilia is the hallmark white blood cell abnormality associated with helminthic infections including hookworm, particularly during the larval migration phase (Loeffler's syndrome) which occurs 1-2 weeks after infection. 1
The characteristic blood findings in hookworm infection include:
- Iron-deficiency anemia - the primary pathologic consequence, resulting from direct blood ingestion by adult worms and tissue trauma at attachment sites in the small intestine 2, 3
- Eosinophilia - typical of helminthic infections, especially during acute larval migration through lungs 1
- Normal or low neutrophil counts - neutrophils are NOT elevated in hookworm infection 2
Understanding the Neutrophil Count of 45
If this represents 45% neutrophils on a differential count, this falls within the normal range of 45-75% and requires no specific explanation. 1
Neutrophilia (elevated neutrophil counts) suggests bacterial infection, not parasitic helminthic infection. 1 The focal intestinal lesions caused by hookworm attachment are characterized by local hemorrhage, tissue cytolysis, and a neutrophilic response at the site of attachment, but this does not translate to systemic neutrophilia in peripheral blood. 2
Clinical Approach to This Patient
Investigate for eosinophilia and anemia, not neutrophilia, when considering hookworm infection. 1, 4
Key diagnostic steps include:
- Stool examination for hookworm eggs - the standard diagnostic test, though sensitivity can be low with light infections 5, 3
- Complete blood count - looking specifically for eosinophilia and microcytic anemia 2, 4
- Iron studies - to assess iron deficiency from chronic blood loss 5, 2
Treatment Considerations
If hookworm infection is confirmed, standard treatment is albendazole 400 mg orally as a single dose, repeated in 2 weeks, with iron supplementation for associated anemia. 5
The neutrophil count of 45 should prompt investigation for alternative diagnoses, particularly bacterial infections if this represents an elevated absolute neutrophil count. 1