What could cause a family to all have anemia besides hookworm infestation?

Causes of Familial Anemia Beyond Hookworm

When an entire family presents with anemia, the most likely causes are shared dietary iron deficiency, inherited hemoglobinopathies (particularly thalassemia), or other shared environmental parasitic infections such as giardiasis. 1

Primary Diagnostic Considerations

Nutritional Iron Deficiency

• Poor dietary iron intake is the most common cause of familial anemia worldwide, particularly in families with limited access to meat and iron-rich foods 1
• Vegetarian or predominantly plant-based diets provide only non-heme iron, which has significantly lower bioavailability (2-3 times less absorbable than heme iron from meat) 1
• A careful dietary history is essential to identify iron-deficient diets, though borderline deficient diets are common and should not be presumed as the sole cause without full investigation 1

Inherited Hemoglobinopathies

• Thalassemia frequently causes microcytic anemia in certain ethnic groups and should be confirmed by laboratory testing rather than presumed 1
• Microcytosis with elevated red cell count is characteristic of thalassemia, distinguishing it from iron deficiency 1
• Family history of haematological disorders including thalassemia and sideroblastic anemia should be actively sought 1
• Other hereditary conditions include glucose-6-phosphate dehydrogenase deficiency and pyruvate kinase deficiency 1

Other Parasitic Infections

• Giardiasis can cause malabsorption leading to iron deficiency anemia in entire families sharing contaminated water sources 2
• Conventional stool microscopy has very low sensitivity for detecting parasites; specialized testing such as ELISA or PCR-based methods are more reliable 2
• Multiple stool samples (at least 3) collected on different days are often needed due to intermittent parasite shedding 2

Gastrointestinal Causes

• Celiac disease affects 2-3% of patients presenting with iron deficiency anemia and can cluster in families 1
• Small bowel bacterial overgrowth can cause malabsorption affecting multiple family members 1
• Fish tapeworm infestation, though uncommon, can cause vitamin B12 deficiency and anemia 3

Diagnostic Algorithm

Initial Laboratory Evaluation

• Serum ferritin concentration is the most powerful test for iron deficiency: <12 μg/dL is diagnostic, though levels may be falsely elevated with concurrent inflammation, malignancy, or hepatic disease 1
• Ferritin <30 μg/L without inflammation or <100 μg/L with inflammation indicates iron deficiency 2
• Complete blood count with MCV and red cell distribution width (RDW) to distinguish microcytic anemias 1
• Transferrin saturation <30% supports iron deficiency diagnosis 1

Pattern Recognition

• Microcytosis with normal or elevated red cell count suggests thalassemia 1
• Microcytosis with low red cell count and low ferritin indicates iron deficiency 1
• Combined deficiency (e.g., iron and folate) may show normal MCV but elevated RDW 1
• Combined iron deficiency and anemia of chronic disease is likely if ferritin is 30-100 μg/L with inflammation 2

Specialized Testing When Indicated

• Hemoglobinopathy testing should be performed rather than presumed based on ethnicity alone 1
• Stool ELISA for Giardia antigen is more sensitive than conventional microscopy 2
• PCR-based stool testing for parasites when available 2
• Serologic testing for hookworm antibodies from specialized laboratories 2
• Anti-endomysial antibody testing for celiac disease 1

Management Approach

Iron Supplementation

• Oral ferrous sulfate 200mg twice daily is the recommended treatment for iron deficiency 2
• Therapeutic response to three weeks of oral iron confirms true iron deficiency 1
• Follow-up testing of hemoglobin, ferritin, and iron studies should be performed 4-6 weeks after treatment 2

Empiric Antiparasitic Treatment

• Empiric antiparasitic treatment is warranted based on clinical suspicion, even with negative stool cultures, particularly when specialized testing is unavailable 2
• This approach is justified given the low sensitivity of conventional stool microscopy 2

Additional Considerations

• Vitamin B12 deficiency should be considered, particularly with fish tapeworm or strict vegetarian diets 1, 3
• Folic acid deficiency may coexist but should not obscure investigation for other causes 4
• Environmental exposures and shared genetic factors should be considered if treatment fails 2

Critical Pitfalls to Avoid

• Do not presume dietary deficiency as the sole cause without full gastrointestinal investigation, as this may miss serious underlying pathology 1
• Do not assume hemoglobinopathy based on ethnicity without laboratory confirmation 1
• Do not rely on single negative stool examinations to exclude parasitic infections 2
• Ferritin levels between 12-100 μg/dL require careful interpretation in the context of inflammation 1
• NSAID use should be documented and stopped whenever possible, as it is a common cause of occult GI blood loss 1