History

Fact Explanation
Ground itch- an intensely pruritic rash on the hands or feet. On penetrating the skin, significant numbers of L3 larvae perish, breaking down to release an extensive range of immunoreactive molecules which leads an immune reaction in the skin [1].
History of fever and cough. Cytokine, acute phase protein and eosinophil responses are initiated by the larvae migrating through the lungs giving rise to pneumonitis [2].
Vague abdominal pain, nausea and diarrhoea. These symptoms occur as the parasite matures into adult worms within the distal duodenum and proximal jejunum [3].
Lethargy, dyspnoea and palpitations. Following the attachment of parasites to the intestinal mucosa, there is release of active peptides that down regulate host inflammation, block the clotting of blood, prevent platelet aggregation, and degrade host connective tissue components resulting in continuous blood loss from capillaries and arterioles, which the parasite ruptures and degrades. This leads to anemia [3].
References
  1. LOUKAS Alex, and Paul PROCIV. Immune responses in hookworm infections. Clinical microbiology reviews[online] 2001, vol 14(4): 689-703. [viewed 23 April 2014]. Available from: DOI: 10.1128/CMR.14.4.689-703.2001
  2. WRIGHT V. and BICKLE Q. Immune responses following experimental human hookworm infection. Clinical & Experimental Immunology[online] 2005, 142: 398–403. [viewed 23 April 2014]. Available from: DOI: 10.1111/j.1365-2249.2005.02945.x
  3. OJHA Suvash Chandra, et al. Geohelminths: public health significance. The Journal of Infection in Developing Countries[online] 2014, vol 8(1): 005-016. [viewed 23 April 2014]. Available from: DOI: 10.3855/jidc.3183

Examination

Fact Explanation
Conjunctival pallor, tachycardia and other clinical signs of anemia. Following the attachment of parasites to the intestinal mucosa, there is release of active peptides that down regulate host inflammation, block the clotting of blood, prevent platelet aggregation, and degrade host connective tissue components resulting in continuous blood loss from capillaries and arterioles, which the parasite ruptures and degrades. This leads to anemia [1].
Generalized edema. Along with the blood loss, there will be loss of plasma proteins which would give rise to protein malnutrition. This protein losing enteropathy would lead to reduced colloid oncotic pressure within the blood vessels, thereby leading to edema [1].
Features of vitamin deficiency. Presence of intestinal parasites is associated with a reduction in food intake, malabsorption and endogenous nutrient loss [2].
Erythematous, papular rash on the hands or feet. On penetrating the skin, significant numbers of L3 larvae perish, breaking down to release an extensive range of immunoreactive molecules which leads an immune reaction in the skin [3].
Pyrexia along with rhonchi and crepitations on auscultation of the lungs. Cytokine, acute phase protein and eosinophil responses are initiated by the larvae migrating through the lungs giving rise to pneumonitis and bronchitis [4].
References
  1. OJHA Suvash Chandra, et al. Geohelminths: public health significance. The Journal of Infection in Developing Countries[online] 2014, vol 8(1): 005-016. [viewed 23 April 2014]. Available from: DOI: 10.3855/jidc.3183
  2. KATONA Peter, and Judit KATONA-APTE. The interaction between nutrition and infection. Clinical Infectious Diseases[online] 2008, vol 46(10): 1582-1588. [viewed 23 April 2014]. Available from: DOI: 10.1086/587658
  3. LOUKAS Alex, and Paul PROCIV. Immune responses in hookworm infections. Clinical microbiology reviews[online] 2001, vol 14(4): 689-703. [viewed 23 April 2014]. Available from: DOI: 10.1128/CMR.14.4.689-703.2001
  4. WRIGHT V. and BICKLE Q. Immune responses following experimental human hookworm infection. Clinical & Experimental Immunology[online] 2005, 142: 398–403. [viewed 23 April 2014]. Available from: DOI: 10.1111/j.1365-2249.2005.02945.x

Differential Diagnoses

Fact Explanation
Celiac disease. Apart from the features of iron deficiency anemia, features of vitamin B12 and folate deficiency as well as hyposplenism occur [1].
Bacterial gastroenteritis. It commonly presents with severe diarrhoea, abdominal pain, vomiting, dehydration and a body temperature at or above 38.5 degrees Celcius. [2].
Bacterial pneumonia. It presents with respiratory symptoms and fever, similar to the pneumonitis caused by N. americanus, but with very high (often >80mg/L) C-reactive protein concentrations [3].
References
  1. HARPER J. W., et al. Anemia in celiac disease is multifactorial in etiology. Am. J. Hematol.[online] 2007, 82: 996–1000. [viewed 23 April 2014] available from DOI: 10.1002/ajh.20996
  2. CHAN S. S. W., et al. Acute bacterial gastroenteritis: a study of adult patients with positive stool cultures treated in the emergency department. Emergency medicine journal[online] 2003, vol 20(4): 335-338. [viewed 23 April 2014] available from DOI: 10.1136/emj.20.4.335
  3. VIRKKI R., et al. Differentiation of bacterial and viral pneumonia in children. Thorax[online] 2002, vol 57(5): 438-441. [viewed 23 April 2014] available from DOI: 10.1136/thorax.57.5.438

Investigations - for Diagnosis

Fact Explanation
Direct microscopic examination of stool smears for ova (with thin colorless shells). Adult worms produce eggs within the intestinal lumen, which are deposited in the feces [1].
Features of iron deficiency anemia (eg: reduced mean corpuscular hemoglobin concentration) in full blood count. Anemia occurs due to the continuous blood loss associated with attachment of parasites to the intestinal mucosa [2].
Eosinophilia in full blood count. The human immune responses to infection with hookworms are characterized by upregulation of the production of specific and nonspecific IgE as well as eosinophilia [3].
Diffuse alveolar infiltrates on chest radiography. The development and migration through the lungs, of N. americanus results in pneumonitis [4].
References
  1. McSORLEY H. J. and A. LOUKAS. The immunology of human hookworm infections. Parasite Immunology[online] 2010, 32: 549–559. [viewed 23 April 2014] Available from: DOI: 10.1111/j.1365-3024.2010.01224.x
  2. OJHA Suvash Chandra, et al. Geohelminths: public health significance. The Journal of Infection in Developing Countries[online] 2014, vol 8(1): 005-016. [viewed 23 April 2014]. Available from: DOI: 10.3855/jidc.3183
  3. QUINNELL Rupert J., et al. Immune responses in human necatoriasis: association between interleukin-5 responses and resistance to reinfection. Journal of Infectious Diseases[online] 2004, vol 190(3): 430-438. [viewed 23 April 2014]. Available from: DOI: 10.1086/422256
  4. WRIGHT V. and BICKLE Q. Immune responses following experimental human hookworm infection. Clinical & Experimental Immunology[online] 2005, 142: 398–403. [viewed 23 April 2014]. Available from: DOI: 10.1111/j.1365-2249.2005.02945.x

Management - General Measures

Fact Explanation
Iron and protein supplimentation. To combat the anemia and hypoproteinemia due to blood loss associated with hookworm infestation of the small intestine [1].
Vitamin supplimentation. To compensate for the poor intake of food due to nausea [2].
References
  1. OJHA Suvash Chandra, et al. Geohelminths: public health significance. The Journal of Infection in Developing Countries[online] 2014, vol 8(1): 005-016. [viewed 23 April 2014]. Available from: DOI: 10.3855/jidc.3183
  2. WRIGHT V. and BICKLE Q. Immune responses following experimental human hookworm infection. Clinical & Experimental Immunology[online] 2005, 142: 398–403. [viewed 23 April 2014]. Available from: DOI: 10.1111/j.1365-2249.2005.02945.x

Management - Specific Treatments

Fact Explanation
Mebendazole (500mg single dose orally). It destroys the cytoplasmic microtubules in the hookworm's intestinal cells, thereby blocking the uptake of glucose and other nutrients, ultimately resulting in death of the parasite [1].
Albendazole (400mg single dose orally). It inhibits tubulin polymerization in the hookworm and blocks glucose uptake. Therofore energy levels are reduced, resulting in death of the parasite [1].
References
  1. OJHA Suvash Chandra, et al. Geohelminths: public health significance. The Journal of Infection in Developing Countries[online] 2014, vol 8(1): 005-016. [viewed 23 April 2014]. Available from: DOI: 10.3855/jidc.3183