diagnosis

Last reviewed 01/2018

The following patients should be investigated for strongyloidiasis:

• travelers or people who migrate from an endemic area and develop the following within 3-4 weeks of travel:
• persistent unexplained eosinophilia
• should be investigated further in the first instance by repeating the test to confirm the result
• other common causes (atopy, drugs) should be excluded by obtaining a carful history of the patient
• present during the acute and chronic stages, but may be absent with dissemination (2)
• gastrointestinal symptoms: nausea, vomiting, abdominal pain, bloating
• pulmonary symptoms: fever, wheeze, persistent cough
• cutaneous symptoms: larva currens, hives, or pustules

Further investigations carried out in patients include:

• three stool samples for microscopy - collected on separate days
• although the test has low sensitivity for detecting S stercoralis (around 50%) it is considered to be the gold standard for diagnosis
• larvae usually appear in stools 3-4 weeks after dermal penetration.
• blood test for S stercoralis serology
• detects IgG to a filariform larval antigen

In patients with massive autoinfection the rhabditiform larvae are present in sputum and faeces.

Reference:

• (1) Greaves D et al. Strongyloides stercoralis infection. BMJ. 2013;347:f4610