Strongyloidiasis

Key Features

Essentials of Diagnosis

• Abdominal pain, diarrhea

• Eosinophilia

• Larvae in stools and duodenal aspirates

• Serum antibodies

General Considerations

• Strongyloides stercoralis is unique in having both parasitic and free-living forms; the latter can survive in the soil for several generations

• Parasite is found in most tropical and subtropical regions of the world

• Older children and adults are infected more often than are young children

• Even low worm burden can result in significant clinical symptoms

Clinical Findings

Symptoms and Signs

• Chronic S stercoralis infections can be asymptomatic or cause cutaneous, gastrointestinal, or pulmonary symptoms

• At the site of skin penetration, a pruritic rash may occur

• Most prominent features include abdominal pain, distention, diarrhea, vomiting, and occasionally malabsorption

• Large numbers of migrating larvae can cause wheezing, cough, shortness of breath, and hemoptysis

• Disseminated infection involving the intestine, the lungs, and the meninges may develop in patients

  • Who have cellular immunodeficiencies

  • Who are receiving corticosteroids or chemotherapy

Differential Diagnosis

• Peptic disease

• Celiac disease

• Regional or tuberculous enteritis

• Hookworm infections

• Pulmonary phase may mimic asthma or bronchopneumonia

Diagnosis

• Finding larvae in the feces, duodenal aspirates, or sputum is diagnostic

• IgG antibodies measured by ELISA or immunoblot are relatively sensitive (83–93%)

• Marked eosinophilia is common

Treatment

• Ivermectin (two doses of 0.2 mg/kg given 1–14 days apart) is the drug of choice

• Tiabendazole at a dose of 25 mg/kg orally twice orally twice a day for 3 days is an alternative therapy

• Albendazole has a much lower efficacy

• In the hyperinfection syndrome,

  • Ivermectin for 1–3 weeks may be necessary

  • Multiple follow-up stool studies for 2 weeks after therapy are indicated to ensure clearance of larvae

• Patients from endemic areas should be tested for specific antibodies and receive treatment before undergoing immunosuppression

Outcome

Complication

• Gram-negative sepsis may complicate disseminated strongyloidiasis

Prognosis

• Fatal disseminated strongyloidiasis, known as the hyperinfection syndrome, may develop in immunosuppressed patients

• Autoinfection can result in persistent infection for decades

References