95-Year-Old Female Farmer in Japan Diagnosed with Disseminated Strongyloidiasis

A 95-year-old female farmer from rural Japan presented at the emergency department with abdominal symptoms that had persisted for months. She denied drinking alcohol, but was taking prednisolone and lansoprazole for bullous pemphigoid diagnosed 8 months prior. Her symptoms included loss of appetite, intermittent abdominal bloating, diarrhea, abdominal pain, and shortness of breath. Upon examination, she had widespread abdominal tenderness, purpuric macules, and small thumbprint-like patches on the skin of her upper abdomen and central chest. Laboratory tests showed inflammation of the small intestine. Clinicians detected Strongyloides stercoralis larvae in the patient’s stool and induced sputum, leading to the diagnosis of disseminated strongyloidiasis. The patient was treated with oral ivermectin but developed complications, such as Enterococcus faecium in the cerebrospinal fluid culture, upper gastrointestinal bleeding, and eventually died in the hospital.

Discussion

Strongyloidiasis is caused by S. stercoralis and affects about 370 million people worldwide, mostly in tropical and subtropical regions. Walking barefoot on soil that contains filariform larvae is a common mode of transmission. The larvae penetrate the skin, travel to the lungs, and are ingested, then they mature into filariform larvae, which reinfect the host by puncturing the wall of the colon or perianal skin. This autoinfection causes persistent S. stercoralis infection. Left untreated, acute strongyloidiasis becomes chronic, and in some cases, it may cause no symptoms or result in minor abdominal symptoms, dermatologic manifestations, and eosinophilia percentages from 5% to 15%. However, chronic strongyloidiasis may lead to hyperinfection syndrome, characterized by an accelerated rate of autoinfection, and disseminated strongyloidiasis, which occurs when the S. stercoralis infection spreads to organs outside the typical autoinfection cycle, causing complications such as peritonitis, respiratory failure, meningitis, and bacteremia caused by enteric bacterial translocation that accompanies larval invasion of the intestines.

There are no evidence-based guidelines for the treatment of severe strongyloidiasis, but daily treatment with ivermectin (200 μg/kg) is often used for at least 2 weeks “and until stool examination is negative for 2 weeks.” Even in treated patients, hyperinfection syndrome and disseminated strongyloidiasis have been associated with mortality rates of 69% to 85%. Patients with hyperinfection syndrome and disseminated strongyloidiasis may not develop eosinophilia, but they will have abundant larvae evident “on examination of stool, sputum, and pleural or cerebrospinal fluid.”