Karius Medical Case Report: The only administered test to detect a case of Strongyloides stercoralis | Karius
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Karius Medical Case Report: The only administered test to detect a case of Strongyloides stercoralis

We report the following clinical scenario:

A 58-year-old male with a history of treatment-refractory multiple myeloma and escalating immunosuppressive treatment was admitted to hospital after two weeks of fatigue, shortness of breath, and low-grade fevers. 

He was hypoxic on admission, and had a CT chest scan with bilateral diffuse ground-glass opacities. The CT also showed mild, diffuse bowel-wall thickening, particularly in the transverse/descending colon, which was suggestive of sigmoid colitis.

At this time, the presumptive diagnosis was a flare-up of myeloma and colitis. The patient received high-dose dexamethasone and showed some improvement. He was discharged with a steroid taper and started on ciprofloxacin.

A Karius Test was also sent, out of concern for the possibility of Pneumocystis jirovecii pneumonia in this immunocompromised patient with lung disease.

Karius Test result: Strongyloides stercoralis

S. stercoralis is a pathogenic roundworm that is a known human parasite. Infection occurs when human skin, typically feet, come into contact with soil or other material infected with human feces. 

The worm penetrates the skin, enters the bloodstream, and migrates into lungs. Larvae ascend up the respiratory tract and are then swallowed, which allows them to enter the gastrointestinal tract. They burrow into the small bowel mucosa, where adult worms can survive for years.

Strongyloidiasis, the infectious disease caused by these roundworms, is most common in tropical or subtropical climates. There are two important infection syndromes that typically present: autoinfection and hyperinfection.

Autoinfection happens when the larvae mature within the GI tract. They can penetrate the GI mucosa or skin during stool passage, re-entering the infection cycle. S. stercoralis is the only helminth that can complete its entire life cycle within a human host. The infection can persist for decades.

Hyperinfection occurs when there is a massive parasite burden, leading to systemic inflammation, sepsis, and shock. It can be caused directly by parasite accumulation in organs or by spillover of GI organisms into the bloodstream. This is usually secondary to immunosuppression, diabetes, alcoholism, organ transplant, or steroid use.



Symptoms of strongyloidiasis include respiratory presentations (coughing with blood, asthma-like wheezing, abdominal pain, nausea/vomiting/diarrhea, and enterocolitis), as well as skin issues (itching, rash, serpiginous tracts).

Diagnosis is typically made via blood serology, stool exam, visual detection of larvae, biopsy, GI studies, endoscopy, duodenal aspirate, or the string-based enterotest.

For this particular patient, serology was negative, stool exam was negative, tissue samples were not obtained, GI studies were not performed, and bronchoscopy was refused.

The Karius Test was the only test administered that detected Strongyloidiasis in this patient.

When the result came in, the patient was immediately contacted, re-hospitalized and put on anti-helminth treatment. Upon readmission he was already doing poorly, having encephalopathy and multi-organ damage including kidneys, liver, and lungs.

The physicians treating this patient decided it was likely a combination of Strongyloides hyperinfection and progressing infiltrative multiple myeloma (elevated myeloma markers). Despite the negative confirmatory testing, the clinical picture was consistent with Strongyloidiasis, with worsening nodular infiltrates on further chest imaging.

This is part of a series of Karius Medical Case Reports. In this case, the Karius Test was able to accurately identify infection with S. stercoralis, allowing the physicians to treat the patient’s infection to the best of their abilities. We will discuss additional case reports in future posts.




DISCLAIMER: Case descriptions have been modified to protect patient privacy and, while every attempt has been made to provide accurate information, errors may occur. This information is provided for educational purposes only, and is not intended to be used as medical advice.