Pulmonary strongyloidiasis and hyperinfection in a Patient with idiopathic inflammatory myopathy：A case report

Abstract

Pulmonary strongyloidiasis is a rare infection in patients with autoimmune diseases, and immunosuppression can lead to the development of hyperinfection syndrome with a high mortality rate. We present a case of a 78-year-old male with previous idiopathic inflammatory myopathy (IIM) with interstitial lung disease. He developed hyperinfection syndrome and respiratory failure, and diagnostic metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) confirmed the presence of Strongyloides stercoralis. After treatment with ivermectin, the patient's symptoms improved. Therefore, adequate screening and prophylactic treatment are needed for people at risk of immunosuppression, which can reduce the occurrence of the devastating S. stercoralis hyperinfection syndrome. It also highlights mNGS as a highly accurate test for the detection of difficult to atypical pathogens.

Keywords: Case report; Hyperinfection syndrome; Idiopathic inflammatory myopathy; Metagenomic next-generation sequencing; Strongyloides stercoralis.

Fig. 1

A: Chest computed tomography (CT) scan on admission. Bilateral lung markings thickened, accompanied by a small amount of inflammatory exudate shadows. B–C: Reexamined X-ray and chest computed tomography 7 days after admission. Both lungs showed multiple inflammatory exudative shadows. D: Reexamined X-ray after 9 days of ivermectin treatment. Both lungs showed a decrease in inflammatory exudative shadows. E–G: Stool specimens were examined microscopically (E: Gram staining, 200 × ; F: 400 × ; G: Gram staining, 1000 × ) and larvae were found in the patient's stool.

Fig. 2

A: The metagenomic next-generation sequencing (mNGS) results of this patient. The coverages of S. stercoralis by mNGS are shown in. B: There was a total of 20310142 reads in mNGS of BALF, and after 98.99 % of the reads were filtered to the human genome, 596 reads were mapped to the microbial genome genus level database. B and C: Of these, 454 reads (76.17 %) were sequenced in the genus Strongyloides, while the number of sequences of S. stercoralis in this genus was 382 reads (84.14 %).