Clinical Insights into Strongyloides stercoralis Pulmonary Hyperinfection Syndrome

Strongyloides stercoralis pulmonary hyperinfection syndrome (SPHS) is a rare, frequently fatal complication of strongyloidiasis that is difficult to recognize because of its nonspecific multisystem manifestations. Diagnosis requires a high index of suspicion.

This retrospective study identified 29 hospitalized patients with strongyloidiasis at Chaozhou Central Hospital between November 2018 and January 2026. We compared the clinical data of five patients with SPHS (SPHS group) and 21 patients with uncomplicated/chronic strongyloidiasis (non-SPHS group) and described the detailed clinical profiles of the five patients with SPHS.

All five SPHS patients (median age, 67; 4/5 were male) had diabetes mellitus, glucocorticoid exposure, rural soil contact, fever, and nonspecific pulmonary computed tomography (CT) abnormalities; four (4/5, 80%) had gastrointestinal and/or neurological manifestations and intestinal obstruction. All five patients had multisystem laboratory abnormalities without eosinophilia. S. stercoralis was detected in respiratory specimens from all patients, and three (3/5, 60%) were confirmed by bronchoalveolar lavage fluid metagenomic next-generation sequencing (mNGS) or targeted next-generation sequencing (tNGS) within 2-5 days. All patients had bacterial coinfections. Adequate antimicrobial coverage was achieved in four (4/5, 80%) patients; one patient (1/5, 20%) received both ivermectin and albendazole, and three (3/5, 60%) received albendazole monotherapy. Three patients (3/5, 60%) died of severe complications. Compared with the non-SPHS group, the SPHS group had a significantly lower median eosinophil count (0.01 × 10⁹/L); higher rates of corticosteroid exposure, diabetes mellitus, neurological and gastrointestinal symptoms, intestinal obstruction, severe complications, and mortality; and a longer time to laboratory confirmation (all P < 0.05).

In high-risk patients, normal or low eosinophil counts do not exclude SPHS. Early examination of respiratory specimens using microscopy and, when available, mNGS/tNGS may shorten the time to diagnosis. For these patients, early recognition of SPHS, antiparasitic therapy, and the management of bacterial coinfections are essential.