[Strongyloides stercoralis: a neglected and latent threat].

Knowledge of tropical parasitic infections, such as Strongyloides stercoralis, remains essential given increased migration from endemic areas and rising international travel. S. stercoralis can persist silently for decades and cause severe disease upon reactivation. We describe two illustrative cases. A 86-year-old former tropical physician developed eosinophilic pneumonia, skin lesions, and sensory ataxia. Symptoms persisted despite corticosteroid therapy but resolved rapidly after empirical ivermectin. In contrast, a 57-year-old Liberian man with prior immunosuppression presented with hyperinfection syndrome and died despite treatment. These cases highlight the need to consider parasitic infections even after long latency, especially in patients with a tropical history or immunosuppression. Timely recognition is crucial to prevent misdiagnosis and inadequate treatment. For accurate detection, serology or PCR-based diagnostics are preferred, as conventional stool microscopy often yields false-negative results due to the parasite's low and intermittent larval output. Empirical ivermectin should be considered in high-risk patients to prevent life-threatening complications.