Strongyloides stercoralis disseminated infection in an HIV-infected adult

In this visual case of Strongyloides stercoralis disseminated infection with Enterobacteriaceae-related invasive infection, we demonstrated the in-host S. stercoralis circulation with DNA found in different fluids and specimens, but also in cerebrospinal fluid (CSF), supporting the role of migrant larvae in the Enterobacteriaceae-related invasive and central nervous system infection.

Here, we reported the case of a 66-year-old man who was admitted to our intensive care unit (ICU) for altered mental status. He was living in India but had returned to France for 6 weeks. He had a history of HIV infection and lack of observance of antiretroviral therapies. He was hospitalized because of chronic asthenia, abdominal pain, diarrhea, and fever. Clinic exam revealed periumbilical linear skin lesions of purpuric nature ( Fig 1A). Abdominal computed tomography (CT) scan pointed out a thickened jejunal wall, without pneumoperitoneum or peritonitis. He rapidly developed mental confusion with slow and inappropriate verbal responses, leading to ICU admission.
In addition to high-dose intravenous cefotaxime and ganciclovir, veterinary parenteral formulation of ivermectin was administered subcutaneously (200 μg/kg q.d. for 2 days). After 5 days, dead larvae were observed in gastric fluid and BAL. The periumbilical skin lesions progressively healed, and the patient recovered from multiple organ failure.
S. stercoralis disseminated infection has been thoroughly reported in various immunocompromised populations, including patients with hematological malignancies, solid organ transplants recipients, and patients receiving immunosuppressive therapy, especially steroid therapy [2,3]. In HIV-infected patients, disseminated infection has also been described, with or without steroid therapy [2]. In our patient, the only long-lasting factor of immunosuppression was the profound HIV-related T-cell deficiency, as other conditions have been excluded (HTLV1 infection, alcohol consumption, and malnutrition). Pulmonary symptoms are highly frequent, and the detection of larvae in respiratory tract specimens is a hallmark of hyperinfection. Cutaneous periumbilical purpura has been described in patients with disseminated infection, in relation with the migration of larvae through vessel walls to the dermis [4].
Parasitological diagnosis relies on larvae visualization in different specimens. Except in stools where larvae may be highly concentrated, other specimens are often negative with conventional tests. Molecular diagnosis of S. stercoralis has been developed and validated in stool samples, with very good sensitivity and specificity [1]. Here, we were able to detect DNA even in low parasitic load specimens such as CSF, which was negative with conventional tests.
The association between disseminated S. stercoralis infection and invasive Enterobacteriaceae infections has been widely reported and is thought to be related to the passive transportation of bacteria on the cuticle of migrating larvae, a phenomenon called phoresis [5]. Here, we demonstrate for the first time the in-host S. stercoralis circulation. Its DNA was found in different fluids and specimens, but also in a CSF sample, supporting the role of migrant larvae in the Enterobacteriaceae-related invasive and central nervous system infections.

Ethics
The authors declare that the informed oral consent for publication has been obtained from the patient's next of kin.