Strongyloides stercoralis infection: an underlying cause of invasive bacterial infections of enteric origin. Results from a prospective cross-sectional study of a northern Italian tertiary hospital

Infection. 2023 Oct;51(5):1541-1548. doi: 10.1007/s15010-023-02072-1. Epub 2023 Jul 18.

Abstract

Purpose of the study: We assessed the prevalence of S. stercoralis in a cohort of inpatients with invasive bacterial infections of enteric origin to investigate whether the parasite may facilitate these bacterial infections even in the absence of larval hyperproliferation.

Methods: We performed a prospective cross-sectional study in a hospital in northern Italy. Subjects admitted due to invasive bacterial infection of enteric origin and potential previous exposure to S. stercoralis were systematically enrolled over a period of 10 months. S. stercoralis infection was investigated with an in-house PCR on a single stool sample and with at least one serological method (in-house IFAT and/or ELISA Bordier). Univariate, bi-variate and logistic regression analyses were performed.

Results: Strongyloidiasis was diagnosed in 14/57 patients (24.6%; 95% confidence interval 14.1-37.8%) of which 10 were Italians (10/49, 20.4%) and 4 were migrants (4/8, 50.0%). Stool PCR was performed in 43/57 patients (75.4%) and no positive results were obtained. Strongyloidiasis was found to be significantly associated (p ≤ 0.05) with male gender, long international travels to areas at higher endemicity, deep extra-intestinal infectious localization and solid tumors. In the logistic regression model, increased risk remained for the variables deep extra-intestinal infectious localization and oncologic malignancy.

Conclusions: Our findings suggest a new role of chronic strongyloidiasis in favoring invasive bacterial infections of enteric origin even in the absence of evident larval dissemination outside the intestinal lumen. Further well-designed studies should be conducted to confirm our results, and possibly establish the underlying mechanisms.

Keywords: Enteric sepsis; Intestinal bacteria; Intestinal helminths; Intestinal parasitosis; Strongyloides stercoralis; Strongyloidiasis.

MeSH terms

  • Animals
  • Bacterial Infections*
  • Cross-Sectional Studies
  • Feces / parasitology
  • Humans
  • Male
  • Prospective Studies
  • Strongyloides stercoralis*
  • Strongyloidiasis* / complications
  • Strongyloidiasis* / diagnosis
  • Strongyloidiasis* / epidemiology
  • Tertiary Care Centers