Use of serology in a systematic screening programme for strongyloidiasis in an immigrant population

Abstract

Objectives: The aim of this cross-sectional study was to describe the results of a systematic serological screening programme for strongyloidiasis.

Methods: A prospective serological screening programme for strongyloidiasis was performed between 2009 and 2014 for all immigrant patients attending the Tropical Medicine Unit. Three formalin-ether concentrated stool samples and an ELISA for anti-Strongyloides stercoralis antibodies were used as screening tools.

Results: Of 659 patients screened, 79 (12%) were positive for S. stercoralis regardless of the diagnostic method used. The prevalence of infection was 42.9% in East African patients, 16.3% in Central African patients, 10.9% in those from South America, and 10% in the case of West Africa. Univariate analysis showed that infection by S. stercoralis was significantly more frequent in patients from Central Africa (p=0.026; OR 1.72, 95% CI 1.03-2.85) and East Africa (p<0.001; OR 5.88, 95% CI 1.75-19.32). Taking West Africa as the reference (as the area of lowest prevalence among the positive prevalence areas), the statistical analysis showed that the risk of infection was higher in East Africa (p=0.001; OR 6.750, 95% CI 2.127-21.423) and Central Africa (p=0.065; OR 1.747, 95% CI 0.965-3.163).

Conclusions: Due to the potential complications of strongyloidiasis infection, we recommend that immigrant patients from developing countries be routinely screened for S. stercoralis, especially those from East Africa. A serological test is a highly appropriate screening tool.

Keywords: Immigrants; Screening; Seroprevalence; Strongyloides stercoralis; Strongyloidiasis.