ABSTRACT
Strongyloides stercoralis is a widely distributed nematode more frequent in tropical areas and particularly severe in immunosuppressed patients. The aim of this study was to determine factors associated with strongyloidiasis in migrants living in a non-endemic area and to assess the response to treatment and follow-up in those diagnosed with the infection. We performed a multicenter case-control study with 158 cases and 294 controls matched 1:2 by a department service. Participants were recruited simultaneously at six hospitals or clinics in Spain. A paired-match analysis was then performed looking for associations and odds ratios in sociodemographic characteristics, pathological background, clinical presentation and analytical details. Cases outcomes after a six-month follow-up visit were also registered and their particularities described. Most cases and controls came from Latin America (63%-47%) or sub-Saharan Africa (26%-35%). The number of years residing in Spain (9.9 vs. 9.8, p = 0.9) and immunosuppression status (30% vs. 36.3%, p = 0.2) were also similar in both groups. Clinical symptoms such as diffuse abdominal pain (21% vs. 13%, p = 0.02), and epigastralgia (29% vs. 18%, p < 0.001); along with a higher eosinophil count (483 vs. 224 cells/mL in cases and controls, p < 0.001) and the mean total Immunoglobulin E (IgE) (354 U/L vs. 157.9 U/L; p < 0.001) were associated with having strongyloidiasis. Finally, 98.2% percent of the cases were treated with ivermectin in different schedules, and 94.5% met the cure criteria at least six months after their first consultation. Abdominal pain, epigastralgia, eosinophilia, increased levels of IgE and Latin American origin remain the main features associated with S. stercoralis infection, although this association is less evident in immunosuppressed patients. The appropriate follow-up time to evaluate treatment response based on serology titers should be extended beyond 6 months if the cure criteria are not achieved.
ABSTRACT
Introduction: Strongyloidiasis is a prevailing helminth infection ubiquitous in tropical and subtropical areas, however, seroprevalence data are scarce in migrant populations, particularly for those coming for Asia. Methods: This study aims at evaluating the prevalence of S. stercoralis at the hospital level in migrant populations or long term travellers being attended in out-patient and in-patient units as part of a systematic screening implemented in six Spanish hospitals. A cross-sectional study was conducted and systematic screening for S. stercoralis infection using serological tests was offered to all eligible participants. Results: The overall seroprevalence of S. stercoralis was 9.04% (95%CI 7.76-10.31). The seroprevalence of people with a risk of infection acquired in Africa and Latin America was 9.35% (95%CI 7.01-11.69), 9.22% (7.5-10.93), respectively. The number of individuals coming from Asian countries was significantly smaller and the overall prevalence in these countries was 2.9% (95%CI -0.3-6.2). The seroprevalence in units attending potentially immunosuppressed patients was significantly lower (5.64%) compared with other units of the hospital (10.20%) or Tropical diseases units (13.33%) (p < 0.001). Conclusions: We report a hospital-based strongyloidiasis seroprevalence of almost 10% in a mobile population coming from endemic areas suggesting the need of implementing strongyloidiasis screening in hospitalized patients coming from endemic areas, particularly if they are at risk of immunosuppression.
