Strongyloides stercoralis infection is frequently underdiagnosed since many infections remain asymptomatic. Aim: To estimate the prevalence and characteristics of asymptomatic S. stercoralis infection in Latin American migrants attending a community-based screening program for Chagas disease in Spain. Methodology: Three community-based Chagas disease screening campaigns were performed in Alicante (Spain) in 2016, 2017, and 2018. Serological testing for S. stercoralis infection was performed using a non-automatized IVD-ELISA detecting IgG (DRG Instruments GmbH, Marburg, Germany). Results: Of the 616 migrants from Central and South America who were screened, 601 were included in the study: 100 children and adolescents (<18 years of age) and 501 adults. Among the younger group, 6 participants tested positive (prevalence 6%, 95% confidence interval [CI] 2.5% to 13.1%), while 60 adults did so (prevalence 12%, 95% CI 9.3% to 15.3%). S. stercoralis infection was more common in men than in women (odds ratio adjusted [ORa] 2.28, 95% CI 1.289 to 4.03) and in those from Bolivia (ORa 2.03, 95% CI 1.15 to 3.59). Prevalence increased with age (ORa 1.02, 95% CI 0.99 to 1.05). In contrast, a university education had a protective effect (ORa 0.29, 95% CI 0.31 to 0.88). Forty-one (41/66; 62.1%) of the total cases of S. stercoralis infection were treated at the health care center. Positive stool samples were observed in 19.5% of the followed-up positive cases. Conclusion: Incorporating serological screening for S. stercoralis into community-based screening for Chagas disease is a useful intervention to detect asymptomatic S. stercoralis infection in Central and South American migrants and an opportunity to tackle neglected tropical diseases in a transversal way. The remaining challenge is to achieve patients’ adherence to the medical follow-up.

Travellers and migrants commonly present to health services with febrile syndrome, which can have different causes, including some that are life-threatening. A better understanding of these causes may help guide management and determine appropriate empirical treatments. The aim was to identify the leading causes of fever and to assess their association with the region of travel and type of travellers. This prospective, multicentre study was conducted within the +REDIVI network. Data were collected on febrile syndrome cases among migrants, travellers, and people visiting friends and relatives (VFRs) from 2009 to 2021. Comparative analyses were performed according to patient categories and regions of travel/origin. Of the 4186 patients with febrile syndrome, the most frequent diagnosis was malaria (31.0 %), followed by dengue fever (12.0 %) and nonspecific fever of less than three weeks' duration (11.6 %). Malaria predominated in people coming from sub-Saharan Africa (58.4 %), while dengue fever was more common in the rest of the regions (19.0 % in South America, 25.0 % in Central America and the Caribbean, 34.2 % in Southeast Asia, and 18.1 % in South-Central Asia). By type of traveller, tuberculosis was more frequent in migrants, malaria in VFRs, and dengue and other arboviral infections in travellers and VFRs. Geographical area of travel and type of traveller are the main determinants of imported fever aetiology. Malaria remains the most common cause of febrile syndrome, especially in VFRs from sub-Saharan Africa, while dengue fever prevails in the other tropical regions.

Strongyloidiasis is traditionally regarded as a tropical disease; however, in the Valencian Community (Spain), it has historically been linked to localized endemic foci considered of declining relevance. This was a multicenter regional case series study across three hospitals including patients ≥16 years with strongyloidiasis defined by positive serology and/or parasitological confirmation diagnosed from 2015 to 2024. A total of 301 patients were included (median age 53 years (quartile 1–quartile 3, 40–72); 135 (44.9%) female). Most cases were autochthonous (176/299, 58.9%), while 123/299 (41.1%) occurred in migrants, predominantly from Latin America. Symptoms were present in 165/296 (55.7%), most frequently cutaneous (68/296, 23.0%) and gastrointestinal (62/296, 20.9%). Eosinophilia (>500 cells/µL) was observed in 144/298 (48.3%) and severe infection (hyperinfection syndrome) in 7/294 (2.4%). Annual diagnoses increased over time, with a significant temporal trend by case origin (p < 0.001), reflecting an increasing contribution of imported infections, whereas trends by sex (p = 0.068) and immune status (p = 0.926) were not significant. Stool-based methods demonstrated a low diagnostic yield (microscopy 7/157, 4.5%; culture 21/136, 15.4%; rtPCR 2/27, 7.4%). These findings document the sustained detection of cases classified as autochthonous beyond historically recognized foci and an increasing proportion of imported diagnoses in a temperate European setting.