Should we look for Strongyloides stercoralis in foreign-born HIV-infected persons?

Epidemiological and clinical profile of immunosuppressed patients with imported strongyloidiasis: a substudy from a larger cohort of the +REDIVI Spanish Collaborative Network

The aim of this study was to describe the clinical and epidemiological profile of immunosuppressed patients with imported strongyloidiasis in a non-endemic setting, and to compare these results with non-immunosuppressed patients. This is a case-control substudy from a larger observational retrospective study that included all patients with strongyloidiasis registered in the +REDIVI Spanish Collaborative Network. Overall, 1245 patients with imported strongyloidiasis were included. From these, 80 (6.4%) patients had some kind of immunosuppression. Three (3.8%) patients had a hyperinfection syndrome, and 34 (52.3%) patients had eosinophilia. The percentages of positive results of the formalin-ether technique, the fecal culture and serology were 12.3%, 21.1% and 95.4%, respectively. When comparing the main characteristics, immunosuppressed patients had higher proportion of severe clinical manifestations and lower proportion of eosinophilia. No differences were found regarding yield of microbiological techniques and treatment response. These results stress the importance of strongyloidiasis screening among immunosuppressed patients coming from endemic areas. Serological tests have an acceptable sensitivity to be used as a screening tool.

Strongyloidiasis in Southern Alicante (Spain): Comparative Retrospective Study of Autochthonous and Imported Cases

BACKGROUND

Strongyloidiasis is a parasitic disease with global prevalence. In Spain, autochthonous cases are concentrated in the Mediterranean basin. We aimed to analyze clinical and epidemiological characteristics of Strongyloides stercoralis infection in Vega Baja del Segura (Spain), comparing autochthonous versus imported cases.

METHODS

Observational retrospective study of all strongyloidiasis cases from January 2009 to January 2019. Cases were diagnosed by stool larvae visualization, positive culture, PCR, Strongyloides serology, and/or compatible histology.

RESULTS

We included 36 patients (21 men) with a mean age of 60.8 years ±17.6; 15 cases were autochthonous and 21 imported 80.9% from Latin America. Autochthonous cases were associated with older age (mean 71.3 vs. 53.3 years; p = 0.002), male sex (odds ratio (OR) 5.33; 95% confidence interval (CI) 1.15-24.68; p = 0.041), and agricultural activity (OR 13.5; 95% CI 2.4-73.7; p = 0.002). Fourteen were asymptomatic, three autochthonous cases presented with hyperinfection syndrome, and two patients died. There was no difference between autochthonous versus imported origin in eosinophilia at diagnosis (93.3% vs. 75%; p = 0.207), treatment received, or clinical response (85.7% vs. 88.9% cured; p = 1).

CONCLUSION

In our region, imported strongyloidiasis coexists with autochthonous cases, which are mainly in older male farmers who are diagnosed at more advanced stages. Systematic screening programs are needed.

Strongyloidiasis screening in migrants living in Spain: systematic review and meta-analysis

OBJECTIVES

To provide information regarding the prevalence of strongyloidiasis among migrants coming from Strongyloides stercoralis-endemic areas who reside in Spain.

METHODS

Systematic review of the literature and meta-analysis of studies showing prevalence of S. stercoralis infection among migrants from Latin America, Africa, Eastern Europe, Asia and Oceania who reside in Spain. We included articles published until 30 April 2019 without language restriction. The keywords used for the search included 'Strongyloides stercoralis', 'strongyloidiasis', 'Spain', 'screening' and 'migrants'.

RESULTS

Twenty-four studies were included in the review and meta-analysis, comprising 12 386 screened people. Eleven studies (7020 patients) evaluated the presence of S. stercoralis infection only through investigation of larvae in faeces, showing an overall prevalence of 1% (95%CI 1-1%). Thirteen studies (5366 patients) used a serological test, showing an overall prevalence of 14% (95%CI 11-17%). Strongyloidiasis seroprevalence was 20% (95%CI 15-24%) among migrants from sub-Saharan Africa, 14% (95%CI 10-18%) among those from Latin America and 8% (95%CI 5-11%) among migrants from North Africa.

CONCLUSIONS

Migrants coming from strongyloidiasis-endemic areas living in Spain had a high S. stercoralis infection prevalence, particularly those from sub-Saharan Africa and Latin America. This population should be screened using serology as the most sensitive test for S. stercoralis infection. This could be easily implemented at primary care level.

High prevalence of S. Stercoralis infection among patients with Chagas disease: A retrospective case-control study

BACKGROUND

We evaluate the association between Trypanosoma cruzi infection and strongyloidiasis in a cohort of Latin American (LA) migrants screened for both infections in a non-endemic setting.

METHODOLOGY

Case-control study including LA individuals who were systematically screened for T. cruzi infection and strongyloidiasis between January 2013 and April 2015. Individuals were included as cases if they had a positive serological result for Strongyloides stercoralis. Controls were randomly selected from the cohort of individuals screened for T. cruzi infection that tested negative for S. stercoralis serology. The association between T. cruzi infection and strongyloidiasis was evaluated by logistic regression models.

PRINCIPAL FINDINGS

During the study period, 361 individuals were screened for both infections. 52 (14.4%) individuals had a positive serological result for strongyloidiasis (cases) and 104 participants with negative results were randomly selected as controls. 76 (48.7%) indiviuals had a positive serological result for T. cruzi. Factors associated with a positive T. cruzi serology were Bolivian origin (94.7% vs 78.7%; p = 0.003), coming from a rural area (90.8% vs 68.7%; p = 0.001), having lived in an adobe house (88.2% vs 70%; p = 0.006) and a referred contact with triatomine bugs (86.7% vs 63.3%; p = 0.001). There were more patients with a positive S. stercoralis serology among those who were infected with T. cruzi (42.1% vs 25%; p = 0.023). Epidemiological variables were not associated with a positive strongyloidiasis serology. T. cruzi infection was more frequent among those with strongyloidiasis (61.5% vs 42.3%; p = 0.023). In multivariate analysis, T. cruzi infection was associated with a two-fold increase in the odds of strongyloidiasis (OR 2.23; 95% CI 1.07-4.64; p = 0.030).

CONCLUSIONS

T. cruzi infection was associated with strongyloidiasis in LA migrants attending a tropical diseases unit even after adjusting for epidemiological variables. These findings should encourage physicians in non-endemic settings to implement a systematic screening for both infections in LA individuals.

Soil-Transmitted Helminths in Tropical Australia and Asia

Soil-transmitted helminths (STH) infect 2 billion people worldwide including significant numbers in South-East Asia (SEA). In Australia, STH are of less concern; however, indigenous communities are endemic for STH, including Strongyloides stercoralis, as well as for serious clinical infections due to other helminths such as Toxocara spp. The zoonotic hookworm Ancylostoma ceylanicum is also present in Australia and SEA, and may contribute to human infections particularly among pet owners. High human immigration rates to Australia from SEA, which is highly endemic for STH Strongyloides and Toxocara, has resulted in a high prevalence of these helminthic infections in immigrant communities, particularly since such individuals are not screened for worm infections upon entry. In this review, we consider the current state of STH infections in Australia and SEA.

Strongyloides stercoralis infection in a Spanish regional hospital: Not just an imported disease

INTRODUCTION

Strongyloides stercoralis infection is more prevalent in tropical regions but autochthonous cases have been reported in Spain, mainly in La Safor (Valencia). The objective is to describe the strongyloidiasis cases registered in a regional hospital of Alicante province (Spain) and to determine if they were autochthonous cases.

METHODS

Retrospective study of all diagnosed cases of strongyloidiasis in Vega Baja Hospital (Orihuela, Alicante) between January 1999 and March 2016.

RESULTS

A total of 10 cases were found, four of which were autochthonous cases. Two of them presented with a hyper-infection syndrome, with a fatal outcome. All autochthonous cases were in patients ≥69years old with gastrointestinal, cutaneous, and/or respiratory symptoms. Serology was positive in the 8 cases studied. Larvae were found in histopathological samples of the gastrointestinal tract of three patients.

CONCLUSIONS

We communicate the first autochthonous cases of strongyloidiasis in the region of Vega Baja. Screening programs should be implemented, especially in immunosuppressed patients or patients under chronic corticosteroid treatment.

Helminthosis and eosinophilia in Spain (1990-2015)

The finding of blood eosinophilia in a patient is a relatively frequent reason to refer him/her to a Clinical Department of Infectious Diseases. The doctor usually intends to rule out a parasitic disease in the autochthonous population, travelers or immigrants. It is uncommon for an eosinophilia to be produced by protozoa infection, whereas helminth parasites are more frequently associated with an increase of eosinophil counts in the infected patient. Eosinophilia can be the only abnormal finding, or it could be part of more complex clinical manifestations suffered by the patient. Furthermore, many, but not all, helminth infections are associated with eosinophilia, and the eosinophil level (low, high) differs according to parasite stages, helminth species, and worm co-infections. The purpose of the present article is to carry out a systematic review of cases and case series on helminth infections and eosinophilia reported in Spain from 1990 to 2015, making a distinction between autochthonous and imported (immigrants and travelers) cases, and studying their relationship with immunodepression situations.

Usefulness of Strongyloides stercoralis serology in the management of patients with eosinophilia

Strongyloides stercoralis infection is being increasingly diagnosed out of endemic areas. The aim of this study is to evaluate the usefulness of S. stercoralis serology for the management of probable strongyloidiasis in patients presenting with eosinophilia. Overall, 147 patients were included, 89 (60.5%) patients had a positive S. stercoralis serology. Strongyloides stercoralis larvae were detected only in 15 (10.2%) patients. Twenty-eight patients had human immunodeficiency virus infection. Eighty patients received ivermectin 200 mcg/Kg/day for 2 days, and follow-up 6 months after treatment could be performed in 32 patients: 26 (81.3%) patients reached the response to treatment criteria (negative serology 6 months after treatment or when by enzyme-linked immunosorbent assay the optical density ratio of post-treatment to pre-treatment decreased to 0.6), and 11 (34.4%) patients fulfilled the cure criteria (negative serology 6 months after treatment). Strongyloides stercoralis serology is a useful diagnostic tool both in the diagnosis of probable strongyloidiasis and follow-up after treatment.