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.

OBJECTIFS: Fournir des informations sur la prévalence de la strongyloïdose parmi les migrants résidant en Espagne et provenant de zones endémiques pour Strongyloides stercoralis. MÉTHODES: Revue systématique de la littérature et méta-analyse des études montrant la prévalence de l'infection à S. stercoralis parmi les migrants d'Amérique latine, d'Afrique, d'Europe de l'Est, d'Asie et d'Océanie qui résident en Espagne. Nous avons inclus des articles publiés jusqu'au 30 avril e 2019 sans restriction de langue. Les mots clés utilisés pour la recherche comprenaient "Strongyloides stercoralis", "strongyloïdose", "Espagne", "dépistage" et "migrants". RÉSULTATS: Vingt-quatre études ont été incluses dans la revue et la méta-analyse, comprenant 12.386 personnes dépistées. Onze études (7.020 patients) ont évalué la présence d'une infection à S. stercoralis uniquement en examinant les larves dans les selles, montrant une prévalence globale de 1% (IC95%: 1-1%). Treize études (5.366 patients) ont utilisé un test sérologique, montrant une prévalence globale de 14% (IC95%: 11-17%). La séroprévalence de la strongyloïdose était de 20% (IC95%: 15-24%) chez les migrants d'Afrique subsaharienne, 14% (IC95%: 10-18%) chez ceux d'Amérique latine et 8% (IC95%: 5-11%) chez ceux d'Afrique du Nord. CONCLUSIONS: Les migrants en provenance de zones d'endémie pour la strongyloïdose vivant en Espagne avaient une prévalence élevée d'infection à S. stercoralis, en particulier ceux d'Afrique subsaharienne et d'Amérique latine. Cette population devrait être dépistée en utilisant la sérologie comme le test le plus sensible pour l' infection à S. stercoralis. Cela pourrait être facilement mis en œuvre au niveau des soins primaires.

Strongyloidiasis in Latin American immigrants: a pilot study.

The United States of America (USA) has the largest international population of any nation in the world. Immigrants from Latin American countries, where intestinal parasites are endemic, comprise more than half of this population. This study aims to determine the prevalence of strongyloidiasis, a potentially deadly parasitic infection, in foreign-born individuals. We conducted a cross-sectional study in Washington, DC, to determine the seroprevalence of Strongyloides stercoralis infection using an NIE-ELISA IgG antibody assay. Multi-parallel quantitative real-time polymerase chain reaction (qPCR) was performed in stool samples of NIE-ELISA-positive patients to investigate possible polyparasitism. The NIE-ELISA assay detected an S. stercoralis prevalence of 4.2% in a group of 119 volunteers. Combining NIE-ELISA and qPCR detected a parasite prevalence of 5.0%. Our results underscore the relevance of systematic testing for gastrointestinal parasites in individuals from endemic regions. It also makes a case for a survey in the USA to identify immigrants' risk for strongyloidiasis and other gastrointestinal parasitic infections.

Prevalence of Strongyloides stercoralis infection among HIV-positive immigrants attending two Italian hospitals, from 2000 to 2009.

In patients with Strongyloides stercoralis infection, a dysregulation of host immunity can lead to hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), characterized by high fatality rate. HS has been reported in HIV-positive patients following use of corticosteroids or during immune reconstitution inflammatory syndrome (IRIS). A retrospective study was conducted to estimate the prevalence of S. stercoralis infection among HIV-positive immigrants, attending two Italian hospitals. From January 2000 to August 2009, 138 HIV-positive immigrants were systematically screened for strongyloidiasis, as a part of their routine care, with an indirect immunofluorescent antibody test (IFAT) developed at the Centre for Tropical Diseases, Sacro Cuore Hospital of Negrar, Verona. The majority were also submitted to stool examination. Fifteen (11%) resulted infected by S. stercoralis, of whom four (27%) had a negative serology (diagnosis made with stool examination). A higher eosinophil count (0·94 versus 0·24×10(9)/l, P<0·01) and more frequent gastrointestinal and cutaneous symptoms (odds ratio: 4·8 and 5·8, respectively) were found in patients with strongyloidiasis compared with controls. The IFAT is more sensitive than direct parasitological methods. The proportion of false negative results was higher than expected based on the theoretical test sensitivity. Considering the high prevalence detected and the apparent, lower sensitivity of serology, we propose a systematic screening for Strongyloides infection, with both serology and stool culture, for all HIV-positive immigrants coming from endemic areas.

Strongyloides hyperinfection in Ethiopian immigrants in Israel.

We report four cases of Strongyloides hyperinfection among Ethiopian immigrants, of which three were fatal. Many immigrants from countries in which Strongyloides is endemic settle in developed countries. A high index of suspicion will lead to earlier diagnosis and treatment of this disease. Testing for Strongyloides infestation in this susceptible population by enzyme-linked immunosorbent assay serology, stool testing or duodenal aspiration may prevent the fatal complications of hyperinfection.

Strongyloides stercoralis: a cause of morbidity and mortality for indigenous people in Central Australia.

BACKGROUND: Strongyloides stercoralis may cause a complicated infection in immunocompromised patients, which has a high case fatality rate. Death generally results from sepsis with enteric pathogens. Globally, infection with the human T-cell lymphotropic virus type 1 (HTLV-1) is a major risk factor for this syndrome. Both S. stercoralis and HTLV-1 are endemic to Central Australia. AIMS: The aim of the study was to determine whether complicated strongyloidiasis occurs in association with HTLV-1 infection in Central Australia. METHODS: A retrospective audit of all cases of complicated strongyloidiasis presenting to Alice Springs Hospital between January 2000 and December 2006 was carried out. Diagnosis was defined as definite or probable according to whether diagnosis was made by faecal studies or serology respectively. The medical records, investigations and outcomes of patients who met predetermined criteria for a diagnosis of complicated strongyloidiasis were reviewed. RESULTS: Eighteen indigenous patients met the criteria for complicated strongyloidiasis (definite 9, probable 9). Seven of 11 patients tested were HTLV-1 seropositive. At diagnosis, no treatment was documented for nine patients (definite 4, probable 5), three received a single dose of ivermectin and one a single dose of albendazole. Fifteen patients (83%) died because of sepsis (definite 7, probable 8). Pathogens isolated and their foci of infection included Klebsiella pneumoniae pneumonia (4), bloodstream infection with Enterococcus spp. (2), K. pneumoniae peritonitis (1) and streptococcal meningitis (1). CONCLUSION: Complicated strongyloidiasis occurs in association with HTLV-1 infection in central Australia. This finding has significant implications for the management of S. stercoralis in the region.

Strongyloides seroprevalence before and after an ivermectin mass drug administration in a remote Australian Aboriginal community.

BACKGROUND: Strongyloides seroprevalence is hyper-endemic in many Australian Aboriginal and Torres Strait Islander communities, ranging from 35-60%. We report the impact on Strongyloides seroprevalence after two oral ivermectin mass drug administrations (MDAs) delivered 12 months apart in a remote Australian Aboriginal community. METHODS: Utilizing a before and after study design, we measured Strongyloides seroprevalence through population census with sequential MDAs at baseline and month 12. Surveys at months 6 and 18 determined changes in serostatus. Serodiagnosis was undertaken by ELISA that used sonicated Strongyloides ratti antigen to detect anti-Strongyloides IgG. Non-pregnant participants weighing ≥15 kg were administered a single 200 µg/kg ivermectin dose, repeated after 10-42 days if Strongyloides and/or scabies was diagnosed; others followed a standard alternative algorithm. A questionnaire on clinical symptoms was administered to identify adverse events from treatment and self-reported symptoms associated with serostatus. FINDINGS: We surveyed 1013 participants at the baseline population census and 1060 (n = 700 from baseline cohort and 360 new entrants) at month 12. Strongyloides seroprevalence fell from 21% (175/818) at baseline to 5% at month 6. For participants from the baseline cohort this reduction was sustained at month 12 (34/618, 6%), falling to 2% at month 18 after the second MDA. For new entrants to the cohort at month 12, seroprevalence reduced from 25% (75/297) to 7% at month 18. Strongyloides positive seroconversions for the baseline cohort six months after each MDA were 2.5% (4/157) at month 6 and 1% at month 18, whilst failure to serorevert remained unchanged at 18%. At 12 months, eosinophilia was identified in 59% of baseline seropositive participants and 89% of seropositive new entrants, compared with 47%baseline seronegative participants and 51% seronegative new entrants. Seropositivity was not correlated with haemoglobin or any self-reported clinical symptoms. Clinical symptoms ascertained on the day of treatment and 24-72 hrs after, did not identify any adverse events. SIGNIFICANCE: Two community ivermectin MDAs delivered 12 months apart by trained Aboriginal researchers in collaboration with non-Indigenous researchers resulted in a sustained and significant reduction in Strongyloides seroprevalence over 18 months. Similar reductions were seen in the baseline cohort and new entrants.

Undiagnosed and potentially lethal parasite infections among immigrants and refugees in Australia.

Intestinal parasite infections are a major cause of ill health in many resource-poor countries. This study compares the types and rates of these infections and their risk factors in recently arrived and long-term immigrants in Australia. Cross-sectional surveys of 127 East African and 234 Cambodian immigrants and refugees were undertaken in 2000 and 2002, respectively, to assess the burden of intestinal parasites and collect demographic information. Serum samples were assessed for eosinophilia and Strongyloides stercoralis and Schistosoma antibodies, and feces examined for ova, cysts, and parasites. Intestinal parasites were identified in 77/117 fecal samples from East African and in 25/204 samples collected from Cambodian participants. Eleven percent (14/124) of East Africans and 42% (97/230) of Cambodians had positive or equivocal serology for S stercoralis. Schistosoma serology was positive or equivocal in 15% (19/124) of East African participants. Potentially serious intestinal parasite infections are common among recent and longer term immigrants despite multiple visits to health care providers. Immigrants and refugees from high-risk countries would benefit from comprehensive health checks soon after resettlement.

Serological study of Trypanosoma cruzi, Strongyloides stercoralis, HIV, human T cell lymphotropic virus (HTLV) and syphilis infections in asymptomatic Latin-American immigrants in Spain.

OBJECTIVE: We aimed to perform a serological screening for T. cruzi, Strongyloides stercoralis, HIV, human T cell lymphotropic virus (HTLV) and syphilis in Latin American immigrants admitted to hospital in Spain. METHODS: We have carried out a cross-sectional study of Latin American immigrants admitted to the Hospital General Universitario Alicante (Spain) from June 2012 to May 2014, where screening of Chagas disease, strongyloidiasis, HTLV, HIV and syphilis was performed by serology. RESULTS: A total 180 patients were included in the study. Patients' median age was 38 years old, 123 (68.3%; 123/180) were female and 57 (31.7%; 57/180) male. Five of the 180 (2.5%) patients were positive for Chagas disease; associated with knowledge about Chagas disease (p=0.005), previous contact with patients with Chagas disease (p=0.04) and being Bolivian (p<0.001). Forty-two of the 157 (26.8%) patients were positive for Strongyloides serology; associated positively with being male (p<0.001), eosinophilia (p=0.001), hyper-IgE (p<0.001) and being Ecuadorian (p=0.001), and negatively associated with being Colombian (p=0.03). Positive serology of latent syphilis was found in 1.8% (3/171) of patients. Serology of HTLV was negative in all cases. No new cases of HIV infection were diagnosed. CONCLUSIONS: We propose that Latin American immigrant patients admitted to hospital in Spain be screened for strongyloidiasis, Chagas disease and syphilis by serology.

The prevalence and response to therapy of Strongyloides stercoralis in patients with asthma from endemic areas.

STUDY OBJECTIVE: To evaluate the prevalence and response to therapy of Strongyloides stercoralis infection in immigrant patients with asthma from areas endemic for Strongyloides. DESIGN AND INTERVENTIONS: In all patients, we performed a complete history and physical examination, complete blood cell counts (CBC), S stercoralis serologic tests, spirometry, and evaluated three stool samples for ova and parasites. Patients treated for S stercoralis infection had follow-up CBC, spirometry, serologic tests, and at least three additional stool examinations to confirm eradication of the parasite. SETTING: Ambulatory and hospitalized patients who were referred to the respiratory medicine clinic of a general hospital for the evaluation and treatment of asthma. PATIENTS: Forty-five asthmatic adults, representing 12 endemic countries, ranging in age from 20 to 76 years, were prospectively evaluated. RESULTS: Six of 45 patients were infected with S stercoralis, which yielded a prevalence of 13 percent. The patients with asthma and S stercoralis infection had higher blood eosinophil counts (p = 0.006) and were younger (p = 0.006) compared with patients with only asthma. There was no difference in the duration of asthma, spirometry, or steroid use between the two groups. Patients with S stercoralis and asthma tended to be more recent immigrants (p = 0.05). Five of the six patients with S stercoralis agreed to be treated with thiabendazole but only four returned for follow-up evaluation. All four patients had eradication of S stercoralis infection confirmed by negative stool examinations and a decline in S stercoralis serology (160 +/- 25 percent vs 13 +/- 13 percent, p = 0.03). All four patients had a decline in total blood eosinophil counts (2,476 +/- 832 cells per cubic millimeter vs 551 +/- 138 cells per cubic millimeter, p = 0.03) without a clinical improvement in asthma. CONCLUSIONS: Our data suggest that patients with asthma from areas endemic for S stercoralis, who have elevated peripheral blood eosinophil counts, should be screened for S stercoralis infection. Successful eradication of S stercoralis, however, may not result in a clinical improvement of asthma.

Household aggregation of Strongyloides stercoralis infection in Bangladesh.

Strongyloides stercoralis infections were shown to be aggregated in households in an urban slum community in Dhaka, Bangladesh. Parasitological data on 880 residents living in 280 households were analysed statistically using 3 different tests, each of which yielded significant evidence of household aggregation of S. stercoralis infection. One test was applied to the data after stratification for 4 variables were previously shown to be independently associated with infection. Evidence of household aggregation of infection remained after stratification, suggesting that aggregation is due not only to shared risk factors, but also to either familial genetic predisposition to infection or close contact person to person transmission of infection within households.

Strongyloides stercoralis in an urban slum community in Bangladesh: factors independently associated with infection.

Stool samples from 880 residents in an urban slum in Dhaka, Bangladesh, were collected on 3 occasions over one year, and examined for intestinal parasites. Information on many potential risk factors for infection was obtained by questionnaire from a respondent in each household studied. In a crude univariate analysis of the data, several of the factors were found to be significantly associated with Strongyloides stercoralis infection. Most of these factors were co-variate with one another, and with poverty generally. Using Mantel-Haenszel chi 2 tests to control for confounding effects of each variable individually, the following 4 factors remained independently associated with S. stercoralis infection: respondent's use of a community latrine rather than a private latrine, living in a house with an earth floor rather than a cement floor, being of Bihari ethnicity, and being 7-10 years of age. Implications of these results for the epidemiology and control of strongyloidiasis are briefly discussed.

Pseudoparasitic pneumonia after bone marrow transplantation.

We present a female patient from Somalia with an acute lymphoblastic leukemia, who received an allogeneic bone marrow transplantation (BMT) and developed several periods of moderate to severe pulmonary symptoms that were accompanied by pulmonary infiltrates and peripheral blood eosinophilia. After several recurrences an open lung biopsy was performed, which initially gave rise to the diagnosis parasitic infection. Later on this diagnosis was questioned and it was suggested that the structures were artifacts that might have been aspirated. Nevertheless, after the immediately given antihelminthic treatment no peripheral blood eosinophilia occurred anymore, but at that point of time pulmonary function was already severely hampered and eventually led to a lethal complication. With the worldwide increasing migration from Third World countries with a high prevalence of parasitic infections, more patients will receive immunosuppressive therapies in countries less familiar with parasites. This may complicate diagnostic procedures, prevent early recognition and delay adequate treatment. Specific screening for opportunistic parasitic infections of the population at risk before BMT and a great awareness for these infections is strongly recommended.

Strongyloides stercoralis: systematic review of barriers to controlling strongyloidiasis for Australian indigenous communities.

BACKGROUND: Strongyloides stercoralis infects human hosts mainly through skin contact with contaminated soil. The result is strongyloidiasis, a parasitic disease, with a unique cycle of auto-infection causing a variety of symptoms and signs, with possible fatality from hyper-infection. Australian Indigenous community members, often living in rural and remote settings, are exposed to and infected with S. stercoralis. The aim of this review is to determine barriers to control of strongyloidiasis. The purpose is to contribute to the development of initiatives for prevention, early detection and effective treatment of strongyloidiasis. METHODOLOGY/PRINCIPLE FINDINGS: Systematic search reviewing research published 2012 and earlier was conducted. Research articles discussing aspects of strongyloidiasis, context of infection and overall health in Indigenous Australians were reviewed. Based on the PRISMA statement, the systematic search of health databases, Academic Search Premier, Informit, Medline, PubMed, AMED, CINAHL, Health Source Nursing and Academic was conducted. Key search terms included strongyloidiasis, Indigenous, Australia, health, and community. 340 articles were retrieved with 16 original research articles published between 1969 and 2006 meeting criteria. Review found barriers to control defined across three key themes, (1) health status, (2) socioeconomic status, and (3) health care literacy and procedures. CONCLUSIONS/SIGNIFICANCE: This study identifies five points of intervention: (1) develop reporting protocols between health care system and communities; (2) test all Indigenous Australian patients, immunocompromised patients and those exposed to areas with S. stercoralis; (3) health professionals require detailed information on strongyloidiasis and potential for exposure to Indigenous Australian people; (4) to establish testing and treatment initiatives within communities; and (5) to measure and report prevalence rates specific to communities and to act with initiatives based on these results. By defining barriers to control of strongyloidiasis in Australian Indigenous people, improved outcomes of prevention, treatment of strongyloidiasis and increased health overall are attainable.

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

The objective was to evaluate the implementation of a systematic Strongyloides stercoralis screening programme in HIV infected immigrants attending an HIV Unit in Spain. An enzyme-linked immunosorbent assay (ELISA) was performed to assess the presence of Strongyloides IgG. Patients with a positive serology were treated with ivermectin; serologic follow-up testing was performed. 237 patients were screened (65.4 % men). Origin: 64.1 % came from Latin America, 16.5 % from Sub-Saharan Africa, 9.7 % from the Caribbean, 9.7 % from other areas. Strongyloides stercolaris IgG was positive in 13 cases (5.5 %). In the multivariate analysis, factors associated with a positive Strongyloides serology were illiteracy (OR: 23.31; p = 0.009) and eosinophilia (OR: 15.44; p < 0.0001). Nine of the 13 patients positive for S. stercoralis IgG and treated with ivermectin had a follow up serologic test: 77.8 % achieved a serologic response (55.5 % seroreversion). Screening of HIV-positive immigrants may be desirable, at least in those with higher risk of hyperinfection syndrome. Serologic testing seems a useful tool in both diagnosis and follow-up of these patients.

Tropical diseases screening in immigrant patients with human immunodeficiency virus infection in Spain.

Latent parasitic infections can reactivate because of immunosuppression. We conducted a prospective observational study of all human immunodeficiency virus (HIV)-infected immigrants who visited the Infectious Diseases Department of the Hospital Universitari Vall d'Hebron, Barcelona, Spain, during June 2010-May 2011. Screening of the most prevalent tropical diseases (intestinal parasitosis, Chagas disease, leishmaniasis, malaria, schistosomiasis, and strongyloidiasis) was performed according to geographic origin. A total of 190 patients were included: 141 (74.2%) from Latin America, 41 (21.6%) from sub-Saharan Africa, and 8 (4.2%) from northern Africa. Overall, 36.8% (70 of 190) of the patients had at least one positive result for any parasitic disease: 5 patients with positive Trypanosoma cruzi serology, 11 patients with positive Schistosoma mansoni serology, 35 patients with positive Strongyloides stercoralis serology, 7 patients with positive Leishmania infantum serology, intestinal parasitosis were detected in 37 patients, malaria was diagnosed in one symptomatic patient. We propose a screening and management strategy of latent parasitic infections in immigrant patients infected with HIV.

Management of chronic strongyloidiasis in immigrants and refugees: is serologic testing useful?

We assessed the usefulness of serologic testing in monitoring strongyloidiasis in immigrants after treatment with two doses of ivermectin. An observational study was conducted in a group of Cambodian immigrants residing in Melbourne who were treated for strongyloidiasis and followed-up in a general practice setting. Two doses of ivermectin (200 microg/kg) were administered orally. Periodic serologic enzyme-linked immunosorbent assay testing was undertaken for up to 30 months after treatment. Antibody titers for Strongyloides sp. decreased in 95% (38 of 40) of the patients, 47.5% (19 of 40) had a decrease in optical density to less than 0.5, and 65% (26 of 40) reached levels consistent with a cure during the follow-up period. Serologic testing for Strongyloides sp. is a useful tool for monitoring a decrease in antibody levels after effective treatment. This testing should be carried out 6-12 months after treatment to ensure a sustained downward trend suggestive of cure.