Prevalence Of Strongyloidiasis Research Articles

Ecological Risk Factors of Strongyloides stercoralis Infection Sourrounding Desforestration Areas East Kalimantan, Indonesia

Aims: The study to assess the prevalence of Strongyloides stercoralis/ S. stercoralis infection, and to correlate environmental risk factors with the prevalence of S. stercoralis infection.
 Study Design: We perform a cross-sectional study in rural community in Muarakaman and Marangkayu district to analysis of geography, texture of soil, humidity, hookworm and strongyloides in pet, vegetation, elevation, volume rain, the number of days of rain yearly, temperature and quality of soil as clay content, organic carbon of soil and pH of soil then was correlated with prevalence of strongyloidiasis..
 Place and Duration of Study: The study was carried out in rural area of Muarakaman District and Marangkayu District East Kalimantan Province, Indonesia. This research is a community based, had conducted during 2021-2022.
 Methodology: This study would show the infection rates, correlation analysis between environmental risk factors and prevalence of hookworm infection with statistical analysis. We performed a cross-sectional study among 213 participants from rural community. In this study used two diagnostic methods: Kato Katz and Koga agar plate culture/KAP culture for diagnosing of S. stercoralis infection. Pearson chi-square analysis was used for study correlation between ecological risk factors S. stercoralis infection.
 Results: S. stercoralis infection was found in this study; 34 (8.0%), Ecological risk factors have significant correlation and high odd ratio of prevalence of S. stercoralis infection. Ecological risk factors have significant correlation and high odd ratio of prevalence of S. stercoralis infection such as district, humidity, temperature, volume and amount day of rain organic carbon of soil, elevation of location from above a sea
 Conclusion: The Ecological risk factors of the infections could be used in preventing program to reduce the prevalence of hookworm and S. stercoralis infection.

Efficacy of Oral Ivermectin as Empirical Prophylaxis for Strongyloidiasis in Patients Treated with High-Dose Corticosteroids: A Retrospective Cohort Study.

People living in areas endemic for strongyloidiasis are at risk of latent Strongyloides stercoralis infection. Corticosteroid therapy is a well-established risk factor for life-threatening hyperinfection syndrome and disseminated disease owing to suppression of the immune system. There are limited data available on the efficacy and cost of providing oral ivermectin prophylaxis to all patients receiving high-dose corticosteroids for strongyloidiasis in endemic areas. We thus conducted this retrospective cohort study at Khon Kaen University's Srinagarind Hospital from 2015 to 2019. Inclusion criteria were as follows: age ≥ 18 years, having received ≥ 0.5 mg/kg/day of prednisolone or equivalent for at least 14 days, and hospitalization during the study period. A total of 250 patients were included in the study: 125 in the empirical prophylaxis group (prescribed ivermectin even if fecal examination results were negative or nonexistent) and the remaining patients in the definite therapy group (prescribed ivermectin only if S. stercoralis was detected by fecal examination). The prevalence of strongyloidiasis at enrollment estimated by fecal examination was 5.5%. Ivermectin was given to 125 patients (100%) in the prophylaxis group compared with 12 (9.6%) in the definite therapy group (P value < 0.001). During the 12-month follow-up period, S. stercoralis was detected in three patients, two in the prophylaxis group and one in the definite therapy group (P value = 1.000). No cases of hyperinfection syndrome or disseminated disease were found. The empirical prophylaxis strategy had a significantly higher cost than the definite therapy strategy (563 versus 254, P value < 0.001) and did not demonstrate superior efficacy in strongyloidiasis prevention.

Seroprevalence and microscopy detection rates of strongyloidiasis in Croatian patients with eosinophilia.

Infection with the parasitic nematode Strongyloides stercoralis is characteristic for tropical and subtropical regions of the world, but autochthonous cases have been reported in European countries as well. Here we present the first nation-wide survey of S. stercoralis seroprevalence in Croatian individuals presenting with eosinophilia, and evaluate the fraction of positive microscopy rates in stool specimens of seropositive individuals. In our sample of 1407 patients tested between 2018 and 2021, the overall prevalence of strongyloidiasis was 9.31%, with significantly higher rates in those older than 60 years of age (P = 0.005). Of those, one-quarter (25.95%) were also positive following microscopy examination of faeces after using the merthiolate-iodine-formaldehyde concentration method. Our findings reinforce the notion of endemic strongyloidiasis transmission in Croatia, particularly in older individuals, and highlight the need to consider the presence of S. stercoralis in patients with eosinophilia.

Strongyloidiasis associated with severe anemia: A case report in Taiwan

Strongyloidiasis is caused by infection with the helminth, Strongyloides stercoralis. The life cycle of S. stercoralis in the host could last decades owing to autoinfection. Most symptoms of strongyloidiasis are nonspecific and may involve the skin, respiratory tract, or gastrointestinal tract. Severe anemia is a less frequently reported symptom of strongyloidiasis. The prevalence of strongyloidiasis is low in Taiwan, and sporadic cases have been previously reported. We present a case of strongyloidiasis in an 82-year-old woman diagnosed by microscopic examination of stool, presenting with severe normocytic anemia. After treatment with the antiparasitic medication, ivermectin, and blood transfusion, her anemia improved. Therefore, parasite infection should be considered in immunosuppressed patients despite atypical laboratory results. Physicians should be aware of the rare incidence of strongyloidiasis in Taiwan and consider it as a possible differential diagnosis for anemia.

Prevalence of Gastrointestinal Nematodes, Cestodes, and Protozoans of Goats in Nyagatare District, Rwanda.

Goat farming significantly contributes to the efficient use of land and socioeconomic development in developed and developing countries. During the fiscal year 2017-2018, goats made up 13.5% of the total live livestock exported by Rwanda. Gastrointestinal parasites (GIPs) can negatively impact goat production, especially in developing countries like Rwanda. This study aimed to determine the impact of the goat' age and location (administrative cell) on the prevalence of gastrointestinal nematodes, cestodes, and protozoans (GiNCPs) of goats in Nyagatare district, Rwanda. In this cross-sectional study, 149 faecal samples were collected from apparently unwell goats and analyzed using the simple flotation technique. Strongyle-type nematodes (STNs) infections were graded using the McMaster method. Pearson chi-square tests of independence were calculated to assess the impact of the goat' age and location on the prevalence of GiNCPs in the study area. All the goats (100%) were infected with GiNCPs. The identified types of parasites were STNs (96.0%), Coccidia (83.2%), Moniezia spp (14.8%), Strongyloides papillosus (12.8%), Nematodirus spp (0.7%) and Trichuris ovis (0.7%). Nearly 85.9% (128/149) of the goats were coinfected with 2 to 4 types of parasites and the coinfection of STNs and coccidia preponderated at 58.4%. The location (administrative cell) of the goats correlated with the prevalence of monieziasis (p<0.05). The goat's age category was also associated with the prevalence of strongyloidiasis (p<0.05). All the goats (100%) were infected with GiNCPs. The location (administrative cell) of the goat also correlated with the prevalence of monieziasis. In addition, the goat's age category was associated with the prevalence of strongyloidiasis. These findings show that any control program for caprine gastrointestinal parasitoses in the study area should focus on STNs and Coccidia.

Monitoring of the epizootic situation sheep strongyloidiasis on Ukrainian territory

One of the reasons that reduce the efficiency of sheep breeding development and lead to significant economic losses of the industry in Ukraine and the world is helminthic diseases, particularly strongyloidiasis caused by parasitic nematodes. Strongyloides parasitize in the small intestine of animals and lead to slow growth and development of young sheep, diarrhea, anemia, ataxia. At the high intensity of invasion - animals can die. The study aimed to analyze monitoring studies on the prevalence of strongyloidiasis in sheep in Ukraine based on statistical data of the reporting documentation of the State Research Institute for Laboratory Diagnostics and Veterinary Sanitary Examination during 2016–2020. Studies have shown that helminthiasis of sheep is a common invasion in farms of various forms of ownership in Ukraine, where the extent of the invasion ranged from 1.44 to 3.27 %. The share of helminthiasis of the digestive tract of sheep from the total number of detected helminthiasis reaches 84.21 %. The most common of the helminthiases of the gastrointestinal tract were nematodes; their share was 63.07 %. Trematodes and cestodes were diagnosed less frequently; their share among helminthiases of the digestive tract was 35.05 and 1.88 %, respectively. It was found that among the nematodes of the digestive tract parasitizing in sheep in Ukraine, the largest share was strongylidosis, in particular bunostomosis, nematodyrosis, hemonchosis (65.20 %), and strongyloidiasis (33.92 %). A smaller proportion were esophagostomosis (0.74 %) and trichurosis (0.14 %). Indicators of prevalence were: for strongylidosis (bunostomosis, nematodyrosis, hemonchosis) – 10.98 %, for strogiloidiasis – 4.48 %, for esophagostomosis – 0.42 %, for trichurosis – 0.21 %. In terms of years, the rates of damage to sheep by the causative agent of strongyloidiasis fluctuated significantly with the increasing prevalence of strongyloidiasis invasion during 2019–2020. Indicators of infestation of sheep with the causative agent of strongyloidiasis during the study period in Ukraine were at the level of 1.91 % (2018) to 16.14 % (2019). The data we obtained testify to the urgency of the problem of nematodes, particularly strongyloidiasis of sheep in Ukrainian farms, and lead to more thorough research on epizootological, biological features of the causative agent strongyloidiasis and the introduction of effective treatment and prevention measures.

Prevalence of strongyloidiasis in Peru: systematic review and meta-analysis

BackgroundStrongyloidiasis is a disease of great public health significance, caused by the parasitic nematodes Strongyloides stercoralis, Strongyloides fuelleborni, and Strongyloides fuelleborni subsp. kellyi. This systematic review and meta-analysis aimed to assess the prevalence of Strongyloides stercoralis infection in Peru.MethodsThe review was based on a literature search in PubMed, SciELO and Google Scholar using the key words or root words “strongyl*” AND “Peru” on 15 July 2020. Eligible studies were published from 1 January 1981 to 15 July 2020 and written in English, Spanish, Italian, or French.ResultsWe included 21 papers in the analysis. Studies were heterogeneous in terms of study population and diagnostic methods (e.g. Baermann technique, agar, Dancescu or charcoal cultures, serology, string capsule). Prevalence of S. stercoralis ranged from 0.3 to 45%. The pooled proportion of Strongyloides in the general population was 7.34% (95% CI 4.97 to 10.13%). Half the studies were designed to detect parasites in general. In studies designed to detect S. stercoralis, the most widely used diagnostic method was the Baermann technique.ConclusionPrevalence of S. stercoralis in Peru was high but varied by geographic area, techniques for stool examination, and participant characteristics.

Control programs for strongyloidiasis in areas of high endemicity: an economic analysis of different approaches

BackgroundImplementation of control programmes for Strongyloides stercoralis infection is among the targets of the World Health Organization Roadmap to 2030. Aim of this work was to evaluate the possible impact in terms of economic resources and health status of two different strategies of preventive chemotherapy (PC) compared to the current situation (strategy A, no PC): administration of ivermectin to school-age children (SAC) and adults (strategy B) versus ivermectin to SAC only (strategy C).MethodsThe study was conducted at the IRCCS Sacro Cuore Don Calabria hospital, Negrar di Valpolicella, Verona, Italy, at the University of Florence, Italy, and at the WHO, Geneva, Switzerland, from May 2020 to April 2021. Data for the model were extracted from literature. A mathematical model was developed in Microsoft Excel to assess the impact of strategies B and C in a standard population of 1 million subjects living in a strongyloidiasis endemic area. In a case base scenario, 15% prevalence of strongyloidiasis was considered; the 3 strategies were then evaluated at different thresholds of prevalence, ranging from 5 to 20%. The results were reported as number of infected subjects, deaths, costs, and Incremental-Effectiveness Ratio (ICER). A 1-year and a 10-year horizons were considered.ResultsIn the case base scenario, cases of infections would reduce dramatically in the first year of implementation of PC with both strategy B and C: from 172 500 cases to 77 040 following strategy B and 146 700 following strategy C. The additional cost per recovered person was United States Dollar (USD) 2.83 and USD 1.13 in strategy B and C, respectively, compared to no treatment in the first year. For both strategies, there was a downtrend in costs per recovered person with increasing prevalence. The number of adverted deaths was larger for strategy B than C, but cost to advert one death was lower for strategy C than B.ConclusionsThis analysis permits to estimate the impact of two PC strategies for the control of strongyloidiasis in terms of costs and adverted infections/deaths. This could represent a basis on which each endemic country can evaluate which strategy can be implemented, based on available funds and national health priorities.

Prevalence of strongyloidiasis among cardiothoracic organ transplant candidates in a non-endemic region: A single-center experience with universal screening.

Disseminated strongyloidiasis and hyperinfection syndrome can cause significant morbidity and mortality after transplantation. Screening and treatment prior to transplantation can reduce or prevent this disease. Targeted screening of transplant candidates based on assessed risk, fails to identify all who would benefit. We implemented universal serology-based screening for Strongyloides at our transplant center, located in a non-endemic area. Of 200 transplant candidates who were evaluated for cardiothoracic transplant from January 2018 to June 2019, 169 were screened serologically and 21 (12.4%) were seropositive. Among seropositive patients, 57% reported travel to an endemic region, 38% were born outside the USA, 38% had eosinophilia, and 5% had history of gram-negative bacteremia. We estimate that universal screening for strongyloidiasis could identify an average of 17 additional candidates for preventive treatment for every 200 transplant candidates.

Strongyloidiasis in clinical practice: challenges in diagnostics and treatment (brief review and clinical observations)

High priority of soil-transmitted helminths worldwide and in the Russian Federation is due to their vast distribution and the severe pathological features they induce in humans. Recently, it was observed that awareness of clinicians regarding this disease category was markedly decreased, although no significant decline of the disease occurrence has been recorded, whereas rate of imported cases of parasitic diseases including soil-transmitted helminths like strongyloidiasis mainly originating from subtropical or tropical countries rose in non-endemic regions. Lack of alertness on diseases like strongyloidiasis impedes timely diagnostics and treatment. Global prevalence of strongyloidiasis was estimated to range within 30—100 million people, however the World Health Organization (WHO) suggests that it was underestimated as precise data in endemic countries remain unknown. The occurrence of these helminths has been recorded in regions of temperate-continental climate: Western Ukraine, Belarus, Moldova, the Caucasus, Central Asia, as well as in Eastern Europe and the Mediterranean region. In the Russian Federation locally acquired infections are frequently recorded in the Krasnodar Territory and Rostov Region. Here, based on multi-year experience in management of patients with strongyloidiasis we present our data and brief review of publications and systematic literature related to the challenges of its clinical picture, diagnostics and treatment. Life cycle, basic biological parameters of free-living helminth in nature and distinctive features of autoinfection related to strongyloidiasis were reviewed. Special attention was paid to the risk of developing severe forms (hyperinfection and disseminated strongyloidiasis) especially in immunocompromised hosts: HIV infection, radiotherapy followed by chemotherapy, long-term corticosteroid use. Difficulties in diagnosing Strongy-loides stercoralis infection are due to its polymorphic and non-specific clinical manifestations, as well as the lack of clinical knowledge and awareness about the disease. Clinical importance of parasitological methods for larvae detection was underlined. It was noted that the drug of choice in therapy of strongyloidiasis is ivermectin unapproved yet in Russia, whereas albendazole as an alternative drug exerts poorer efficacy, justifying a need to repeat treatment courses to establish full recovery from the disease.

Two Cases of Meningitis Associated with Gram Negative Bacteremiae and Strongyloidiasis

Background: Strongyloidiasis is a neglected tropical disease and is widely distributed. HTLV-1 coinfection is frequent, and this disease increases the risk of hyper infestation. Disseminated strongyloidiasis often causes severe enterobacteria infection. Case Presentation: We report the cases of two patients presenting with meningial syndrome. The meningitis was associated with a Gram negative bacteremiae. The investigations performed proved an infection or a previous contact with Strongyloides stercoralis. The infectious outcome was favorable after antibiotic treatment and antiparasitic treatment but one of them was also co-infected with HTLV-1 and died after a lymphoma occurred. Discussion: S. stercoralis infects the intestinal mucosa, and chronic infection of this pathogen induces inflammation of the intestinal mucosa. Enteric bacteria can gain systemic access and be responsible of organ involvement, including Central Nervous System. HTLV-1 infection increases the prevalence of strongyloidiasis, the rate of treatment failure, and the risk of hyperinfestation. Conclusions: Strongyloidiasis should not be underdiagnosed, as a specific treatment with antiparasitic drugs is available. We should perform direct microscopy of the stool to detect S. stercoralis in patients who develop severe enterobacterial infection when patients are from an endemic area.

Strongyloides Screening in Heart Transplant Candidates

The ability of Strongyloides to establish auto-infection in the human host allows it to sustain subclinical infection that can go on for a lifetime. In solid-organ transplant recipients, Strongyloides can cause hyper-infection syndrome which has very high morbidity and mortality. Clinical suspicion for chronic infection should be considered for any persons with birth or travel to endemic regions, history of incarceration, homelessness and group home residence. Targeted screening based on epidemiologic risk is recommended by AST and ISHLT however, testing remains challenging due to variability in the diagnostic yield of currently available serologic assays. We performed a retrospective chart review of heart transplant (HT) recipients from 2010-2019, who had Strongyloides serologic screening performed pre-transplant, with the aim to correlate results with epidemiological risk factors for infection. Two-hundred and fifty HT recipients were reviewed. Of these, 197 had pre-transplant Strongyloides serology performed, in accordance with institutional policy of universal pre-transplant screening. Based on serologic testing, prevalence of strongyloidiasis was 2.5%. Of the 5 patients with positive serology, all but 1 had epidemiologic risk for infection; 3 due to birth in an endemic region and 1 due to history of incarceration. Eosinophilia was noted in 3/5, all of whom were from endemic regions by birth. All with positive serologic screening were treated pre-transplant with ivermectin. One-hundred and ninety two patients tested negative for Strongyloides, and 58% (111/192) of those had epidemiological risk factors, due to birth (90) or travel to endemic regions (21). There were no cases of clinical strongyloidiasis in the study cohort. In this population with high epidemiologic risk, we found a lower than expected rate of Strongyloides infection. Given the variability in diagnostic yield across commercially available serologic assays, these findings raise the possibility of false negative results and thus, bring into question the utility and reliability of using serologic testing alone, for screening of Strongyloides infection among HT candidates. Accordingly, a thoughtful assessment of epidemiologic risk is essential for appropriate risk stratification and management of Strongyloides in HT candidates and recipients.

Prevalence and risk factors of strongyloidiasis in patients with systemic lupus erythematosus in Southern Thailand.

Strongyloidiasis can be fatal in systemic lupus erythematosus (SLE) patients, but few epidemiological studies have investigated the burden of this tropical disease among the SLE population. This study aimed to assess the prevalence and associated factors of strongyloidiasis among SLE patients in Southern Thailand. A cross-sectional study was conducted on 180 SLE patients attending the Rheumatology Clinic at Songklanagarind Hospital. Stool specimens were collected and examined using the direct smear technique and agar plate culture technique. Serum anti-Strongyloides stercoralis IgG was measured by IgG-ELISA. The overall prevalence of strongyloidiasis by combined parasitologyl and/or serology was 15.6%. The prevalence of strongyloidiasis by parasitological methods was 2.2%. Positive parasitology and/or serology was associated with male sex and a SLE disease duration of less than two years. Strongyloidiasis is highly prevalent among the SLE population. A combination of serological and parasitological methods increases the rate of diagnosis of strongyloidiasis in SLE patients.

Mapping the Prevalence of Strongyloides stercoralis Infection in Ecuador: A Serosurvey.

Data on the prevalence of strongyloidiasis in Ecuador are patchy. The aim of this study was to document the presence of Strongyloides stercoralis infection in rural communities of different provinces of Ecuador. We tested 1,418 serum samples stored at the biobank of the Central University of Ecuador, Quito, with an ELISA test for Strongyloides. The samples had been collected in eight different provinces of Ecuador. Two hundred ninety-four samples (20.7%) were positive, and Jipijapa, Manabí Province, was the site with the largest proportion of positive samples (66.7%). Further surveys aimed at estimating the prevalence of the infection should be carried out in areas where the infection seems highly prevalent, and ad hoc control measures should be adopted.

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

To provide information regarding the prevalence of strongyloidiasis among migrants coming from Strongyloides stercoralis-endemic areas who reside in Spain. 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'. Twenty-four studies were included in the review and meta-analysis, comprising 12386 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. 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.

Comparison of ELISA and PCR of the 18S rRNA gene for detection of human strongyloidiasis using serum sample

Background: Strongyloides stercoralis infection is a neglected tropical disease with global distribution which is fatal in immunosuppressed patients. This study aimed to determine the prevalence of strongyloidiasis in immunocompromised individuals and cases with infectious diseases, as well as comparing ELISA and conventional PCR with coprological examination, in the central parts of Mazandaran province, northern Iran.Methods: A single serum and a fresh stool samples were obtained from 272 and 220 patients, respectively. Serum was tested by ELISA and PCR of the 18S rRNA gene, and stool samples were examined with various parasitological methods. The optimum point for ELISA reaction and cut-off points were recognized by receiver operating characteristic curves (ROC).Results: Out of 220 stool specimens, 14(6.3%) cases were positive for S. stercoralis larvae. The overall seroprevalence rate was 27.9% (76/272). The seroprevalence rate was 25.2% and 30.1% in immunocompromised group and patients with infection, respectively. Based on the ROC curve of ELISA compared with microscopy, the optimum cut-off point was 12.74 with 79% sensitivity and 76% specificity. The optimum cut-off point was 10.42 with 69% sensitivity and specificity using ROC curve of ELISA compared with PCR.Conclusions: This study seroprevalence rate for Strongyloides infection in the studied group. It also observed that the ELISA technique and the PCR used here have 100 demonstrated a high % sensitivity and acceptable specificity compared with coprological examination. It seems that the ELISA technique is a good screening assay in ruling out strongyloidiasis in such patients.

Characterization of patients with aggressive adult T-cell leukemia-lymphoma in Okinawa, Japan: a retrospective analysis of a large cohort.

Okinawa Prefecture, located in the subtropics, is an area of endemic adult T-cell leukemia-lymphoma (ATL) in Japan. We retrospectively analyzed 659 patients with aggressive ATL in seven institutions in Okinawa between 2002 and 2011. The median patient age was 68years. More patients were aged ≥90years (2.6%), in this study, than in a nationwide survey (<1%). The median survival time (MST) of the entire cohort was 6.5months. Of the 217 patients who had a clinical status similar to that stated in the eligibility criteria of JCOG9801 (a randomized phase III study comparing VCAP-AMP-VECP with CHOP-14), 147 who received the CHOP regimen had a poorer MST than those in the CHOP-14 arm of JCOG9801 (8 vs 11months). The prevalence of strongyloidiasis in the ATL patients was much higher (12.4%) than in the historical cohort who visited the University of the Ryukyus Hospital (3.4%). Furthermore, strongyloidiasis may be associated with ATL-related deaths. These findings suggest that, compared with other areas in Japan, in Okinawa, the proportion of patients aged ≥90years with clinical features of aggressive ATL is higher, outcomes are poorer, and the disease is associated with a higher prevalence of strongyloidiasis.

Mass Administration of Ivermectin for the Elimination of Onchocerciasis Significantly Reduced and Maintained Low the Prevalence of Strongyloides stercoralis in Esmeraldas, Ecuador

ObjectivesTo evaluate the effect of ivermectin mass drug administration on strongyloidiasis and other soil transmitted helminthiases.MethodsWe conducted a retrospective analysis of data collected in Esmeraldas (Ecuador) during surveys conducted in areas where ivermectin was annually administered to the entire population for the control of onchocerciasis.Data from 5 surveys, conducted between 1990 (before the start of the distribution of ivermectin) and 2013 (six years after the interruption of the intervention) were analyzed. The surveys also comprised areas where ivermectin was not distributed because onchocerciasis was not endemic.Different laboratory techniques were used in the different surveys (direct fecal smear, formol-ether concentration, IFAT and IVD ELISA for Strongyloides stercoralis).ResultsIn the areas where ivermectin was distributed the strongyloidiasis prevalence fell from 6.8% in 1990 to zero in 1996 and 1999. In 2013 prevalence in children was zero with stool examination and 1.3% with serology, in adult 0.7% and 2.7%.In areas not covered by ivermectin distribution the prevalence was 23.5% and 16.1% in 1996 and 1999, respectively. In 2013 the prevalence was 0.6% with fecal exam and 9.3% with serology in children and 2.3% and 17.9% in adults.Regarding other soil transmitted helminthiases: in areas where ivermectin was distributed the prevalence of T. trichiura was significantly reduced, while A. lumbricoides and hookworms were seemingly unaffected.ConclusionsPeriodic mass distribution of ivermectin had a significant impact on the prevalence of strongyloidiasis, less on trichuriasis and apparently no effect on ascariasis and hookworm infections.

Prevalence of strongyloidiasis in Latin America: a systematic review of the literature.

Strongyloides stercoralis is rarely recognized as a major public health issue, probably because its burden is largely underestimated. We reviewed the literature (both PubMed and 'grey' literature) about the prevalence of strongyloidiasis in Latin America, an area of presumable high endemicity. There were finally 88 papers involved in the analysis, covering the period between 1981 and 2011. Studies were heterogeneous in several aspects, such as the populations screened and the diagnostic methods used. Most of the studies relied on direct coproparasitological examination, which has low sensitivity for the detection of S. stercoralis larvae. The following countries presented areas of high prevalence (>20%): Argentina, Ecuador, Venezuela, Peru and Brazil. Globally, for most of the included countries it was not possible to define reliable data because of paucity and/or inadequacy of studies. S. stercoralis requires specific diagnostic methods for its detection; therefore, surveys should be specifically designed in order to avoid underestimation of the infection.

Strongyloides stercoralis: a field-based survey of mothers and their preschool children using ELISA, Baermann and Koga plate methods reveals low endemicity in western Uganda

To ascertain the current status of strongyloidiasis in mothers and their preschool children, a field-based survey was conducted in western Uganda using a combination of diagnostic methods: ELISA, Baermann concentration and Koga agar plate. The prevalence of other soil-transmitted helminthiasis and intestinal schistosomiasis were also determined. In total, 158 mothers and 143 children were examined from five villages within Kabale, Hoima and Masindi districts. In mothers and children, the general prevalence of strongyloidiasis inferred by ELISA was approximately 4% and approximately 2%, respectively. Using the Baermann concentration method, two parasitologically proven cases were encountered in an unrelated mother and child, both of whom were sero-negative for strongyloidiasis. No infections were detected by Koga agar plate method. The general level of awareness of strongyloidiasis was very poor ( < 5%) in comparison to schistosomiasis (51%) and ascariasis (36%). Strongyloidiasis is presently at insufficient levels to justify inclusion within a community treatment programme targeting maternal and child health. Better epidemiological screening is needed, however, especially identifying infections in HIV-positive women of childbearing age. In the rural clinic setting, further use of the Baermann concentration method would appear to be the most immediate and pragmatic option for disease diagnosis.