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1.
Acta Trop ; 224: 106137, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34562419

RESUMO

The parasitological examination of feces is recommended for the laboratory diagnosis of intestinal parasites due to its practicality, low-cost, and moderate diagnostic sensitivity. Dissolved Air Flotation (DAF) is an efficient technical principle used in other areas to separate dispersed solids. This study sought the preliminary evaluation of a proof-of-concept prototype as a tool for detecting species of parasites by adjusting DAF. Two DAF prototype units were developed to evaluate microbubbles' generation amidst fecal suspension and parasites' capture. For this evaluation, samples were screened and processed by the TF-Test technique (Control) and simultaneously by DAF device. The dimensional and attachment characteristics in the formation of the microbubbles were evaluated, and the percentage of parasitic recovery in floated and not-floated regions compared by Student's t-test. The second prototype unit proved to be more efficient in forming microbubbles with diameters between 34 and 170µm. The flotation tests showed a recovery of 73.27%, 58.12%, 37.85%, and 91.89% for Ascaris lumbricoides, Hymenolepis diminuta, Giardia duodenalis, and Strongyloides stercoralis, respectively. This study confirmed the selective interaction between microbubbles and parasite eggs and larvae during the flotation process using the DAF principle for the first time through imaging.


Assuntos
Enteropatias Parasitárias , Parasitos , Strongyloides stercoralis , Animais , Ascaris lumbricoides , Fezes , Humanos , Enteropatias Parasitárias/diagnóstico
2.
BMC Infect Dis ; 21(1): 755, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348671

RESUMO

BACKGROUND: Strongyloidiasis 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. METHODS: The 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. RESULTS: We 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. CONCLUSION: Prevalence of S. stercoralis in Peru was high but varied by geographic area, techniques for stool examination, and participant characteristics.


Assuntos
Strongyloides stercoralis , Estrongiloidíase , Animais , Fezes , Humanos , Peru/epidemiologia , Prevalência , Estrongiloidíase/diagnóstico , Estrongiloidíase/epidemiologia
3.
Acta Trop ; 223: 106079, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34363777

RESUMO

Parasitic infections caused by Opisthorchis viverrini and Strongyloides stercoralis remain a major public health threat in the Greater Mekong Sub-region. An understanding of climate and other environmental influences on the geographical distribution and emergence of parasitic diseases is a crucial step to guide targeted control and prevention programs. A parasitological survey was conducted from 2008 to 2013 and included 12,554 individuals (age between 20 and 60 years) from 142 villages in five districts in Khon Kaen Province, Thailand. Geographical information systems, remote sensing technologies and a Bayesian geostatistical framework were used to develop models for O. viverrini and S. stercoralis mono- and co-infections in areas where both parasites are known to co-occur. The results indicate that male sex, increased age, altitude, precipitation, and land surface temperature have influenced the infection rate and geographical distribution of mono- and co-infections of O. viverrini and S. stercoralis in this area. Males were 6.69 times (95% CrI: 5.26-8.58) more likely to have O. viverrini - S. stercoralis co-infection. We observed that O. viverrini and S. stercoralis mono-infections display distinct spatial pattern, while co-infection is predicted in the center and southeast of the study area. The observed spatial clustering of O. viverrini and S. stercoralis provides valuable information for the spatial targeting of prevention interventions in this area.


Assuntos
Coinfecção , Opistorquíase , Estrongiloidíase , Adulto , Animais , Teorema de Bayes , Coinfecção/epidemiologia , Coinfecção/parasitologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Opistorquíase/complicações , Opistorquíase/epidemiologia , Opisthorchis , Prevalência , Strongyloides stercoralis , Estrongiloidíase/complicações , Estrongiloidíase/epidemiologia , Tailândia/epidemiologia , Adulto Jovem
4.
J Helminthol ; 95: e34, 2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34250883

RESUMO

Strongyloidiasis and leptospirosis are neglected tropical diseases that have affected many countries across the world. In this study, we evaluated the seroprevalence of Strongyloides stercoralis among patients with leptospirosis in northern Iran. We evaluated 156 laboratory- or clinically confirmed leptospirosis cases. The overall seroprevalence of S. stercoralis was 32.0% (95% confidence interval (CI): 27.4-36.5%, 50/156). Seropositivity was significantly associated with agricultural activities (odds ratio (OR): 2.84, 95% CI: 1.0-8.77) and gastrointestinal disorders (OR: 2.4, 95% CI: 1.1-4.9). Laboratory findings indicated that seropositivity of S. stercoralis was significantly associated with decreased levels of platelet and elevated levels of creatinine, alanine aminotransferase and aspartate aminotransferase (P < 0.05). Our findings suggested a higher exposure to S. stercoralis larvae among patients with leptospirosis. The public health and medical communities may benefit from this research through preventive measures to improve farmers' knowledge and awareness regarding strongyloidiasis and leptospirosis and the associated risk factors.


Assuntos
Leptospirose , Strongyloides stercoralis , Animais , Estudos Transversais , Fezes , Humanos , Irã (Geográfico)/epidemiologia , Leptospirose/epidemiologia , População Rural , Estudos Soroepidemiológicos , Estrongiloidíase/epidemiologia
5.
Am J Trop Med Hyg ; 105(3): 688-691, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34237022

RESUMO

Strongyloides stercoralis affects more than half a billion people worldwide, and hyperinfection in immunocompromised patients can be fatal. Elimination of this neglected tropical disease requires field-applicable diagnostic tools. We conducted a laboratory evaluation of a lateral flow rapid dipstick test (SsRapid™) using sera samples from a Strongyloides-endemic area in northeast Thailand. Group 1 was S. stercoralis-positive and larvae- and/or antibody-positive (according to the IgG ELISA) (N = 100). Group 2 had negative fecal examination and IgG ELISA results (N = 25). Group 3 had other parasitic infections and negative IgG ELISA results (N = 25). The results showed good diagnostic sensitivity (82%) and excellent specificity (96%). Suggested improvements in the SsRapid™ test include increased diagnostic sensitivity and conversion to the more robust cassette format. Field studies should be performed as well.


Assuntos
Anticorpos Anti-Helmínticos/imunologia , Imunoglobulina G/imunologia , Strongyloides stercoralis/imunologia , Estrongiloidíase/diagnóstico , Animais , Anticorpos Anti-Helmínticos/sangue , Fezes/parasitologia , Proteínas de Helminto , Humanos , Proteínas Recombinantes , Sensibilidade e Especificidade , Testes Sorológicos , Estrongiloidíase/sangue , Tailândia
6.
PLoS Negl Trop Dis ; 15(7): e0009559, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34314415

RESUMO

Viral and parasitic coinfections are known to lead to both enhanced disease progression and altered disease states. HTLV-1 and Strongyloides stercoralis are co-endemic throughout much of their worldwide ranges resulting in a significant incidence of coinfection. Independently, HTLV-1 induces a Th1 response and S. stercoralis infection induces a Th2 response. However, coinfection with the two pathogens has been associated with the development of S. stercoralis hyperinfection and an alteration of the Th1/Th2 balance. In this study, a model of HTLV-1 and S. stercoralis coinfection in CD34+ umbilical cord blood hematopoietic stem cell engrafted humanized mice was established. An increased level of mortality was observed in the HTLV-1 and coinfected animals when compared to the S. stercoralis infected group. The mortality was not correlated with proviral loads or total viral RNA. Analysis of cytokine profiles showed a distinct shift towards Th1 responses in HTLV-1 infected animals, a shift towards Th2 cytokines in S. stercoralis infected animals and elevated TNF-α responses in coinfected animals. HTLV-1 infected and coinfection groups showed a significant, yet non-clonal expansion of the CD4+CD25+ T-cell population. Numbers of worms in the coinfection group did not differ from those of the S. stercoralis infected group and no autoinfective larvae were found. However, infective larvae recovered from the coinfection group showed an enhancement in growth, as was seen in mice with S. stercoralis hyperinfection caused by treatment with steroids. Humanized mice coinfected with S. stercoralis and HTLV-1 demonstrate features associated with human infection with these pathogens and provide a unique opportunity to study the interaction between these two infections in vivo in the context of human immune cells.


Assuntos
Antígenos CD34/sangue , Citocinas/metabolismo , Infecções por HTLV-I/imunologia , Células-Tronco Hematopoéticas/metabolismo , Strongyloides stercoralis/crescimento & desenvolvimento , Estrongiloidíase/imunologia , Animais , Linhagem Celular , Coinfecção , Citocinas/genética , Sangue Fetal , Infecções por HTLV-I/complicações , Vírus Linfotrópico T Tipo 1 Humano , Larva/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Estrongiloidíase/complicações
7.
BMJ Case Rep ; 14(6)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34078621

RESUMO

A 45-year-old man presents with 48-hour status of high temperature, cough and dyspnoea. In the context of pandemic, the patient is initially diagnosed with COVID-19 syndrome. Later, the laboratory and ultrasound study supported acute appendicitis diagnosis. Appendicectomy was performed. The histopathology study confirmed eosinophilic appendicitis and that a parasitic infection was suspected. The stool sample was positive for Strongyloides stercoralis The diagnosis of a S stercoralis is a rare finding in Spain. S. stercoralis simulates clinical findings of inflammatory bowel disease or eosinophilic gastroenteritis, which may lead to the wrong therapeutic choice. Since in inflammatory diseases corticosteroid treatments are considered the initial choice in many cases, in the case of S. stercoralis infection, the administration of this therapy can be fatal. In Spain, the number of diagnoses is much lower than in the past decade, although it is highly probable that the infection has been underdiagnosed due to low clinical awareness among Spanish population.


Assuntos
Apendicite , COVID-19 , Strongyloides stercoralis , Estrongiloidíase , Animais , Apendicite/complicações , Apendicite/diagnóstico , Apendicite/cirurgia , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Espanha , Estrongiloidíase/complicações , Estrongiloidíase/diagnóstico , Estrongiloidíase/tratamento farmacológico
8.
Transplant Rev (Orlando) ; 35(4): 100632, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34130253

RESUMO

International migration from Sub-Saharan African countries to the European Union and the United States has significantly increased over the past decades. Although the vast majority of these immigrants are young and healthy people, a minority can be affected by chronic conditions eventually leading to solid organ transplantation (SOT). Importantly, these candidates can bear geographically restricted fungal and parasitic latent infections that can reactivate after the procedure. An appropriate evaluation before transplantation followed by treatment, whenever necessary, is essential to minimize such risk, as covered in the present review. In short, infection due to helminths (Schistosoma spp. and Strongyloides stercoralis) and intestinal protozoa (Entamoeba histolytica, Giardia lamblia or Cyclospora cayetanensis) can be diagnosed by multiple direct stool examination, serological assays and stool antigen testing. Leishmaniasis can be assessed by means of serology, followed by nucleic acid amplification testing (NAAT) if the former test is positive. Submicroscopic malaria should be ruled out by NAAT. Screening for Histoplasma spp. or Cryptococcus spp. is not routinely indicated. Consultation with an Infectious Diseases specialist is recommended in order to adjust preemptive treatment among Sub-Saharan African SOT candidates and recipients.


Assuntos
Enteropatias Parasitárias , Infecção Latente , Transplante de Órgãos , Strongyloides stercoralis , África ao Sul do Saara/epidemiologia , Animais , Humanos , Transplante de Órgãos/efeitos adversos , Transplantados
9.
PLoS One ; 16(6): e0253701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34181669

RESUMO

Hyperinfection and disseminated infection by the parasitic nematode Strongyloides stercoralis can be induced by iatrogenic administration of steroids and immunosuppression and lead to an elevated risk of mortality. Responses of free-living stages of S. stercoralis to the therapeutic corticosteroid dexamethasone (DXM) were investigated using RNA-seq transcriptomes of DXM-treated female and male worms. A total of 17,950 genes representing the transcriptome of these free-living adult stages were obtained, among which 199 and 263 were differentially expressed between DXM-treated females and DXM-treated males, respectively, compared with controls. According to Gene Ontology analysis, differentially expressed genes from DXM-treated females participate in developmental process, multicellular organismal process, cell differentiation, carbohydrate metabolic process and embryonic morphogenesis. Others are involved in signaling and signal transduction, including cAMP, cGMP-dependent protein kinase pathway, endocrine system, and thyroid hormone pathway, as based on Kyoto Encyclopedia of Genes and Genomes analysis. The novel findings warrant deeper investigation of the influence of DXM on growth and other pathways in this neglected tropical disease pathogen, particularly in a setting of autoimmune and/or allergic disease, which may require the clinical use of steroid-like hormones during latent or covert strongyloidiasis.


Assuntos
Dexametasona/farmacologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Strongyloides stercoralis/metabolismo , Transcriptoma/efeitos dos fármacos , Animais , Feminino , Masculino
10.
Acta Trop ; 221: 105986, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34058161

RESUMO

Serodiagnosis is an essential component of the laboratory diagnosis of Strongyloides infection and is usually performed using an indirect IgG antibody test. A direct antigen detection method can complement the IgG assay, particularly for detecting early infection and post-treatment follow-up. In the present study, a recombinant scFv monoclonal antibody against NIE recombinant protein (rMAb23) that we had previously produced was used to develop a Strongyloides antigen detection ELISA (SsAg-ELISA). The assay is based on detecting immune complexes of circulating NIE antigens bound to Strongyloides-specific IgG antibodies. The optimized ELISA parameters were 10 µg/mL of rMAb23 coated on microtitre plate wells, 2% skim milk as blocking reagent, 1:100 serum dilution, and 1:1000 goat anti-human IgG F(ab')2 conjugated to horseradish peroxidase. Four groups of serum samples were used, i.e., Strongyloides-positive serum samples categorized into Groups IA and IB; the former were from probable chronic infections and the latter from probable early/acute infections. Strongyloides-negative samples comprising Groups II (healthy samples) and III (other infections); the latter were from eleven different types of other parasitic infections. The receiver operating characteristic (ROC) curve showed an area under the curve (AUC) of 1.00, cut-off optical density (OD405) of 0.5002, and 100% diagnostic sensitivity and specificity. The results of the commercial IgG-ELISA and SsAg-ELISA from Group IA were found to be moderately correlated (r = 0.416; p < 0.05). Notably, ANOVA showed that the average ODs405 of Group 1B were significantly higher (p < 0.05) than Group 1A, indicating that the assay may be useful to differentiate early and chronic infection. In conclusion, the developed SsAg-ELISA showed good diagnostic potential, and it merits further evaluation.


Assuntos
Strongyloides stercoralis , Estrongiloidíase , Animais , Anticorpos Anti-Helmínticos , Antígenos de Helmintos , Ensaio de Imunoadsorção Enzimática , Humanos , Sensibilidade e Especificidade , Testes Sorológicos , Strongyloides , Strongyloides stercoralis/imunologia , Estrongiloidíase/diagnóstico
11.
Infect Dis Poverty ; 10(1): 76, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34030741

RESUMO

BACKGROUND: Implementation 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). METHODS: The 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. RESULTS: In 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. CONCLUSIONS: This 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.


Assuntos
Strongyloides stercoralis , Estrongiloidíase , Adulto , Animais , Quimioprevenção , Criança , Humanos , Ivermectina/uso terapêutico , Prevalência , Estrongiloidíase/tratamento farmacológico , Estrongiloidíase/epidemiologia , Estrongiloidíase/prevenção & controle
12.
Lancet Infect Dis ; 21(8): 1151-1160, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33798487

RESUMO

BACKGROUND: Strongyloidiasis represents a major public health issue, particularly in resource-limited countries. Preliminary studies suggest that moxidectin might serve as an alternative to the only available treatment option, ivermectin. We aimed to evaluate the efficacy and safety of ascending doses of moxidectin in Strongyloides stercoralis-infected patients. METHODS: We did a randomised, parallel-group, single-blinded, placebo-controlled, dose-ranging, phase 2a trial in four villages in northern Laos. Eligible adults (aged 18-65 years) with S stercoralis infection intensities of at least 0·4 larvae per g of stool in at least two stool samples were randomly assigned (1:1:1:1:1:1:1) by use of computerised, stratified, block randomisation into seven treatment groups: 2 mg of moxidectin, 4 mg of moxidectin, 6 mg of moxidectin, 8 mg of moxidectin, 10 mg of moxidectin, 12 mg of moxidectin, or placebo. Participants and primary outcome assessors were masked to treatment allocation, but study site investigators were not. Participants received a single oral dose of their allocated dose of moxidectin in 2 mg tablets, or four placebo tablets. Three stool samples were collected at baseline and two stool samples were collected 28 days after treatment from each participant. A Baermann assay was used to quantify S stercoralis infection and Kato-Katz thick smears were used to qualitatively identify coinfections with additional helminths species. The primary endpoint was cure rate against S stercoralis and was analysed in an available case analysis set, defined as all randomly assigned participants with primary endpoint data. Predicted cure rates and associated CIs were estimated with hyperbolic Emax models. Safety was evaluated in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04056325, and is complete. FINDINGS: Between Nov 27, 2019, and March 15, 2020, 785 adults were screened for trial eligibility. Of these, 223 participants were randomly assigned to treatment groups and 209 completed the study and were analysed for the primary outcome. 2 mg of moxidectin had a predicted cure rate of 75% (95% CI 59-87; 22 [73%] of 30 cured) against S stercoralis compared with a predicted cure rate of 14% (5-31; four [14%] of 29 cured) for placebo. With escalating doses, the probability of cure increased from 83% (95% CI 76-88; 26 [90%] of 29 cured) at 4 mg to 86% (79-90; 27 [84%] of 32 cured) at 6 mg, and to 87% (80-92; 24 [83%] of 29 cured) at 8 mg, levelling off at 88% (80-93; 29 [97%] of 30 cured) at 10 mg and 88% (80-93; 26 [87%] of 30 cured) at 12 mg. Moxidectin was well tolerated across all treatment groups, with no serious adverse events being recorded and all reported symptoms being classified as mild. INTERPRETATION: 4-12 mg of moxidectin showed promising tolerability and efficacy profiles in the treatment of S stercoralis infections in adults. Because 8 mg of moxidectin is used for the treatment of onchocerciasis and has been evaluated for other helminth infections, we recommend this dose for phase 2b and phase 3 trials of strongyloidiasis therapy. FUNDING: Fondazione Adiuvare.


Assuntos
Anti-Helmínticos/administração & dosagem , Macrolídeos/administração & dosagem , Strongyloides stercoralis/efeitos dos fármacos , Estrongiloidíase/tratamento farmacológico , Adulto , Animais , Anti-Helmínticos/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Fezes/parasitologia , Feminino , Humanos , Laos , Macrolídeos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Strongyloides stercoralis/isolamento & purificação , Resultado do Tratamento
14.
Transpl Infect Dis ; 23(4): e13614, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33844416

RESUMO

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.


Assuntos
Transplante de Órgãos , Strongyloides stercoralis , Estrongiloidíase , Animais , Humanos , Programas de Rastreamento , Transplante de Órgãos/efeitos adversos , Prevalência , Estrongiloidíase/diagnóstico , Estrongiloidíase/epidemiologia
16.
PLoS Negl Trop Dis ; 15(4): e0009314, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33857134

RESUMO

BACKGROUND: Strongyloides stercoralis is a soil-transmitted helminth (STH) that affects approximately 600 million people worldwide. Interventions targeting S. stercoralis have not been implemented yet. Specific treatment (ivermectin) could be included in already ongoing preventive chemotherapy (PC) campaigns targeting other STHs. The aim of this study was to estimate the quantity of ivermectin needed for an integrated STH/S. stercoralis control program. METHODODOLOGY/PRINCIPAL FINDINGS: Our study estimates the number of school- age children (SAC) (the main focus of STH deworming campaigns) in need of PC with ivermectin. The normal approximation of the binomial distribution was adopted to calculate the hypothetical prevalence distribution in each endemic country. Considering prevalence thresholds for PC equal to 10%, 15%, and 20%, we estimated the number of SAC in need of treatment. We adjusted the estimates accounting for ivermectin distributed in lymphatic filariasis and onchocerciasis elimination programs and excluded from our calculation areas where Loa loa is endemic. The global number of SAC that should be targeted in PC campaigns was estimated at 283.9 M (95% CI: 163.4-368.8), 207.2 M (95% CI: 160.9-380.7), and 160.7 M (95% CI: 86.6-225.7) when the threshold for intervention was set to 10%, 15%, and 20%, respectively. India, China, Indonesia, Bangladesh, and Nigeria accounted for about 50% of the global SAC would have to be covered by PC intervention. CONCLUSIONS/SIGNIFICANCE: Our analysis may support endemic countries to evaluate the ivermectin quantity needed for integrating strongyloidiasis in the existing STH programs. These estimates might also show to generic drug manufacturers the size of the potential market for ivermectin and encourage its production.


Assuntos
Ivermectina/uso terapêutico , Solo/parasitologia , Strongyloides stercoralis/efeitos dos fármacos , Estrongiloidíase/tratamento farmacológico , Estrongiloidíase/epidemiologia , Adolescente , África/epidemiologia , Animais , Ásia/epidemiologia , Quimioprevenção , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Programas Nacionais de Saúde , Prevalência , Instituições Acadêmicas , Estrongiloidíase/prevenção & controle , Organização Mundial da Saúde
18.
Sci Rep ; 11(1): 8254, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33859232

RESUMO

The human and canine parasitic nematode Strongyloides stercoralis utilizes an XX/XO sex determination system, with parasitic females reproducing by mitotic parthenogenesis and free-living males and females reproducing sexually. However, the genes controlling S. stercoralis sex determination and male development are unknown. We observed precocious development of rhabditiform males in permissive hosts treated with corticosteroids, suggesting that steroid hormones can regulate male development. To examine differences in transcript abundance between free-living adult males and other developmental stages, we utilized RNA-Seq. We found two clusters of S. stercoralis-specific genes encoding predicted transmembrane proteins that are only expressed in free-living males. We additionally identified homologs of several genes important for sex determination in Caenorhabditis species, including mab-3, tra-1, fem-2, and sex-1, which may have similar functions. However, we identified three paralogs of gld-1; Ss-qki-1 transcripts were highly abundant in adult males, while Ss-qki-2 and Ss-qki-3 transcripts were highly abundant in adult females. We also identified paralogs of pumilio domain-containing proteins with sex-specific transcripts. Intriguingly, her-1 appears to have been lost in several parasite lineages, and we were unable to identify homologs of tra-2 outside of Caenorhabditis species. Together, our data suggest that different mechanisms control male development in S. stercoralis and Caenorhabditis species.


Assuntos
Caenorhabditis/genética , Genes de Helmintos/genética , Genes de Helmintos/fisiologia , Proteínas de Helminto/genética , Proteínas de Helminto/fisiologia , Processos de Determinação Sexual/genética , Strongyloides stercoralis/genética , Transcrição Genética , Animais , Caenorhabditis/fisiologia , Feminino , Hormônios Esteroides Gonadais/fisiologia , Masculino , Modelos Genéticos , Strongyloides stercoralis/fisiologia
19.
Acta Parasitol ; 66(3): 1089-1092, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33740235

RESUMO

INTRODUCTION: Human strongyloidiasis is a generally neglected parasitic disease of major global distribution, spreading commonly in tropical and subtropical areas. As for China, strongyloidiasis occur mainly in South of China and no relevant information about the parasite infection in North China was available. CASE PRESENTATION: An 84-year-old man from Shanxi province, North China, was admitted to Department of Nephrology with complaints of a 7-month history of intermittent edema of both lower extremity with foam urine and 3-day history of fever, chill and diarrhea. Large numbers of rhabditiform larva of Strongyloides stercoralis (S. stercoralis) were observed in a stool sample. Diagnosis of S. stercoralis infection was established by morphological observations of larvae under the microscope in both wet mount and Wright-Giemsa staining smear and further confirmed by molecular biology identification. CONCLUSIONS: We report a rare case of S. stercoralis infection in a patient with chronic renal failure from North China, which implies the possibility of developing human strongyloidiasis in cooler climates. In addition, our case suggests that clinicians should consider the complication of S. stercoralis infection in immunosuppressed patient populations with chronic renal failure. Morphological details of S. stercoralis in Wright-Giemsa staining was first described in the present case. Our results also support the use of molecular techniques targeting COX1 gene sequence for the diagnosis of S. stercoralis infection, which was prove to be necessary in laboratory practice, especially for those inexperienced morphologists in temperature zone.


Assuntos
Falência Renal Crônica , Strongyloides stercoralis , Estrongiloidíase , Idoso de 80 Anos ou mais , Animais , Fezes , Humanos , Hospedeiro Imunocomprometido , Falência Renal Crônica/complicações , Masculino , Estrongiloidíase/complicações , Estrongiloidíase/diagnóstico
20.
PLoS Negl Trop Dis ; 15(3): e0009160, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33690623

RESUMO

BACKGROUND: There are no national prevalence studies of Strongyloides stercoralis infection in Australia, although it is known to be endemic in northern Australia and is reported in high risk groups such as immigrants and returned travellers. We aimed to determine the seropositivity (number positive per 100,000 of population and percent positive of those tested) and geographical distribution of S. stercoralis by using data from pathology laboratories. METHODOLOGY: We contacted all seven Australian laboratories that undertake Strongyloides serological (ELISA antibody) testing to request de-identified data from 2012-2016 inclusive. Six responded. One provided positive data only. The number of people positive, number negative and number tested per 100,000 of population (Australian Bureau of Statistics data) were calculated including for each state/territory, each Australian Bureau of Statistics Statistical Area Level 3 (region), and each suburb/town/community/locality. The data was summarized and expressed as maps of Australia and Greater Capital Cities. PRINCIPAL FINDINGS: We obtained data for 81,777 people who underwent serological testing for Strongyloides infection, 631 of whom were from a laboratory that provided positive data only. Overall, 32 (95% CI: 31, 33) people per 100,000 of population were seropositive, ranging between 23/100,000 (95% CI: 19, 29) (Tasmania) and 489/100,000 population (95%CI: 462, 517) (Northern Territory). Positive cases were detected across all states and territories, with the highest (260-996/100,000 and 17-40% of those tested) in regions across northern Australia, north-east New South Wales and north-west South Australia. Some regions in Greater Capital Cities also had a high seropositivity (112-188/100,000 and 17-20% of those tested). Relatively more males than females tested positive. Relatively more adults than children tested positive. Children were under-represented in the data. CONCLUSIONS/SIGNIFICANCE: The study confirms that substantial numbers of S. stercoralis infections occur in Australia and provides data to inform public health planning.


Assuntos
Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/epidemiologia , Adolescente , Adulto , Idoso , Animais , Anticorpos Anti-Helmínticos , Austrália/epidemiologia , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos
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