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Humans can be infected with anthroponotic (Ancylostoma duodenale and Necator americanus) and with zoonotic (Ancylostoma ceylanicum, A. caninum, A. braziliense, and Uncinaria stenocephala) hookworms from dogs. Anthroponotic species are usually thought not to infect dogs. We used the internal transcribed spacer–1 (ITS1) gene in a quantitative PCR to detect anthroponotic and zoonotic hookworm species in fecal samples from 54 children and 79 dogs living in an indigenous community in tropical Northwestern Ecuador. Hookworm DNA was detected in 59.3% of children and 92.4% of dogs. Among samples from children, zoonotic hookworms were detected in 24.1% (A. ceylanicum 14.8%, A. caninum 11.1%, and A. braziliense 1.9%), whilst in dog samples, anthroponotic species were detected in 19.0% (N. americanus 12.4% and A. duodenale 6.3%). Sanger sequencing was performed successfully on 60 qPCR-positive samples (16 from children and 44 from dogs), and consensus sequences were obtained with >98% homology to GenBank references for hookworm spp. Phylogenetic analysis showed a close relationship between anthroponotic and zoonotic Ancylostoma species and no heterogeneity between A. duodenale and A. caninum; in human samples, we found A. ceylanicum but not A. braziliense sequences and we were unable to identify N. americanus in the dog samples. No infections with U. stenocephala were detected. Our data provide evidence for high rates of hookworm infections in indigenous children and dogs in a marginalized rural setting in coastal Ecuador. We also found evidence for potential cross-transmission of hookworm spp. between humans and dogs that represent a potential domestic reservoir for zoonotic and anthroponotic hookworms.

Neurocysticercosis prevalence estimates often are based on serosurveys. However, assessments of Taenia solium seropositivity durability in patients with various neurocysticercosis types are lacking. We optimized a triplex serologic ELISA by using synthetic GP50, T24H, and Ts18var3 antigens for T. solium. We used that assay to test sequential serologic responses over several years after neurocysticercosis cure in 46 patients, 9 each with parenchymal or ventricular neurocysticercosis and 28 with subarachnoid disease. Triplex results were concordant with 98% of positive and 100% of negative enzyme-linked immunoelectrotransfer blots. Eight years after neurocysticercosis cure, 11.1% of patients with parenchymal, 47.3% with subarachnoid, and 41.7% with ventricular disease were still seropositive. Median time to seroreversion after cure in this cohort in a T. solium nonendemic area was 2 years for parenchymal disease, 4 years for ventricular disease, and 8 years for subarachnoid disease. Our findings can inform epidemiologic models that rely on serosurveys to estimate disease burden.

BackgroundMultisystem inflammatory syndrome (MIS) in children is considered to be a post-infectious complication of COVID-19. T-cell responses in children with this condition have not been well-studied.MethodsWe aimed to study the immune responses in children with MIS in comparison to children with acute COVID-19 and children with other infections. Whole blood was stimulated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)–specific antigens and flow cytometry was performed to examine CD4+ and CD8+ T-cell responses.ResultsChildren with MIS had higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen–specific stimulation in comparison to children with COVID-19 and/or other infections. Children with COVID-19 also exhibited higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen–specific stimulation in comparison to children with other infections. At 6–9 months following treatment and recovery, this enhanced response against SARS-CoV-2 antigens was down modulated in children with MIS.ConclusionOur study, therefore, provides evidence of enhanced activation of CD4+ and CD8+ T-cell responses in children with MIS and reversal following recovery.

Background: The immunologic mechanisms underlying pulmonary type 2 inflammation, including the dynamics of eosinophil recruitment to the lungs, still need to be elucidated. Objective: We sought to investigate how IL-13–producing TH2 effector cells trigger eosinophil migration in house dust mite (HDM)-driven allergic pulmonary inflammation. Methods: Multiparameter and molecular profiling of murine lungs with HDM-induced allergy was investigated in the absence of IL-13 signaling by using IL-13Rα1–deficient mice and separately through adoptive transfer of CD4+ T cells from IL-5–deficient mice into TCRα–/– mice before allergic inflammation. Results: We demonstrated through single-cell techniques that HDM-driven pulmonary inflammation displays a profile characterized by TH2 effector cell–induced IL-13–dominated eosinophilic inflammation. Using HDM-sensitized IL-13Rα1–/– mice, we found a marked reduction in the influx of eosinophils into the lungs along with a significant downregulation of both CCL-11 and CCL-24. We further found that eosinophil trafficking to the lung relies on production of IL-13–driven CCL-11 and CCL-24 by fibroblasts and Ly6C+ (so-called classical) monocytes. Moreover, this IL-13–mediated eotaxin-dependent eosinophil influx to the lung tissue required IL-5–induced eosinophilia. Finally, we demonstrated that this IL-13–driven eosinophil-dominated pulmonary inflammation was critical for limiting bystander lung transiting Ascaris parasites in a model of allergy and helminth interaction. Conclusion: Our data suggest that IL-5–dependent allergen-specific TH2 effector cell response and subsequent signaling through the IL-13/IL-13Rα1 axis in fibroblasts and myeloid cells regulate the eotaxin-dependent recruitment of eosinophils to the lungs, with multiple downstream consequences, including bystander control of lung transiting parasitic helminths.

Parasitic nematodes responsible for filarial diseases cause chronic disablement in humans worldwide. Elimination programs have substantially reduced the rate of infection in certain areas, but limitations of current diagnostics for population surveillance have been pointed out and improved assays are needed to reach the elimination targets. While serological tests detecting antibodies to parasite antigens are convenient tools, those currently available are compromised by the occurrence of antibodies cross-reactive between nematodes, as well as by the presence of residual antibodies in sera years after treatment and clearance of the infection. We recently characterized the N-linked and glycosphingolipid derived glycans of the parasitic nematode Brugia malayi and revealed the presence of various antigenic structures that triggered immunoglobulin G (IgG) responses in infected individuals. To address the specificity of IgG binding to these glycan antigens, we screened microarrays containing Brugia malayi glycans with plasma from uninfected individuals and from individuals infected with Loa loa, Onchocerca volvulus, Mansonella perstans and Wuchereria bancrofti, four closely related filarial nematodes. IgG to a restricted subset of cross-reactive glycans was observed in infection plasmas from all four species. In plasma from Onchocerca volvulus and Mansonella perstans infected individuals, IgG binding to many more glycans was additionally detected, resulting in total IgG responses similar to the ones of Brugia malayi infected individuals. For these infection groups, Brugia malayi, Onchocerca volvulus and Mansonella perstans, we further studied the different IgG subclasses to Brugia malayi glycans. In all three infections, IgG1 and IgG2 appeared to be the major subclasses involved in response to glycan antigens. Interestingly, in Brugia malayi infected individuals, we observed a marked reduction in particular in IgG2 to parasite glycans post-treatment with anthelminthic, suggesting a promising potential for diagnostic applications. Thus, we compared the IgG response to a broad repertoire of Brugia malayi glycans in individuals infected with various filarial nematodes. We identified broadly cross-reactive and more specific glycan targets, extending the currently scarce knowledge of filarial nematode glycosylation and host anti-glycan antibody response. We believe that our initial findings could be further exploited to develop disease-specific diagnostics as part of an integrated approach for filarial disease control.

Ancylostoma ceylanicum hookworms are zoonotic parasites that can infect humans. To detect autochthonous transmission, we analyzed human fecal samples collected in 2000. Multiparallel quantitative PCR detected infection in persons who had never traveled outside Ecuador. These data indicate human transmission of A. ceylanicum in the Americas, although endemicity remains unknown.

IntroductionMultisystem Inflammatory Syndrome in children (MIS-C) is a serious inflammatory sequela of SARS-CoV2 infection. The pathogenesis of MIS-C is vague and matrix metalloproteinases (MMPs) may have an important role. Matrix metalloproteinases (MMPs) are known drivers of lung pathology in many diseases.MethodsTo elucidate the role of MMPs in pathogenesis of pediatric COVID-19, we examined their plasma levels in MIS-C and acute COVID-19 children and compared them to convalescent COVID-19 and children with other common tropical diseases (with overlapping clinical manifestations).ResultsChildren with MIS-C had elevated levels of MMPs (P < 0.005 statistically significant) in comparison to acute COVID-19, other tropical diseases (Dengue fever, typhoid fever, and scrub typhus fever) and convalescent COVID-19 children. PCA and ROC analysis (sensitivity 84–100% and specificity 80–100%) showed that MMP-8, 12, 13 could help distinguish MIS-C from acute COVID-19 and other tropical diseases with high sensitivity and specificity. Among MIS-C children, elevated levels of MMPs were seen in children requiring intensive care unit admission as compared to children not needing intensive care. Similar findings were noted when children with severe/moderate COVID-19 were compared to children with mild COVID-19. Finally, MMP levels exhibited significant correlation with laboratory parameters, including lymphocyte counts, CRP, D-dimer, Ferritin and Sodium levels.DiscussionOur findings suggest that MMPs play a pivotal role in the pathogenesis of MIS-C and COVID-19 in children and may help distinguish MIS-C from other conditions with overlapping clinical presentation.

The clinical presentation of MIS-C overlaps with other infectious/non-infectious diseases such as acute COVID-19, Kawasaki disease, acute dengue, enteric fever, and systemic lupus erythematosus. We examined the ex-vivo cellular parameters with the aim of distinguishing MIS-C from other syndromes with overlapping clinical presentations. MIS-C children differed from children with non-MIS-C conditions by having increased numbers of naïve CD8+ T cells, naïve, immature and atypical memory B cells and diminished numbers of transitional memory, stem cell memory, central and effector memory CD4+ and CD8+ T cells, classical, activated memory B and plasma cells and monocyte (intermediate and non-classical) and dendritic cell (plasmacytoid and myeloid) subsets. All of the above alterations were significantly reversed at 6–9 months post-recovery in MIS-C. Thus, MIS-C is characterized by a distinct cellular signature that distinguishes it from other syndromes with overlapping clinical presentations. Trial Registration: ClinicalTrials.gov clinicaltrial.gov. No: NCT04844242. Author summary Multisystem inflammatory syndrome in children (MIS-C) is a severe disease that happens several weeks after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We performed an in-depth analysis of immune cell subsets and demonstrated that children with MIS-C had a distinctive cellular signature that differentiates it from other overlapping clinical presentations. T, B and myeloid cellular compartments were altered in MIS-C children. Post-recovery (6–9 months post-treatment), most of these alterations were significantly reversed and returned to normal levels. Thus, MIS-C varies from acute COVID-19, other infectious, non-infectious diseases and healthy pediatric controls by exhibiting a unique cellular signature.

Abstract Objective Nodding syndrome is a poorly understood epileptic encephalopathy characterized by a unique seizure type—head nodding—and associated with Onchocerca volvulus infection. We hypothesized that altered immune activation in the cerebrospinal fluid (CSF) and plasma of children with nodding syndrome may yield insights into the pathophysiology and progression of this seizure disorder. Method We conducted a case‐control study of 154 children (8 years or older) with long‐standing nodding syndrome and 154 healthy age‐matched community controls in 3 districts of northern Uganda affected by nodding syndrome. Control CSF samples were obtained from Ugandan children in remission from hematological malignancy during routine follow‐up. Markers of immune activation and inflammation (cytokines and chemokines) and complement activation (C5a) were measured in plasma and CSF using ELISA or Multiplex Luminex assays. O volvulus infection was assessed by serology for anti–OV‐16 IgG levels. Results The mean (SD) age of the population was 15.1 (SD: 1.9) years, and the mean duration of nodding syndrome from diagnosis to enrollment was 8.3 (SD: 2.7) years. The majority with nodding syndrome had been exposed to O volvulus (147/154 (95.4%)) compared with community children (86/154 (55.8%)), with an OR of 17.04 (95% CI: 7.33, 45.58), P

ABSTRACT Lymphatic filariasis is a debilitating disease that afflicts over 70 million people worldwide. It is caused by the parasitic nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori. Despite substantial success, efforts to eliminate LF will likely require more time and resources than predicted. Identifying new drug and vaccine targets in adult filariae could help elimination efforts. This study’s aim was to evaluate intestinal proteins in adult Brugia malayi worms as possible therapeutic targets. Using short interfering RNA (siRNA), we successfully targeted four candidate gene transcripts: Bma-Serpin, Bma-ShTK, Bma-Reprolysin, and Bma-LAD-2. Of those, Bma-LAD-2, an immunoglobulin superfamily cell adhesion molecule (IgSF CAM), was determined to be essential for adult worm survival. We observed a 70.42% knockdown in Bma-LAD-2 transcript levels 1 day post-siRNA incubation and an 87.02% reduction in protein expression 2 days post-siRNA incubation. This inhibition of Bma-LAD-2 expression resulted in an 80% decrease in worm motility over 6 days, a 93.43% reduction in microfilaria release (Mf) by day 6 post-siRNA incubation, and a dramatic decrease in (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Transmission electron microscopy revealed the loss of microvilli and unraveling of mitochondrial cristae in the intestinal epithelium of Bma-LAD-2 siRNA-treated worms. Strikingly, Bma-LAD-2 siRNA-treated worms exhibited an almost complete loss of pseudocoelomic fluid. A luciferase immunoprecipitation system assay did not detect anti-Bma-LAD-2 IgE in the serum of 30 LF patients, indicating that LF exposure does not result in IgE sensitization to this antigen. These results indicate that Bma-LAD-2 is an essential protein for adult Brugia malayi and may be an effective therapeutic target. IMPORTANCE Brugia malayi is a parasitic nematode that can cause lymphatic filariasis, a debilitating disease prevalent in tropical and subtropical countries. Significant progress has been made toward eliminating the disease. However, complete eradication may require new therapeutics such as drugs or a vaccine that kill adult filariae. In this study, we identified an immunoglobulin superfamily cell adhesion molecule (Bma-LAD-2) as a potential drug and vaccine candidate. When we knocked down Bma-LAD-2 expression, we observed a decrease in worm motility, fecundity, and metabolism. We also visualized the loss of microvilli, destruction of the mitochondria in the intestinal epithelium, and loss of pseudocoelomic fluid contents after Bma-LAD-2 siRNA treatment. Finally, we demonstrated that serum from filaria-infected patients does not contain preexisting IgE to Bma-LAD-2, which indicates that this antigen would be safe to administer as a vaccine in populations where the disease is endemic.

We generated CD4+ T cell lines (TCLs) reactive to either SARS-CoV-2 spike (S) or membrane (M) proteins from unexposed naïve T cells from six healthy donor volunteers to understand in fine detail whether the S and M structural proteins have intrinsic differences in driving antigen-specific CD4+ T cell responses. Having shown that each of the TCLs were antigen-specific and antigen-reactive, single cell mRNA analyses demonstrated that SARS-CoV-2 S and M proteins drive strikingly distinct molecular signatures. Whereas the S-specific CD4+ T cell transcriptional signature showed a marked upregulation of CCL1, CD44, IL17RB, TNFRSF18 (GITR) and IGLC3 genes, in general their overall transcriptome signature was more similar to CD4+ T cell responses induced by other viral antigens (e.g. CMV). However, the M protein-specific CD4+ TCLs have a transcriptomic signature that indicate a marked suppression of interferon signaling, characterized by a downregulation of the genes encoding ISG15, IFITM1, IFI6, MX1, STAT1, OAS1, IFI35, IFIT3 and IRF7 (a molecular signature which is not dissimilar to that found in severe COVID-19). Our study suggests a potential link between the antigen specificity of the SARS-CoV-2-reactive CD4+ T cells and the development of specific sets of adaptive immune responses. Moreover, the balance between T cells of significantly different specificities may be the key to understand how CD4+ T cell dysregulation can determine the clinical outcomes of COVID-19.

Abstract Background As new lymphatic filariasis infections are eliminated through mass chemotherapy, previously affected individuals are left with the sequellae, especially chronic progressive lymphoedema. Currently this is managed by careful attention to limb hygiene to prevent infection. Studies over the past 15 years have suggested that the incorporation of doxycycline treatment may arrest or even reverse progression of lymphoedema. Most of this work has been observational or based on small studies, and if this intervention is effective, studies need to be conducted on a larger scale and under diverse geographical and social conditions before it can be incorporated into treatment policy. Methods/Design The double-blind, placebo-controlled study was designed to investigate the impact of six weeks treatment with doxycycline added to standard limb hygiene on early stage filarial lymphoedema in five sites in Africa and the Indian subcontinent. One site in Cameroon is selected for studying lymphoedema in podoconiosis. Each site was individually powered with the potential to undertake a meta-analysis on completion. Evaluation methods followed those used in Ghana in 2012 with additions resulting from advances in technology. The details of the core protocol and how it was varied to take account of differing situations at each of the sites are provided. The study will enrol up to 1800 patients and will complete in mid-2021. Conclusions This paper provides details of what challenges were faced during its development and discusses the issues and how they were resolved. In particular, the reasons for inclusion of new technology and the problems encountered with the supply of drugs for the studies are described in detail. By making these details available, it is hoped that the study protocol will help others interested in improving treatment for filarial lymphoedema in the design of future studies. Trial registration India: Clintrials.gov. NCT02929121 registered 10 Oct 2016: https://clinicaltrials.gov/ct2/show/NCT02929121 Mali: Clintrials.gov. NCT02927496 registered 7 Oct 2016: https://clinicaltrials.gov/ct2/show/NCT0292749 Sri Lanka: Clintrials.gov. NCT02929134 registered 10 Oct 2016: https://clinicaltrials.gov/ct2/show/NCT02929134 Ghana: ISRCTN. 14042737 registered 10 July 2017: https://doi.org/10.1186/ISRCTN14042737 Tanzania: ISRCTN. 65756724 registered 21 July 2017: https://doi.org/10.1186/ISRCTN65756724 Cameroon: ISRCTN. 1181662 registered 25 July 2017: https://doi.org/10.1186/ISRCTN11881662

Abstract Background Lymphedema is a public health problem in countries with lymphatic filariasis (LF) including Mali. We studied the epidemiology and clinical presentation of lymphedema in three previously LF-endemic health districts of Mali after at least five consecutive rounds of mass drug administration (MDA) with albendazole and ivermectin. Methods From 2016 to 2018, we used passive and active case finding methods to identify lymphedema cases in three health districts with high pre-MDA LF prevalence: Kolondieba (66%), Bougouni (44%) and Kolokani (34%). Results Three hundred and thirty nine cases of lymphedema were identified, 235 (69.32%) through active case finding. Their median age was 56 years (range 2–90) and 286 (84.36%) were women. Lymphedema was reported in 226 (78.5%) people aged 41 years and older compared to 73 (21.5%) people below the age of 41 years (Chi2 = 17.28, df = 5, p = 0.004). One hundred and seventy five cases of lymphedema were found in Kolondieba (66 per 100,000 people), 116 in Bougouni (19 per 100,000) and 48 in Kolokani (16 per 100,000). Stage III lymphedema was observed in 131 (38.64%), stage II in 108 (31.86%), stage IV in 46 (13.57%), stage I in 23 (6.78%), stage V in 21 (6.19%) and stage VI in ten (2.95%). In the three study districts, lymphedema affected the legs in 281 (82.89%), the arms in 42 (12.39%) and both in 16 (4.72%) (Chi2 = 13.63, p = 0.008). Conclusion Health districts in Mali with the highest pre-MDA LF prevalences had the highest prevalence of lymphedema. Efforts to actively identify lymphedema cases should be scaled up in previous LF-endemic areas, and should be supplemented by a morbidity management and disability prevention plan at the peripheral health system level.

Background Strongyloides stercoralis (Ss) is the etiological agent of strongyloidiasis, a neglected tropical disease of global concern. Laboratory diagnosis of strongyloidiasis is most often based on detection of antibodies against antigens in an enzyme linked immunosorbent assay (ELISA). Herein, we report a preliminary validation study of newly developed IgG4- and/or IgG- based ELISAs to detect strongyloidiasis (Strongy Detect, InBios) incorporating a cocktail of 2 previously described recombinant antigens, Ss-NIE and Ss-IR. Methods The sensitivity and specificity were determined by using the assay in 150 cryopreserved serum samples from humans known to be Ss infected (n = 74), helminth uninfected (n = 47), or infected with a helminth other than Ss [n = 29). The treatment associated dynamics of antibody detection were then assessed using 35 paired samples obtained before and after definitive therapy. Results The IgG and IgG4 assays were 99% and 96% sensitive, respectively, and 99% and 100% specific, respectively. Neither the IgG or IgG4 assay showed cross reactions with sera from those infected with other helminths. Although ELISA values did decline post-treatment few returned to levels below the cutoff for infection. Conclusion Strongy Detect is the most sensitive and specific commercialized immunoassay for detection of strongyloidiasis. The assay remains positive for greater than a year post-treatment. Author summary Strongyloides stercoralis is a worm that infects people and some animals. It can live in its host for decades because it can continually produce more larvae that develop inside the body of its host. The initial infection usually occurs by larvae burrowing through the skin of a person. The growing larvae travel to the lungs where they are coughed up and swallowed. Then, in the intestine, they mature to adults capable of producing eggs. The eggs hatch before they can be passed out of the body in the stool. The newly hatched larvae burrow through the gut wall and repeat this internal cycle. To diagnose this infection, one strategy is detecting antibodies against these worms. Herein, we discuss a prototype ELISA assay using recombinant Strongyloides stercoralis proteins. The test, called Strongy Detect, did well at detecting antibodies in patients known to have the infection and at calling samples negative when the patients were uninfected. The antibodies were detectable more than a year after patients were treated for the disease. If further validation studies confirm the utility of this assay, it will be an important addition to the armamentarium of tests to diagnose Strongyloides stercoralis infection.

ABSTRACT High-throughput 16S rRNA sequencing has allowed the characterization of helminth-uninfected (HU) and helminth-infected (HI) gut microbiomes, revealing distinct profiles. However, there have been no qualitative or quantitative syntheses of these studies, which show marked variation in participant age, diet, pathogen of interest, and study location. A predefined minimally biased search strategy identified 23 studies in humans. For each of these studies, we qualitatively addressed the effects of helminth infection on within-individual (alpha) and between-individual (beta) fecal microbiome diversity, infection-associated microbial taxa, the effect of helminth clearance on microbiome composition, microbiome composition as a predictor of infection status or treatment outcome, and treatment-specific effects on the fecal microbiome. Concomitantly, we performed a meta-analysis on a subset of 7 of these studies containing raw, paired-end 16S reads and individual-level metadata, comprising 424 pretreatment or untreated HI individuals and 497 HU controls. After reducing the batch effect and adjusting for age, our data demonstrated that intestinal helminth parasites can alter the host gut microbiome by increasing alpha diversity and promoting taxonomic reassortment and gradient collapse. Most strongly influencing the microbiome composition were the helminths found in the large intestine, Enterobius vermicularis and Trichuris trichiura, suggesting that this influence appears to be specific to soil-transmitted helminths (STH) species and host anatomical niche. In summary, using a large and diverse sample set captured in the meta-analysis, we were able to evaluate the influence of individual helminth species as well as species-species interactions, each of which explained a significant portion of the variation in the microbiome. IMPORTANCE The gut microbiome has established importance in regulating many aspects of human health, including nutrition and immunity. While many internal and environmental factors are known to influence the microbiome, less is known about the effects of intestinal helminth parasites (worms), which together affect one-sixth of the world's population. Through a comprehensive qualitative systematic review and quantitative meta-analysis of existing literature, we provide strong evidence that helminth infection dynamically shifts the intestinal microbiome structure. Moreover, we demonstrated that such influence seems to be specific to helminth species and host anatomical niche. Our findings suggest that the gut microbiome may underlie some of the pathology associated with intestinal worm infection and support future work to understand the precise nature of the helminth-microbiome relationship.

Several epidemiological and immunological studies indicate a reciprocal association between obesity/metabolic syndrome and helminth infections. Numerous studies demonstrated that obesity is concomitant with chronic low-grade inflammation, which is marked by vital changes in cellular composition and function of adipose tissue. However, the effect of helminth infection on the homeostatic milieu in obesity is not well-understood. To determine the relationship between Strongyloides stercoralis (Ss) infection and obesity, we examined an array of parameters linked with obesity both before and at 6 months following anthelmintic treatment. To this end, we measured serum levels of pancreatic hormones, incretins, adipokines and Type-1, Type-2, Type-17, and other proinflammatory cytokines in those with non-diabetic obesity with (INF) or without Ss infection (UN). In INF individuals, we evaluated the levels of these parameters at 6 months following anthelmintic treatment. INF individuals revealed significantly lower levels of insulin, glucagon, C-peptide, and GLP-1 and significantly elevated levels of GIP compared to UN individuals. INF individuals also showed significantly lower levels of Type-1, Type-17 and other pro-inflammatory cytokines and significantly increased levels of Type-2 and regulatory cytokines in comparison to UN individuals. Most of these changes were significantly reversed following anthelmintic treatment. Ss infection is associated with a significant alteration of pancreatic hormones, incretins, adipokines, and cytokines in obese individuals and its partial reversal following anthelmintic treatment. Our data offer a possible biological mechanism for the protective effect of Ss infection on obesity.

Type 2 diabetes mellitus (T2DM) is characterized by heightened systemic inflammation and microbial translocation. Whether concomitant helminth infections can modulate this systemic response is unclear. We examined the presence of markers of systemic inflammation (levels of acute phase proteins) and of microbial translocation [levels of lipopolysaccharide (LPS) and its associated products] in T2DM individuals with (Ss+) or without (Ss−) Strongyloides stercoralis (Ss) infection. We also analyzed these parameters at 6 months following anthelmintic treatment in Ss+ individuals. Ss+ individuals exhibited significantly diminished levels of alpha-2 macroglobulin, C-reactive protein, haptoglobin and serum amyloid protein A1 compared to Ss− individuals and these levels increased significantly following therapy. Similarly, Ss+ individuals exhibited significantly diminished levels of LPS, sCD14, intestinal fatty acid binding protein, LPS binding protein and endotoxin IgG antibody and most of these levels increased significantly following therapy. Thus, helminth infection is associated with attenuation of systemic inflammation and microbial translocation in T2DM and its reversal following anthelmintic therapy.

During 2012–2015, US-bound refugees living in Myanmar–Thailand border camps (n = 1,839) were surveyed for hookworm infection and treatment response by using quantitative PCR. Samples were collected at 3 time points: after each of 2 treatments with albendazole and after resettlement in the United States. Baseline prevalence of Necator americanus hookworm was 25.4%, Ancylostoma duodenale 0%, and Ancylostoma ceylanicum (a zoonosis) 5.4%. Compared with N. americanus prevalence, A. ceylanicum hookworm prevalence peaked in younger age groups, and blood eosinophil concentrations during A. ceylanicum infection were higher than those for N. americanus infection. Female sex was associated with a lower risk for either hookworm infection. Cure rates after 1 dose of albendazole were greater for A. ceylanicum (93.3%) than N. americanus (65.9%) hookworm (p

Abstract Background Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where onchocerciasis is still endemic. Main text On October 12–14th 2017, the first international workshop on onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries. Recent research findings strongly suggest that O. volvulus is an important contributor to epilepsy, particularly in meso- and hyperendemic areas for onchocerciasis. Infection with O. volvulus is associated with a spectrum of epileptic seizures, mainly generalised tonic-clonic seizures but also atonic neck seizures (nodding), and stunted growth. OAE is characterised by an onset of seizures between the ages of 3–18 years. Multidisciplinary working groups discussed topics such as how to 1) strengthen the evidence for an association between onchocerciasis and epilepsy, 2) determine the burden of disease caused by OAE, 3) prevent OAE, 4) improve the treatment/care for persons with OAE and affected families, 5) identify the pathophysiological mechanism of OAE, and 6) deal with misconceptions, stigma, discrimination and gender violence associated with OAE. An OAE Alliance was created to increase awareness about OAE and its public health importance, stimulate research and disseminate research findings, and create partnerships between OAE researchers, communities, advocacy groups, ministries of health, non-governmental organisations, the pharmaceutical industry and funding organizations. Conclusions Although the exact pathophysiological mechanism underlying OAE remains unknown, there is increasing evidence that by controlling and eliminating onchocerciasis, OAE will also disappear. Therefore, OAE constitutes an additional argument for strengthening onchocerciasis elimination efforts. Given the high numbers of people with epilepsy in O. volvulus-endemic regions, more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.

A patient in Pennsylvania, USA, with common variable immunodeficiency sought care for fever, cough, and abdominal pain. Imaging revealed lesions involving multiple organs. Liver resection demonstrated necrotizing granulomas, recognizable tegument, and calcareous corpuscles indicative of an invasive cestode infection. Sequencing revealed 98% identity to a Versteria species of cestode found in mink.

Abstract Background Understanding and quantifying the sources and implications of error in the measurement of helminth egg intensity using Kato-Katz (KK) and the newly emerging “gold standard” quantitative polymerase chain reaction (qPCR) technique is necessary for the appropriate design of epidemiological studies, including impact assessments for deworming programs. Methods Repeated measurements of Ascaris lumbricoides infection intensity were made from samples collected in western Kenya using the qPCR and KK techniques. These data were combined with data on post-treatment worm expulsions. Random effects regression models were used to quantify the variability associated with different technical and biological factors for qPCR and KK diagnosis. The relative precision of these methods was compared, as was the precision of multiple qPCR replicates. Results For both KK and qPCR, intensity measurements were largely determined by the identity of the stool donor. Stool donor explained 92.4% of variability in qPCR measurements and 54.5% of observed measurement variance for KK. An additional 39.1% of variance in KK measurements was attributable to having expelled adult A. lumbricoides worms following anthelmintic treatment. For qPCR, the remaining 7.6% of variability was explained by the efficiency of the DNA extraction (2.4%), plate-to-plate variability (0.2%) and other residual factors (5%). Differences in replicate measurements by qPCR were comparatively small. In addition to KK variability based on stool donor infection levels, the slide reader was highly statistically significant, although it only explained 1.4% of the total variation. In a comparison of qPCR and KK variance to mean ratios under ideal conditions, the coefficient of variation was on average 3.6 times larger for KK highlighting increased precision of qPCR. Conclusions Person-to-person differences explain the majority of variability in egg intensity measurements by qPCR and KK, with very little additional variability explained by the technical factors associated with the practical implementation of these techniques. qPCR provides approximately 3.6 times more precision in estimating A. lumbricoides egg intensity than KK, and could potentially be made more cost-effective by testing each sample only once without diminishing the power of a study to assess population-level intensity and prevalence.

ABSTRACT Murine studies suggest that the presence of some species of intestinal helminths is associated with changes in host microbiota composition and diversity. However, studies in humans have produced varied conclusions, and the impact appears to vary widely depending on the helminth species present. To demonstrate how molecular approaches to the human gut microbiome can provide insights into the complex interplay among disparate organisms, DNA was extracted from cryopreserved stools collected from residents of 5 rural Kenyan villages prior to and 3 weeks and 3 months following albendazole (ALB) therapy. Samples were analyzed by quantitative PCR (qPCR) for the presence of 8 species of intestinal parasites and by MiSeq 16S rRNA gene sequencing. Based on pretreatment results, the presence of neither Ascaris lumbricoides nor Necator americanus infection significantly altered the overall diversity of the microbiota in comparison with age-matched controls. Following ALB therapy and clearance of soil-transmitted helminths (STH), there were significant increases in the proportion of the microbiota made up by Clostridiales (P = 0.0002; average fold change, 0.57) and reductions in the proportion made up by Enterobacteriales (P = 0.0004; average fold change, −0.58). There was a significant posttreatment decrease in Chao1 richness, even among individuals who were uninfected pretreatment, suggesting that antimicrobial effects must be considered in any posttreatment setting. Nevertheless, the helminth-associated changes in Clostridiales and Enterobacteriales suggest that clearance of STH, and of N. americanus in particular, alters the gut microbiota. IMPORTANCE The gut microbiome is an important factor in human health. It is affected by what we eat, what medicines we take, and what infections we acquire. In turn, it affects the way we absorb nutrients and whether we have excessive intestinal inflammation. Intestinal worms may have an important impact on the composition of the gut microbiome. Without a complete understanding of the impact of mass deworming programs on the microbiome, it is impossible to accurately calculate the cost-effectiveness of such public health interventions and to guard against any possible deleterious side effects. Our research examines this question in a “real-world” setting, using a longitudinal cohort, in which individuals with and without worm infections are treated with deworming medication and followed up at both three weeks and three months posttreatment. We quantify the impact of roundworms and hookworms on gut microbial composition, suggesting that the impact is small, but that treatment of hookworm infection results in significant changes. This work points to the need for follow-up studies to further examine the impact of hookworm on the gut microbiota and determine the health consequences of the observed changes.

The filarial parasite Loa loa overlaps geographically with Onchocera volvulus and Wuchereria bancrofti filariae in central Africa. Accurate information regarding this overlap is critical to elimination programs targeting O. volvulus and W. bancrofti. We describe a case of loiasis in a traveler returning from Bioko Island, Equatorial Guinea, a location heretofore unknown for L. loa transmission.

Type III IFNs are important players in immunity to viral and bacterial infections. However, their association with helminth infections has not been examined. To explore the association of Type III IFNs with Strongyloides stercoralis (Ss) infection, we examined the systemic levels of IFN lambda-1, IFN lambda-2 and IFN lambda-3, IL-10, and CXCL10/IP-10 in Ss infected (INF, n = 44), helminth—uninfected (UN, n = 44) and in post-treatment INF individuals. We also examined the levels of IFN lambda-1, IFN lambda-2 and IFN lambda-3, IL-10, and CXCL10/IP-10 in whole blood culture supernatants stimulated with Ss somatic antigens, or PPD or LPS. Finally, we performed correlations of systemic Type III IFN levels with absolute numbers of dendritic cell subsets. Ss infection is characterized by elevated systemic levels of IFN lambda-1, IFN lambda-2 and IFN lambda-3, IL-10, and CXCL10/IP-10 in comparison to UN individuals and a significant reduction following anthelmintic treatment. Ss infection is also characterized by elevated levels of unstimulated or Ss antigen stimulated levels of IFN lambda-1, IFN lambda-2 and IFN lambda-3, CXCL10/IP-10 and a significant reduction following treatment. In addition, Ss infection is characterized by increased numbers of plasmacytoid and myeloid dendritic cells in comparison to UN individuals, with a significant reduction following anthelmintic treatment of INF individuals. Finally, Ss infection exhibits a significant positive correlation between the systemic levels of IFN lambda-2 and IFN lambda-3 and the numbers of plasmacytoid dendritic cells. Thus, Ss infection is characterized by elevations in systemic and antigen—induced levels of Type III IFNs, which is positively associated with the numbers of plasmacytoid dendritic cells and reversed upon anthelmintic treatment.

Helminth parasites are complex metazoans that belong to different taxonomic families but that collectively share the capacity to downregulate the host immune response directed toward themselves (parasite-specific immunoregulation). During long-standing chronic infection, these helminths appear able to suppress immune responses to bystander pathogens/antigens and atopic, autoimmune, and metabolic disorders. Helminth-induced immunoregulation occurs through the induction of regulatory T cells or Th2-type cells (or both). However, secreted or excreted parasite metabolites, proteins, or extracellular vesicles (or a combination of these) may also directly induce signaling pathways in host cells. Therefore, the focus of this review will be to highlight recent advances in understanding the immune responses to helminth infection, emphasizing the strategies/molecules and some of the mechanisms used by helminth parasites to modulate the immune response of their hosts.

Infection with the helminth parasite Strongyloides stercoralis (Ss) is commonly clinically asymptomatic that is often accompanied by peripheral eosinophilia. Granulocytes are activated during helminth infection and can act as immune effector cells. Plasma levels of eosinophil and neutrophil granular proteins convey an indirect measure of granulocyte degranulation and are prominently augmented in numerous helminth-infected patients. In this study, we sought to examine the levels of eosinophil, neutrophil, and mast cell activation-associated granule proteins in asymptomatic Ss infection and to understand their kinetics following anthelmintic therapy. To this end, we measured the plasma levels of eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophil peroxidase, eosinophil major basic protein, neutrophil elastase, myeloperoxidase, neutrophil proteinase-3, mast cell tryptase, leukotriene C4, and mast cell carboxypeptidase-A3 in individuals with asymptomatic Ss infection or without Ss infection [uninfected (UN)]. We also estimated the levels of all of these analytes in infected individuals following definitive treatment of Ss infection. We demonstrated that those infected individuals have significantly enhanced plasma levels of eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophil peroxidase, eosinophil major basic protein, elastase, myeloperoxidase, mast cell tryptase, leukotriene C4, and carboxypeptidase-A3 compared to UN individuals. Following the treatment of Ss infection, each of these granulocyte-associated proteins drops significantly. Our data suggest that eosinophil, neutrophil, and mast cell activation may play a role in the response to Ss infection.

In southern California, ocular infections caused by Onchocerca lupi were diagnosed in 3 dogs (1 in 2006, 2 in 2012). The infectious agent was confirmed through morphologic analysis of fixed parasites in tissues and by PCR and sequencing of amplicons derived from 2 mitochondrially encoded genes and 1 nuclear-encoded gene. A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. Six (2.8%; 95% CI 0.6%–5.0%) of 213 black flies contained O. lupi DNA. Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum. These data implicate S. tribulatum flies as a putative vector for O. lupi in southern California.

ABSTRACT Onchocerciasis (river blindness) is a neglected tropical disease that has been successfully targeted by mass drug treatment programs in the Americas and small parts of Africa. Achieving the long-term goal of elimination of onchocerciasis, however, requires additional tools, including drugs, vaccines, and biomarkers of infection. Here, we describe the transcriptome and proteome profiles of the major vector and the human host stages (L1, L2, L3, molting L3, L4, adult male, and adult female) of Onchocerca volvulus along with the proteome of each parasitic stage and of its Wolbachia endosymbiont (wOv). In so doing, we have identified stage-specific pathways important to the parasite’s adaptation to its human host during its early development. Further, we generated a protein array that, when screened with well-characterized human samples, identified novel diagnostic biomarkers of O. volvulus infection and new potential vaccine candidates. This immunomic approach not only demonstrates the power of this postgenomic discovery platform but also provides additional tools for onchocerciasis control programs. IMPORTANCE The global onchocerciasis (river blindness) elimination program will have to rely on the development of new tools (drugs, vaccines, biomarkers) to achieve its goals by 2025. As an adjunct to the completed genomic sequencing of O. volvulus, we used a comprehensive proteomic and transcriptomic profiling strategy to gain a comprehensive understanding of both the vector-derived and human host-derived parasite stages. In so doing, we have identified proteins and pathways that enable novel drug targeting studies and the discovery of novel vaccine candidates, as well as useful biomarkers of active infection.

ABSTRACT Immunoassays are currently needed to quantify Loa loa microfilariae (mf). To address this need, we have conducted proteomic and bioinformatic analyses of proteins present in the urine of a Loa mf-infected patient and used this information to identify putative biomarkers produced by L. loa mf. In total, 70 of the 15,444 described putative L. loa proteins were identified. Of these 70, 18 were L. loa mf specific, and 2 of these 18 (LOAG_16297 and LOAG_17808) were biologically immunogenic. We developed novel reverse luciferase immunoprecipitation system (LIPS) immunoassays to quantify these 2 proteins in individual plasma samples. Levels of these 2 proteins in microfilaremic L. loa-infected patients were positively correlated to mf densities in the corresponding blood samples (r = 0.71 and P < 0.0001 for LOAG_16297 and r = 0.61 and P = 0.0002 for LOAG_17808). For LOAG_16297, the levels in plasma were significantly higher in Loa-infected (geometric mean [GM], 0.045 µg/ml) than in uninfected (P < 0.0001), Wuchereria bancrofti-infected (P = 0.0005), and Onchocerca volvulus-infected (P < 0.0001) individuals, whereas for LOAG_17808 protein, they were not significantly different between Loa-infected (GM, 0.123 µg/ml) and uninfected (P = 0.06) and W. bancrofti-infected (P = 0.32) individuals. Moreover, only LOAG_16297 showed clear discriminative ability between L. loa and the other potentially coendemic filariae. Indeed, the specificity of the LOAG_16297 reverse LIPS assay was 96% (with a sensitivity of 77%). Thus, LOAG_16297 is a very promising biomarker that will be exploited in a quantitative point-of-care immunoassay for determination of L. loa mf densities. IMPORTANCE Loa loa, the causative agent of loiasis, is a parasitic nematode transmitted to humans by the tabanid Chrysops fly. Some individuals infected with L. loa microfilariae (mf) in high densities are known to experience post-ivermectin severe adverse events (SAEs [encephalopathy, coma, or death]). Thus, ivermectin-based mass drug administration (MDA) programs for onchocerciasis and for lymphatic filariasis control have been interrupted in parts of Africa where these filarial infections coexist with L. loa. To allow for implementation of MDA for onchocerciasis and lymphatic filariasis, tools that can accurately identify people at risk of developing post-ivermectin SAEs are needed. Our study, using host-based proteomics in combination with novel immunoassays, identified a single Loa-specific antigen (LOAG_16297) that can be used as a biomarker for the prediction of L. loa mf levels in the blood of infected patients. Therefore, the use of such biomarker could be important in the point-of-care assessment of L. loa mf densities.