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1.
Proc Natl Acad Sci U S A ; 121(2): e2315463120, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38181058

ABSTRACT

Schistosomiasis is a neglected tropical disease affecting over 150 million people. Hotspots of Schistosoma transmission-communities where infection prevalence does not decline adequately with mass drug administration-present a key challenge in eliminating schistosomiasis. Current approaches to identify hotspots require evaluation 2-5 y after a baseline survey and subsequent mass drug administration. Here, we develop statistical models to predict hotspots at baseline prior to treatment comparing three common hotspot definitions, using epidemiologic, survey-based, and remote sensing data. In a reanalysis of randomized trials in 589 communities in five endemic countries, a regression model predicts whether Schistosoma mansoni infection prevalence will exceed the WHO threshold of 10% in year 5 ("prevalence hotspot") with 86% sensitivity, 74% specificity, and 93% negative predictive value (NPV; assuming 30% hotspot prevalence), and a regression model for Schistosoma haematobium achieves 90% sensitivity, 90% specificity, and 96% NPV. A random forest model predicts whether S. mansoni moderate and heavy infection prevalence will exceed a public health goal of 1% in year 5 ("intensity hotspot") with 92% sensitivity, 79% specificity, and 96% NPV, and a boosted trees model for S. haematobium achieves 77% sensitivity, 95% specificity, and 91% NPV. Baseline prevalence is a top predictor in all models. Prediction is less accurate in countries not represented in training data and for a third hotspot definition based on relative prevalence reduction over time ("persistent hotspot"). These models may be a tool to prioritize high-risk communities for more frequent surveillance or intervention against schistosomiasis, but prediction of hotspots remains a challenge.


Subject(s)
Schistosomiasis mansoni , Schistosomiasis , Humans , Animals , Mass Drug Administration , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/epidemiology , Schistosoma haematobium , Models, Statistical
2.
Parasitol Res ; 123(2): 125, 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38326631

ABSTRACT

During bacterial and viral pathogen investigation of 30 specimens of bats captured in periurban forest areas in the city of Belém, Pará, Brazil, a case of cerebral filariasis was observed. In the course of histopathological examination, adult filariae were found in pseudocystic cavities brain of Molossus barnesi (Molossidae) and classified morphologically as Litomosoides by the shape of the spicules-left spicule with a handle longer than the blade; right spicule curved, with a sclerotized heel supporting a dorsal notch; the area rugosa constituted by a ventral band of small longitudinal crests; tail rounded in males; long esophagus with a slightly glandular distal portion; and a muscular bent vagina. All the specimens lack a stoma (buccal capsule). We compared our filarioids with the description of specimens of Molossinema wimsatti. Morphological characteristics of M. wimsatti resemble the genus Litomosoides. Thus, we believe that M. wimsatti is a synonym of L. molossi Esslinger, 1973, and filarioid specimens from material reported by Lichtenfels et al. (Trans Am Micros Soc 100:216-219, 1981) and from de Souto et al. (J. Helminthol 1195:e65, 2021) most probably correspond to Litomosoides. We suggest that the reduction of the buccal capsule may be attributable to the ectopic location. No evidence of tissue responses by the host was observed. This is the first record of Litomosoides infecting brain tissue of Molossus barnesi from Brazil, representing a record of a new host species. More specimens of bats should be examined in order to find filarioids in the brain and verify its taxonomic position using molecular techniques.


Subject(s)
Chiroptera , Filariasis , Filarioidea , Animals , Female , Male , Brazil , Environment , Filariasis/veterinary
3.
Clin Infect Dis ; 77(9): 1294-1302, 2023 11 11.
Article in English | MEDLINE | ID: mdl-37357904

ABSTRACT

BACKGROUND: The currently recommended benzimidazole monotherapy is insufficiently effective to control infection with the soil-transmitted helminth Trichuris trichiura. Ivermectin-albendazole combination has shown promising, but setting-dependent efficacy, with therapeutic underperformance in Côte d'Ivoire. We evaluated whether moxidectin-albendazole could serve as an alternative to albendazole monotherapy in Côte d'Ivoire. METHODS: In this community-based, randomized, placebo-controlled, parallel-group superiority trial, individuals aged 12-60 years were screened for T. trichiura eggs in their stool using quadruplicate Kato-Katz thick smears. Diagnostically and clinically eligible participants were randomly assigned (1:1:1) to receive single oral doses of moxidectin (8 mg) and albendazole (400 mg), ivermectin (200 µg/kg) and albendazole (400 mg), or albendazole (400 mg) and placebo. The primary outcome was proportion cured, ie, cure rate (CR), assessed at 2-3 weeks post-treatment. Safety endpoints were assessed pre-treatment and at 3 and 24 hours post-treatment. RESULTS: For the 210 participants with primary outcome data, we observed CRs of 15.3% in the moxidectin-albendazole arm and 22.5% in the ivermectin-albendazole arm, which did not differ significantly from the CR of 13.4% in the albendazole arm (differences: 1.8%-points [95% confidence interval: -10.1 to 13.6] and 9.1%-points [-3.9 to 21.8], respectively). Most common adverse events were abdominal pain (range across arms: 11.9%-20.9%), headache (4.7%-14.3%), and itching (5.8%-13.1%), which were predominantly mild and transient. CONCLUSIONS: All therapies showed similar low efficacy in treating trichuriasis in Côte d'Ivoire. Alternative treatment options need to be evaluated, and further analyses should be conducted to understand the lack of enhanced activity of the combination therapies in Côte d'Ivoire. CLINICAL TRIALS REGISTRATION: NCT04726969.


Subject(s)
Albendazole , Anthelmintics , Adolescent , Adult , Animals , Humans , Albendazole/adverse effects , Anthelmintics/adverse effects , Feces , Ivermectin/adverse effects , Trichuris , Child , Young Adult , Middle Aged
4.
PLoS Pathog ; 17(11): e1010017, 2021 11.
Article in English | MEDLINE | ID: mdl-34724007

ABSTRACT

The plant pathogen Pseudomonas syringae secretes multiple effectors that modulate plant defenses. Some effectors trigger defenses due to specific recognition by plant immune complexes, whereas others can suppress the resulting immune responses. The HopZ3 effector of P. syringae pv. syringae B728a (PsyB728a) is an acetyltransferase that modifies not only components of plant immune complexes, but also the Psy effectors that activate these complexes. In Arabidopsis, HopZ3 acetylates the host RPM1 complex and the Psy effectors AvrRpm1 and AvrB3. This study focuses on the role of HopZ3 during tomato infection. In Psy-resistant tomato, the main immune complex includes PRF and PTO, a RIPK-family kinase that recognizes the AvrPto effector. HopZ3 acts as a virulence factor on tomato by suppressing AvrPto1Psy-triggered immunity. HopZ3 acetylates AvrPto1Psy and the host proteins PTO, SlRIPK and SlRIN4s. Biochemical reconstruction and site-directed mutagenesis experiments suggest that acetylation acts in multiple ways to suppress immune signaling in tomato. First, acetylation disrupts the critical AvrPto1Psy-PTO interaction needed to initiate the immune response. Unmodified residues at the binding interface of both proteins and at other residues needed for binding are acetylated. Second, acetylation occurs at residues important for AvrPto1Psy function but not for binding to PTO. Finally, acetylation reduces specific phosphorylations needed for promoting the immune-inducing activity of HopZ3's targets such as AvrPto1Psy and PTO. In some cases, acetylation competes with phosphorylation. HopZ3-mediated acetylation suppresses the kinase activity of SlRIPK and the phosphorylation of its SlRIN4 substrate previously implicated in PTO-signaling. Thus, HopZ3 disrupts the functions of multiple immune components and the effectors that trigger them, leading to increased susceptibility to infection. Finally, mass spectrometry used to map specific acetylated residues confirmed HopZ3's unusual capacity to modify histidine in addition to serine, threonine and lysine residues.


Subject(s)
Acetyltransferases/metabolism , Antigen-Antibody Complex/immunology , Bacterial Proteins/antagonists & inhibitors , Plant Diseases/immunology , Plant Proteins/metabolism , Pseudomonas syringae/pathogenicity , Solanum lycopersicum/immunology , Acetylation , Acetyltransferases/genetics , Acetyltransferases/immunology , Bacterial Proteins/genetics , Bacterial Proteins/immunology , Bacterial Proteins/metabolism , Solanum lycopersicum/microbiology , Plant Diseases/microbiology , Plant Proteins/genetics , Plant Proteins/immunology , Virulence , Virulence Factors/genetics , Virulence Factors/immunology , Virulence Factors/metabolism
5.
Plant Physiol ; 190(1): 860-881, 2022 08 29.
Article in English | MEDLINE | ID: mdl-35642916

ABSTRACT

Plant plastids generate signals, including some derived from lipids, that need to be mobilized to effect signaling. We used informatics to discover potential plastid membrane proteins involved in microbial responses in Arabidopsis (Arabidopsis thaliana). Among these are proteins co-regulated with the systemic immunity component AZELAIC ACID INDUCED 1, a hybrid proline-rich protein (HyPRP), and HyPRP superfamily members. HyPRPs have a transmembrane domain, a proline-rich region (PRR), and a lipid transfer protein domain. The precise subcellular location(s) and function(s) are unknown for most HyPRP family members. As predicted by informatics, a subset of HyPRPs has a pool of proteins that target plastid outer envelope membranes via a mechanism that requires the PRR. Additionally, two HyPRPs may be associated with thylakoid membranes. Most of the plastid- and nonplastid-localized family members also have pools that localize to the endoplasmic reticulum, plasma membrane, or plasmodesmata. HyPRPs with plastid pools regulate, positively or negatively, systemic immunity against the pathogen Pseudomonas syringae. HyPRPs also regulate the interaction with the plant growth-promoting rhizobacteria Pseudomonas simiae WCS417 in the roots to influence colonization, root system architecture, and/or biomass. Thus, HyPRPs have broad and distinct roles in immunity, development, and growth responses to microbes and reside at sites that may facilitate signal molecule transport.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Plants/metabolism , Plastids/metabolism , Proline/metabolism , Pseudomonas syringae/metabolism
6.
Plant J ; 105(6): 1615-1629, 2021 03.
Article in English | MEDLINE | ID: mdl-33342031

ABSTRACT

The proper subcellular localization of defense factors is an important part of the plant immune system. A key component for systemic resistance, lipid transfer protein (LTP)-like AZI1, is needed for the systemic movement of the priming signal azelaic acid (AZA) and a pool of AZI1 exists at the site of AZA production, the plastid envelope. Moreover, after systemic defense-triggering infections, the proportion of AZI1 localized to plastids increases. However, AZI1 does not possess a classical plastid transit peptide that can explain its localization. Instead, AZI1 uses a bipartite N-terminal signature that allows for its plastid targeting. Furthermore, the kinases MPK3 and MPK6, associated with systemic immunity, promote the accumulation of AZI1 at plastids during priming induction. Our results indicate the existence of a mode of plastid targeting possibly related to defense responses.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Carrier Proteins/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Carrier Proteins/genetics , Gene Expression Regulation, Plant/genetics , Gene Expression Regulation, Plant/physiology
7.
Clin Infect Dis ; 74(12): 2181-2190, 2022 07 06.
Article in English | MEDLINE | ID: mdl-34519344

ABSTRACT

BACKGROUND: Annual mass drug administration (MDA) using praziquantel is the cornerstone of schistosomiasis morbidity control but is not sufficient to interrupt transmission. We implemented a cluster-randomized trial to compare the effectiveness of 4 different intervention packages to interrupt transmission of Schistosoma haematobium in a seasonal transmission setting of Côte d'Ivoire. METHODS: Sixty-four localities with a S. haematobium prevalence in school children aged 13-14 years above 4% were randomly assigned to 1 of 4 intervention arms over a 3-year period: (1) the current standard strategy consisting of annual MDA before peak of transmission, (2) annual MDA after peak of transmission, (3) biannual MDA, and (4) standard MDA combined with snail control. The primary outcome was prevalence and intensity of S. haematobium infection in children aged 9-12 years 1 year after the final intervention, using urine filtration performed by experienced microscopists. RESULTS: By study end, we observed the lowest S. haematobium prevalence in the biannual MDA, compared to the standard treatment arm (0.6% vs 7.5%; odds ratio [OR] = 0.07, 95% confidence interval [CI] = .02 to .24). The prevalence in arms 2 and 4 was about 3.5%, which was not statistically significantly different from the standard strategy (both ORs 0.4, 95% CI = .1 to ~1.8). New cases of infection were still observed in all arms at study end. CONCLUSIONS: Biannual MDA was the only regimen that outperformed the standard treatment. All strategies resulted in decreased prevalence of infection; however, none of them was able to interrupt transmission of S. haematobium within a 3-year period. CLINICAL TRIALS REGISTRATION: ISRCTN10926858.


Subject(s)
Schistosomiasis haematobia , Schistosomiasis , Animals , Child , Cote d'Ivoire/epidemiology , Humans , Praziquantel/therapeutic use , Prevalence , Schistosoma haematobium , Schistosomiasis/drug therapy , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/epidemiology , Schistosomiasis haematobia/prevention & control , Seasons
8.
J Antimicrob Chemother ; 77(4): 1082-1093, 2022 03 31.
Article in English | MEDLINE | ID: mdl-35152279

ABSTRACT

BACKGROUND: Albendazole is the most commonly used drug in preventive chemotherapy programmes against soil-transmitted helminth (STH) infections, with the standard dose of 400 mg resulting in suboptimal clinical outcomes. Population pharmacokinetic (PK) models that could inform dosing strategies are not yet available. METHODS: A population pharmacokinetic model was developed based on micro-blood samples collected from 252 patients aged 2 to 65 years, infected with either hookworm or Trichuris trichiura and treated with albendazole doses ranging from of 200 to 800 mg. An exposure-response analysis was performed relating albendazole and its two metabolites to cure rates and egg reduction rates (ERR). Finally, model-based simulations were conducted to determine equivalent exposure coverage in infants to adults. RESULTS: A population PK model, with one distribution compartment for each compound and one peripheral compartment, following oral administration with a lag time, assuming first-order absorption and linear elimination, best described the concentration-time profiles. Clearance and volume parameters were scaled to body size (weight for albendazole and height for albendazole sulfoxide and sulfone). Dose proportionality was observed for the active metabolite, albendazole sulfoxide, but only in hookworm-infected individuals, with increasing exposure resulting in increased ERR. Exposure of sulfoxide was lowest in the tallest individuals. CONCLUSIONS: Pharmacometric simulations indicate that doses up to 800 mg could further increase albendazole efficacy in hookworm-infected adults, whereas the standard dose of 400 mg is sufficient in the youngest age cohorts. In the absence of evidence-based arguments for adjusting albendazole doses in T. trichiura-infected individuals, the search for new treatment options is further emphasized.


Subject(s)
Anthelmintics , Trichuriasis , Adolescent , Adult , Aged , Albendazole/therapeutic use , Ancylostomatoidea , Animals , Anthelmintics/therapeutic use , Child , Child, Preschool , Feces , Humans , Infant , Middle Aged , Trichuriasis/drug therapy , Trichuris , Young Adult
9.
Malar J ; 21(1): 111, 2022 Apr 02.
Article in English | MEDLINE | ID: mdl-35366883

ABSTRACT

BACKGROUND: Highly sensitive and accurate malaria diagnostic tools are essential to identify asymptomatic low parasitaemia infections. This study evaluated the performance of histidine-rich protein 2 (HRP-2) based rapid diagnostic tests (RDTs), microscopy and loop-mediated isothermal amplification (LAMP) for the detection of asymptomatic Plasmodium spp. infections in Northern Côte d'Ivoire, using nested polymerase chain reaction (nPCR) as reference. METHODS: A household-based survey was carried out in July 2016, in the health district of Korhogo, involving 1011 adults without malaria symptom nor history of fever during the week before recruitment. The fresh capillary blood samples were collected to detect Plasmodium infections using on HRP-2-based RDTs, microscopy and LAMP and stored as dried blood spots (DBS). A subset of the DBS (247/1011, 24.4%) was randomly selected for nPCR analyses. Additionally, venous blood samples, according to LAMP result (45 LAMP positive and 65 LAMP negative) were collected among the included participants to perform the nested PCR used as the reference. RESULTS: The prevalence of asymptomatic Plasmodium spp. infections determined by RDT, microscopy, and LAMP were 4% (95% confidence interval (CI) 2.8-5.3), 5.2% (95% CI 3.9-6.6) and 18.8% (95% CI 16.4-21.2), respectively. Considering PCR on venous blood as reference, performed on 110 samples, the sensibility and specificity were, respectively, 17.8% (95% CI 6.1-29.4) and 100% for RDT, 20.0% (95% CI 7.8-32) and 100% for microscopy, and 93.3% (95% CI 85.7-100) and 95.4% (95% CI 92.2-100) for LAMP. CONCLUSION: In Northern Côte d'Ivoire, asymptomatic Plasmodium infection was found to be widely distributed as approximately one out of five study participants was found to be Plasmodium infected. LAMP appears currently to be the only available diagnostic method that can identify in the field this reservoir of infections and should be the method to consider for potential future active case detection interventions targeting elimination of these infections.


Subject(s)
Malaria , Plasmodium , Adult , Cote d'Ivoire , Humans , Malaria/diagnosis , Microscopy/methods , Molecular Diagnostic Techniques , Nucleic Acid Amplification Techniques , Plasmodium/genetics , Sensitivity and Specificity
10.
BMC Pediatr ; 22(1): 651, 2022 Nov 09.
Article in English | MEDLINE | ID: mdl-36348381

ABSTRACT

BACKGROUND: A balanced nutrition is important for children's physical and cognitive development; yet, remains a challenge in many parts of low- and middle-income countries (LMICs). Early detection of nutritional deficiency and metabolic syndrome in school-aged children is necessary to prevent non-communicable diseases (NCDs) in later life. This study aimed at obtaining baseline data on health, nutritional status, and metabolic markers of NCDs among primary schoolchildren in Côte d'Ivoire. METHODS: A cross-sectional survey was conducted among 620 children from 8 public primary schools located in the south-central part of Côte d'Ivoire. Underweight and overweight were defined as a body mass index (BMI; kg/m2) < 5th and 85th up to 95th percentile for sex and age, respectively. Dietary diversity of children was calculated based on a 24-hour recall conducted with the primary caretaker according to the guideline of Food and Agriculture Organization. Anaemia, malaria, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and blood glucose levels (HbA1c) were assessed, using capillary blood samples. Logistic models were performed to identify risk factors associated with overweight, HDL-C, LDL-C, and HbA1c. RESULTS: Among the 620 children (330 girls, 290 boys; Mage 8.0 (± 1.7) years), 530 children attended school in a semi-urban and 90 in a rural area. Around 60% of children had a medium dietary diversity score (DDS). Children in peri-urban areas consumed more cereals (80.2% vs. 63.3%, p < 0.05). Most children were normal weight (n = 496), whereas 3.9% of children classified as prediabetic, 5% were underweight, and 15% overweight. LDL-C and HDL-C levels of children were associated with age, high DDS, and moderate anaemia. A significant association was found between prediabetes and malaria infection, as well as medium and high DDS. Overweight was associated with malaria infection and moderate anaemia. CONCLUSION: Overweight, prediabetes, low HDL-C, malaria, and anaemia are the main concerns of children's health in Taabo. Our findings highlight interactions between infectious diseases, particularly malaria, and NCD risk factors. Monitoring NCD risk and infectious disease comorbidity in LMIC paediatric populations simultaneously is essential to better understand the dual diseases burden and apply early prevention measures.


Subject(s)
Anemia , Malaria , Noncommunicable Diseases , Prediabetic State , Child , Male , Female , Humans , Cross-Sectional Studies , Thinness/complications , Overweight/epidemiology , Overweight/complications , Cote d'Ivoire/epidemiology , Prediabetic State/complications , Cholesterol, LDL , Glycated Hemoglobin , Malaria/complications , Risk Factors , Anemia/complications
11.
Int J Mol Sci ; 23(19)2022 Oct 01.
Article in English | MEDLINE | ID: mdl-36232932

ABSTRACT

Salicylic acid (SA) is a hormone that modulates plant defenses by inducing changes in gene expression. The mechanisms that control SA accumulation are essential for understanding the defensive process. TGA transcription factors from clade II in Arabidopsis, which include the proteins TGA2, TGA5, and TGA6, are known to be key positive mediators for the transcription of genes such as PR-1 that are induced by SA application. However, unexpectedly, stress conditions that induce SA accumulation, such as infection with the avirulent pathogen P. syringae DC3000/AvrRPM1 and UV-C irradiation, result in enhanced PR-1 induction in plants lacking the clade II TGAs (tga256 plants). Increased PR-1 induction was accompanied by enhanced isochorismate synthase-dependent SA production as well as the upregulation of several genes involved in the hormone's accumulation. In response to avirulent P. syringae, PR-1 was previously shown to be controlled by both SA-dependent and -independent pathways. Therefore, the enhanced induction of PR-1 (and other defense genes) and accumulation of SA in the tga256 mutant plants is consistent with the clade II TGA factors providing negative feedback regulation of the SA-dependent and/or -independent pathways. Together, our results indicate that the TGA transcription factors from clade II negatively control SA accumulation under stress conditions that induce the hormone production. Our study describes a mechanism involving old actors playing new roles in regulating SA homeostasis under stress.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Basic-Leucine Zipper Transcription Factors/genetics , Gene Expression Regulation, Plant , Hormones/metabolism , Mutation , Plant Diseases/genetics , Pseudomonas syringae , Salicylic Acid/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
12.
Clin Infect Dis ; 73(2): e494-e502, 2021 07 15.
Article in English | MEDLINE | ID: mdl-32668456

ABSTRACT

BACKGROUND: Infections with hookworms affect about half a billion people worldwide. Recommended therapy includes 400 mg of albendazole, which is moderately efficacious. Higher doses have been rarely assessed. METHODS: A randomized, controlled dose-finding trial was conducted in Côte d'Ivoire with the aim of recruiting 120 preschool-aged children (PSAC), 200 school-aged children (SAC), and 200 adults. Eligible PSAC were randomized 1:1:1 to 200 mg, 400 mg, or 600 mg of albendazole; the other age groups were randomized 1:1:1:1:1 to placebo or 200 mg, 400 mg, 600 mg, or 800 mg. The primary outcome was cure rates (CRs) assessed 14-21 days post-treatment by quadruplicate Kato-Katz thick smears. Hyperbolic Emax models were used to determine dose-response. RESULTS: 38 PSAC, 133 SAC, and 196 adults were enrolled. In adults, predicted CRs increased with ascending doses of albendazole, with a CR of 74.9% (95% confidence interval [CI], 55.6%-87.7%) in the 800-mg arm. Observed CRs increased with ascending doses of albendazole reaching a maximum of 94.1% (95% CI, 80.3%-99.3%). In SAC, the predicted dose-response curve increased marginally, with CRs ranging from 64.0% in the 200-mg arm to 76.0% in the 800-mg arm. Sample size in PSAC was considered too small to derive meaningful conclusions. 10.7% and 5.1% of participants reported any adverse event at 3 hours and 24 hours post-treatment, respectively. CONCLUSIONS: A single 800-mg albendazole dose provides higher efficacy against hookworm and is well tolerated in adults and should be considered for community-based strategies targeting adults. For PSAC and SAC, current recommendations suffice. CLINICAL TRIALS REGISTRATION: NCT03527745.


Subject(s)
Albendazole , Anthelmintics , Adult , Albendazole/adverse effects , Ancylostomatoidea , Animals , Anthelmintics/adverse effects , Child , Child, Preschool , Cote d'Ivoire , Humans , Schools
13.
Article in English | MEDLINE | ID: mdl-33139276

ABSTRACT

In the treatment of hookworm infections, pharmacotherapy has been only moderately successful and drug resistance is a threat. Therefore, novel treatment options including combination therapies should be considered, in which tribendimidine could play a role. Our aims were to (i) characterize the pharmacokinetics of tribendimidine's metabolites in adolescents receiving tribendimidine monotherapy or in combination with ivermectin or oxantel pamoate, (ii) evaluate possible drug-drug interactions (DDI), (iii) link exposure to response, and (iv) identify a treatment strategy associated with high efficacy, i.e., >90% cure rates (CRs), utilizing model-based simulations. A population pharmacokinetic model was developed for tribendimidine's primary and secondary metabolites, dADT and adADT, in 54 hookworm-positive adolescents, with combination therapy evaluated as a possible covariate. Subsequently, an exposure-response analysis was performed utilizing CRs as response markers. Simulations were performed to identify a treatment strategy to achieve >90% CRs. A two-compartmental model best described metabolite disposition. No pharmacokinetic DDI was identified with ivermectin or oxantel pamoate. All participants receiving tribendimidine plus ivermectin were cured. For the monotherapy arm and the arm including the combination with oxantel pamoate, Emax models adequately described the correlation between dADT exposure and probability of being cured, with required exposures to achieve 50% of maximum effect of 39.6 and 15.6 nmol/ml·h, respectively. Based on our simulations, an unrealistically high monotherapy tribendimidine dose would be necessary to achieve CRs of >90%, while combination therapy with ivermectin would meet this desired target product profile. Further clinical studies should be launched to develop this combination for the treatment of hookworm and other helminth infections.


Subject(s)
Anthelmintics , Hookworm Infections , Adolescent , Ancylostomatoidea , Animals , Anthelmintics/therapeutic use , Hookworm Infections/drug therapy , Humans , Phenylenediamines/therapeutic use
14.
Article in English | MEDLINE | ID: mdl-33139293

ABSTRACT

Tribendimidine has been successful in treating hookworm infections and may serve as an alternative to albendazole should resistance arise. Our aims were to (i) characterize the pharmacokinetics (PK) of tribendimidine's primary metabolite, deacetylated amidantel (dADT), and secondary metabolite, acetylated derivative of amidantel (adADT), in school-aged children and adolescents, (ii) link exposure to efficacy against hookworm, and (iii) evaluate whether tribendimidine pharmacotherapy in children could be further improved. First, a population PK model was developed based on dried-blood-spot samples collected from 155 school-aged children and adolescents with hookworm infections, following tribendimidine doses ranging from 100 to 400 mg. Second, an exposure-response analysis was conducted to link the active metabolite dADT to cure rates (CRs) and egg reduction rates (ERRs). Third, simulations were performed to identify a treatment strategy associated with >90% CRs. A two-compartmental model with transit compartments describing observed delay in absorption adequately described PK data of dADT and adADT. Allometric scaling was included to account for growth and development. The absorption rate was 56% lower with 200-mg tablets than with 50-mg tablets, while the extent of absorption remained unaffected. The identified Emax models linking dADT exposure to ERRs and CRs showed shallow curves, as increasing exposure led to marginal efficacy increase. Combination therapy should be considered, as a 12-fold-higher dose would be needed to achieve 95% ERRs and CRs >90% with tribendimidine alone. Further studies are warranted to evaluate safety of higher tribendimidine doses and combination therapies with other anthelmintic agents to improve treatment strategy for children with hookworm infection.


Subject(s)
Anthelmintics , Hookworm Infections , Adolescent , Albendazole/therapeutic use , Ancylostomatoidea , Animals , Anthelmintics/therapeutic use , Child , Hookworm Infections/drug therapy , Humans , Phenylenediamines , Treatment Outcome
15.
J Exp Bot ; 72(7): 2710-2726, 2021 03 29.
Article in English | MEDLINE | ID: mdl-33463678

ABSTRACT

The Arabidopsis plastid-localized ALD1 protein acts in the lysine catabolic pathway that produces infection-induced pipecolic acid (Pip), Pip derivatives, and basal non-Pip metabolite(s). ALD1 is indispensable for disease resistance associated with Pseudomonas syringae infections of naïve plants as well as those previously immunized by a local infection, a phenomenon called systemic acquired resistance (SAR). Pseudomonas syringae is known to associate with mesophyll as well as epidermal cells. To probe the importance of epidermal cells in conferring bacterial disease resistance, we studied plants in which ALD1 was only detectable in the epidermal cells of specific leaves. Local disease resistance and many features of SAR were restored when ALD1 preferentially accumulated in the epidermal plastids at immunization sites. Interestingly, SAR restoration occurred without appreciable accumulation of Pip or known Pip derivatives in secondary distal leaves. Our findings establish that ALD1 has a non-autonomous effect on pathogen growth and defense activation. We propose that ALD1 is sufficient in the epidermis of the immunized leaves to activate SAR, but basal ALD1 and possibly a non-Pip metabolite(s) are also needed at all infection sites to fully suppress bacterial growth. Thus, epidermal plastids that contain ALD1 play a key role in local and whole-plant immune signaling.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Disease Resistance , Epidermis , Plant Diseases , Plastids , Pseudomonas syringae
16.
Proc Natl Acad Sci U S A ; 115(4): E584-E591, 2018 01 23.
Article in English | MEDLINE | ID: mdl-29301964

ABSTRACT

Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5-20%) and high-prevalence (25-50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, "hot spots" of transmission, and noncompliance to MDA.


Subject(s)
Models, Economic , Schistosomiasis/prevention & control , Snails , Animals , Computer Simulation , Cost-Benefit Analysis , Humans , Kenya , Schistosomiasis/economics , Schistosomiasis/transmission
17.
Parasitol Res ; 120(11): 3663-3671, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34586479

ABSTRACT

Agroecosystems have been associated with risk of malaria. The aim of this study was to determine the relationship between three agroecosystems: (i) rubber plantation (RP); (ii) oil palm plantation (OPP); (iii) no cash crop plantation (NCCP) and the prevalence of Plasmodium falciparum infection among children living in the Aboisso region. In the three villages within (Ehania-V5) or close (N'zikro) or far from (Ayébo) to each agroecosystem (RP, OPP, and NCCP), two cross-sectional parasitological surveys were carried out during the dry and the peak of the long wet seasons. A total of 586 children aged 1-14 years were recruited in the three villages to determine the prevalence of malaria using conventional microscopy. Plasmodium falciparum was the dominant species with an overall infection prevalence of 40.8%. There was a significant difference in prevalence between agroecosystems, during both the dry (p = 0.002) and wet seasons (p < 0.001), which was higher in agricultural settings compared with the NCCP environment, whatever the season. The prevalence of P. falciparum infection increased from the dry to the wet season in agricultural settings (RP and OPP), whereas no difference was noted for NCCP. Less than 18% of children use insecticide-treated nets (ITNs) in the three villages, ranging from 6 (in RP) to 30% (in OPP). Multivariate analysis indicated that age (1-4; 5-9; and 10-14 years) was not associated with malaria risk, but the season and living in agricultural villages were associated with a greater risk of malaria infection. Risk of malaria exposure was fourfold higher in children from agricultural villages than their counterpart from the non-agricultural area. Our findings highlight significant variations in the prevalence of P. falciparum according to agroecosystem and season. The findings will be useful in designing and implementing malaria control interventions by the National Malaria Control Program.


Subject(s)
Insecticides , Malaria, Falciparum , Child , Cote d'Ivoire/epidemiology , Cross-Sectional Studies , Humans , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Plasmodium falciparum , Prevalence , Seasons
18.
Gastroenterol Nurs ; 44(4): 259-267, 2021.
Article in English | MEDLINE | ID: mdl-34238884

ABSTRACT

Young adults, 18-35 years of age, account for nearly half of all inflammatory bowel disease emergency department visits annually, costing millions of healthcare dollars and signifying undue pain and suffering. To mitigate this sequela, the study aimed to characterize the relationships between transition readiness (self-management ability), stress, and patient-centered outcomes. Outcomes were defined as disease activity and inflammatory bowel disease-related healthcare utilization (emergency department visits and inpatient hospitalization). This was a descriptive, correlational design via online survey of young adults with inflammatory bowel disease. Participants (n = 284) utilized an estimated 2.77 million healthcare dollars in 12 months. Transition readiness decreased the odds of having consistently active disease and healthcare utilization, with adjusted odds ratio ranging from 6.4 to 10.9 (p < .05). Higher stress levels increased the odds of having consistently active disease and healthcare utilization, with adjusted odds ratio ranging from 9.5 to 10.5 (p < .0001). Twenty-five percent (24.7%) of the variation in transition readiness was explained by changes in stress (p < .0001). Transition readiness and stress impacted all patient-centered outcomes. Stress negatively impacted transition readiness. These results are powerful reminders for healthcare providers to assess and treat stress and support transition readiness in young adults with inflammatory bowel disease. The potential to decrease pain, suffering, and healthcare cost is enormous.


Subject(s)
Inflammatory Bowel Diseases , Self-Management , Transition to Adult Care , Humans , Inflammatory Bowel Diseases/therapy , Outcome Assessment, Health Care , Patient-Centered Care , Young Adult
19.
Parasitology ; 147(3): 287-294, 2020 03.
Article in English | MEDLINE | ID: mdl-31727202

ABSTRACT

Schistosomiasis is a neglected tropical disease, though it is highly prevalent in many parts of sub-Saharan Africa. While Schistosoma haematobium-bovis hybrids have been reported in West Africa, no data about Schistosoma hybrids in humans are available from Côte d'Ivoire. This study aimed to identify and quantify S. haematobium-bovis hybrids among schoolchildren in four localities of Côte d'Ivoire. Urine samples were collected and examined by filtration to detect Schistosoma eggs. Eggs were hatched and 503 miracidia were individually collected and stored on Whatman® FTA cards for molecular analysis. Individual miracidia were molecularly characterized by analysis of mitochondrial cox1 and nuclear internal transcribed spacer 2 (ITS 2) DNA regions. A mitochondrial cox1-based diagnostic polymerase chain reaction was performed on 459 miracidia, with 239 (52.1%) exhibiting the typical band for S. haematobium and 220 (47.9%) the S. bovis band. The cox1 and ITS 2 amplicons were Sanger sequenced from 40 randomly selected miracidia to confirm species and hybrids status. Among the 33 cox1 sequences analysed, we identified 15 S. haematobium sequences (45.5%) belonging to seven haplotypes and 18 S. bovis sequences (54.5%) belonging to 12 haplotypes. Of 40 ITS 2 sequences analysed, 31 (77.5%) were assigned to pure S. haematobium, four (10.0%) to pure S. bovis and five (12.5%) to S. haematobium-bovis hybrids. Our findings suggest that S. haematobium-bovis hybrids are common in Côte d'Ivoire. Hence, intense prospection of domestic and wild animals is warranted to determine whether zoonotic transmission occurs.


Subject(s)
Hybridization, Genetic , Schistosoma/physiology , Schistosomiasis/epidemiology , Adolescent , Animals , Child , Child, Preschool , Cote d'Ivoire/epidemiology , DNA, Helminth/analysis , DNA, Intergenic/analysis , Electron Transport Complex IV/analysis , Helminth Proteins/analysis , Humans , Mitochondrial Proteins/analysis , Prevalence , Schistosoma/genetics , Schistosoma haematobium/genetics , Schistosoma haematobium/physiology , Schistosomiasis/parasitology
20.
J Interprof Care ; 34(5): 682-686, 2020.
Article in English | MEDLINE | ID: mdl-32674638

ABSTRACT

The COVID-19 pandemic has created multiple, complex and intense demands on hospitals, including the need for surge planning in the many locations outside epicenters such as northern Italy or New York City. We here describe such surge planning in an Academic Health Center that encompasses a children's hospital. Interprofessional teams from every aspect of inpatient care and hospital operations worked to prepare for a COVID-19 surge. In so doing, they successfully innovated ways to integrate pediatric and adult care and maximize bed capacity. The success of this intense collaborative effort offers an opportunity for ongoing teamwork to enhance efficient, effective, and high-quality patient care.


Subject(s)
Cooperative Behavior , Coronavirus Infections , Interdisciplinary Communication , Pandemics , Patient Care Team , Pneumonia, Viral , Academic Medical Centers , Betacoronavirus , COVID-19 , Health Workforce/organization & administration , Hospitals, Pediatric , Humans , Italy , New York City , Organizational Case Studies , SARS-CoV-2
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