Intestinal Nematode Infections Research Articles

Equine enteroid-derived monolayers recapitulate key features of parasitic intestinal nematode infection

Stem cell-derived organoid cultures have emerged as attractive experimental models for infection biology research regarding various types of gastro-intestinal pathogens and host species. However, the large size of infectious nematode larvae and the closed structure of 3-dimensional organoids often hinder studies of the natural route of infection. To enable easy administration to the apical surface of the epithelium, organoids from the equine small intestine, i.e. enteroids, were used in the present study to establish epithelial monolayer cultures. These monolayers were functionally tested by stimulation with IL-4 and IL-13, and/or exposure to infectious stage larvae of the equine nematodes Parascaris univalens, cyathostominae and/or Strongylus vulgaris. Effects were recorded using transcriptional analysis combined with histochemistry, immunofluorescence-, live-cell- and scanning electron microscopy. These analyses revealed heterogeneous monolayers containing both immature and differentiated cells including tuft cells and mucus-producing goblet cells. Stimulation with IL-4/IL-13 increased tuft- and goblet cell differentiation as demonstrated by the expression of DCLK1 and MUC2. In these cytokine-primed monolayers, the expression of MUC2 was further promoted by co-culture with P. univalens. Moreover, live-cell imaging revealed morphological alterations of the epithelial cells following exposure to larvae even in the absence of cytokine stimulation. Thus, the present work describes the design, characterization and usability of an experimental model representing the equine nematode-infected small intestinal epithelium. The presence of tuft cells and goblet cells whose mucus production is affected by Th2 cytokines and/or the presence of larvae opens up for mechanistic studies of the physical interactions between nematodes and the equine intestinal mucosa.

Temporal trends in disease burden of major human parasitic diseases in China from 1990 to 2019

To analysize the temporal trends in the disease burden of major human parasitic diseases in China from 1990 to 2019, so as to provide the evidence for improving the parasitic disease control strategy in China. The disability-adjusted life years (DALYs) of malaria, intestinal nematode infections, schistosomiasis, food-borne trematodiases, cysticercosis and echinococcosis in China from 1990 to 2019 were captured from the Global Burden of Disease Study 2019 (GBD 2019), and age- and gender-specific DALYs of parasitic diseases were estimated. The temporal trends in DALYs of malaria, intestinal nematode infections, schistosomiasis, food-borne trematodiases, cysticercosis and echinococcosis were evaluated in China from 1990 to 2019 using average annual percent change (AAPC) with Joinpoint regression analysis. The DALYs were 643 836.42 person-years due to food-borne trematodiases, 156 853.03 person-years due to cysticercosis, 79 764.62 person-years due to schistosomiasis, 70 989.73 person-years due to intestinal nematode infections, 4 258.61 person-years due to echinococcosis and 264.86 person-years due to malaria in China in 2019, respectively. The overall DALYs of six parasitic diseases were higher among men (546 441.93 person-years) than among women (409 525.33 person-years), and were greater among adults at ages of 14 to 65 years (684 780.84 person-years) than among children at 14 years and lower (35 437.38 person-years) and the elderly at ages of 65 years and older (235 749.04 person-years). During the period from 1990 to 2019, food-borne trematodiases were the leading cause of DALYs among the six parasitic diseases, and cysticercosis shifted from the fourth leading cause in 1990 to the second leading cause of DALYs in China in 2019, while intestinal nematode infections shifted from the second leading cause in 1990 to the fourth leading cause of DALYs in 2019. The DALYs of major human parasitic diseases appeared an overall tendency towards a decline in China from 1990 to 2019, with the fastest drop seen in DALYs due to malaria (AAPC = -19.6%, P = 0.003), followed by due to intestinal nematode infections (AAPC = -8.2%, P < 0.001) and schistosomiasis (AAPC = -3.1%, P < 0.001), and a slow decline was seen in the DALYs of food-borne trematodiases (AAPC = -1.0%, P < 0.001), while there were no significant decrease in the DALYs of echinococcosis (AAPC = -0.5%, P = 0.264) and the DALYs of cysticercosis appeared a tendency towards a rise (AAPC = 0.7%, P < 0.001). The disease burden of major human parasitic diseases appeared an overall tendency towards a decline in China from 1990 to 2019, with a high disease burden seen due to food-borne parasitic diseases, no remarkable reduction seen in echinococcosis, and a tendency towards a rise seen in cysticercosis. It is recommended to focus on echinococcosis control, and continue to consolidate the control achievements of other major human parasitic diseases in China; meanwhile, the surveillance and prevention of food-borne parasitic diseases should be reinforced.

The accuracy of nucleic acid amplification tests (NAATs) in detecting human intestinal nematode infections: A protocol for a systematic review and meta-analysis.

Human intestinal nematode infections are a global public health issue as they can result in considerable morbidity in infected individuals, mainly in developing countries. These infections continue to go undiagnosed, as they tend to be mainly endemic in resource-poor communities where there is a shortage of experienced laboratory staff and relevant diagnostic technologies. This is further exacerbated by the nature of intermittent shedding of eggs and larvae by these parasites. Diagnostic methods range from simple morphological identification to more specialised high-throughput sequencing technologies. Microscopy-based methods, although simple, are labour-intensive and considerably less sensitive than molecular methods which are rapid and have high levels of accuracy. Molecular methods use nucleic acid amplification (NAA) to amplify the deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) fragments of the parasite to detect and determine its presence using different technologies (NAAT). They have increased the sensitivity of detection and quantitation of intestinal nematode infections, especially in low infection intensity settings. The absence of a gold standard test limits current diagnosis and, in turn, restricts intervention measures and effective control efforts. The objective of this review is to determine the accuracy of NAATs in detecting human intestinal nematode infections using Kato-Katz as the reference test for the most common soil-transmitted helminth (STH) infections and the scotch tape test for enterobiasis and Baermann method for strongyloidiasis. Relevant studies will be identified by searches in electronic databases. Two reviewers will independently screen the literature against eligibility criteria. The methodological quality of studies will then be appraised by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Discrepancies will be addressed by a third reviewer. The true positives, false positives, true negatives and false negatives of all the studies will be extracted into contingency tables. In paired forest plots, study-specific sensitivity and specificity with a 95 per cent confidence interval will be displayed. The systematic review of this protocol will report the diagnostic accuracy of currently available NAATs for the detection of human intestinal nematode infections. This will help healthcare providers and administrators determine the diagnostic method to be used in different clinical and preventive settings. Trial registration: PROSPERO registration number for this protocol is CRD42022315730.

Age-dependent rise in IFN-γ competence undermines effective type 2 responses to nematode infection

The efficient induction of type 2 immune responses is central to the control of helminth infections. Previous studies demonstrated that strong Th1 responses driven by intracellular pathogens as well as a bias for type 1 activity in senescent mice impedes the generation of Th2 responses and the control of intestinal nematode infections. Here, we show that the spontaneous differentiation of Th1 cells and their expansion with age restrains type 2 immunity to infection with the small intestinal nematode H. polygyrus much earlier in life than previously anticipated. This includes the more extensive induction of IFN-γ competent, nematode-specific Th2/1 hybrid cells in BALB/c mice older than three months compared to younger animals. In C57BL/6 mice, Th1 cells accumulate more rapidly at steady state, translating to elevated Th2/1 differentiation and poor control of parasite fitness in primary infections experienced at a young age. Blocking of early IFN-γ and IL-12 signals during the first week of nematode infection leads to sharply decreased Th2/1 differentiation and promotes resistance in both mouse lines. Together, these data suggest that IFN-γ competent, type 1 like effector cells spontaneously accumulating in the vertebrate host progressively curtail the effectiveness of anti-nematode type 2 responses with rising host age.

NAD(P)H fluorescence lifetime imaging of live intestinal nematodes reveals metabolic crosstalk between parasite and host

Infections with intestinal nematodes have an equivocal impact: they represent a burden for human health and animal husbandry, but, at the same time, may ameliorate auto-immune diseases due to the immunomodulatory effect of the parasites. Thus, it is key to understand how intestinal nematodes arrive and persist in their luminal niche and interact with the host over long periods of time. One basic mechanism governing parasite and host cellular and tissue functions, metabolism, has largely been neglected in the study of intestinal nematode infections. Here we use NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate) fluorescence lifetime imaging of explanted murine duodenum infected with the natural nematode Heligmosomoides polygyrus and define the link between general metabolic activity and possible metabolic pathways in parasite and host tissue, during acute infection. In both healthy and infected host intestine, energy is effectively produced, mainly via metabolic pathways resembling oxidative phosphorylation/aerobic glycolysis features. In contrast, the nematodes shift their energy production from balanced fast anaerobic glycolysis-like and effective oxidative phosphorylation-like metabolic pathways, towards mainly anaerobic glycolysis-like pathways, back to oxidative phosphorylation/aerobic glycolysis-like pathways during their different life cycle phases in the submucosa versus the intestinal lumen. Additionally, we found an increased NADPH oxidase (NOX) enzymes-dependent oxidative burst in infected intestinal host tissue as compared to healthy tissue, which was mirrored by a similar defense reaction in the parasites. We expect that, the here presented application of NAD(P)H-FLIM in live tissues constitutes a unique tool to study possible shifts between metabolic pathways in host-parasite crosstalk, in various parasitic intestinal infections.

Influence of breed and parasite challenge on the immune response to naturally acquired intestinal nematode infection in sheep.

Natural infection by intestinal nematodes was assessed in Santa Ines and Ile de France sheep breeds, over a five-month grazing period, with emphasis on the development of the immune response in lambs under two anthelmintic treatment regimens. Nineteen Santa Ines and 19 Ile de France male lambs were allocated into two treatment groups: animals under suppressive treatment with anthelmintics; and animals under targeted selective treatment (TST). The nematodes Trichostrongylus colubriformis and Strongyloides papillosus showed the highest infection intensity in the TST animals in both breeds. Parasite-specific immunoglobulin G levels were significantly higher and more rapidly induced in Santa Ines lambs. Additionally, these lambs had higher levels of parasite-specific immunoglobulin A in intestinal mucus. Animals under TST had higher means of mast cells and globule leukocytes in the intestinal mucosa due to longer and greater parasite challenge in comparison with the suppressive group. A breed effect (P < 0.05) was recorded for mast cells, with Santa Ines lambs presenting the highest counts. Although Santa Ines lambs had lower intestinal nematode counts than Ile de France lambs, they had shown a large variation in T. colubriformis burden, with most of them presenting a marked worm burden, despite showing an earlier and more intense immune response to intestinal nematode infection.

Maternal nematode infection upregulates expression of Th2/Treg and diapedesis related genes in the neonatal brain

Intestinal nematode infections common during pregnancy have recently been shown to have impacts that extend to their uninfected offspring including altered brain gene expression. If maternal immune signals reach the neonatal brain, they might alter neuroimmune development. We explored expression of genes associated with four distinct types of T cells (Th1, Th2, Th17, Treg) and with leukocyte transendothelial migration and endocytosis transport across the blood–brain barrier (BBB) in the postnatal brain of offspring of nematode-infected mice, through secondary analysis of a whole brain gene expression database. Th1/Th17 expression was lowered by maternal infection as evidenced by down-regulated expression of IL1β, Th1 receptors and related proteins, and of IL22 and several Th17 genes associated with immunopathology. In contrast, Th2/Treg related pathways were upregulated as shown by higher expression of IL4 and TGF-β family genes. Maternal infection also upregulated expression of pathways and integrin genes involved in transport of leukocytes in between endothelial cells but downregulated endosome vesicle formation related genes that are necessary for endocytosis of immunoglobulins across the BBB. Taken together, pup brain gene expression indicates that maternal nematode infection enhanced movement of leukocytes across the neonatal BBB and promoted a Th2/Treg environment that presumably minimizes the proinflammatory Th1 response in the pup brain.

Strongyloidiasis as a Hidden Cause of Protein Losing ‎Enteropathy

Parasitic infection still surprises us with amazing case presentation every ‎now and then. Intestinal nematode infection is a worldwide health problem ‎especially in humid and hot areas. Strongyloides stercoralis (S. stercoralis) ‎is a common soil- transmitted nematode infection in tropics and subtropics. ‎Its severity ranges from asymptomatic infection in immunocompetent ‎patients to hyperinfection and even disseminated infection in ‎immunocompromised patients. Here, we report a case of severe protein ‎losing enteropathy caused by S. stercoralis‎‎‎‎‎‎.

Paediatric assessment of immune responses in 3 to 5 years olds having intestinal nematode infection and vaccinated with valent10-PCV

Valent 10 - Pneumococcal conjugate vaccine (PCV10) introduction into routine immunization schedule has resulted in reduction of the incidence of Invasive Pneumococcal disease (IPD) in children in Kenya. This study assessed immunological effect of nematode infection in children aged 3 to 5 years vaccinated with PCV10. The study subjects were from Mukuru Kwa Njenga settlement in Nairobi County, Kenya. The children were medically examined for the presence of other infectious diseases by a qualified clinical officer. Questionnaires on the PCV10 vaccination history and deworming history of children were administered to the parents or guardians of children with the help of community health workers. The intensity of nematode infections was examined in the faecal samples using Kato-Katz technique and expressed as eggs per gram (EPG) of faeces. Serum samples were obtained from blood collected during sampling and used in Flow cytometry to determine levels of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ in cellular immune responses, whereas, ELISA was used to determine the levels of IgG and IgE antibodies in humoral responses. Results showed 73.4% of children completed the PCV10 vaccination dose schedule, 21.6% of children sampled had suffered invasive pneumococcal infections post PCV10 vaccination. Ascaris lumbricoides was the only species identified in 34.9% of children having light to moderate infection intensity with mean intensity of 17808EPG. Significant IL-6 levels expressed in children having nematode infection impacted increased secretion of IgG and IgE, thus, an indication that the humoral responses were significantly stimulated. Results indicate suppression of TNF-α expression in the category of children who had nematode infection and were also vaccinated with PCV10, however, a higher expression of IFN-γ in the same category implied a negative impact on PCV10 responses. The study also indicated that presence of nematodes and vaccination had a profound influence on the expression of IL-2, however, PCV10 vaccination and intestinal nematode infection did not significantly impact the expression of IL-4 and IL-10 cytokines. Immune responses due to infection with Ascaris lumbricoides stimulated multiple effector mechanisms influencing induction of cellular responses in PCV10 vaccination. Further investigation of other key cytokines as well as other parasites and pneumonia vaccines in other vulnerable individuals is therefore necessary in the management of concomitant infections in order to reduce the suppression of immune responses often resulting in difficulties in disease management.

Albendazole and Mebendazole as Anti-Parasitic and Anti-Cancer Agents: an Update.

The use of albendazole and mebendazole, i.e., benzimidazole broad-spectrum anthelmintics, in treatment of parasitic infections, as well as cancers, is briefly reviewed. These drugs are known to block the microtubule systems of parasites and mammalian cells leading to inhibition of glucose uptake and transport and finally cell death. Eventually they exhibit ovicidal, larvicidal, and vermicidal effects on parasites, and tumoricidal effects on hosts. Albendazole and mebendazole are most frequently prescribed for treatment of intestinal nematode infections (ascariasis, hookworm infections, trichuriasis, strongyloidiasis, and enterobiasis) and can also be used for intestinal tapeworm infections (taeniases and hymenolepiasis). However, these drugs also exhibit considerable therapeutic effects against tissue nematode/cestode infections (visceral, ocular, neural, and cutaneous larva migrans, anisakiasis, trichinosis, hepatic and intestinal capillariasis, angiostrongyliasis, gnathostomiasis, gongylonemiasis, thelaziasis, dracunculiasis, cerebral and subcutaneous cysticercosis, and echinococcosis). Albendazole is also used for treatment of filarial infections (lymphatic filariasis, onchocerciasis, loiasis, mansonellosis, and dirofilariasis) alone or in combination with other drugs, such as ivermectin or diethylcarbamazine. Albendazole was tried even for treatment of trematode (fascioliasis, clonorchiasis, opisthorchiasis, and intestinal fluke infections) and protozoan infections (giardiasis, vaginal trichomoniasis, cryptosporidiosis, and microsporidiosis). These drugs are generally safe with few side effects; however, when they are used for prolonged time (>14–28 days) or even only 1 time, liver toxicity and other side reactions may occur. In hookworms, Trichuris trichiura, possibly Ascaris lumbricoides, Wuchereria bancrofti, and Giardia sp., there are emerging issues of drug resistance. It is of particular note that albendazole and mebendazole have been repositioned as promising anti-cancer drugs. These drugs have been shown to be active in vitro and in vivo (animals) against liver, lung, ovary, prostate, colorectal, breast, head and neck cancers, and melanoma. Two clinical reports for albendazole and 2 case reports for mebendazole have revealed promising effects of these drugs in human patients having variable types of cancers. However, because of the toxicity of albendazole, for example, neutropenia due to myelosuppression, if high doses are used for a prolonged time, mebendazole is currently more popularly used than albendazole in anti-cancer clinical trials.

Field study to investigate the effectiveness and safety of a novel orally administered combination drug product containing milbemycin oxime and lotilaner (Credelio\xae Plus) against natural intestinal nematode infections in dogs presented as veterinary patients in Europe

BackgroundA randomised, blinded, positive controlled, multicentre, Good Clinical Practice-compliant, pivotal field study was conducted to evaluate the effectiveness and safety of a new combination of lotilaner + milbemycin oxime tablets (Credelio® Plus; Elanco Animal Health) administered orally to client-owned dogs naturally infected with intestinal nematodes.MethodsClient-owned dogs presenting to veterinary clinics from households in France, Hungary and Germany were screened for intestinal nematodes. Dogs with an initial positive faecal egg count that was subsequently confirmed with a follow-up faecal examination to demonstrate the presence of naturally occurring mixed or mono-infections with Toxocara canis, Toxascaris leonina, Trichuris vulpis or Ancylostoma caninum were enrolled on Day 0 into the study. Households were randomised in an approximately 2:1 ratio to receive either an investigational product (IP; Credelio Plus tablets) or control product (CP; Nexgard Spectra® tablets) as treatment. Dogs were administered the IP (n = 278) or CP (n = 117) once on Day 0 at a dose rate of 0.75–1.56 mg/kg bodyweight milbemycin oxime and 20.0–41.5 mg/kg bodyweight lotilaner (IP) or as recommended (CP). Effectiveness of the IP and CP treatments was based on the post-treatment reduction in geometric mean faecal egg counts on Day 8 (range Day 7–10) after treatment as compared to their pre-treatment nematode faecal egg counts.ResultsGeometric mean (GM) faecal egg counts for T. canis, A caninum and T. vulpis were reduced by ≥ 97.2% in the Credelio Plus group and by ≥ 95.3% in the afoxolaner + milbemycin oxime group. There were insufficient data to calculate a percentage reduction in GM faecal egg counts between Day 0 and Day 8 for T. leonina due to low prevalence. Credelio Plus was well tolerated in this field study. Of the 355 total doses administered, 82.3% were accepted free choice in the IP group compared to 80.8% in the CP group.ConclusionsThis study demonstrated effectiveness (≥ 97.2% reduction), safety and tablet acceptance of a combination of milbemycin oxime and lotilaner (Credelio Plus) administered orally to dogs with natural intestinal infections of T. canis, A. caninum and T. vulpis.Graphical

High resistance to intestinal nematode infection is associated with a strong bias for TFH cell responses, rapid IgG1 class switch and limited Th2 effector cell expansion

Abstract Gastrointestinal nematode infections are highly prevalent in nature, lead to considerable morbidity in infected humans and cause high economical loss in animal husbandry. While it is clear that type 2 responses orchestrated by CD4+GATA-3+ Th2 cells are pivotal for the control of GI nematodes, the basis for differential susceptibility of distinct host genetic backgrounds is less well understood. The high resistance of ‘rapid responder’ SJL mice to infections with the small intestinal nematode H. polygyrus is evident in low parasite egg production and the termination of infection within a few weeks. Comparing the SJL line to slow responder C57BL/6 mice, we found that SJL mice generated relatively few Th2 effector cells, many follicular T helper cells and strong antibody responses in spleen and gut draining lymph nodes. These Th2 effector cells of SJL mice expressed high levels of the gut/mucosal homing markers CCR9/a4b7, resulting in the rapid accumulation of Th2 cells in the infected small intestine. Surprisingly, resistance was further associated with exceptionally high proportions of Treg in the spleen of SJL mice at steady state and the vigorous expansion of Treg in mLN after infection. This coincided with a bias for follicular T helper cells expansion in both mLN and spleen and, consequently, more extensive IgG1 class switching by GL7+ germinal center B cells in both organs. Infection-derived B cells transfer provides protection in SJL mice, not in B6 mice. In conclusion, resistance versus susceptibility to primary H. polygyrus infection appears to be less dependent on the overall magnitude of Th2 responses, but rather seems to depend on rapid Th2 effector homing, follicular T helper cells and the rapid instruction of antibody responses.

Helminth infections in the US military: from strongyloidiasis to schistosomiasis.

Helminth infections caused by parasitic worms, including nematodes (roundworms), cestodes (tapeworms) and trematodes (flukes), can cause chronic symptoms and serious clinical outcomes if left untreated. The US military frequently conducts activities in helminth-endemic regions, particularly Africa, the Middle East and Southeast Asia. However, the military does not currently screen for these infections, and to date, no comprehensive surveillance studies have been completed to assess the frequency of helminth diagnoses in the military personnel and their families. To determine the burden of helminth infections in the US Military Health System (MHS), we conducted a retrospective analysis of International Classification of Diseases (ICD)-9/10 diagnosis codes from all medical encounters in the MHS Data Repository (MDR) from fiscal years (FY) 2012 to 2018. Chart reviews were conducted to assign ICD diagnoses as incorrect, suspected, probable or confirmed based on the laboratory results and symptoms. Abstraction of MHS data revealed over 50 000 helminth diagnoses between FY 2012 and FY 2018. Of these, 38 445 of diagnoses were amongst unique subjects. After chart review, we found there were 34 425 validated helminth infections diagnosed amongst the unique subjects of US military personnel, retirees and dependents. Nearly 4000 of these cases represented infections other than enterobiasis. There were 351 validated strongyloidiasis diagnoses, 317 schistosomiasis diagnoses and 191 diagnoses of cysticercosis during the study period. Incidence of intestinal nematode infection diagnoses showed an upward trend, whilst the incidence of cestode infection diagnoses decreased. The results of this study demonstrate that helminth infections capable of causing severe morbidity are often diagnosed in the US military. As helminth infections are often asymptomatic or go undiagnosed, the true burden of helminth infections in US military personnel and dependents may be higher than observed here. Prospective studies of US military personnel deployed to helminth-endemic areas may be indicated to determine if post-deployment screening and/or empirical treatment are warranted.

Evaluation of Commercially Available Anthelminthics in Laboratory Models of Human Intestinal Nematode Infections.

Drug repurposing from veterinary to human medicine has been the main strategy to develop the four recommended human anthelminthics, albendazole, mebendazole, levamisole, and pyrantel pamoate, for the treatment of soil-transmitted helminthiasis. A systematic, head-to-head comparison of the anthelminthic activity profile of derivatives of these drugs and other anthelminthics developed in succession has not been conducted to date. We studied eight benzimidazoles, five macrocyclic lactones, tribendimidine, levamisole, and pyrantel pamoate in laboratory models of human intestinal nematode infections. In vitro studies were performed on Trichuris muris L1 larval stage and adults, as well as Ancylostoma ceylanicum, Necator americanus, Heligmosomoides polygyrus, and Strongyloides ratti L3 larvae and adults. The benzimidazoles showed pronounced differences against larval and adult stages, with low activity against larvae and the highest activity observed against adult N.americanus (IC50 of flubendazole 1.1 μM). The macrocyclic lactones, on the other hand, revealed a higher activity on the larval stages, with the lowest IC50 values observed against N.americanus L3 (IC50 values of 0.03-3 μM). In vivo studies were performed in the T.muris and H.polygyrus mice models, with moxidectin and milbemycin oxime showing the highest activity against H.polygyrus (ED50 values of 0.009 and 0.006 mg/kg, respectively) and moxidectin and abamectin being the most effective drugs against T.muris (ED50 values of 0.2 and 0.5 mg/kg, respectively). Laboratory models for soil-transmitted helminthiasis can assist characterizing potential drug candidates. Drugs should be evaluated against different species, and both the adult and larval stages as activities could differ considerably.

Correlation of Nutritional Status with Hookworm and Strongyloides stercoralis Infection in Children Under Five Years in Kokar Public Health Center, Alor Regency, East Nusa Tenggara

Malnutrition can reduce immune response particularly in cytokine (IL-4, IL-5, IL-10) production and immune effector (eosinophil, IgE, and mast cell), thus increasing the probability of intestinal nematode infection. Through this study, intestinal nematode infections occurred among children under five years, at different nutrition status, in Kokar Public Health center, Alor Regency, East Nusa Tenggara was captured. Hookworm and Strongyloides stercoralis were studied as both of them have devastating impacts compare to other helminthes compare to other helminths. This study is a cross- sectional study with a quote sampling technique. As many as 238 children, aged 12-59 months living in Kokar’s Public Health Center area, Alor regency were recruited in this study i.e. 7.7% severely underweight, 19.2% underweight, 70.5% normal and 2.6% overweight. Data were collected in August - October 2016. Hookworm and S. stercoralis infection were determined from collected fecal samples of all subjects using either Baermann test, Koga Agar Plate (KAP), or Harada- Mori culture method. The prevalence of hookworm and S. stercoralis infection was 8.82%, and 0,42%. Correlation between nutritional status and hookworm infection were analyzed by Mann-Whitney test with p value = 0.54 (p &gt; 0.05). Prevalence of hookworm and S. stercoralis among children under five years in Kokar were 8.82% and 0.42%. There was no significant correlation between nutritional status with hookworm infection prevalence.

Evaluation of control effect of implement effective control for intestinal nematode disease in Nanjing

Objective To evaluate the control effect of effective control for intestinal nematode disease, and to analyze the dynamic change of epidemic trend, we provide basis for adjusting control strategy of intestinal nematode disease. Methods The data of control strategies in Nanjing from 2001 to 2019 were analyzed, including monitoring data of intestinal nematode disease, drug deworming, health education and rural toilet improvement. Results From 2001 to 2019, 191 172 person-times of residents were surveyed fecal examination in Nanjing City, and 2 596 person-times of residents were detected with intestinal nematode infections, with annual average infection rate 1.36%. The positive rate of human intestinal nematode infections showed a significantly declining trend in total ( P <0.01). In Nanjing, intestinal nematode infections were mainly caused by ascaris (0.90%, 1 724 cases), hookworm (0.30%, 564 cases), pinworm (0.09%, 179 cases) and trichuris (0.07%, 129 cases). Among them, 2 345 cases (96.98%) had mild infection. In 2001, the infection rate was the highest (7.00%), while in 2018 and 2019, the infection rate was the lowest (both 0.01%). The difference of infection rate in each year was statistically significant ( P <0.01). 114 940 person-times of children under 12 years old were surveyed for the special surveillance of pinworm in Nanjing, and 500 cases were detected with positive infection. Moreover, the positive rate showed a significantly decreasing trend in total ( P <0.01). At the end of 2019, 9 237.5 million person-times have been treated with medicine, the awareness rate of intestinal nematode control among the population in Nanjing reached more than 90%, the penetration rate of harmless toilets was 99.99%. Conclusion The effective control of intestinal nematode disease in Nanjing has achieved remarkable results, however, the surveillance network of intestinal nematode disease still should be improved, and health education in key population groups should be strengthened, in order to adjust control strategies in time, and effectively consolidate the effectiveness of the control of intestinal nematode disease. 摘要：目的 评价有效控制肠道线虫病项目的防治效果,分析流行趋势的动态变化,为调整肠道线虫病防控策略 提供依据。 方法 对2001—2019年南京市肠道线虫病监测数据、以及实施驱虫服药、健康教育、农村改厕等防治策略 资料进行统计分析。 结果 2001—2019年,南京市共粪检191 172人次,检出肠道线虫阳性感染2 596人次,年平均感 染率为1.36%,人群肠道线虫感染率逐年下降趋势( P <0.01)。南京市肠道线虫感染以蛔虫、钩虫、蛲虫、鞭虫为主,且以 轻度感染为主,共计2 345 例（占96.98%),感染人数分别为1 724例、564例、179例和129例,感染率分别为0.90%、0.30%,0.09%和0.07%。以2001年的人群感染率最髙,为7.00%,2018年和2019年的感染率最低,均为0.01%,各年份人 群感染率差异有统计学意义( P <0.01)。南京市儿童蛲虫病专项监测累计检査儿童114 940人次,阳性感染者500人次。儿童蛲虫感染率亦呈现逐年下降趋势( P <0.01)。截至2019年12月,南京市已累计服药驱虫923 750万人次,人群肠道 线虫病卫生知识知晓率大于90%,无害化卫生户厕普及率为99.99%。 结论 南京市有效控制肠道线虫病防治项目取 得显著效果,但仍需不断完善肠道线虫病的监测网络,加强重点人群健康教育,适时调整防控策略,有效巩固肠道线虫 病的防治成效。

Copro-molecular identification of intestinal nematode infections in a rural community in East Malaysia.

Soil-transmitted helminth (STH) infections are the most common intestinal parasitic infections of medical importance in humans. The infections are widely distributed throughout tropical and subtropical countries, particularly among disadvantaged and underprivileged communities. In Malaysia, STH infections is highly prevalent, especially among the indigenous groups. However, species identification through molecular studies is still lacking. Using molecular techniques, this study was conducted to identify STH species that infect humans. Faecal samples were collected from three Iban tribal longhouses in the rural area of Sarikei Division, Sarawak. Positive faecal samples by microscopy were subjected to PCR and sequenced for species identification. Based on the microscopy examination, the most prevalent STH infection was Ascaris, followed by hookworm and Trichuris. All microscopy-positive samples were then PCR-amplified. The amplicons were sequenced, aligned, and compared with other sequences in the GenBank database. The results showed that Ascaris lumbricoides was the predominant STH species, followed by Trichuris trichiura, Ancylostoma duodenale, and Necator americanus. Our findings were contradictory to past studies, as we showed that A. duodenale was more abundant than N. americanus. Socioeconomic improvement and health education programs should be included in the management and prevention of public health strategies against STH.

Development of a Solid Formulation Containing a Microemulsion of a Novel Artemisia Extract with Nematocidal Activity for Oral Administration

Background: Intestinal nematode infections are usually treated with benzimidazole drugs, but the emergence of resistance to these drugs has led to an increasing demand of new anthelmintic strategies. A new microemulsion formulation (ME) consisting of an Artemisia absinthium extract with proven nematocidal efficacy was previously developed. The aim of our study is to implement a D-optimal mixture design methodology to increase the amount of a silica material (loaded with this ME) in a tablet formulation, considering its tensile strength and disintegration time. Methods: 16 experiments or combinations of the 6 tablet components (loaded silica, microcrystalline cellulose, polyvinylpyrrolidone, croscarmellose, Syloid® 244 FP and magnesium stearate) were assessed. Tensile strength and disintegration time models were developed, and an optimization process was carried out. Results: Tensile strength was improved by increasing the polyvinylpyrrolidone content, while croscarmellose decreased the disintegration time. The optimized powder mixture contains 49.7% w/w of the loaded silica material. A compression force of 12 kN was applied to the powder mixture to form tablets with a tensile strength of 2.0 MPa and a disintegration time of 3.8 min. Conclusions: Our results show that D-optimal mixture designs provide a promising approach to formulate liquid-loaded silica materials.

Characterisation of the secreted apyrase family of Heligmosomoides polygyrus

Apyrases are a recurrent feature of secretomes from numerous species of parasitic nematodes. Here we characterise the five apyrases secreted by Heligmosomoides polygyrus, a natural parasite of mice and a widely used laboratory model for intestinal nematode infection. All five enzymes are closely related to soluble calcium-activated nucleotidases described in a variety of organisms, and distinct from the CD39 family of ecto-nucleotidases. Expression is maximal in adult worms and restricted to adults and L4s. Recombinant apyrases were produced and purified from Pichia pastoris. The five enzymes showed very similar biochemical properties, with strict calcium dependence and a broad substrate specificity, catalysing the hydrolysis of all nucleoside tri- and diphosphates, with no activity against nucleoside monophosphates. Natural infection of mice provoked very low antibodies to any enzyme, but immunisation with an apyrase cocktail showed partial protection against reinfection, with reduced egg output and parasite recovery. The most likely role for nematode secreted apyrases is hydrolysis of extracellular ATP, which acts as an alarmin for cellular release of IL-33 and initiation of type 2 immunity.

Effectiveness of a community-based integrated strategy to control soil-transmitted helminthiasis and clonorchiasis in the People's Republic of China

Soil-transmitted helminthiases (STHs) are caused by a group of intestinal nematode infections due to poor hygiene and environments, and clonorchiasis is a food-borne trematode (FBT) infection caused by ingestion of raw freshwater fish. Both are endemic in the People's Republic of China. To explore a suitable control strategy, integrated interventions were applied between 2007 and 2009 in ten pilot counties (eight for the STHs and two for clonorchiasis). Drug administration was used for treatment and complementary efforts to improve the situation based on health education, provision of clean water and sanitation were carried out. Significant achievements were gained as reflected by a drastic decrease in prevalence these infections were demonstrated. The overall prevalence of STHs and clonorchiasis decreased from 35.9% to 7.8% and from 41.4% to 7.0%, respectively. The reduction of prevalence and high cost-effectiveness were documented supporting large-scale application of this integrated intervention in China and elsewhere.