Contribution of socio-demographic factors in prevalence of soil-transmitted helminth infections among newly arrived laborers in Jeddah, Saudi Arabia.

Background: Soil-transmitted diseases are caused by intestinal worms transmitted via various routes into the human body resulting in various clinical manifestations. This study aimed to investigate the socio-demographic factors contributing mainly to the prevalence of soil-transmitted helminths (STHs) among newly arrived laborers in Jeddah, Saudi Arabia. Methods: A total of 188 stool specimens were collected and examined macroscopically and microscopically using different techniques. In addition, real-time PCR was used as a molecular tool to detect several STHs. The descriptive analysis was used to evaluate demographic data and categorical variables in association with STHs infection. Results: Of all participants, the mean age was 26.08 ± 2.67 years, including 103 females and 85 males. A total of 86 (45.70%) were illiterate, followed by 60 (31.90%) of participants belonging to elementary level. STHs and other intestinal parasites were detected among 35 newly arrived laborers (18.61%). Nineteen cases (10.11%) were infected with STHs, including 15 cases with one STHs (four A. lumbricoides, four N. americanus, four T. trichiura, two S. stercoralis, one A. duodenale) and four cases with two STHs (two T. trichiura and N. americanus; one S. stercoralis and A. duodenale; one T. trichiura and S. stercoralis). High rates of STHs infection were detected among drivers (11.70%) followed by housemaids (11.20%), but with no significant association to occupation. Higher rates of STHs infection were detected among those used to walk on soil barefoot in their home countries before arriving in Jeddah. Conclusion: This study found that none of the newly arrived expatriate laborers in Jeddah was aware of STHs. About 10% of them had infection with one or two STHs, mainly among newly arrived laborers from Asian countries. There is a need for awareness programs and regular screening for STHs and other intestinal parasites among newly arrived expatriate laborers.

Assessment of the Distribution of Intestinal Parasites Detected in the Parasitology Laboratory of Çukurova University Faculty of Medicine Between 2017 and 2021.

OBJECTIVE: It is known that protozoa and helminths that cause intestinal infections adversely affect human life. Changing climate and demographic and socio-economic factors worldwide necessitate the determination and updating of the incidence of these parasites. Our study aimed to retrospectively examine the distribution of intestinal parasites detected in the Parasitology Laboratory of Çukurova University Faculty of Medicine between 2017 and 2021. METHODS: Parasitological examinations were performed using the native-lugol and formol-ether condensation method. Staining method (Modified Ziehl-Neelsen) and cellophane tape method were then applied to evaluate the specimens considered necessary. RESULTS: One or more parasites were detected in 33 of 373 patients (8.8%) evaluated in the study. These were Giardia intestinalis at a rate of 30.5% (11/36), Enterobius vermicularis at a rate of 27.7% (10/36), Blastocystis sp. at a rate of 19.4% (7/36), Entamoeba coli at a rate of 11.1% (4/36), Cryptosporidium spp. at a rate of 8.3% (3/36) and Taenia saginata at a rate of 2.7% (1/36). It was determined that two patients were coinfected by Entamoeba coli and Blastocystis sp. while one patient was coinfected by Entamoeba coli and Giardia intestinalis. CONCLUSION: It is thought that determining the incidence of intestinal parasites, which are an important public health problem, may help guide studies for preventive health services. Although the five-year laboratory data obtained from the study do not reflect our region, it is thought that intestinal parasites maintain their importance.

Gut-microbiome profiles among Soil-transmitted helminths (STHs) infected Ethiopian children enrolled in the school-based mass deworming program.

BACKGROUND: Soil-transmitted helminths (STHs) and mutualistic gut microbes coexist in the gastrointestinal tract. However, limited data exist regarding how STH infections are associated with gut microbiome profiles. METHOD: We conducted a cross-sectional analysis of baseline data collected in a longitudinal study to identify and explain differences in microbial communities between STH-infected and non-infected Ethiopian school children. We collected 138 stool samples and analyzed them for STH infection using standard direct wet mount and Kato Katz methods. The gut microbiome profiles were characterized using targeted amplicon sequencing of the 16S rRNA gene from the total DNA extracted from the stools. RESULTS: Children infected with Trichuris trichiura showed significantly lower microbial diversity than those who were non-infected (p<0.05). We also observed significant difference in microbiome composition based on Trichuris trichiura infection status (PERMANOVA p< 0.01). A comparison of microbial taxa at the genus level among participants infected with different helminth species showed a significant increase in Agathobacter relative abundance among children infected with Trichuris trichiura compared to non-infected subjects (adjusted p = 0.001). CONCLUSIONS: Our results indicate that changes in the gut microbiome composition may vary depending on the species of helminth present. Further studies should investigate how Trichuris trichiura selectively alters microbiome composition compared to other STH species.

Artificial intelligence-based digital pathology for the detection and quantification of soil-transmitted helminths eggs.

BACKGROUND: Conventional microscopy of Kato-Katz (KK1.0) thick smears, the primary method for diagnosing soil-transmitted helminth (STH) infections, has limited sensitivity and is error-prone. Artificial intelligence-based digital pathology (AI-DP) may overcome the constraints of traditional microscopy-based diagnostics. This study in Ucayali, a remote Amazonian region of Peru, compares the performance of AI-DP-based Kato-Katz (KK2.0) method to KK1.0 at diagnosing STH infections in school-aged children (SAC). METHODS: In this prospective, non-interventional study, 510 stool samples from SAC (aged 5-14 years) were analyzed using KK1.0, KK2.0, and tube spontaneous sedimentation technique (TSET). KK1.0 and KK2.0 slides were evaluated at 30-minute and 24-hour timepoints for detection of Ascaris lumbricoides, Trichuris trichiura, and hookworms (at 30-minute only). Diagnostic performance was assessed by measuring STH eggs per gram of stool (EPG), sensitivity of methods, and agreement between the methods. RESULTS: KK2.0 detected more A. lumbricoides positive samples than KK1.0, with detection rates for T. trichiura and hookworms being comparable. At 30-minutes, 37.6%, 23.0%, and 2.6% of the samples tested positive based on KK1.0 for A. lumbricoides, T. trichiura, and hookworms, while this was 49.8%, 24.4%, and 1.9% for KK2.0. At 24-hours, 37.1% and 27.1% of the samples tested positive based on KK1.0 for A. lumbricoides and T. trichiura, while this was 45.8% and 24.1% for KK2.0. Mean EPG between KK2.0 and KK1.0 were not statistically different across STH species and timepoints, except for T. trichiura at 24-hours (higher mean EPG for KK1.0, p = 0.036). When considering infection intensity levels, KK2.0 identified 10% more of the total population as low-infection intensity samples of A. lumbricoides than KK1.0 (p ≤ 0.001, both timepoints) and similar to KK1.0 for T. trichiura and hookworms. Varying agreement existed between KK1.0 and KK2.0 in detecting STH eggs (A. lumbricoides: moderate; T. trichiura: substantial; hookworms: slight). However, these findings should be interpreted carefully as there are certain limitations that may have impacted the results of this study. CONCLUSIONS: This study demonstrates the potential of the AI-DP-based method for STH diagnosis. While similar to KK1.0, the AI-DP-based method outperforms it in certain aspects. These findings underscore the potential of advancing the AI-DP KK2.0 prototype for dependable STH diagnosis and furthering the development of automated digital microscopes in accordance with WHO guidelines for STH diagnosis.

Efficacy of albendazole against soil-transmitted helminth infections in Ethiopia: a systematic review and meta-analysis.

Soil-transmitted helminths (STH) are neglected parasites more prevalent in the tropics. Periodic mass distribution of albendazole, is one key strategy to control STHI in endemic areas. However, benzimidazoles have low efficacy against STHI, and there is a lack of information on the magnitude of the problem in Ethiopia. Articles were searched from PubMed using MeSH words, Google Scholar, Web of science, EMBASE and Scopus database to retrieve the data published and available until December 30, 2022. Totally, 107 published articles were retrieved. Only studies conducted in English that reported the efficacy of albendazole against STHI in any year and studies with more than fifty positive cases were included in the present study. The efficacy of albendazole was estimated by its cure rate and egg reduction rate. Excel software was used to extract the name of the authors, the total sample size, number of cured participants, treatment assessment time, STH parasite involved, the study area, and the year of publication. The pooled efficacy of albendazole against STHs was analyzed using comprehensive meta-analysis version 2.2 software. A total of 14 studies (13 for hookworm, 12 for Ascaris lumbricoides, and 12 for Trichuris trichiura) fulfilled the inclusion criteria for the present systematic review and meta-analysis. The total positives for hookworm, A. lumbricoides, and T. trichiura were 1253 (24.9%), 1570 (29.5%), and 1647 (30.6%), respectively. The overall pooled efficacy of albendazole was 92.2% (95% CI 86.2-98.9%) against hookworm, 97.7% (95% CI 96.3-98.6%) against A. lumbricoides, and 38.6% (95% CI 31.0-46.9%) against T. trichiura. In subgroup analysis, the efficacy of albendazole against hookworm was 93.4% (95% CI 85.1-97.2%) in Oromia, 96.7% (95% CI 93.8-98.2%) in Sidama, and 77.2% (95% CI 64.4-86.4%) in Amhara region. Its heterogeneity was high (I2 = 89.418). The efficacy of albendazole against A. lumbricoides was 98.3% (95% CI 97.0-99.0%) in Oromia and 96.63% (95% CI 93.2-98.3%) in Sidama region. Its heterogeneity was moderate (I2 = 41.5%). Albendazole efficacy against T. trichiura was 39.0% (95% CI 30.4-48.5%) in Oromia and 37.8% (95% CI 21.8-56.9%) in Sidama region with high heterogeneity (I2 = 90.6%). In the present review, albendazole is effective against hookworm and A. lumbricoides but less effective against T. trichiura. Albendazole should therefore be used as a treatment option in hookworm and A. lumbricoides endemic areas. However, alternative drugs should be sought for T. trichiura.

Comparison of multi-parallel quantitative real-time PCRs targeting different DNA regions and detecting soil-transmitted helminths in stool.

BACKGROUND: Soil-transmitted helminths infect an estimated 18% of the world's population, causing a significant health burden. Microscopy has been the primary tool for diagnosing eggs from fecal samples, but its sensitivity drops in low-prevalence settings. Quantitative real-time polymerase chain reaction (qPCR) is slowly increasing in research and clinical settings. However, there is still no consensus on preferred qPCR targets. METHODS: We aimed to compare soil-transmitted helminth (STH) DNA detection methods by testing naïve stool samples spiked with known quantities of STH eggs and larvae. DNA extracts from spiked samples were tested using independent quantitative realtime PCR (qPCR) assays targeting ribosomal or putative non-protein coding satellite sequences. RESULTS: For Trichuris trichiura, there was a strong correlation between egg/larvae counts and qPCR results using either qPCR method (0.86 and 0.87, respectively). Strong correlations also existed for A. lumbricoides (0.60 and 0.63, respectively), but weaker correlations were found for Ancylostoma duodenale (0.41 for both assays) and Strongyloides stercoralis (0.48 and 0.65, respectively). No correlation for Necator americanus was observed when testing with either qPCR assay. Both assays had fair-to-moderate agreement across targets when using field-collected stool samples (0.28-0.45, for all STHs), except for S. stercoralis (0.12) with slight agreement. CONCLUSIONS: There is a strong correlation between qPCR results and egg/larvae counts. Our study confirms that qPCR is an effective diagnostic tool, even with low-intensity infections, regardless of the DNA-based diagnostic marker used. However, the moderate agreement between the two different qPCR assays when testing field samples highlights the need to understand the role of these targets in the genome so that the parasite burden can be quantified more accurately and consistently by qPCR.

Unveiling the Transmission Potential of Opisthorchis viverrini and Intestinal Helminths Along the Thailand-Laos Border in Thailand.

AIMS: In pursuit of enhancing prevention efforts for the notably high endemic Opisthorchis viverrini infection in lower Mekong sub-region countries, particularly Thailand and Laos, this cross-sectional study investigated the transmission potential of O. viverrini and other intestinal helminths along the Thailand-Laos border in seven Thai villages. METHODS AND RESULTS: Human and pet faecal samples, Bithynia snails and cyprinid fish were analysed for helminth infections. Additionally, a questionnaire survey assessed relevant risk factors among the human population. Two groups of helminth infections were detected in humans: foodborne infections (FBIs) including O. viverrini, minute intestinal flukes (MIFs), and Taenia spp., and soil-transmitted infections (STIs) including hookworm and Strongyloides stercoralis, with prevalence rates of 7.4%, 0.5%, 2.5%, 0.5%, 2.5% and 3%, respectively. Smoking was identified as a risk factor for O. viverrini infection [adjusted odds ratios (ORa) = 3.12, 95% confidence intervals (CI): 1.33-7.30, p = 0.009] and FBIs (ORa = 2.47, 95% CI: 1.14-5.33, p = 0.022), while male was a risk factor for FBIs (ORa = 2.62, 95% CI: 1.16-5.94, p = 0.021). In dogs, hookworm, Toxocara spp., Spirometra mansoni, Trichuris vulpis and Hymenolepis diminuta were identified with prevalence rates of 35.6%, 8.1%, 8.1%, 1.2% and 1.2%, respectively. In cats, hookworm, Toxocara spp., S. mansoni, Strongyloides spp., Platynosomum fastosum, MIFs and H. diminuta were identified with prevalence rates of 50%, 17.9%, 10.7%, 7.1%, 3.6%, 3.6% and 3.6%, respectively. Bithynia snails showed 2% virgulate and 0.7% unknown cercariae infections, while among 19 cyprinid fish species, only unknown metacercariae were found. CONCLUSIONS: Our findings underscore the necessity of an integrated approach following the One Health concept to effectively combat these parasitic diseases while addressing human, animal and environmental health.

Gastrointestinal Helminthic Infection among the Population in Northern Thailand.

PURPOSE: Gastrointestinal (GI) helminthic infections pose substantial public health threat, particularly in northern Thailand, with a heightened concern in Nan province. This study aims to evaluate the prevalence of GI helminthic infections in Nan province and identify associated risk factors in local population. METHODS: A cross-sectional survey was conducted in 2022. Fecal specimens were collected and examined using Kato-Katz technique and Formalin Ethyl-Acetate Concentration Technique (FECT). Univariate analysis employed the Chi-square test to explore correlations, while logistic regression was defined risk factors associated with parasite infections. RESULTS: Among 739 individuals surveyed, 14.34% were revealed GI helminthic infections. Notably, infection rates were higher in males (20.40%) compared to females (8.95%), with a notable prevalence among individuals aged ≥ 60 (17.78%) and high infection rate was demonstrated in Kiew Chan village (21.67%). The most commonly detected helminths were minute intestinal flukes (MIFs) (10.01%) and Capillaria spp. (3.11%). Males were significantly associated with GI helminthic infections, while individuals aged 40-49 and aged 50-59 commonly displayed of parasite infections. Additionally, Kiew Chan village exhibited a significant association with GI helminthic infections, followed by Sop Puen village. Furthermore, fecal specimens of 13 rodent specimens were frequency revealed Strongyloides spp. (92.30%) and mostly exposed Ancylostoma caninum (41.93%) among 93 canines. CONCLUSION: These findings highlight the imperative for immediate public health interventions in Nan province and analogous areas in northern Thailand. Implementing strategies to enhance sanitation infrastructure and promote hygiene education can significantly contribute for reducing the prevalence of GI helminthic infections and improve overall community health.

Humans seropositive for Trypanosoma cruzi co-infected with intestinal helminths have higher infectiousness, parasitaemia and Th2-type response in the Argentine Chaco.

BACKGROUND: The Gran Chaco ecoregion is a well-known hotspot of several neglected tropical diseases (NTDs) including Chagas disease, soil-transmitted helminthiasis and multiparasitic infections. Interspecific interactions between parasite species can modify host susceptibility, pathogenesis and transmissibility through immunomodulation. Our objective was to test the association between human co-infection with intestinal parasites and host parasitaemia, infectiousness to the vector and immunological profiles in Trypanosoma cruzi-seropositive individuals residing in an endemic region of the Argentine Chaco. METHODS: We conducted a cross-sectional serological survey for T. cruzi infection along with an intestinal parasite survey in two adjacent rural villages. Each participant was tested for T. cruzi and Strongyloides stercoralis infection by serodiagnosis, and by coprological tests for intestinal parasite detection. Trypanosoma cruzi bloodstream parasite load was determined by quantitative PCR (qPCR), host infectiousness by artificial xenodiagnosis and serum human cytokine levels by flow cytometry. RESULTS: The seroprevalence for T. cruzi was 16.1% and for S. stercoralis 11.5% (n = 87). We found 25.3% of patients with Enterobius vermicularis. The most frequent protozoan parasites were Blastocystis spp. (39.1%), Giardia lamblia (6.9%) and Cryptosporidium spp. (3.4%). Multiparasitism occurred in 36.8% of the examined patients. Co-infection ranged from 6.9% to 8.1% for T. cruzi-seropositive humans simultaneously infected with at least one protozoan or helminth species, respectively. The relative odds of being positive by qPCR or xenodiagnosis (i.e. infectious) of 28 T. cruzi-seropositive patients was eight times higher in people co-infected with at least one helminth species than in patients with no such co-infection. Trypanosoma cruzi parasite load and host infectiousness were positively associated with helminth co-infection in a multiple regression analysis. Interferon-gamma (IFN-γ) response, measured in relation to interleukin (IL)-4 among humans infected with T. cruzi only, was 1.5-fold higher than for T. cruzi-seropositive patients co-infected with helminths. The median concentration of IL-4 was significantly higher in T. cruzi-seropositive patients with a positive qPCR test than in qPCR-negative patients. CONCLUSIONS: Our results show a high level of multiparasitism and suggest that co-infection with intestinal helminths increased T. cruzi parasitaemia and upregulated the Th2-type response in the study patients.

Wriggly woes: Helminths stirring up T cell trouble.

Understanding determinants of immune response variation is central to developing treatment options. Even et al. show that naive CD4+ T cell transcriptional heterogeneity is altered by helminth infection leading to impaired immune responses independent of commensals.

Association of Intestinal Helminthiasis with Disseminated Leishmaniasis, Brazil.

Disseminated leishmaniasis is an emerging clinical form of Leishmania braziliensis infection. Evidence shows that co-infection by L. braziliensis and intestinal helminths does not affect clinical manifestations or response to therapy in cutaneous leishmaniasis patients. We evaluated whether co-infection was associated with those aspects in disseminated leishmaniasis patients in Brazil.

Bacilli load in PTB- intestinal helminths co-infected and PTB non -infected patients at selected public health facilities in Jimma zone, Oromia, Ethiopia: comparative cross-sectional study.

BACKGROUND: Tuberculosis (TB) and intestinal helminths are diseases that pose a dual burden on public health in low-income countries. Previous studies have shown that helminths can affect the shedding of bacteria or the bacterial load in the sputum of active TB patients. However, there is limited information on bacterial load in TB patients with helminth infections. OBJECTIVE: This study aimed to compare bacterial load in helminths-infected and non-infected pulmonary tuberculosis patients at selected public health facilities in Jimma zone, Oromia, Ethiopia. METHODS: The study was conducted in Jimma Zone, Oromia, Ethiopia. A facility-based comparative cross-sectional study was employed from August 01, 2020, to January 2021. A total of 124 (55 intestinal helminths-infected and 69 non-infected) newly diagnosed smear-positive pulmonary tuberculosis (PTB) patients were included in the study. A convenience sampling technique was employed to recruit study participants, and a semi-structured questionnaire was used to collect data regarding socio-demographic characteristics and possible risk factors for intestinal helminths co-infection. Stool examination was performed using both wet mount and Kato Katz technique. Additionally, weight and height measurements, sputum, and blood samples were taken to determine body mass index, bacilli load, and diabetic mellitus, respectively. Data were entered into Epi-Data software version 3.1 and analyzed using Statistical Packages for Social Sciences (SPSS) Version 25. A statistically significant difference was defined as a P-value of less than 0.05. RESULTS: Intestinal helminths reduced bacilli load 3 times more than intestinal helminths non-infected PTB (AOR = 3.44; 95% CI; 1.52, 7.79; P = 0.003) However, diabetes mellitus, HIV, drinking alcohol and cigarette smoking were not associated with bacilli load. The rate of co-infection TB with intestinal helminths was 44%. The three most prevalent parasites detected were Trichuris trichiura 29 (66%), hookworm 19 (43%), and Ascaris lumbricoides 11(25%)). Among co-infected patients about 36 (81.8%) had a single parasite infection, and 19 (43.2%) had multiple infections. A body mass index < 18.5 (AOR = 3.26; 95% CI; 1.25, 8.56;P = 0.016) and untrimmed fingernail status (AOR = 3.63; 95%CI;1.32,9.93;P = 0.012) were significantly associated with PTB- intestinal helminth -co-infection. CONCLUSION: Helminth infection was associated with a lower bacilli load compared to helmenths non-infected PTB. The rate of co-infection TB with intestinal helminths was 44%. Trichuris trichiura was the most prevalent helminth. Untrimmed fingernail and a body mass index were associated with PTB-intestinal helminth co-infection.

Exploring extracellular vesicles in zoonotic helminth biology: implications for diagnosis, therapeutic and delivery.

Extracellular vesicles (EVs) have emerged as key intercellular communication and pathogenesis mediators. Parasitic organisms' helminths, cause widespread infections with significant health impacts worldwide. Recent research has shed light on the role of EVs in the lifecycle, immune evasion, and disease progression of these parasitic organisms. These tiny membrane-bound organelles including microvesicles and exosomes, facilitate the transfer of proteins, lipids, mRNAs, and microRNAs between cells. EVs have been isolated from various bodily fluids, offering a potential diagnostic and therapeutic avenue for combating infectious agents. According to recent research, EVs from helminths hold great promise in the diagnosis of parasitic infections due to their specificity, early detection capabilities, accessibility, and the potential for staging and monitoring infections, promote intercellular communication, and are a viable therapeutic tool for the treatment of infectious agents. Exploring host-parasite interactions has identified promising new targets for diagnostic, therapy, and vaccine development against helminths. This literature review delves into EVS's origin, nature, biogenesis, and composition in these parasitic organisms. It also highlights the proteins and miRNAs involved in EV release, providing a comprehensive summary of the latest findings on the significance of EVs in the biology of helminths, promising targets for therapeutic and diagnostic biomarkers.

Detection of soil-transmitted helminths and Schistosoma spp. by nucleic acid amplification test: Results of the first 5 years of the only international external quality assessment scheme.

BACKGROUND: Infections with soil-transmitted helminths (STH) and schistosomiasis (SCH) result in a significant global health burden, particularly in rural communities in low and middle-income countries. While microscopy remains the primary diagnostic method for STH and SCH in resource-limited settings, nucleic acid amplification tests (NAATs) are gaining prominence as tools for evaluation of public health control programs in endemic countries, and individual diagnosis in high-income countries. Despite the high sensitivity and specificity of NAATs, previous research has highlighted inter-laboratory variations, both in technical and clinical performance, justifying the need for continuous proficiency testing. METHODOLOGY: Results from 5 rounds over a 5-year period of the so far only longitudinal international Helminth External Molecular Quality Assessment Scheme (HEMQAS), coordinated by the Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), were examined in order to (i) assess the diagnostic proficiency of laboratories in detecting helminths in stool and (ii) identify potential factors contributing to variations in performance. OUTCOME AND CONCLUSIONS: Thirty-six laboratories, from 18 countries and 5 continents, participated in HEMQAS. The overall diagnostic performances were satisfying, with remarkably low numbers (<2%) of false-positive results. False-negative results were more often reported for stool (15%) than for DNA (5%) samples. False-negative results varied largely between targets (the highest number (29%) for Trichuris trichiura). Twenty-five laboratories provided a sufficient number of results for a robust comparison between participating laboratories, which confirmed substantial inter-laboratory variability in quantitative NAAT results (Cq-values). This variability likely arises from differences in pre-treatment, DNA isolation and DNA-target amplification procedures. This study emphasizes the complexity of molecular diagnosis for STH and SCH, highlighting the critical role of proper stool preparation and DNA isolation methods. The results underscore the necessity for laboratory professionals and public health decision-makers to recognize these complexities and continuously undertake external quality assessment schemes to ensure accurate and reliable performance in molecular diagnosis.

Helminth infection driven gastrointestinal hypermotility is independent of eosinophils and mediated by alterations in smooth muscle instead of enteric neurons.

Intestinal helminth infection triggers a type 2 immune response that promotes a 'weep-and sweep' response characterised by increased mucus secretion and intestinal hypermotility, which function to dislodge the worm from its intestinal habitat. Recent studies have discovered that several other pathogens cause intestinal dysmotility through major alterations to the immune and enteric nervous systems (ENS), and their interactions, within the gastrointestinal tract. However, the involvement of these systems has not been investigated for helminth infections. Eosinophils represent a key cell type recruited by the type 2 immune response and alter intestinal motility under steady-state conditions. Our study aimed to investigate whether altered intestinal motility driven by the murine hookworm, Nippostrongylus brasiliensis, infection involves eosinophils and how the ENS and smooth muscles of the gut are impacted. Eosinophil deficiency did not influence helminth-induced intestinal hypermotility and hypermotility did not involve gross structural or functional changes to the ENS. Hypermotility was instead associated with a dramatic increase in smooth muscle thickness and contractility, an observation that extended to another rodent nematode, Heligmosomoides polygyrus. In summary our data indicate that, in contrast to other pathogens, helminth-induced intestinal hypermotility is driven by largely by myogenic, rather than neurogenic, alterations with such changes occurring independently of eosinophils. (<300 words).

Gut microbiota metabolically mediate intestinal helminth infection in zebrafish.

Intestinal helminth parasite (IHP) infection induces alterations in the composition of microbial communities across vertebrates, although how gut microbiota may facilitate or hinder parasite infection remains poorly defined. In this work, we utilized a zebrafish model to investigate the relationship between gut microbiota, gut metabolites, and IHP infection. We found that extreme disparity in zebrafish parasite infection burden is linked to the composition of the gut microbiome and that changes in the gut microbiome are associated with variation in a class of endogenously produced signaling compounds, N-acylethanolamines, that are known to be involved in parasite infection. Using a statistical mediation analysis, we uncovered a set of gut microbes whose relative abundance explains the association between gut metabolites and infection outcomes. Experimental investigation of one of the compounds in this analysis reveals salicylaldehyde, which is putatively produced by the gut microbe Pelomonas, as a potent anthelmintic with activity against Pseudocapillaria tomentosa egg hatching, both in vitro and in vivo. Collectively, our findings underscore the importance of the gut microbiome as a mediating agent in parasitic infection and highlight specific gut metabolites as tools for the advancement of novel therapeutic interventions against IHP infection. IMPORTANCE: Intestinal helminth parasites (IHPs) impact human health globally and interfere with animal health and agricultural productivity. While anthelmintics are critical to controlling parasite infections, their efficacy is increasingly compromised by drug resistance. Recent investigations suggest the gut microbiome might mediate helminth infection dynamics. So, identifying how gut microbes interact with parasites could yield new therapeutic targets for infection prevention and management. We conducted a study using a zebrafish model of parasitic infection to identify routes by which gut microbes might impact helminth infection outcomes. Our research linked the gut microbiome to both parasite infection and to metabolites in the gut to understand how microbes could alter parasite infection. We identified a metabolite in the gut, salicylaldehyde, that is putatively produced by a gut microbe and that inhibits parasitic egg growth. Our results also point to a class of compounds, N-acyl-ethanolamines, which are affected by changes in the gut microbiome and are linked to parasite infection. Collectively, our results indicate the gut microbiome may be a source of novel anthelmintics that can be harnessed to control IHPs.

The impact of soil transmitted helminth on malaria clinical presentation and treatment outcome: A case control study among children in Bagamoyo district, coastal region of Tanzania.

BACKGROUND: Parasitic infectious agents rarely occur in isolation. Epidemiological evidence is mostly lacking, and little is known on how the two common parasites Plasmodium and soil transmitted helminths (STH) interact. There are contradictory findings in different studies. Synergism, antagonism and neutral effect have been documented between Plasmodium and STH. This study investigated the impact of STH on clinical malaria presentation and treatment outcome. METHODS: A matched case control study with a semi longitudinal follow up according to World Health Organization (WHO) antimalarial surveillance guideline was done among children aged 2 months to 9 years inclusively living in western rural areas of Bagamoyo, coastal region of Tanzania. Cases were children with uncomplicated and severe malaria enrolled from the health facilities while controls were children with asymptomatic Plasmodium parasitemia enrolled from the same community. RESULTS: In simple conditional regression analysis there was a tendency for a protective effect of STH on the development of clinical malaria [OR = 0.6, 95% CI of 0.3-1.3] which was more marked for Enterobius vermicularis species [OR = 0.2, 95% CI of 0.0-0.9]. On the contrary, hookworm species tended to be associated with increased risk of clinical malaria [OR = 3.0, 95% CI of 0.9-9.5]. In multiple conditional regression analysis, the overall protective effect was lower for all helminth infection [OR = 0.8, 95% CI of 0.3-1.9] but remained significantly protective for E. vermicularis species [OR = 0.1, 95% CI of 0.0-1.0] and borderline significant for hookworm species [OR = 3.6, 95% CI of 0.9-14.3]. Using ordinal logistic regression which better reflects the progression of asymptomatic Plasmodium parasitemia to severe malaria, there was a 50% significant protective effect with overall helminths [OR = 0.5, 95% CI of 0.3-0.9]. On the contrary, hookworm species was highly predictive of uncomplicated and severe malaria [OR = 7.8, 95% (CI of 1.8-33.9) and 49.7 (95% CI of 1.9-1298.9) respectively]. Generally, children infected with STH had higher geometric mean time to first clearance of parasitemia. CONCLUSION: The findings of a protective effect of E. vermicularis and an enhancing effect of hookworms may explain the contradictory results found in the literature about impact of helminths on clinical malaria. More insight should be gained on possible mechanisms for these opposite effects. These results should not deter at this stage deworming programs but rather foster implementation of integrated control program for these two common parasites.

Associations of Plasmodium and Intestinal Helminth Infections with Maternal Anemia and Adverse Pregnancy Outcomes in Northwest Ethiopia.

Malaria and intestinal helminth infections are significant public health challenges in Ethiopia. However, little is known about the relationship of Plasmodium and intestinal helminth infections in pregnancy with maternal anemia and adverse pregnancy outcomes. A health-facility-based cross-sectional study was conducted among 526 parturients in northwest Ethiopia to investigate the associations of these parasitic infections with anemia and adverse pregnancy outcomes. Maternal and newborn profiles were collected using questionnaires and checklists. Maternal hematocrit was determined using the micro-hematocrit method. Malaria was diagnosed by microscopy, rapid diagnostic tests, and quantitative polymerase chain reaction, whereas intestinal parasites were detected microscopically using stool wet mount and Kato-Katz preparations. Among the women, 38.6% were anemic, and 36.5% had adverse pregnancy outcomes. Single infections of hookworm (adjusted odds ratio [aOR] = 3.11, 95% CI: 1.64-5.87) in pregnancy were associated with anemia at parturiency, whereas malaria single infections were associated with anemia (aOR = 4.28, 95% CI: 2.17-8.23) and adverse pregnancy outcomes (aOR = 2.94, 95% CI: 1.47-5.91). Moreover, intestinal helminth coinfections in pregnancy were associated with anemia (aOR = 13.3, 95% CI: 4.8-36.8), whereas malaria-helminth coinfections were associated with anemia (aOR = 7.47, 95% CI: 3.71-15.04) and adverse pregnancies (aOR = 4.75, 95% CI: 2.36-9.57). Overall, the study showed that Plasmodium and intestinal helminth infections in pregnancy are associated with anemia and adverse pregnancy outcomes. Thus, strengthening malaria and intestinal parasite infection prevention and control practices in pregnancy is warranted to alleviate the burden of anemia and adverse pregnancy outcomes.

The enhancive effect of the 2014-2016 El Niño-induced drought on the control of soil-transmitted helminthiases without anthelmintics: A longitudinal study.

BACKGROUND: Soil-transmitted helminthiases (STHs) are common in tropical and subtropical regions. Southern Thailand experiences an extended rainy season, leading to persistently moist soil. This condition supports the life cycle of STHs, hindering effective control due to reinfection and low drug efficacy. We implemented a novel STH control strategy during the dry season aimed at decreasing reinfection rates without enhancing sanitation or hygiene practices. However, there were unexpected, prolonged droughts linked to El Niño events from 2014 to 2016. Additionally, we assessed the effects of these drought conditions on further control measures without the use of anthelmintics. METHODOLOGY/PRINCIPAL FINDINGS: A longitudinal study was conducted from 2012 to 2016. Stool samples collected from 299 participants were analyzed using the Kato-Katz and agar plate culture methods. Participants who tested positive for STHs received a single 400 mg dose of albendazole. The efficacy of the treatment was evaluated three weeks later. To confirm the control measures were implemented during the dry season, we monitored the number of rainy days following albendazole treatment for 52 days, of which 38 were without rain. Follow-up stool examinations were carried out in 2013 and 2016, with no additional doses of albendazole administered. Rainfall and rainy day data, which served as indicators of unexpected droughts due to El Niño, were collected from the nearest local meteorological stations. Before the drought, there was a decrease in STH prevalence in 2013-except for trichuriasis-attributable to the dry season control efforts. Despite these efforts, STH prevalence remained high. Remarkably, in 2016, following the drought period, the prevalence of trichuriasis, which had not changed previously, spontaneously declined without further albendazole treatment compared to 2013. Furthermore, the prevalence of strongyloidiasis remained unchanged likely due to its low susceptibility to drought conditions, as it can reproduce within hosts. Conversely, the prevalence of other STHs consistently declined. The drought and possible improvements in sanitation and hygiene practices contributed to this decrease by reducing rates of reinfection and new infection and by increasing the natural cure rate. Additionally, some participants infected with hookworms or Trichuris who were not cured by albendazole experienced natural remission. CONCLUSIONS/SIGNIFICANCE: Control measures implemented during the dry season, combined with a 14-month-long drought induced by the El Niño event of 2014-2016, and some improvements in sanitation and hygiene practices, contributed to a decrease in both the prevalence and intensity of STHs, except for S. stercoralis. Over time, S. stercoralis is likely to become the predominant species among the STHs.

Transforming gastrointestinal helminth parasite identification in vertebrate hosts with metabarcoding: a systematic review.

BACKGROUND: Gastrointestinal helminths are a very widespread group of intestinal parasites that can cause major health issues in their hosts, including severe illness or death. Traditional methods of helminth parasite identification using microscopy are time-consuming and poor in terms of taxonomic resolution, and require skilled observers. DNA metabarcoding has emerged as a powerful alternative for assessing community composition in a variety of sample types over the last few decades. While metabarcoding approaches have been reviewed for use in other research areas, the use of metabarcoding for parasites has only recently become widespread. As such, there is a need to synthesize parasite metabarcoding methodology and highlight the considerations to be taken into account when developing a protocol. METHODS: We reviewed published literature that utilized DNA metabarcoding to identify gastrointestinal helminth parasites in vertebrate hosts. We extracted information from 62 peer-reviewed papers published between 2014 and 2023 and created a stepwise guide to the metabarcoding process. RESULTS: We found that studies in our review varied in technique and methodology, such as the sample type utilized, genetic marker regions targeted and bioinformatic databases used. The main limitations of metabarcoding are that parasite abundance data may not be reliably attained from sequence read numbers, metabarcoding data may not be representative of the species present in the host and the cost and bioinformatic expertise required to utilize this method may be prohibitive to some groups. CONCLUSIONS: Overall, using metabarcoding to assess gastrointestinal parasite communities is preferable to traditional methods, yielding higher taxonomic resolution, higher throughput and increased versatility due to its utility in any geographical location, with a variety of sample types, and with virtually any vertebrate host species. Additionally, metabarcoding has the potential for exciting new discoveries regarding host and parasite evolution.