The porcine roundworm, Ascaris suum, affects host intestinal physiology, microbiota composition and metabolic profiles. To better understand the mediators of these alterations, six pigs each were experimentally exposed to (i) 30 adult roundworms via gastric tube, or (ii) received injections into the duodenum of A. suum total excretory-secretory (ES) antigens, ES antigens secreted exclusively from the parasites' body surface (trans-cuticular ES), or cuticular somatic antigens, respectively. Six further pigs served as untreated controls. Microbiome composition in faeces, ingesta and mucosa samples from different intestinal compartments three days after transfer was studied by next-generation 16S rDNA sequencing. Metabolite profiles were assessed in ingesta and serum samples by nuclear magnetic resonance. Transfer of adult worms and their antigens significantly affected the caecal and colonic microbiome. Adult worm transfer also led to significantly increased levels of short-chain fatty acids (SCFAs) in the colon. Similarities between pigs exposed to adult A. suum and their antigens included increased relative abundance of operational taxonomic units (OTUs) representing potentially beneficial bacteria like Lactobacillus spp., Prevotella spp., and Eubacterium coprostanoligenes, while some opportunistic pathogens like Citrobacter spp. and Mucispirillum schaedleri were also increased. The net health effect during natural A. suum infections requires further study, but these preliminary findings warrant the hypothesis that low A. suum burdens might promote intestinal health. The results further indicate that certain microbial alterations are indeed mediated by A. suum antigens, although SCFA levels were unaffected in the antigen-treated groups, possibly due to the single application. Further investigations on chronically exposed animals are warranted, especially as porcine A. suum infections serve as a model for human ascariosis.

A 2.5-year-old boy who had recently migrated from a northern highland area of Vietnam to the south presented with fever, diarrhea, progressive respiratory distress, and severe abdominal distension. He was referred in septic shock, requiring mechanical ventilation and two vasopressors. Emergency laparotomy revealed complete jejunoileal obstruction from a dense bolus of more than 100 Ascaris lumbricoides worms and approximately 70 cm of transmural bowel necrosis. Segmental resection, complete worm extraction, and primary end-to-end anastomosis were performed. Histopathology confirmed transmural hemorrhagic infarction consistent with ischemic necrosis from mechanical obstruction. The child recovered after intensive care, antimicrobial treatment, transfusion support, and a single oral dose of albendazole after postoperative stabilization and return of oral intake; he was discharged on postoperative day 20 and remained well at 2 months when a second single dose of albendazole was administered. Massive ascariasis should remain a differential diagnosis in children with acute abdomen in endemic settings or after migration from endemic areas.

We detail a case of gallbladder ascariasis, presenting as an acute episode of acalculous biliary colic, nausea, bloating, an unremarkable abdominal ultrasound, and negative helminth and protozoa stool smears. A follow-up ultrasound provided unexpected images consistent with gallbladder infection by Ascaris lumbricoides. Repeat ultrasonography performed 10 days after anthelmintic therapy showed no live worms and 2 newly appearing echogenic areas suggestive of gallbladder calculi that were confirmed following elective cholecystectomy. The case course highlights key clinical, diagnostic, and management considerations in gallbladder ascariasis and underscores the value of repeated ultrasonographic evaluation in affected patients.

Ascariasis, caused by Ascaris lumbricoides, is a common parasitic infection in developing countries, whereas biliary ascariasis is an uncommon manifestation that may present as cholangitis, biliary obstruction, or cholecystitis. We report the first documented case of biliary ascariasis in a 43-year-old Saudi man presenting with right upper quadrant pain and initially diagnosed with acute cholecystitis. Imaging revealed tubular filling defects within the biliary tree consistent with ascariasis, complicated by a liver abscess. The patient was treated with albendazole, followed by percutaneous drainage using a pigtail catheter and endoscopic retrograde cholangiopancreatography for worm extraction. Management was complicated by a haemothorax secondary to pigtail catheter insertion, requiring thoracic surgical intervention. The patient recovered successfully following multidisciplinary management. This case highlights the diagnostic challenges of biliary ascariasis in non-endemic settings, its potential for severe complications, and the importance of coordinated multidisciplinary care in achieving favorable outcomes.

Ascariasis is a prevalent parasitic infection in both humans and pigs, resulting in significant human morbidity and economic losses in the porcine industry. Experimental infections are often studied by mimicking natural settings, exposing the host to frequent, small doses (trickle infection) or by administering a single (bolus) dose of infective eggs. However, the impact of infection schemes and doses on the host immune response inA. suum infected pigs is still unclear. Using trickle and bolus infections and applying different doses, we found systemic GATA3+CD4+ T cells and eosinophils increased dose-dependently during A. suum body migration, while CD4+ T cells that specifically recognize A. suum antigens showed no association with the infection dose. In contrast, all dose-dependent differences were resolved by 8-9 weeks post infection, when adult worms were present. The results further showed that adult worm burden did not differ detectably across all groups, though a high intragroup variability was observed. Local type 2, germinal center B cell, and Tfh cell responses were dose-dependent in bolus infected animals only. Our data suggest that the initial immune response generated during A. suum larval migration is pivotal in determining the fate of the antiparasite response and adult worm population. Moreover, our results indicate that the host can regulate the worm load independent of the infection dose and scheme.

Ascaris roundworms impair human and swine health. While treatments using anthelmintic drugs are generally effective in eliminating worms, their effects on the gut microenvironment remain poorly understood. Here we applied integrated multi-omics to characterize infection- and treatment-associated alterations in the pig-Ascaris system. In vitro anaerobic cultures were conducted as supportive validation of selected observations. Ascaris suum infection altered microbial composition and dysregulated 182 serum and fecal metabolites, including histamine and p-cresol sulfate. Compared with time-matched uninfected controls, infected pigs treated with fenbendazole showed marked differences in gut microbial composition 13 days after confirmed worm clearance. Eleven microbial pathways were enriched in successfully treated pigs, including peptidoglycan biosynthesis and histidine metabolism, indicating that infection-associated alterations may persist after treatment. In vitro co-exposure of Lactobacillus reuteri to fenbendazole and A. suum proteins increased histamine production by approximately 79% at 48 h (p < 0.05), serving as supportive evidence of a microbiome contribution. Collectively, our in vivo findings support that host-microbiota-parasite interactions are multifaceted. Microbiota-derived metabolites were associated with regulation of host gene expression, such as TFF2 and IL8. Microbiota plasticity allows the exploitation of the niche differentiated upon infection, resulting in the proliferation of certain Lactobacillus strains in treated animals. Nevertheless, interpretations of treatment effects are made cautiously given the absence of an uninfected drug-only group and the cross-sectional design. Understanding these complex interactions will be important for the design of next-generation functional anthelmintics.

Soil-transmitted helminths, especially Ascaris lumbricoides, have remained a significant public health concern in Nigeria, particularly in rural communities. This study assessed the prevalence and intensity of Ascariasis among residents of Aguleri in the Anambra East Local Government Area, Anambra State, Nigeria. The study employed a cross-sectional design and a community-based approach. A total of 362 participants were selected using stratified and convenient sampling methods. Stool specimens collected were examined using direct wet mount and Kato-Katz techniques. The overall prevalence of A. lumbricoides infection was 38.1 %. Males had a higher prevalence (43.7 %) than females (33.0 %) (P = 0.036). Prevalence by age was highest (49.0 %) in children <5 years and lowest (25.4 %) in participants aged 16 - 25 years (P = 0.013). By education, nursery-level participants had the highest prevalence (46.4 %), while those with secondary education had the lowest (26.0 %) (P = 0.002). Occupational variation was significant (P = 0.002), with farmers (55.9 %) the most affected and students the least (15.1 %). Infection intensity was generally light to moderate (range = 24 to 3000 EPG; mean egg count = 192.5 ± 71.1 EPG), though with no significant difference among categories of the variables investigated (P > 0.05). These research findings demonstrate that A. lumbricoides infection occurred at varying prevalences but with similar intensities among groups of infected individuals. This reflects gaps in intervention coverage and compliance. There is therefore a need for further investigation into STH control practices in the study area to ascertain which aspects of the control strategies require improvement.

To describe changes in intestinal parasitic infections in Santa Catalina, Bolívar (Caribbean Colombia) between 2014 and 2015 and 2022, and to assess sociodemographic, hygiene, sanitation, and drinking-water factors associated with infection.

Ascaris lumbricoides is the most common soil-transmitted helminth affecting humans, predominantly in low-income countries. Although usually asymptomatic, heavy infestation can lead to serious complications such as intestinal obstruction, particularly in children whose narrower intestinal lumen predisposes them to luminal blockage by worm boluses. A 6-year-old male child presented to the surgical emergency department of Tibebe Ghion Specialized Teaching Hospital, Northwest Ethiopia, with 3 days of severe crampy, centrally located abdominal pain and frequent vomiting. Examination revealed classic signs of intestinal obstruction. Laboratory tests showed leukocytosis with marked eosinophilia. Abdominal radiography demonstrated multiple air‑fluid levels consistent with small bowel obstruction. After preoperative stabilization, exploratory laparotomy revealed massively distended, congested small bowel filled with Ascaris worms, necessitating enterotomy with extraction of 59 live worms, as milking was unsuccessful due to dense impaction and thinning of the bowel wall. Postoperatively, the patient recovered uneventfully. Ascariasis should be considered in children presenting with intestinal obstruction in endemic regions. Early recognition and timely surgical intervention are essential for favorable outcomes.

World Health Organization guidelines for control of soil-transmitted helminths (STHs) rely on coproscopic methods to assess population prevalence. In low-prevalence and light-intensity STH settings, quantitative PCR (qPCR) has higher sensitivity and specificity for detection. For qPCR to accurately identify transmissible infections of public health significance, it is essential to interpret qPCR cycle threshold (Ct) results. As part of the DeWorm3 community-based cluster-randomized trial on interrupting STH transmission, we conducted population-based surveys using high-throughput qPCR and aimed to establish appropriate Ct cutoffs to detect transmissible infections. Experimental approaches, including egg and genome-equivalent spiking experiments, were hindered by inefficient fecal DNA extraction despite optimization efforts. The Ct results for 29,980 samples (pre-intervention, cross-sectional surveys) revealed a bimodal distribution for two of the four species tested, Necator americanus and Ascaris lumbricoides. The first peak was assumed to represent transmissible infections, and the second peak to represent indeterminate or non-transmissible infections. Using a finite mixture model, we defined true qPCR positivity as any Ct result with a ≥5% chance of belonging to the first peak. This approach yielded Ct cutoffs of 34.4398 for N. americanus and 28.57587 for A. lumbricoides. For hookworms, the sensitivity of qPCR was 96.7%, compared to 73.2% for Kato-Katz, and moderate- to heavy-intensity infections (median Ct, 19.1; interquartile range [IQR], 17.9-19.8) were differentiated from both light-intensity infections and Kato-Katz-negative samples (25.3; IQR, 22.5-27.9). Our findings demonstrate the feasibility and utility of evidence-based Ct cutoffs to identify transmissible STH infections in large-scale surveys and categorize infection intensity as programmatically relevant.IMPORTANCECurrently, appropriate cycle threshold (Ct) cutoff values for soil-transmitted helminth quantitative PCR (qPCR) testing do not exist. As a result, it is not possible to differentiate a qPCR "positive" that represents a transmission risk from a signal resulting from non-infectious material such as fragmented eggs or sloughed cells. Leveraging samples collected and tested as part of the DeWorm3 cluster-randomized controlled trials, we used a data-driven statistical approach to establish a qPCR Ct cutoff that distinguishes epidemiologically relevant transmissible infections from non-transmissible DNA. This study highlights the utility of evidence-based qPCR Ct cutoffs to identify soil-transmitted helminth infections when evaluating and informing deworming programs.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT03014167.

Biliary ascariasis is a well-recognized hepatobiliary complication of infection with Ascaris lumbricoides. The disease remains highly prevalent in tropical and subtropical regions, particularly in Southeast Asia, where environmental and socioeconomic factors facilitate transmission. We report a 73-year-old female who presented with right hypochondriac pain with abdominal ultrasonography of biliary ascariasis, which was successfully managed with endoscopic retrograde cholangiopancreatography, extracting 14 A. lumbricoides.

This paper reports the diagnosis and treatment process of a patient with severe anemia caused by hookworm and Ascaris lumbricoides co-infections, so as to provide insights into clinical diagnosis and treatment and avoid misdiagnosis and under-diagnosis of parasitic infections. Living parasites were found by endoscopy, which were morphologically identified as hookworm and A. lumbricoides, and routine stool examinations detected hookworm and A. lumbricoides eggs. The patient was diagnosed with severe anemia caused by hookworm and A. lumbricoides co-infections by means of clinical symptoms, epidemiological history, endoscopic findings, and laboratory tests. Following blood transfusion, hemostasis, oral administration with albendazole, and symptomatic treatments, the patient showed remarkable symptomatic improvement and had a good prognosis.

Ascariasis is one of the most prevalent parasitic infections worldwide, particularly in developing countries, and is caused by Ascaris lumbricoides. Diagnosis can be challenging during the early stages of infection, especially when adult helminths have not yet become established in the intestine and routine parasitological examinations yield negative results. A 40-year-old female patient was referred to a hospital in South Tehran, Iran, with various clinical manifestations, including gastrointestinal symptoms, abdominal cramps, respiratory distress, cough, wheezing, localized skin itching, and blood-tinged sputum. Routine laboratory investigations were within normal limits. On November 28, 2024, following the expulsion of an immature helminth, the specimen was sent to the Helminthology Laboratory, School of Public Health, Tehran University of Medical Sciences, for detailed parasitological examination. Three stool samples were examined using direct smear, formalin-ethyl acetate concentration, zinc sulfate flotation, and agar plate culture techniques. No helminth eggs were detected in any of the samples, and all parasitological examinations yielded negative results. Molecular characterization of the immature helminth was performed using conventional polymerase chain reaction (PCR) targeting the Cox1 gene, which yielded the expected 520-bp amplicon and confirmed the diagnosis of A. lumbricoides. This case underscores the importance of a comprehensive laboratory workup for the diagnosis of ascariasis in patients with heterogeneous clinical presentations, particularly during the early stages of infection. The combined use of molecular and parasitological methods can facilitate the early detection of cases in which adult helminths have not yet developed and routine stool examinations are negative.

Rodents are well-recognized agricultural pests, causing significant damage to crops and infrastructure, as well as posing health risks to both animals and humans by transmitting various infectious agents. On livestock farms, they can contribute to disease transmission dynamics, for example by acting as mechanical vectors that carry pathogens from one stable to another, forming a hidden transmission network. This study explored the potential role of commensal rodents as mechanical vectors for the roundworm Ascaris suum on pig farms in Belgium. While A. suum is a highly prevalent intestinal parasite in pigs worldwide, its potential spread by rodents on pig farms has not been thoroughly investigated. It addresses this gap by examining whether Mus musculus and Rattus norvegicus, two common rodent species found on farms, can carry and spread A. suum eggs between different areas of the farm. Rodents were trapped on two pig farms and their faecal samples were analysed microscopically for the presence of A. suum eggs. The results showed a low prevalence of eggs in the faecal samples, with 4.17% in M. musculus and 17.14% in R. norvegicus. Serological screening of pigs further confirmed prior exposure to A. suum in both farms. Despite the low prevalence, these findings suggest that rodents could act as mechanical vectors of A. suum eggs between stables, potentially leading to persistent environmental contamination. This highlights the potential need to include rodent control as part of broader biosafety strategies to limit A. suum transmission on pig farms, particularly by reducing the risk of reintroducing eggs into stables that have already been cleaned and disinfected.