Intestinal Parasitic Infections in 2023

Systems biology of Haemonchus contortus - Advancing biotechnology for parasitic nematode control

Parasitic nematodes represent a substantial global burden, impacting animal health, agriculture and economies worldwide. Of these worms, Haemonchus contortus - a blood-feeding nematode of ruminants - is a major pathogen and a model for molecular and applied parasitology research. This review synthesises some key advances in understanding the molecular biology, genetic diversity and host-parasite interactions of H. contortus, highlighting its value for comparative studies with the free-living nematode Caenorhabditis elegans. Key themes include recent developments in genomic, transcriptomic and proteomic technologies and resources, which are illuminating critical molecular pathways, including the ubiquitination pathway, protease/protease inhibitor systems and the secretome of H. contortus. Some of these insights are providing a foundation for identifying essential genes and exploring their potential as targets for novel anthelmintics or vaccines, particularly in the face of widespread anthelmintic resistance. Advanced bioinformatic tools, such as machine learning (ML) algorithms and artificial intelligence (AI)-driven protein structure prediction, are enhancing annotation capabilities, facilitating and accelerating analyses of gene functions, and biological pathways and processes. This review also discusses the integration of these tools with cutting-edge single-cell sequencing and spatial transcriptomics to dissect host-parasite interactions at the cellular level. The discussion emphasises the importance of curated databases, improved culture systems and functional genomics platforms to translate molecular discoveries into practical outcomes, such as novel interventions. New research findings and resources not only advance research on H. contortus and related nematodes but may also pave the way for innovative solutions to the global challenges with anthelmintic resistance.

A review of the genotoxic effects of antiparasitic drugs on parasites and their hosts

Antiparasitic medications are drugs used to treat infections caused by parasites like protozoa, helminths, and ectoparasites by either killing the parasite or inhibiting its growth and reproduction. These medications are crucial for treating parasitic diseases and can vary in dosage and administration depending on the type of infection with proper diagnosis being essential for effective treatment. Nevertheless, such drugs can also cause a range of side effects including genotoxicity, depending on the type of medication and the individual's response. Therefore, here we will summarize data on the genotoxic effects of some antiparasitic drugs since many parasites provoke DNA damage per se, and therapy can enhance such genotoxic effects. The DNA-damaging effects of antiparasitic drugs enable the use of some of them for cancer treatment. Since a parasitic disease comes with severe consequences, the cost-benefit should be considered when taking drugs against such a disease even in terms of their potential genotoxicity. While some antiparasitic drugs have shown genotoxic potential in laboratory studies, most are considered safe for human use at therapeutic doses. Long-term or high-dose exposure may carry more risk; moreover, the genotoxic effects of the drugs can interfere with the genotoxicity of the parasitic infection. More research is needed to fully understand the implications for human health. Nevertheless, the present study has confirmed the need for further cytogenetic research and regular patient monitoring to minimize the risk of an adverse event, especially among frequent travellers visiting parasite-affected areas.

Parasitic appendicitis, what do we know?-a literature review

Background and Objective

Acute appendicitis (AA) is a leading cause of emergency abdominal surgery worldwide, with surgical intervention as its mainstay of treatment. As a primarily clinical diagnosis, it is important for physicians to have ample information to diagnose cases accurately. Given the high rates of negative appendectomies, robust diagnostic workups are crucial to minimize unnecessary surgeries and consider adjunct therapy. Various etiologies, including parasitic infections, are associated with AA. In this review, we report that Schistosoma spp., Enterobius vermicularis (E. vermicularis), Taenia spp., and Ascaris lumbricoides (A. lumbricoides) contribute to or mimic AA. As globalization expands, areas once considered "safe zones" for parasites now face higher risks. It is therefore increasingly important for physicians in all countries to recognize the association between parasites and AA and include proper investigations for high-risk patients. Our findings aim to assist physicians on when to consider a parasitic infection and AA, potentially reducing the number of negative appendectomies, as some parasitic infections can be treated with medication alone.

Methods

To our knowledge, this narrative review incorporating three databases (PubMed, Ovid and Embase), is the first to synthesize research on the relationship between parasites and AA. Articles were screened using Covidence, and inclusion criteria required references to Schistosoma spp., E. vermicularis, Taenia spp., and A. lumbricoides. We limited results to English and French manuscripts published between 1949 and 2023. Two independent reviewers performed title and abstract screening, followed by full-text analysis, ultimately selecting 71 studies that met the inclusion criteria.

Key Content and Findings

Our analysis identifies four parasitic organisms strongly associated with AA-Schistosoma spp., E. vermicularis, Taenia spp., and A. lumbricoides-and highlights countries where these infections are most prevalent. Furthermore, it highlights the need for more research in this area as causal relationships are still yet to be made.

Conclusions

While strong associations exist between parasitic infections and AA, further research is needed to establish a causal relationship.

Prevalence of intestinal parasite contamination in raw vegetables and school soil samples in Koh Yao, Phang Nga Province, southern Thailand

Parasitic infections remain a significant public health issue in Thailand. Exposure to intestinal parasites occurs through consumption of improperly washed raw vegetables and handling of contaminated soil without proper hygiene. This study assessed the prevalence of intestinal parasites in raw vegetables and school soil, along with the associated factors, in Koh Yao, Phang Nga Province, Thailand. Vegetables (21 types) were collected from local markets and stores in Koh Yao Noi, Koh Yao Yai, and Phru Nai. Moreover, soil samples were collected from playgrounds, football fields, sidewalks, schoolyards, and areas around cafeterias in 13 public primary schools. Approximately 2.3% of vegetable samples (3 out of 131) were contaminated with parasites (one peppermint and two Chinese morning glory samples). The most commonly detected parasites were Ascaris spp. eggs (1.5%) and hookworms (0.8%). Koh Yao Noi had the highest contamination rate of 7.1%, whereas no contamination was observed in samples from Koh Yao Yai and Phru Nai. The contamination rates in vegetables obtained from the three subdistricts showed significant differences (p <  0.05). All contaminated vegetables were grown locally. In soil samples, parasites were detected in 11 of the 13 schools (84.6%). Of the 141 soil samples, 42 (29.8%) were contaminated, and Toxocara spp. were found in all contaminated samples. Phru Nai had the highest soil contamination rate (50%), followed by Koh Yao Yai (20.5%), and Koh Yao Noi (11.4%). There were significant differences in the distribution of parasite contamination across the three subdistricts (p <  0.001) and seasons (p <  0.001). Football fields were the most contaminated areas, with 36% of samples testing positive for parasites. This study highlights the risk of parasitic transmission through contaminated vegetables and soil. Hence, this emphasizes the need for health authorities to educate local communities on proper hygiene practices, including hand washing and thorough vegetable cleaning, to prevent parasitic infections. Implementing preventive measures in schools and communities is crucial for limiting parasitic disease spread.

Knowledge, experience, and willingness to vaccinate against intestinal parasitic infections: A multi-country study in Asia

BACKGROUND

Intestinal parasitic infections (IPIs) remain a significant public health challenge and a neglected disease in many parts of Asia, contributing to morbidity and mortality, particularly in vulnerable populations. Despite the potential of vaccines to reduce the burden of these neglected IPIs, little is known about the public's willingness to be vaccinated against these infections.

OBJECTIVE

This study aimed to assess the general population's knowledge, symptom experiences, and willingness to vaccinate against IPIs across six countries: Malaysia, Vietnam, India, Pakistan, and China.

MATERIALS AND METHODS

A cross-sectional online survey was conducted between June and December 2023 across six countries in Asia region. Participants completed a self-administered online questionnaire that assessed demographic information, knowledge of IPIs, symptom experiences, and willingness to receive a vaccine against IPIs for themselves and their children. Univariate and multivariable logistic analyses were performed to determine the factors related to vaccination the willingness.

RESULTS

A total of 5470 complete responses were received. The highest proportion of individuals willing to receive the vaccine was in India (86.1 %), followed by China (80.8 %) and Pakistan (75 %), with Vietnam having the lowest proportion at 50.1 %. For child vaccination, China had the highest willingness (83.3 %). A higher knowledge score was significantly associated with increased willingness to be vaccinated [adjusted odds ratio (aOR)= 1.91, 95 % CI: 1.70-2.15]. Additionally, a higher symptom experience score was significantly associated with greater vaccination willingness (aOR=1.71, 95 % CI: 1.50-1.94). Females residing in urban-suburban areas showed significantly higher vaccination intentions. The willingness to vaccinate children against IPIs closely mirrored the trends observed in self-vaccination willingness, with knowledge being the only factor significantly associated with the willingness to vaccinate children.

CONCLUSION

The study underscores the importance of enhancing educational efforts regarding neglected IPIs and vaccination, particularly when vaccines are available and recommended.

Leveraging microphysiological systems to expedite understanding of host-parasite interactions

Microphysiological systems (MPS) replicate the dynamic interactions between cells, tissues, and fluids. They have emerged as transformative tools for biology and have been increasingly applied to host-parasite interactions. Offering a better representation of cellular behavior compared with traditional in vitro models, MPS can facilitate the study of parasite tropism, immune evasion, and life cycle transitions across diverse parasitic diseases. Applications span multiple host tissues and pathogens, leveraging advanced bioengineering and microfabrication techniques to address long-standing knowledge gaps. Here, we review recent advances in MPS applied to parasitic diseases and identify persisting challenges and opportunities for investment. By refining these systems and integrating host multicellular models and parasites, MPS hold vast potential to revolutionize parasitology, enhancing our ability to combat parasitic diseases through deeper mechanistic understanding and targeted interventions.

High parasite prevalence driven by the human-animal-environment interface: a One Health study in an urban area in southern of Chile

Parasitic infections remain a global health concern, affecting human populations worldwide. However, comprehensive studies evaluating human, animal, and environmental interactions driven transmission of parasites are limited. We conducted a One Health study in an urban area of Valdivia, Chile. Human participants provided fecal and blood samples for parasitological and serological analysis. Environmental soil samples were collected from public parks, and fecal samples from owned and stray dogs were analyzed. Detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS), while anti-Toxocara canis antibodies in humans were assessed using ELISA. Socioeconomic surveys explored risk factors associated with parasitism. Parasite prevalence was 28% in humans, 26% in owned dogs, and 44% in environmental dog feces. Anti-T. canis IgG antibodies were present in 33% of humans. Soil contamination was identified in up to 30.5% of park samples, harboring zoonotic parasites such as Toxocara sp. and Trichuris vulpis, the same species identified in environmental dog feces. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were detected in humans. Our findings highlight significant zoonotic and environmental transmission contributing to human parasitic infections in urban settings, underscoring the need for integrated public health interventions. This study demonstrates the importance of adopting an OneHealth approach in the study of parasitology. The complex ecology of parasites requires an integrated perspective to fully understand their transmission pathways and develop effective control strategies. By emphasizing the interconnectedness of human, animal, and environmental health, we aim to contribute to the management and mitigation of this persistent public health issue.

Intestinal Parasitic Infection: Prevalence and Associated Risk Factors at Delgi Primary Hospital, Northwest Ethiopia

Intestinal parasitic infections (IPIs) are among the leading causes of mortality and morbidity in developing nations such as Ethiopia. Determining epidemiological information of IPI is crucial for effective public health planning and intervention. The present study is aimed at assessing the prevalence and associated risk factors of human IPIs at Delgi Primary Hospital, Central Gondar Zone, Northwest Ethiopia. An institutional-based cross-sectional study was conducted from March to May 2023. A stool specimen was collected from 404 selected participants and examined microscopically for the presence of developmental stages of the intestinal parasites. A structured questionnaire was used to obtain information regarding the sociodemographic and associated risk factors. Data were analyzed using SPSS Version 23, and a crude odd ratio was calculated to verify and measure the possible association between IPIs and potential risk factors. A p value < 0.05 was taken as statistically significant. The overall prevalence of IPIs was 47.20%. Six species of intestinal parasites were identified: Entamoeba histolytica/dispar (16.8%) was the most predominant parasite, followed by Giardia lamblia (9.9%), Ascaris lumbricoides (8.1%), Hookworm species (7.6%), Schistosoma mansoni (4.2%), and Hymenolepis nana (0.5%). Furthermore, double and triple parasitic infections were observed in 10.39% and 0.49% of the study participants, respectively. Not having a habit of handwashing after toilet (AOR = 2.048, CI = 0.694, 3.583, p = 0.001), the habit of eating unwashed vegetables (AOR = 3.046, CI = 0.685, 5.596, p = 0.016), and presence of dirt matter under the nail (AOR = 2.939, CI = 0.621, 4.418, p = 0.001) were found to be significantly associated risk factors. This study showed that IPIs remained a public health concern in the study area. Therefore, regular provision of health education on personal hygiene and sanitation is recommended to prevent and control IPIs in the study area.

Pinosylvin: A Multifunctional Stilbenoid with Antimicrobial, Antioxidant, and Anti-Inflammatory Potential

Stilbenoids are a category of plant compounds exhibiting notable health-related benefits. After resveratrol, perhaps the most well-known stilbenoid is pinosylvin, a major phytochemical constituent of most plants characterised by the pine spines among others. Pinosylvin and its derivatives have been found to exert potent antibacterial and antifungal effects, while their antiparasitic and antiviral properties are still a subject of ongoing research. The antioxidant properties of pinosylvin are mostly based on its scavenging of free radicals, inhibition of iNOS and protein kinase C, and promotion of HO-1 expression. Its anti-inflammatory properties are based on a variety of mechanisms, such as COX-2 inhibition, NF-κB and TRPA1 activation inhibition, and reduction in IL-6 levels. Its anticancer properties are partly associated with its antioxidant and anti-inflammatory potential, although a number of other mechanisms are described, such as apoptosis induction and matrix metalloproteinase inhibition. A couple of experiments have also suggested a neuroprotective potential. A multitude of ethnomedical and ethnobotanical effects of pinosylvin-containing plants are reported, like antimicrobial, antioxidant, anti-inflammatory, hepatoprotective, and prokinetic actions; many of these are corroborated by recent research. The advent of novel methods of artificial pinosylvin synthesis may facilitate its mass production and adoption as a medical compound. Finally, pinosylvin may be a tool in promoting environmentally friendly pesticide and insecticide policies and be used in land remediation schemes.

Global impact of parasitic infections and the importance of parasite control

Parasites have a severe impact on animal and human health. Parasites like worms, ticks, mites, fleas, biting flies, mosquitoes, and pathogenic protozoa affect humans and their pets as well as their livestock globally, both in terms of severity and numbers. Parasitic infections are a global phenomenon, and they can be associated with severe or mild symptoms but represent a continuous risk of severe diseases for animals and humans. Therefore, effective treatment options and the prevention of infection are key for the wellbeing of pets, livestock, and humans, including the reduction of zoonotic risk of infection. The effective control of parasites in animals can greatly improve their quality of life and is also beneficial for humans; this is threatened by drug-resistant parasite populations. Today's key areas for improvement of parasite control are as follows: a) convenience of prevention and treatment, b) effectiveness against drug-resistant parasites, c) availability and reduced costs of treatment, and d) control measurements that are environmentally friendly.

Cloning and Recombinant Expression of the Caspase-Activated DNase Orthologous Gene of Giardia lamblia

In eukaryotic cells, mitochondria play a key role in apoptosis; however, ancestral eukaryotic cells such as Giardia lamblia only possess a mitochondrial remnant, the mitosome. Interestingly, this protozoan still undergoes an apoptosis-like process; therefore, we focused primarily on the search for the mitochondria-independent executor DNase. Here, we identified, cloned, expressed, and characterized the caspase-activated DNase (CAD) from Giardia lamblia. Using a commercial polyclonal antibody that recognizes mouse, rat, and human caspase-activated DNase (hCAD), we developed an immunoproteomic analysis using a crude extract of curcumin-treated Giardia lamblia trophozoites (CEGl) and detected a spot of 42 kDa and pI 9.4, similar to hCAD and sequenced by LC-MS. The proteomic profile matched a novel protein of 383 residues, with a predicted 42 kDa, pI 9.4, a CIDE-N domain, and putative H-K-H catalytic motif. Afterward, we cloned the full-length gene (GenBank: ON707040), expressed it, and purified it as a 6-His tag-recombinant protein in Escherichia coli, which was also recognized by commercial anti-CAD. In conclusion, genetic, proteomic, and structural analyses showed that the identified gCAD is an orthologous protein of hCAD, and its DNase role in the apoptosis-like signaling pathway of Giardia lamblia can be further analyzed.

Comparative gastrointestinal organoid models across species: A Zoobiquity approach for precision medicine

Gastrointestinal (GI) health underpins systemic well-being, yet the complexity of gut physiology poses significant challenges to understanding disease mechanisms and developing effective, personalized therapies. Traditional models often fail to capture the intricate interplay between epithelial, mesenchymal, immune, and neuronal cells that govern gut homeostasis and disease. Over the past five years, advances in organoid technology have created physiologically relevant, three-dimensional GI models that replicate native tissue architecture and function. These models have revolutionized the study of autoimmune disorders, homeostatic dysfunction, and pathogen infections, such as norovirus and Salmonella, which affect millions of humans and animals globally. In this review, we explore how organoids, derived from intestinal and pluripotent stem cells, are transforming our understanding of GI development, disease etiology, and therapeutic innovation. Through the "Zoobiquity" paradigm and "One Health" framework, we highlight the integration of companion animal organoids, which provide invaluable insights into shared disease mechanisms and preclinical therapeutic development. Despite their promise, challenges remain in achieving organoid maturation, expanding immune and neuronal integration, and bridging the gap between organoid responses and in vivo outcomes. By refining these cutting-edge platforms, we can advance human and veterinary medicine alike, fostering a holistic approach to health and disease.

Risk of Environmental Contamination by Gastrointestinal Parasites in Public Areas of the Central Plateau Microregion of Brazil: A Public Health Concern

The risk of zoonotic parasitic infections is closely linked to direct and indirect interactions between animals and humans. The mutual coexistence of species in public spaces predisposes individuals to gastrointestinal parasitosis owing to various social and hygienic-sanitary factors. This study aimed to assess the risk of environmental contamination by gastrointestinal parasites in fecal samples collected from parks and public squares in 18 municipalities located in a microregion of the central plateau of Brazil, correlating the collection with the population size of each municipality. We collected 536 soil fecal samples from 117 randomly selected public areas across a 56,111.874 km2 region. Eggs, cysts, and oocysts were detected using the Willis flotation technique and the Hoffman's spontaneous sedimentation method. The Hoffman's analysis revealed that 70.3% of the fecal samples were infected across 91.5% of the sampled areas. Identified parasites included the members of the family Ancylostomatidae (56.5%), Toxocara spp. (6.2%), Trichuris spp. (1.7%), Strongyloides spp. (0.2%), Dipylidium caninum (25.8%), Spirometra spp. (0.4%), Taeniidae (0.2%), Platynosomum fastosum (0.6%), Trematoda (0.2%), Giardia spp. (3.2%), Cystoisospora spp. (5.6%), Sarcocystis spp. (0.2%), and Entamoeba spp. (2.4%). The presence of positive fecal samples in public areas and municipalities correlated with populations of up to 10,000 inhabitants (p = 0.023). Areas contaminated with feces were 63.4% more likely to contain parasites than other areas (odds ratio 1.6336). Favorable environmental factors combined with inadequate sanitary management contribute to a high risk of environmental contamination, representing a significant zoonotic potential and highlighting the need for improved public health policies and preventive measures.

Prevalence and Genetic Diversity of Parasites in Humans and Pet Dogs in Rural Areas of Los Ríos Region, Southern Chile

Parasitic infections pose a significant global health burden, affecting millions of people worldwide. Despite their importance, studies integrating human and animal parasitology to understand transmission pathways are scarce. This study, conducted between August 2022 and April 2023, aimed to investigate the prevalence of parasites in humans and domestic dogs in the Los Rios Region, southern Chile, and explore the risk factors associated with parasitism. A total of 291 human participants provided fecal and blood samples for parasitological and serological analyses, while 92 fecal samples from owned dogs were analyzed. The detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS). Anti-Toxocara canis and anti-Echinococcus granulosus antibodies in humans were assessed using ELISA. Socioeconomic surveys explored the risk factors associated with parasitism. The results showed a parasite prevalence of 39% in humans and 40% in dogs. Anti-Toxocara canis IgG antibodies were detected in 28.2% of humans. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were identified. Thus, the results of our study indicate a high prevalence of intestinal and extraintestinal parasites in the human population of our region. Furthermore, our findings underscore the significant risk of zoonotic transmission of parasites from companion animals. This study contributes to the understanding of parasite transmission dynamics in southern Chile and has implications for public health policy and practice. The results emphasize the importance of considering the connection between human, animal, and environmental health to develop effective control strategies and mitigate the impact of parasitic infections.

Comparison of in vitro and in vivo resurrection success of three ovine gastrointestinal nematode species following different cryopreservation strategies

Nematode infective larvae (L3) of veterinary importance have been cryopreserved in liquid nitrogen (LN2) to minimize the need for continued passage through live animals. Health and safety concerns, combined with increasing pressures to reduce running and maintenance costs have driven the need to explore alternative preservation techniques. Super-cold (-150°C) freezers have been used for long term storage of cell lines, but no published data were available for livestock gastro-intestinal nematodes (GIN). In vitro and in vivo survivability of L3 of three GIN species (Teladorsagia circumcincta (MTci2), Trichostrongylus colubriformis (MTco1) and Haemonchus contortus (MHco3 and MHco18)) were assessed following three cryopreservation storage methods. In brief, fifty thousand larvae were exsheathed, and cryopreserved using one of three methods; either snap frozen in LN2 before storage at -150 °C (LN/-150°C); stored directly at -150°C or stored in LN2 (LN). In vitro survivability of L3 (dead versus alive) were assessed at approximately 1, 2, 4, 6, 11 and 23 months post -150°C and LN/-150°C storage. Larvae were defrosted and left in PBS overnight at 39.6°C and 10 % CO2 prior to dead/alive assessment. An in vivo study was undertaken with L3 following 4 months of storage. The tubes stored directly in -150°C have consistently shown ≥ 90 % in vitro survivability for all isolates, whereas LN/-150°C showed inter species variability (range: 7-63 % survivability). The in vivo assessment demonstrated a significant difference in establishment with overall group mean establishment ranging from 9 % in the LN/-150°C to 62 % of the fresh larvae, with the -150°C and LN groups establishing 25 % and 10 % respectively.

Carbon dioxide shapes parasite-host interactions in a human-infective nematode

Skin-penetrating nematodes infect nearly one billion people worldwide. The developmentally arrested infective larvae (iL3s) seek out hosts, invade hosts via skin penetration, and resume development inside the host in a process called activation. Activated infective larvae (iL3as) traverse the host body, ending up as parasitic adults in the small intestine. Skin-penetrating nematodes respond to many chemosensory cues, but how chemosensation contributes to host seeking and intra-host navigation-two crucial steps of the parasite-host interaction-remains poorly understood. Here, we investigate the role of carbon dioxide (CO2) in promoting host seeking and intra-host navigation in the human-infective threadworm Strongyloides stercoralis. We show that S. stercoralis exhibits life-stage-specific behavioral preferences for CO2: iL3s are repelled, non-infective larvae and adults are neutral, and iL3as are attracted. CO2 repulsion in iL3s may prime them for host seeking by stimulating dispersal from host feces, while CO2 attraction in iL3as may direct worms toward high-CO2 areas of the body, such as the lungs and intestine. We also identify sensory neurons that detect CO2; these neurons display CO2-evoked calcium activity, promote behavioral responses to CO2, and express the receptor guanylate cyclase Ss-GCY-9. Finally, we develop an approach for generating stable knockout lines in S. stercoralis and use this approach to show that Ss-gcy-9 is required for CO2-evoked behavioral responses in both iL3s and iL3as. Our results highlight chemosensory mechanisms that shape the interaction between parasitic nematodes and their human hosts and may aid in the design of novel anthelmintics that target the CO2-sensing pathway.

Prevalence and Risk Factors of Waterborne and Foodborne Protozoan Pathogens in Kenya: A One Health Perspective

Intestinal infections affect approximately 450 million people globally, predominantly impacting children and immunocompromised individuals in low- and middle-income countries (LMICs) due to inadequate water, sanitation, and hygiene (WASH) conditions, poverty, malnutrition, and low literacy. In Kenya, the prevalence of intestinal infections is elevated by warm tropical climates and socioeconomic factors. This scoping review evaluates the national prevalence, risk factors, and contamination sources of intestinal protozoa in Kenya, using a One Health approach to synthesize existing data from various human, animal, and environmental studies. A comprehensive literature search identified 292 studies, of which 67 met the inclusion criteria, covering the period from 1966 to 2024. The review found that most studies utilized stool microscopy, a method with limited sensitivity, and largely focused on vulnerable human populations, with minimal investigation into environmental reservoirs. Key protozoa identified included Entamoeba histolytica, Cryptosporidium, and Giardia, with transmission driven by poor WASH conditions, environmental factors, and close human-animal interactions. The findings highlight significant gaps in environmental surveillance and suggest the need for a robust, integrated One Health approach to better understand and control protozoan infections in Kenya.

Severe symptomatic hypocalcemia due to Cyclospora cayetanensis infestation: A rare case

Introduction

Severe hypocalcemia can affect multiple systems, causing a wide variety of symptoms ranging from muscle weakness to twitching. In severe cases, it can lead to heart rhythm disturbances and seizures. A rare cause of hypocalcemia is due to malabsorption associated with prolonged gastroenteritis.

Case presentation

We present a 35-year-old female with persistent watery diarrhea of eight weeks presented with neuromuscular symptoms. Trousseau sign and Chvostek sign were positive bilaterally. Laboratory test results revealed severe hypokalemia, hypocalcemia, and anemia, with prolonged QT interval in electrocardiogram (EKG). Her stool polymerase chain reaction (PCR) revealed Cyclospora cayetanensis. Her electrolytes were appropriately replaced during her hospital stay. The patient was successfully treated with trimethoprim-sulfamethoxazole, calcium, and oral iron supplementation.

Conclusion

This case demonstrates a unique presentation of a healthy young female with symptomatic hypocalcemia resulting from malabsorption due to Cycolospora cayetanensis. This case emphasizes the importance of early diagnosis using newer techniques, such as polymerase chain reaction (PCR) for parasite DNA, which can result in appropriate diagnosis and timely treatment.

Emergency Care for Refugee Patients at Suceava Hospital, Romania: Challenges and Insights from the First Year of the Russian-Ukrainian Conflict

BACKGROUND

The ongoing military conflict in Ukraine has had a devastating impact on children's health, exposing them to a range of illnesses. The aim of this study was to analyze the most common medical conditions among Ukrainian children since the beginning of the conflict, with a focus on identifying and understanding these problems in a wartime setting.

METHOD

To assess the health status of affected children, we collected data from 422 pediatric patients who presented to the emergency department. The analysis included reviewing medical records, documenting the nature of illness, treatments administered, and the need for hospitalization.

RESULTS

Preliminary results indicate that interstitial pneumonia, contusions, gastroenterocolitis, and traumatic brain injury were the most common conditions. Of the 422 children studied, 80% received appropriate care without hospitalization, while 20% were admitted for further evaluation.

CONCLUSIONS

Interstitial pneumonia was diagnosed in 23% of patients, highlighting the vulnerability of the respiratory system under conflict conditions. Contusions were predominant among musculoskeletal injuries, accounting for 81% of cases, and gastroenterocolitis was diagnosed in 46% of patients, reflecting the impact of poor living conditions.

Detection of Eimeria oocysts in chicken feces using flotation recovery with sucrose or saturated saline solution

PURPOSE

Flotation methods are widely used to detect oocysts/cysts of protozoans and eggs of helminths, except trematodes. However, details regarding the concentration and recovery rates of these parasites are poorly understood.

METHODS

Using Eimeria tenella oocysts as a model parasite, the present study evaluated three check points: (1) the proportion of parasites that remain floating in flotation solution (sucrose or saturated saline) during centrifugation, (2) the proportion of oocysts that naturally float after addition of flotation solution after centrifugation, and (3) the rate of recovery on cover slips after completion of the flotation protocol.

RESULTS

After centrifugation in sucrose solution and saturated saline solution, 82.4% and 60.3% of oocysts floated, respectively. After addition of flotation solution after the final centrifugation step, the recovery rates for oocysts that naturally floated again for 30 min in sucrose and saturated saline were 39.2% and 38.2%, respectively. The recovery rate on cover slips as the final step after performing a commonly used flotation method was 36.4% in sucrose solution (the rate for saturated saline solution could not be assessed due to rapid crystallization).

CONCLUSION

Our results suggest that floating oocysts could have become dispersed by the addition of flotation solution, and not all of these oocysts remained floating after an additional 30 min of settling time although collection on cover slips could be effective for accurate recovery.

Prevalence of Intestinal Parasitic Infections and Associated Factors Among Food Handlers in East Africa: A Systematic Review and Meta-analysis

BACKGROUND

Intestinal parasitic infections are a significant public health concern, especially among food handlers, who can transmit these infections to the public through food preparation and handling. This systematic review and meta-analysis aimed to determine the pooled prevalence and associated factors of intestinal parasitic infections among food handlers in the East African region.

METHODS

A systematic review and meta-analysis on intestinal parasitic infections among food handlers involved a comprehensive search across various databases, including Scopus, PubMed, ScienceDirect, Google Scholar, and the institution's library registers. Forty relevant articles were identified and analyzed using STATA Software version 17.0. Sensitivity analysis, publication bias assessment with Egger's test, and the Trim-and-fill meta-analysis for bias adjustment were conducted. Heterogeneity across the studies was assessed using Cochran's Q statistic and I2 statistics, and subgroup analysis computed for significant heterogeneity (I2 value ≥ 50%). A random effect model was used to determine the pooled prevalence of intestinal parasitic infections.

RESULTS

The pooled prevalence of intestinal parasitic infections among food handlers was 32.27% (95% CI 27.90-36.65). The most prevalent parasites were Entamoeba histolytica/dispar 20.83% (95% CI 13.66-28%), Ascaris lumbricoides 13.84% (95% CI 10-17.68%), Giardia lamblia 8.55% (95% CI 6.03-11.06%), and hookworm 6.43% (95% CI 3.93-8.93%). Using a common knife for cutting raw meat (AOR = 2.27, 95% CI 1.21-4.31), food handler's untrimmed fingernails (AOR = 2.14, 95% CI 1.50-2.78), and no hand washing practices with soap after using the toilet (AOR = 2.25, 95% CI 1.33-3.18) were associated with higher rates of intestinal parasitic infections among food handlers.

CONCLUSIONS

Parasitic infections among food handlers were found to be significantly prevalent. Factors contributing to this high prevalence included food handlers' untrimmed fingernails, poor hand hygiene practices, and using a shared knife for chopping various food items, including raw meat. These findings emphasize the need for proper personal hygiene and sanitation practices among food handlers to prevent transmitting parasitic infections to consumers.

Prevalence of Intestinal Parasites and Associated Factors Among Public Primary Second-Cycle Schoolchildren in Debre Markos Town, Northwest Ethiopia: A Cross-Sectional Study

Background and Aims

Intestinal parasitic infection is a common disease that causes significant morbidity and mortality in developing countries, including Ethiopia. The burden of intestinal parasites is worse in schoolchildren, which leads to absenteeism from school, lower cognitive ability, affects academic performance, and causes malnutrition and anemia. While many studies have been reported, there is a paucity of published data in Debre Markos. Therefore, this study aimed to assess the prevalence of intestinal parasites and associated factors among public primary second-cycle schoolchildren in Debre Markos Town, Northwest Ethiopia.

Methods

A school-based cross-sectional study was conducted among three selected public primary second-cycle schools in Debre Markos town from May 1 to 30, 2022. Study participants were selected by using random and systematic sampling techniques with proportional allocation to each grade. Data were collected using semi-structured questionnaires. A single stool specimen was collected from the study participants and processed using direct wet mount and formol ether concentration technique. Binary logistic regression models were applied to assess the association between independent and outcome variables at a 95% confidence level.

Results

A total of 343 students were included in the study. The overall prevalence of intestinal parasites was 12% (41/343) with a predominance of hookworms (5.2%, 18/343), followed by Ascaris lumbricoides 2.3% (8/343), Entamoeba histolytica/dispar 1.2% (4/343), Hymenolepis nana 0.9% (3/343), Strongyloides stercoralis 0.9% (3/343), Giardia lamblia 0.9% (3/343), and Trichuris trichiura 0.6% (2/343). The habit of open-field defecation (AOR, 95% CI; 2.43 [1.16-5.09]), not using soap to wash hands (AOR, 95% CI; 2.93 [1.33-6.42]), and not wearing closed shoes (AOR, 95% CI; 3.12 [1.19-8.23]) were factors significantly associated with the prevalence of intestinal parasitic infection.

Conclusion

The prevalence of intestinal parasites was comparatively low in the study area. Open-field defecation, not using soap to wash hands, and not wearing closed shoes were identified as independent predictors.

Intestinal Parasitic Infections in Children: A 10-Year Retrospective Study

Background and objective Intestinal parasitic infections are a major public health concern, especially in low-income regions with poor sanitation. Our hospital caters to a large migrant population, but data on these infections in Portugal is limited. This study aimed to assess the prevalence and characteristics of intestinal parasitic infections in pediatric patients from epidemiological, clinical, and microbiological perspectives. Methods A retrospective, descriptive study was conducted involving symptomatic or opportunistically screened children and adolescents, with positive stool examination for eggs, cysts, and parasites (O&P) or positive serologies for Strongyloides/Schistosoma, at a level II hospital in Portugal, between January 2012 and June 2022. Results Seventy-seven patients were included in the study, of whom 56% were migrants. The median age was six years. A total of 79 intestinal parasitic infections were diagnosed, corresponding to a positivity rate of 2.5%. Among these, 7.8% occurred in children aged under one year, a particularly vulnerable group. The most frequently identified parasite was Giardia lamblia, followed by Strongyloides stercoralis. The rate of diagnoses increased over the study period, linked to the growing migrant population. Clinically, most children and adolescents were asymptomatic. Additionally, there was a significant rate of loss to medical follow-up, which could contribute to transmission. Conclusions This study is unique in its focus on characterizing intestinal parasitic infections in the pediatric population, addressing a gap in existing research. It highlights the need for further research among children living in Europe, especially given the rising migrant population. Multicenter studies are crucial to better understand infection patterns and improve diagnostic and treatment protocols.

Disentangling the effects of intermittent faecal shedding and imperfect test sensitivity on the microscopy-based detection of gut parasites in stool samples

BACKGROUND

Gut-parasite transmission often involves faecal shedding, and detecting parasites in stool samples remains the cornerstone of diagnosis. However, not all samples drawn from infected hosts contain parasites (because of intermittent shedding), and no test can detect the target parasites in 100% of parasite-bearing samples (because of imperfect sensitivity). Disentangling the effects of intermittent shedding and imperfect sensitivity on pathogen detection would help us better understand transmission dynamics, disease epidemiology, and diagnostic-test performance. Using paediatric Giardia infections as a case-study, here we illustrate a hierarchical-modelling approach to separately estimating the probabilities of host-level infection ([Formula: see text]); stool-sample-level shedding, given infection ([Formula: see text]); and test-level detection, given infection and shedding ([Formula: see text]).

METHODS/FINDINGS

We collected 1-3 stool samples, in consecutive weeks, from 276 children. Samples (413 overall) were independently examined, via standard sedimentation/optical microscopy, by a senior parasitologist and a junior, trained student (826 tests overall). Using replicate test results and multilevel hierarchical models, we estimated per-sample Giardia shedding probability at [Formula: see text] and observer-specific test sensitivities at [Formula: see text] and [Formula: see text]. Gender-specific infection-frequency estimates were [Formula: see text] and [Formula: see text]. Had we used a (hypothetical) Perfect Test with 100% narrow-sense sensitivity ([Formula: see text]), the average probability of detecting Giardia in a sample drawn from an infected child ([Formula: see text]) would have been [Formula: see text]. Because no test can be >100% sensitive, [Formula: see text] (which measures clinical sensitivity) can only be brought above ~ 0.44 by tinkering with the availability of Giardia in stool samples (i.e., [Formula: see text]); for example, drawing-and-pooling 3 replicate samples would yield [Formula: see text].

CONCLUSIONS

By allowing separate estimation (and modelling) of pathogen-shedding probabilities, the approach we illustrate provides a means to study pathogen transmission cycles and dynamics in unprecedented detail. Separate estimation (and modelling) of true test sensitivity, moreover, may cast new light on the performance of diagnostic tests and procedures, whether novel or routine-practice.

Antiprotozoal Activity Against Entamoeba hystolitica and Giardia lamblia of Cyclopeptides Isolated from Annona diversifolia Saff

Diseases caused by intestinal parasites such as protozoa represent a worldwide problem mainly for developing countries. From morbidity in different groups of people to cases of mortality in children and/or immunocompromised patients. In addition to the above, there is growing resistance to the drugs used in the treatment of these diseases, as well as undesirable side effects in patients. Therefore, there is an interest in the search for new alternatives for the base and/or development of new drugs with antiparasitic activities without harmful effects. In this sense, natural products offer to be a diverse source of compounds with biological activities. In this work, we describe the isolation and elucidation by 1D and 2D NMR spectroscopy of three cyclopeptides obtained from seeds of A. diversifolia Saff.: cherimolacyclopeptide D (1), squamin D (2), and squamin C (3). The fractions enriched in cyclopeptides, as well as a pure compound (1), showed antiprotozoal activity against E. hystolitica Schaudinn and Giardia lamblia Kunstler in vitro assays, with values of IC50 = 3.49 and 5.39 μg mL-1, respectively. The molecular docking study revealed that 1 has a strong interaction with targets used, including aldose reductase and PFOR enzymes. The antiprotozoal activity of cherimolacyclopeptide D is reported for the first time in this study.

Prevalence of Intestinal Parasite Infection Among Prison Inmates and Their Associated Risk Factors at Hosanna Town, South-Central Ethiopia: A Cross-Sectional Study

Introduction: In developing countries, prisoners are one of the marginalized groups most susceptible to intestinal parasite infection due to inadequate living conditions, malnutrition, a lack of potable water, overcrowding, and poor hygiene. Thus, this study is aimed at assessing the prevalence and associated factors of intestinal parasitic infections among inmates of Hosanna town prison. Materials and Methods: An institution-based cross-sectional study was conducted in Hosanna Town's prisoners from June 1 to July 30, 2022, on a total of 420 inmates. The study participants were chosen using a simple random sampling technique. Sociodemographic, sanitation, hygienic, and related information were collected by using pretested questionnaires. In addition, about 5 g of stool sample was collected using a leak-proof plastic stool cup and examined microscopically by using direct wet mount preparation and formalin-ether concentration techniques, and data were analyzed by using SPSS Version 25. Results: This study indicated an overall 39.2% (95% CI: 34.6-44.1) prevalence of intestinal parasites (165/420). Entamoeba histolytica/dispar was the most prevalent intestinal parasite found, followed by Giardia lamblia, Ascaris lumbricoides, Hookworms, Taenia species, and Schistosoma mansoni. About 3.1% of participants had dual parasitic infections. In addition, there is a significant association in multivariable logistic regression analysis between intestinal parasitic infection and various hygiene practices such as not using soap when washing hands after using the toilet ((aOR 1.62 (95% CI: 1.06-2.48)), p ≤ 0.027), not regularly washing hands before meals ((aOR 2.83 (95% CI: 1.79-4.46)), p ≤ 0.001), poor hand hygiene overall ((aOR 3.18 (95% CI: 2.00-4.99)), p ≤ 0.001), not trimming fingernails ((aOR 2.09 (95% CI: 1.29-3.37)), p ≤ 0.003), and length of time in prison (aOR: 4.27, 95% CI: 22.62-6.96, p = 0.001). Conclusions: The findings of the study indicated that the overall prevalence of intestinal parasitic infections was 39.2%, with 38.8% of the infected individuals falling within the 25-34 age range. Additionally, 67.3% of those infected had been imprisoned for over a year. Furthermore, the personal hygiene status of prisoners was found to be substantially correlated with the presence of parasites. Hosanna town prison should ensure sufficient sanitary supplies, promote personal hygiene, and implement health education. Regular medical checkups and routine nail-clipping sessions are crucial for maintaining cleanliness and reducing parasite transmission among inmates.

Application of digital slide scanning in external quality assessment program on intestinal parasites

BACKGROUND

Intestinal parasitic infections remain prevalent in Viet Nam. Therefore, ensuring quality assurance in intestinal parasite testing is crucial for screening laboratories. The challenges associated with liquid or glass slide samples necessitate the exploration of digital slide applications, which can offer numerous benefits to program suppliers and participants.

OBJECTIVES

Compare the true and concordance rates of digital and glass slides for diagnosis.

DESIGN

Experimental research design.

MATERIALS AND METHODS

In total, 30 medical professionals from 30 hospitals participated in the trial. The sets of slides encompassed a range of densities, including negative and coinfected slides. Seven types of glass slides were selected for scanning and digital slide production.

MAIN OUTCOME MEASURES

The primary outcomes were true and concordance variables. Secondary outcomes included time sample sending and time completion. The digital slides were uploaded to a secure website for participant access while glass slides were sent individually by mail. Data collection involved participants analyzing specimens and reporting their results using a scoring method based on parasite detection and identification accuracy.

SAMPLE SIZE

210 glass and digital slide-reading results each.

RESULTS

The mean true rate between original and glass slides diagnosis was 97.6% (range 90.0%-100%), and it slightly increased to 98.1% (range 90.0%-100%) when using digital slides. The average concordance diagnosis rate between glass and digital slides was 99.5%. Importantly, there were no differences in the diagnostic results between glass and digital slides. The findings revealed that the use of digital slides reduced the total time required by approximately 1.1 days compared with that of glass slides.

CONCLUSION

Altogether, the application of digital slides in the external quality assessment program for intestinal parasites offers convenience for users through online platforms and saves operational time process.

LIMITATIONS

The small sample size in this experimental study limited the statistical significance of the comparisons.

Concomitant Infection of Helicobacter pylori and Intestinal Parasites: Burden, Sociodemographic and Clinical Characteristics in Hospitalized Children and Adolescents in Northern Lebanon

Background

Helicobacter pylori and intestinal parasites are well-known for their high prevalence in children, especially in developing countries. However, their concomitant infections are poorly documented. In this study, we aimed to evaluate the association between intestinal parasites and H. pylori among hospitalized children and adolescents with upper gastrointestinal complaints in Northern Lebanon.

Methods

A cross-sectional study was conducted involving 297 hospitalized pediatric patients, aged between 1 and 15 years, who presented with gastrointestinal symptoms. The socio-demographic, lifestyle, and gastrointestinal characteristics of all participants were analyzed. Fresh stool samples were collected and screened for the presence of intestinal parasites and H. pylori infections.

Results

6.4% of the patients were positive for intestinal parasitic infections, 5.4% were positive for H. pylori infection, and 11.8% were co-infected. The results of the Chi-square test showed that H. pylori infection is significantly associated with parasitic infection but not with a particular species. The most frequent coinfection was H. pylori-Entamoeba histolytica (77.1%). Moreover, H. pylori infection was associated with overcrowding and infrequent washing of vegetables before eating. The prevalence of co-infections increased in patients of mothers with a primary educational level or less. In regards to clinical characteristics, our findings showed a statistically significant relationship between i) gastric reflux and H. pylori, and ii) severe diarrhea and parasitic infection.

Conclusion

Our data highlighted the association between H. pylori and intestinal parasitic infections. Thus, H. pylori detection could be taken into consideration while screening for parasitic infections in children and adolescents.

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.

Effective Laboratory Diagnosis of Parasitic Infections of the Gastrointestinal Tract: Where, When, How, and What Should We Look For?

(1) Introduction: Gastrointestinal parasites (GIPs) are one of the most common causes of disease in the world. Clinical diagnosis of most parasitic diseases is difficult because they do not produce characteristic symptoms. (2) Methods: The PubMed, Science Direct, and Wiley Online Library medical databases were reviewed using the following phrases: "parasitic infections and diagnostics", "intestinal parasites", "gastrointestinal parasites", "parasitic infections and diagnostics", and their combinations. (3) Results and Conclusions: Correct diagnosis of GIP involves determining the presence of a parasite and establishing a relationship between parasite invasion and disease symptoms. The diagnostic process should consider the possibility of the coexistence of infection with several parasites at the same time. In such a situation, diagnostics should be planned with consideration of their frequency in each population and the local epidemiological situation. The importance of the proper interpretation of laboratory test results, based on good knowledge of the biology of the parasite, should be emphasized. The presence of the parasite may not be causally related to the disease symptoms. Due to wide access to laboratories, patients often decide to perform tests themselves without clinical justification. Research is carried out using various methods which are often unreliable. This review briefly covers current laboratory methods for diagnosing the most common gastrointestinal parasitic diseases in Europe. In particular, we provide useful information on the following aspects: (i) what to look for and where to look for it (suitability of feces, blood, duodenal contents, material taken from endoscopy or biopsy, tissue samples, and locations for searching for eggs, cysts, parasites, parasite genetic material, and characteristics of immune responses indicating parasitic infections); (ii) when material should be collected for diagnosis and/or to check the effectiveness of treatment; (iii) how-that is, by what methods-laboratory diagnostics should be carried out. Here, the advantages and disadvantages of direct and indirect methods of detecting parasites will be discussed. False-positive or false-negative results are a problem facing many tests. Available tests have different sensitivities and specificities. Therefore, especially in doubtful situations, tests for the presence of the pathogen should be performed using various available methods. It is important that the methods used make it possible to distinguish an active infection from a past infection. Finally, we present laboratory "case reports", in which we will discuss the diagnostic procedure that allows for the successful identification of parasites. Additionally, we briefly present the possibilities of using artificial intelligence to improve the effectiveness of diagnosing parasitic diseases.

Prevalence and distribution of intestinal parasitic infections in taeniasis endemic area of North Sumatera, Indonesia

A group of helminthic and intestinal protozoa causes intestinal parasitic infections (IPIs), affecting more than 2.5 billion people worldwide. IPIs are diseases closely associated with poor hygiene and sanitation, concentrated in underdeveloped regions and among populations with low socioeconomic status. Consequently, most prevalence is in Sub-Saharan Africa and Asia, with local habits or risk factors that could affect its prevalence. The aim of this study was to determine how hygienic practices, sanitation, and local behavior of eating raw meat (hinasumba) contributed to the prevalence of IPI. A cross-sectional study was conducted in the Simalungun District of North Sumatera Province, involving 428 people of Batak Simalungun. There were 15 villages randomly selected across the district based on the local registry, which consequently, non-purposive sampling was conducted. Face-to-face interviews assessed various risk factors, such as demographic characteristics, water source, traditional raw meat consumption, or hinasumba as local risk factors, hygienic practices, and sanitation. The findings indicated that an overall prevalence rate of IPI was 42.9%, consisting of 87.5% with helminthic infection and 12.5% with protozoal infection. More than half of IPI cases were associated with Taenia sp. infections (21.8%), followed by hookworms' infections with a 6.1% positivity rate. Based on multivariate analysis, farming and consuming traditional delicacies, namely hinasumba, increased the likelihood of IPI occurrence among the population by 1.7 and 3 times, respectively. It can be concluded that the high prevalence of taeniasis in the study area was associated with local behavior and hinasumba consumption, which may contribute to determining the dominance of specific IPI species.

Intestinal parasitic infections in children from marginalised Roma communities: prevalence and risk factors

BACKGROUND

Intestinal parasitic infections remain a significant global health issue, particularly affecting poor and marginalised populations. These infections significantly contribute to children's diseases, malnutrition, poor school performance, cognitive disorders, and future economic losses. This study aimed to explore and compare the occurrence of intestinal parasites in early childhood among the group of infants from the Slovak majority population and from marginalised Roma communities (MRCs). Furthermore, it aimed to explore the health complaints of children with and without intestinal parasitic infection in the past month and assess the effect of various risk factors on the occurrence of intestinal parasitic infection in infants from MRCs.

METHODS

We obtained cross-sectional data from mothers and stool samples of their children aged 13-21 months using the first wave of the longitudinal RomaREACH study. A total of 181 stools from infants were analysed: 105 infants from the Slovak majority population and 76 from MRCs.

RESULTS

Infants from MRCs are significantly more often infected by Ascaris lumbricoides, Trichuris trichiura and Giardia duodenalis than their better-off peers from the majority population. Infection rates are 30% in infants from MRCs vs. 0% in the majority population (p < 0.001). Single and mixed infections were observed in children from MRCs. Infants with intestinal parasitic infections suffer significantly more often from various health complaints, particularly cough, stomach ache, irritability, and diarrhoea. Within MRCs, the risk of parasitic infections in infants is significantly increased by risk factors such as the absence of flushing toilets in households (OR = 4.17, p < 0.05) and contact with un-dewormed animals (OR = 3.61, p < 0.05). Together with the absence of running water in the household, these three factors combined increase the risk more than ten times (p < 0.01).

CONCLUSION

Maintaining hygienic standards in conditions of socioeconomic deprivation in MRCs without running water and sewage in the presence of un-dewormed animals is problematic. These living conditions contribute to the higher prevalence of parasitic infections in children from MRCs, causing various health complaints and thus threatening their health and healthy development.

Selection of ssDNA aptamers and construction of aptameric electrochemical biosensor for the detection of Giardia intestinalis trophozoite protein

Giardia intestinalis is one of the most widespread intestinal parasites and is considered a major cause of epidemic or sporadic diarrhea worldwide. In this study, we aimed to develop a rapid aptameric diagnostic technique for G. intestinalis infection. First, the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) process generated DNA aptamers specific to a recombinant protein of the parasite's trophozoite. Ten selection rounds were performed; each round, the DNA library was incubated with the target protein conjugated to Sepharose beads. Then, the unbound sequences were removed by washing and the specific sequences were eluted and amplified by Polymerase Chain Reaction (PCR). Two aptamers were selected, and the dissociation constants (Kd), were determined as 2.45 and 16.95 nM, showed their high affinity for the G. intestinalis trophozoite protein. Subsequently, the aptamer sequence T1, which exhibited better affinity, was employed to develop a label-free electrochemical biosensor. A thiolated aptamer was covalently immobilized onto a gold screen-printed electrode (SPGE), and the binding of the targeted protein was monitored using square wave voltammetry (SWV). The developed aptasensor enabled accurate detection of the G. intestinalis recombinant protein within the range of 0.1 pg/mL to 100 ng/mL, with an excellent sensitivity (LOD of 0.35 pg/mL). Moreover, selectivity studies showed a negligible cross-reactivity toward other proteins such as bovine serum albumin, globulin, and G. intestinalis cyst protein.

Astacin metalloproteases in human-parasitic nematodes

Parasitic nematodes infect over 2 billion individuals worldwide, primarily in low-resource areas, and are responsible for several chronic and potentially deadly diseases. Throughout their life cycle, these parasites are thought to use astacin metalloproteases, a subfamily of zinc-containing metalloendopeptidases, for processes such as skin penetration, molting, and tissue migration. Here, we review the known functions of astacins in human-infective, soil-transmitted parasitic nematodes - including the hookworms Necator americanus and Ancylostoma duodenale, the threadworm Strongyloides stercoralis, the giant roundworm Ascaris lumbricoides, and the whipworm Trichuris trichiura - as well as the human-infective, vector-borne filarial nematodes Wuchereria bancrofti, Onchocerca volvulus, and Brugia malayi. We also review astacin function in parasitic nematodes that infect other mammalian hosts and discuss the potential of astacins as anthelmintic drug targets. Finally, we highlight the molecular and genetic tools that are now available for further exploration of astacin function and discuss how a better understanding of astacin function in human-parasitic nematodes could lead to new avenues for nematode control and drug therapies.

The involvement of cytokine gene polymorphism in determining the vulnerability to Blastocystis and Helicobacter pylori co-infection in the Egyptian population

AIMS

The present study aimed to identify any potential association between IL-1β and TNF-α gene polymorphism and the risk of Blastocystis infection as well as co-infection of Blastocystis with Helicobacter pylori (H.pylori).

METHODOLOGY

A total of 314 stool samples were collected and examined microscopically for the detection of parasitic infection. DNA was extracted from all samples and utilized to identify Blastocystis molecularly. Positive samples were used for H. pylori detection by rapid tests and PCR. Moreover, we investigate polymorphism in the TNF-α gene at position -1031T/C, -308 G/A, and IL-1β at position +3954C/T using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

Out of the 314 stool samples, Blastocystis was detected in 93 (29.6 %); among them, 54 (58.1 %) had a mixed infection of Blastocystis with H. pylori. The TT genotype of the IL-1β gene at position +3954 was significantly higher in Blasocystis-infected patients than in uninfected patients (17.2% vs. 6.3 %, P = 0.02), which might be considered a risk factor (OR = 3.2; CI =1.21-8.52). The TNF-α at position -1031 TT genotype was significantly higher in Blastocystis-infected patients than uninfected patients (44.1% vs. 10.8 %, P< 0.0001). The T allele (OR= 2.67; CI=1.51-4.72, P = 0.0008) might be considered a risk factor. The TNF- α at position -308 AA genotype is higher in Blasocystis infected than uninfected (17.2% vs 7.2 %, P = 0.03). TNF-α -308 AA (OR = 2.72; CI = 1.08-6.89) and A allele (OR= 1.46; CI= 0.797-2.66) might be considered risk factors. The TNF- α at position -308 G/A showed that the GG is the most frequent genotype in Blastocystis with H. pylori-positive patients with a significant association (P = 0.004), as well as the G allele (P = 0.02). The G allele (OR=1.924; CI= 1.071-3.454) might be considered a risk factor for co-infection of Blastocystis and H. pylori.

CONCLUSION

SNPs (-1031 T/C and -308 G/A) of the TNF-α and (+3954 C/T) of the IL-1β may be a useful marker in the assessment of the risk of Blastocystis infection, and TNF-α at position -308 G/A) may be a predictor for co-infection of Blastocystis with H. pylori.

Carbon dioxide shapes parasite-host interactions in a human-infective nematode

Skin-penetrating nematodes infect nearly one billion people worldwide. The developmentally arrested infective larvae (iL3s) seek out hosts, invade hosts via skin penetration, and resume development inside the host in a process called activation. Activated infective larvae (iL3as) traverse the host body, ending up as parasitic adults in the small intestine. Skin-penetrating nematodes respond to many chemosensory cues, but how chemosensation contributes to host seeking, intra-host development, and intra-host navigation - three crucial steps of the parasite-host interaction - remains poorly understood. Here, we investigate the role of carbon dioxide (CO2) in promoting parasite-host interactions in the human-infective threadworm Strongyloides stercoralis. We show that S. stercoralis exhibits life-stage-specific preferences for CO2: iL3s are repelled, non-infective larvae and adults are neutral, and iL3as are attracted. CO2 repulsion in iL3s may prime them for host seeking by stimulating dispersal from host feces, while CO2 attraction in iL3as may direct worms toward high-CO2 areas of the body such as the lungs and intestine. We also identify sensory neurons that detect CO2; these neurons are depolarized by CO2 in iL3s and iL3as. In addition, we demonstrate that the receptor guanylate cyclase Ss-GCY-9 is expressed specifically in CO2-sensing neurons and is required for CO2-evoked behavior. Ss-GCY-9 also promotes activation, indicating that a single receptor can mediate both behavioral and physiological responses to CO2. Our results illuminate chemosensory mechanisms that shape the interaction between parasitic nematodes and their human hosts and may aid in the design of novel anthelmintics that target the CO2-sensing pathway.

Therapeutic efficacy of Citrus aurantifolia (lime) juice in experimental Eimeria tenella-infected broiler chickens

The purpose of the present experiment was to explore the therapeutic effect of the crude fruit juice of Citrus aurantifolia (CAJ) on Eimeria tenella disorder in chickens. One hundred twenty 3-week-old Ross 308 broilers of equal sexes were assigned to six experimental groups of 20 birds each. Groups A, B, C, D, and E were experimentally infected with 20,000 sporulated Eimeria tenella oocysts. Broilers in groups A, B, and C were infected and allocated to three treatment-graded doses of C. aurantifolia fruit juice (20, 10, and 5 mL/kg body weight, respectively) which were administered orally for 7 consecutive days of the trial. Group D was infected and treated with a reference drug, Amprolium 1.5 g/L of drinking water (positive control), group E served as infected-untreated control, and group F was uninfected and non-treated (negative control). Oocysts per gram of feces were counted using the McMaster counting device, weight gain was calculated, and blood samples from each experimental group were collected on days 0, 7, 14, 21, and 28 post-infection for hematological evaluation. Results revealed that medication of broilers with C. aurantifolia fruit juice dose-dependently increased body weight, improved cecal lesion, decreased the E. tenella oocyst production rate, and significantly (P<0.05) increased the PCV of the infected broilers. C. aurantifolia provided valuable therapeutic effects against E. tenella-induced coccidiosis in broiler chickens. The plant fruit juice should be further validated to explore the vital compounds responsible for the anticoccidial efficacy.