Surface waters as a potential source of Giardia and Cryptosporidium in Serbia

Gastrointestinal Parasites in Owned Dogs in Serbia: Prevalence and Risk Factors

Dogs are the most popular pets worldwide. Close contact between dogs and people increases the risk of transmission of various zoonotic parasitic infections. Given the importance of veterinary medicine in preserving the One Health concept, the aim of this research was to identify intestinal parasites that may have zoonotic potential and to evaluate risk factors (individual and environmental). The research was conducted in Serbia in 2022 and 2023 on 382 owned dogs, using qualitative methods of coprological examination with a concentration on parasitic elements. The overall prevalence of intestinal parasites was 62.6%, with the following detected: protozoa: Cystoisospora spp. (9.2%), Sarcocystis spp. (4.5%), Neospora caninum/Hammondia spp. (3.7%), Giardia intestinalis (11.8%); nematoda: Toxocara canis (11.5%), Toxascaris leonina (4.2%), family Ancylostomatidae (38.0%), Trichuris vulpis (21.5%), Capillaria spp. (10.5%); trematoda: Alaria alata (1.6%) and cestodes from the Taeniidae family (1.3%). Factors like age, size and coat length, as well as the way of living, attitude and diet were linked to a significantly higher (p < 0.05) prevalence of intestinal parasites. Based on the results of coprological diagnostics, this research indicates the importance of educating dog owners, conducting routine parasitological tests on their pets and regular deworming strategies.

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quindío River basin, Colombia

Two zoonotic protozoan pathogens, Giardia duodenalis and Toxoplasma gondii, are important causes of waterborne infections in the Quindío region in Colombia. No previous data exist on how contamination occurs at the source for drinking water consumed by the human population in this region. Our aim was to describe the frequency of G. duodenalis and T. gondii DNA in 11 sampling points during a five-month period in water and adjacent soil at the Quindío River basin (Andean region in the central western part of Colombia). The study employed nested PCR for T. gondii, using the B1 gene as the amplification target, and single-round PCR for G. duodenalis assemblage A and assemblage B, amplifying the gdh gene, followed by DNA sequencing. In 50 soil samples, 28% (14/50) were positive for T. gondii. For G. duodenalis, distribution was in equal parts for assemblage A (8%; 4/50) and assemblage B (8%, 4/50). Genotyping of T. gondii sequences showed two soil samples with type I strain, another two samples of soil with type III strain, but most samples were of unidentified strains. In water samples, T. gondii was detected in 9.1% (5/55), G. duodenalis assemblage A in 34.5% (19/55), and G. duodenalis assemblage B in 12.7% (7/55). T. gondii DNA positivity was associated with lower soil temperature (p = 0.0239). Presence of G. duodenalis and T. gondii was evidenced in soil and water samples in the Quindío River basin, indicating soil as the potential source of contamination for the river that it is destined for human consumption. Monitoring these protozoa in drinking water is necessary to prevent public health risks in human populations.

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55 water and 50 soil samples from Colombian Quindio river basin were studied.

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Positive soil: 28% T. gondii, 8% G. intestinalis assemblages A and B.

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Positive water: 9.1% T. gondii, 4.5% G. intestinalis assemblages A and B.

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Soil and water are potential sources of contamination for river water that is destined for human consumption.

Human health risk assessment for (re)emerging protozoan parasites in surface water used for public supply and recreational activities

Gastrointestinal diseases caused by protozoan parasites remain a major challenge in developing countries and ingestion of contaminated surface water represents one of the main sources by which these diseases are contracted. This study assessed the risk of infection and diseases caused by Cryptosporidium spp. and Giardia sp. due to ingestion of surface water used for public supply and recreational activities, focusing on the southeastern Brazilian Pardo River and applying the USEPA 1623 method to quantify (oo)cyst concentrations. Infection and disease probabilities due to ingestion of drinking water or during recreational activities were estimated using the Quantitative Microbial Risk Assessment (QMRA) approach. Mean concentrations of Cryptosporidium spp. and Giardia sp. in surface water ranged from 0.2 to 0.4 oocysts L^-1 and 0.2 to 4.4 cysts L^-1, respectively. Considering public water supply, annual infection probabilities were higher for adults than children and exceeded the USEPA limit; also, disease probabilities were higher for adults than children. For recreational activities, annual infection and disease probabilities were higher for children, followed by men and women. The occurrence of both parasites likely reflects raw sewage discharge, effluent from sewage treatment plants, and diffuse sources of pollution, such as runoff from pasture lands and deforested riparian forest corridors. Our results highlight substantial infection risks by both parasite types after conventional treatment of water used for public supply and also call for careful monitoring of water bodies used for recreational purposes.

Molecular Diagnostic Tools Applied for Assessing Microbial Water Quality

Microbial water quality is of vital importance for human, animal, and environmental health. Notably, pathogenically contaminated water can result in serious health problems, such as waterborne outbreaks, which have caused huge economic and social losses. In this context, the prompt detection of microbial contamination becomes essential to enable early warning and timely reaction with proper interventions. Recently, molecular diagnostics have been increasingly employed for the rapid and robust assessment of microbial water quality implicated by various microbial pollutants, e.g., waterborne pathogens and antibiotic-resistance genes (ARGs), imposing the most critical health threats to humans and the environment. Continuous technological advances have led to constant improvements and expansions of molecular methods, such as conventional end-point PCR, DNA microarray, real-time quantitative PCR (qPCR), multiplex qPCR (mqPCR), loop-mediated isothermal amplification (LAMP), digital droplet PCR (ddPCR), and high-throughput next-generation DNA sequencing (HT-NGS). These state-of-the-art molecular approaches largely facilitate the surveillance of microbial water quality in diverse aquatic systems and wastewater. This review provides an up-to-date overview of the advancement of the key molecular tools frequently employed for microbial water quality assessment, with future perspectives on their applications.

Surface Waters and Urban Brown Rats as Potential Sources of Human-Infective Cryptosporidium and Giardia in Vienna, Austria

Cryptosporidium and Giardia are waterborne protozoa that cause intestinal infections in a wide range of warm-blooded animals. Human infections vary from asymptomatic to life-threatening in immunocompromised people, and can cause growth retardation in children. The aim of our study was to assess the prevalence and diversity of Cryptosporidium and Giardia in urban surface water and in brown rats trapped in the center of Vienna, Austria, using molecular methods, and to subsequently identify their source and potential transmission pathways. Out of 15 water samples taken from a side arm of the River Danube, Cryptosporidium and Giardia (oo)cysts were detected in 60% and 73% of them, with concentrations ranging between 0.3-4 oocysts/L and 0.6-96 cysts/L, respectively. Cryptosporidium and Giardia were identified in 13 and 16 out of 50 rats, respectively. Eimeria, a parasite of high veterinary importance, was also identified in seven rats. Parasite co-ocurrence was detected in nine rats. Rat-associated genotypes did not match those found in water, but matched Giardia previously isolated from patients with diarrhea in Austria, bringing up a potential role of rats as sources or reservoirs of zoonotic pathogenic Giardia. Following a One Health approach, molecular typing across potential animal and environmental reservoirs and human cases gives an insight into environmental transmission pathways and therefore helps design efficient surveillance strategies and relevant outbreak responses.

Urban public squares as potential hotspots of dog-human contact: A spatial analysis of zoonotic parasites detection in Gran Santiago, Chile

Zoonotic parasites are a major public health problem globally, representing a hazard to human health. The infections occur through contact with different parasite forms. Public squares are a common meeting place for people and dogs, becoming a risk area for transmission to other dogs and humans. A spatial analysis of zoonotic parasite distribution in urban public squares in Gran Santiago, Chile was performed to elucidate its importance, exploring spatial aggregation on positivity rates at commune level. A total of 170 stool samples were analysed; 54 (31.7%) were positive for gastrointestinal-zoonotic parasites. Positivity was detected in 27 (79.4%) squares. Diversity of parasite species was variable across sites. Toxocara canis was the most frequently detected (27 samples, 21/34 squares), followed by Toxascaris leonina (13 samples, 10/34 squares), cestode eggs (10 samples, 9/34 squares), Giardia sp. (6 samples, 5/34 squares), Ancylostomatidae-like eggs (4 samples, 4/34 squares), Cryptosporidium spp. (2 samples, 2/34 squares) and Entamoeba spp. (1 sample, 1/34 square). Spatial autocorrelation (SA) was observed at commune level. The local indicators of the spatial association test showed statistical significance for cestode eggs (p < 0.001) with a negative SA (Moran's I Index = -0.2929, CI-95% = -0.3869--0.1989) and Ancylostomatidae (p = 0.046) with a positive SA (Moran's I Index = 0.1404, CI-95% = 0.0499-0.2309). Toxocara canis is the most prevalent geo-helminth in public places of Santiago, Chile. Spatial autocorrelation was detected for cestode eggs and Ancylostomatidae. Diagnosis and detection of parasites is key for the establishment of control/eradication of environmental dissemination following One Health guidelines.

The Occurrence of Cryptosporidium and Giardia Parasites in Drinking Water Resources of Alborz province , the Central Part of Iran in 2018

Background: Giardia and Cryptosporidium are common parasitic protozoa that cause acute intestinal infections in children. These two parasites are mostly found in aquatic environments, including raw water, wastewater, and even treated water. Objective: The present study aimed to examine parasitic contamination of drinking water resources by cysts and the oocyst of Giardia and Cryptosporidium in Alborz province, Iran. Materials and Methods: Water samples from three rivers and seven randomly-selected wells of Alborz province were examined using Sheather, formol-ether, and immuno-fluorescence assay (IFA) techniques. The prepared slides were examined with optical and fluorescence microscopes. Results: IFA technique revealed that 28% of the wells were contaminated with both parasites. It was also shown that all rivers’ drainage basins were contaminated with Cryptosporidium parasite, while 66% of rivers’ drainage basins were contaminated with Giardia parasite. Conclusion: The results showed that water resources of Alborz province contained Giardia cysts and Cryptosporidium oocysts, which required health care officials to pay serious attention to treating drinking water.

Why we need a European focus on foodborne parasites

Foodborne parasites (FBP) are recognized as being a neglected pathogen group, often associated with marginalized or disadvantaged populations, especially those living in regions where water supply or sanitation are inadequate. Nevertheless, we are also increasingly recognising that FBP are not just restricted to such places, and even those that do have a circumscribed endemic area may also travel further in our globalised world; FBP are relevant everywhere, including Europe. Against this background, COST Action Euro-FBP (FA1408) was established and ran for a period of 4 years, addressing a number of different questions related to FBP, particularly in the European setting. In this special issue (SI), some of the issues and outputs associated with Euro-FBP are considered in greater depth, as an output also of the final Euro-FBP meeting. As well as more general issues regarding, for example, globalization and climate change, use of economic models, and the value of risk-based surveillance that puts the topic in perspective, individual articles are included that address specific parasites. These include protozoan parasites, such as Cryptosporidium, Giardia, and Toxoplasma, as contaminants of water, shellfish, and fresh produce, fishborne parasites such as Anisakid nematodes, and meatborne parasites, such as Trichinella. Some of the works provide specific data on occurrence or outbreaks, whilst others are concerned with techniques. In addition, implementation of some of the educational and collaborative tools that are unique to COST Actions are described. COST Actions are not generally intended to deliver a scientific endpoint, and Euro-FBP does not do so. However, the articles in this SI, along with other articles published elsewhere during and subsequent to the course of the Action, as direct outputs of the Euro-FBP activities, indicate that FBP are indeed a relevant topic for European scientists.