Cryptosporidium suis and Cryptosporidium scrofarum in Eurasian wild boars (Sus scrofa) in Central Europe

Cryptosporidium spp. in German wildlife: Detection, regional occurrence and diversity in wild boar, roe, red and fallow deer

Cryptosporidium is a cause of diarrheal infections responsible for a loss of human and animal welfare worldwide. The impact of the parasite is underestimated and the reported sources of infection are diverse, as it occurs in a wide variety of hosts. Wildlife has been reported as a notifiable source, but few studies are available on its occurrence in European wild boar and cervid species. To determine the occurrence of Cryptosporidium in game in Brandenburg, Germany, a molecular survey was conducted during the 2017 to 2020 hunting seasons. A total of 562 fecal samples from wild boar (Sus scrofa, n = 262), roe deer (Capreolus capreolus, n = 174), red deer (Cervus elaphus, n = 62), fallow deer (Dama, n = 51) and 13 samples of unspecified species were analyzed for both 18S ribosomal RNA (18S rRNA) and Cryptosporidium oocyst wall protein (COWP) gene sequence regions. PCR results showed that 21.2 % of the samples (n = 119/562) were positive for at least one target gene (18S rRNA: n = 114; COWP: n = 14), but differences in Cryptosporidium occurrence were observed within species and hunting seasons, with variations ranging from 1.8 % to 41.7 % (roe deer), respectively. Analysis of Sanger sequences of the 18S rRNA and COWP PCR products indicated that the C. sp. deer genotype was predominant in deer (roe deer: 86.7 %, red deer: 66.7 %, fallow deer: 58.8 %), while C. suis and C. scrofarum were mainly detected in wild boar (88.5 %). The human pathogenic species C. parvum was detected in only 1.2 % (n = 7) of the samples analyzed, but without a clear indication of a specific wild animal host. The highest Cryptosporidium diversity was found in wild boar and roe deer with five and four different species, respectively. Comparison of the 18S rRNA sequences with the designated reference revealed minor variations at several nucleotide positions in some isolates, possibly indicating evolutionary adaptations and the development of new subtypes. In conclusion, wildlife represents a reservoir for a diverse spectrum of Cryptosporidium species and may thus contribute to their environmental spread and the transmission to humans.

Prevalence and Genetic Diversity of Entamoeba and Cryptosporidium in Pigs and Wild Boars in Central and Southern Vietnam: Implications for Zoonotic Risks and Surveillance

Background: Parasites of Entamoeba and Cryptosporidium genera, prevalent among various vertebrates such as humans and pigs, pose a zoonotic threat as common protozoan pathogens. This study investigated the prevalence and genetic diversity of Entamoeba and Cryptosporidium species in pigs and wild boars across central and southern Vietnam, to ascertain parasite transmission dynamics. Methods: A total of 113 independent stool samples from 77 pigs and 36 wild boars were analyzed using PCR-based molecular methodologies to detect the presence of Entamoeba spp. and Cryptosporidium spp. The identified species were further characterized through Sanger sequencing, and phylogenetic relationships were analyzed. Results: The study revealed a high prevalence of Entamoeba spp. (62%, n = 70/113) and Cryptosporidium spp. (31%, n = 35/113). Entamoeba suis (57%, n = 40) was predominant, followed by Entamoeba polecki (40%, n = 40) and Entamoeba hartmanni (3%, n = 2). Among Cryptosporidium species, Cryptosporidium scrofarum (89%, n = 31) was the most common, followed by Cryptosporidium suis (11%, n = 4). Wild boars exhibited a higher prevalence of Entamoeba infection compared with domestic pigs (p = 0.019). Conclusions: The study highlights a high prevalence of Entamoeba and Cryptosporidium, suggesting a potential for zoonotic transmission in Vietnam. Further investigations are necessary to determine the extent to which these parasites in pigs and wild boars contribute to the burden in the human population.

Molecular Detection and Epidemiology of Potentially Zoonotic Cryptosporidium spp. and Giardia duodenalis in Wild Boar (Sus scrofa) from Eastern Spain

The protozoans Giardia duodenalis and Cryptosporidium spp. are common causes of gastrointestinal disease in humans and animals. While both are commonly documented in domestic animals, few studies have analysed their presence in wildlife. To assess the prevalence of both parasites in wild boar (Sus scrofa) in the Valencian Community (eastern Spain), 498 wild boar faecal samples were collected from 2018 to 2022. Cryptosporidium spp. was detected by performing a nested PCR targeting a 578 bp sequence of the small subunit ribosomal RNA gene (SSU rRNA), followed by sequencing and phylogenetic analysis. For G. duodenalis, a qPCR amplifying a fragment of 62 bp from the SSU rRNA was employed. Positive samples were genotyped for glutamate dehydrogenase and β-giardin genes. Different epidemiological factors were considered potential modulating variables in the transmission of both parasites. G. duodenalis prevalence was 1.20%, while Cryptosporidium spp. prevalence reached 21.7%. Coinfection was observed in 0.2%. Genotyping of G. duodenalis isolates only detected genotype E. Two species of Cryptosporidium spp. were identified: Cryptosporidium scrofarum and Cryptosporidium suis. The results of this study demonstrate that the exposure to Cryptosporidium spp. in wild boars is high, particularly among young individuals belonging to the Typical Mediterranean climate. Moreover, the probability of infection is dependent on both the season and the density of wild boars. On the other side, exposure to G. duodenalis seems scarce and is influenced, in turn, by the climate. Both Cryptosporidium species detected in the present study have been reported in humans. Due to wild boar increasing in number and their colonisation of urban and peri-urban areas, this could represent an inherent health risk for the human population.

Occurrence and limited zoonotic potential of Cryptosporidium spp., Giardia duodenalis, and Balantioides coli infections in free-ranging and farmed wild ungulates in Spain

Little information is currently available on the occurrence and molecular diversity of the enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Balantioides coli in wild ungulates and the role of these host species as potential sources of environmental contamination and consequent human infections. The presence of these three pathogens was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were retrospectively collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from the five Spanish bioregions. Overall infection rates were 3.0% (42/1382; 95% CI: 2.1-3.9%) for Cryptosporidium spp., 5.4% (74/1382; 95% CI: 4.2-6.5%) for G. duodenalis, and 0.7% (9/1382; 95% CI: 0.3-1.2%) for B. coli. Cryptosporidium infection was detected in roe deer (7.5%), wild boar (7.0%) and red deer (1.5%), and G. duodenalis in southern chamois (12.9%), mouflon (10.0%), Iberian wild goat (9.0%), roe deer (7.5%), wild boar (5.6%), fallow deer (5.2%) and red deer (3.8%). Balantioides coli was only detected in wild boar (2.5%, 9/359). Sequence analyses revealed the presence of six distinct Cryptosporidium species: C. ryanae in red deer, roe deer, and wild boar; C. parvum in red deer and wild boar; C. ubiquitum in roe deer; C. scrofarum in wild boar; C. canis in roe deer; and C. suis in red deer. Zoonotic assemblages A and B were detected in wild boar and red deer, respectively. Ungulate-adapted assemblage E was identified in mouflon, red deer, and southern chamois. Attempts to genotype samples positive for B. coli failed. Sporadic infections by canine- or swine-adapted species may be indicative of potential cross-species transmission, although spurious infections cannot be ruled out. Molecular evidence gathered is consistent with parasite mild infections and limited environmental contamination with (oo)cysts. Free-ranging wild ungulate species would not presumably play a significant role as source of human infections by these pathogens. Wild ruminants do not seem to be susceptible hosts for B. coli.

Global prevalence of Cryptosporidium spp. in pigs: a systematic review and meta-analysis

Cryptosporidium spp. are significant opportunistic pathogens causing diarrhoea in humans and animals. Pigs are one of the most important potential hosts for Cryptosporidium. We evaluated the prevalence of Cryptosporidium in pigs globally using published information and a random-effects model. In total, 131 datasets from 36 countries were included in the final quantitative analysis. The global prevalence of Cryptosporidium in pigs was 16.3% (8560/64 809; 95% confidence interval [CI] 15.0–17.6%). The highest prevalence of Cryptosporidium in pigs was 40.8% (478/1271) in Africa. Post-weaned pigs had a significantly higher prevalence (25.8%; 2739/11 824) than pre-weaned, fattening and adult pigs. The prevalence of Cryptosporidium was higher in pigs with no diarrhoea (12.2%; 371/3501) than in pigs that had diarrhoea (8.0%; 348/4874). Seven Cryptosporidium species (Cryptosporidium scrofarum, Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium muris, Cryptosporidium tyzzeri, Cryptosporidium andersoni and Cryptosporidium struthioni) were detected in pigs globally. The proportion of C. scrofarum was 34.3% (1491/4351); the proportion of C. suis was 31.8% (1385/4351) and the proportion of C. parvum was 2.3% (98/4351). The influence of different geographic factors (latitude, longitude, mean yearly temperature, mean yearly relative humidity and mean yearly precipitation) on the infection rate of Cryptosporidium in pigs was also analysed. The results indicate that C. suis is the dominant species in pre-weaned pigs, while C. scrofarum is the dominant species in fattening and adult pigs. The findings highlight the role of pigs as possible potential hosts of zoonotic cryptosporidiosis and the need for additional studies on the prevalence, transmission and control of Cryptosporidium in pigs.

The Occurrence of Cryptosporidium spp. in Wild-Living Carnivores in Poland-A Question Concerning Its Host Specificity

Cryptosporidium is an apicomplexan protozoan parasite that primarily infects the gastrointestinal epithelium in humans and domestic and wild animals. The majority of studies have been focused on human, livestock, and pet infections. Hence, Cryptosporidium spp. in wildlife, including wild carnivores, remained neglected. There are several studies reporting the occurrence of Cryptosporidium spp. in wild foxes, but these are only a few molecular surveys; no data is available concerning the occurrence of this parasite in raccoon dogs and martens in Europe, and to the best of our knowledge to date, only one study has reported Cryptosporidium from badgers in Spain. Therefore, we used molecular analyses to identify and genotype Cryptosporidium spp. in wild-living mesocarnivores in Poland. A total of 322 individual fecal samples from six carnivore species, i.e., raccoon, raccoon dog, red fox, European badger, pine, and beech martens were collected and then analyzed for the presence of Cryptosporidium spp. using the nested PCR method. The appearance of PCR products in the reaction with Cryptosporidium-specific primers against the 18S rRNA and actin genes demonstrated that Cryptosporidium spp. occurred in 23.0% of all examined species of animals. Performed sequence analyses showed the presence of the Cryptosporidium skunk genotype, Cryptosporidium vole genotype II, Cryptosporidium canis dog and fox genotypes, as well as Cryptosporidium erinacei, Cryptosporidium ditrichi, Cryptosporidium suis, and Cryptosporidium alticolis, in these hosts. Molecular data presented here indicate that examined mesocarnivores may be a significant reservoir of specific and non-specific Cryptosporidium species, including those with zoonotic potential. Most studies of carnivores have described the presence of non-specific Cryptosporidium spp. in carnivore hosts, and this is probably the result of the transfer of these parasites from prey species through the digestive tract or the transfer of the parasite from a contaminated environment.

Probabilistic fecal pollution source profiling and microbial source tracking for an urban river catchment

We developed an innovative approach to estimate the occurrence and extent of fecal pollution sources for urban river catchments. The methodology consists of 1) catchment surveys complemented by literature data where needed for probabilistic estimates of daily produced fecal indicator (FIBs, E. coli, enterococci) and zoonotic reference pathogen numbers (Campylobacter, Cryptosporidium and Giardia) excreted by human and animal sources in a river catchment, 2) generating a hypothesis about the dominant sources of fecal pollution and selecting a source targeted monitoring design, and 3) verifying the results by comparing measured concentrations of the informed choice of parameters (i.e. chemical tracers, C. perfringensspores, and host-associated genetic microbial source tracking (MST) markers) in the river, and by multi-parametric correlation analysis. We tested the approach at a study area in Vienna, Austria. The daily produced microbial particle numbers according to the probabilistic estimates indicated that, for the dry weather scenario, the discharge of treated wastewater (WWTP) was the primary contributor to fecal pollution. For the wet weather scenario, 80-99 % of the daily produced FIBs and pathogens resulted from combined sewer overflows (CSOs) according to the probabilistic estimates. When testing our hypothesis in the river, the measured concentrations of the human genetic fecal marker were log₁₀ 4 higher than for selected animal genetic fecal markers. Our analyses showed for the first-time statistical relationships between C. perfringens spores (used as conservative microbial tracer for communal sewage) and a human genetic fecal marker (i.e. HF183/BacR287) with the reference pathogen Giardia in river water (Spearman rank correlation: 0.78-0.83, p < 0.05. The developed approach facilitates urban water safety management and provides a robust basis for microbial fate and transport models and microbial infection risk assessment.

Survey of Zoonotic Diarrheagenic Protist and Hepatitis E Virus in Wild Boar (Sus scrofa) of Portugal

Enteropathogenic parasites and viruses have been frequently reported in swine and can infect a wide range of mammals, including humans. Among the wide variety of parasites infecting swine, diarrhoeagenic protists are among those that cause significant morbidity. Hepatitis E virus (HEV) has also been reported both in domestic pigs and wild boar and is known to have an important public health significance. These agents share the fecal−oral transmission route, but data on their fecal shedding and circulation pathways are still lacking or incomplete. Hence, the aim of the present study was to characterize the presence of microeukaryotes and HEV in the wild boar of Portugal. Wild boar stool samples (n = 144) were obtained during the official hunting seasons (October to February) in 2018/2019, 2019/2020, and 2021/2022 and tested for Cryptosporidium spp., Balantioides coli, Giardia duodenalis, Blastocystis sp., Enterocytozoon bieneusi and HEV by molecular assays, followed by sequencing and phylogenetic analysis. We have detected Cryptosporidium scrofarum (1.4%, 95% CI: 0.2−4.9), B. coli (14.6%, 95% CI: 9.2−21.4), Blastocystis ST5 (29.2%, 95% CI: 21.9−37.2) and HEV genotype 3 (2.8%, 95% CI: 0.7−6.9; subgenotypes 3e and 3m). Co-infections were observed in thirteen animals where two were positive for both HEV and B. coli, one was positive for both C. scrofarum and Blastocystis ST5, and ten were positive for both B. coli and Blastocystis ST5. Giardia duodenalis and E. bieneusi were not detected in the surveyed wild boar population. As far as we know, this is the first report describing protist infections by Cryptosporidium spp., B. coli, and Blastocystis sp., as well as the first identification of the emerging HEV genotype 3m in wild boar of Portugal. The present work shows that potentially zoonotic protozoa and HEV are circulating in wild boar populations in Portugal. Awareness and epidemic-surveillance network implementation measures targeting wild boar are needed to prevent the spread of these pathogenic agents to humans.

Standardised Sampling Approach for Investigating Pathogens or Environmental Chemicals in Wild Game at Community Hunts

Simple Summary

Wild game can host pathogens capable of infecting humans, livestock, and companion animals or accumulate environmental chemicals that may be transferred via food of animal origin. For food safety research, as well as for various other scientific purposes, the provision of a sufficient number of samples without unnecessary disturbance or killing of animals is a major limitation. With the presented approach, it was possible to obtain samples from game animals killed as part of standard ungulate management practice. Examples of organs, tissues, and other matrices that have been used in wild ungulate studies in Europe and that may be obtained through this approach are summarised as well. The basis of this approach was a framework agreement with the BImA, whereby federal forest officials carried out sampling with the help of hunters at drive hunts from 2017/18 to 2020/21 in Brandenburg, Germany. Numerous samples from four ungulate species were obtained. The number of sampled animals per hunt differed between hunting districts and hunting seasons. Districts with higher hunting bags also promise higher sampling success. This approach can serve as the basis for long-term monitoring of animal and public health threats associated with wildlife and is adaptable to other regions.

Abstract

Wildlife may host pathogens and chemicals of veterinary and public health relevance, as well as pathogens with significant economic relevance for domestic livestock. In conducting research on the occurrence and distribution of these agents in wildlife, a major challenge is the acquisition of a sufficient number of samples coupled with efficient use of manpower and time. The aim of this article is to present the methodology and output of a sampling approach for game animals, which was implemented from 2017/18 to 2020/21 at drive hunts in Brandenburg, Germany. The central element was a framework agreement with the BImA, whereby federal forest officials and other hunters collected most of the samples during field dressing. Further samples of game carcasses were obtained by scientists during subsequent gathering at a collection point. Altogether, 3185 samples from 938 wild ungulates of four species were obtained for various studies analysing—in this case—food-borne agents in game animals. Sampling was representative and reflected the proportional distribution of ungulate species hunted in Brandenburg. Hunting district and hunting season strongly influenced hunting bag and hence sampling success. This sampling approach was demonstrated to be a suitable basis for monitoring programs, that can be adapted to other regions.

Infectious Wildlife Diseases in Austria-A Literature Review From 1980 Until 2017

This literature review examines infectious wildlife disease research in Austria. We analyzed 226 research papers, published between 1980 and 2017. We determined that wildlife disease papers increased significantly from 0.8 ± 0.8 publications per year in the first decade (1980–1989) when compared to 2008–2017 with an average of 12.9 ± 4.1 publications per year. We illustrate information about the most investigated diseases and highlight the lack of research into certain wildlife pathogens. A special emphasis was given to diseases with zoonotic potential. The review showed that research focused on a few select species like the red fox (Vulpes vulpes), red deer (Cervus elaphus), and wild boar (Sus scrofa), all game species. Moreover, diseases affecting livestock and human health were seen more often. The review also found that only a low number of publications actually stated disease prevalence and confidence interval data. The reported diseases identified were classified according to their notifiable status and the distribution at the wildlife–human and wildlife–livestock interface. Furthermore, we try to argue why research into some diseases is prioritized, and why other diseases are underrepresented in current Austrian research. While spatiotemporal indicators could not be assessed due to the variability in methodologies and objectives of various studies, the information provided by this review offers the first comprehensive evaluation of the status of infectious wildlife disease research in Austria. Therefore, this study could assist investigators to identify further areas of priorities for research and conservation efforts and for wildlife management professionals to inform policy and funding strategies. With this review, we want to encourage research in the field of wildlife diseases in Austria to enhance current knowledge in the prevention of further loss in biodiversity and to find new measures to promote “One Health” on a global scale.

Identification of Enterocytozoon bieneusi and Cryptosporidium spp. in farmed wild boars (Sus scrofa) in Beijing, China

Enterocytozoon bieneusi and Cryptosporidium spp. are opportunistic pathogen that can infected humans and other animals. However, the data on the prevalence and genotypes of the parasites in captive wild boars is not available in Beijing, China. In this study, a total of 257 fecal specimens of wild boars were collected. The overall prevalence of E. bieneusi and Cryptosporidium spp. was 42.0% (108/257) and 5.8%, respectively. Higher infection rate of E. bieneusi was discovered in the wild boar ≤2 months old (58.3%). The differences between the feeding pattern and gender were not significant. Furthermore, eight genotypes of E. bieneusi were determined by analyzing the internal transcribed spacer (ITS) of the rRNA gene, including seven known genotypes and one novel genotype. Phylogenetic analysis revealed that all the eight genotypes belonged to the zoonotic potential Group 1. For Cryptosporidium spp., no significant differences were found between groups of gender, age and feeding pattern. Only C. scrofarum was identified in the investigated samples. The findings suggest that wild boar could be reservoirs of E. bieneusi and C. scrofarum which could be potentially transmitted to humans and other animals.

Molecular identification and epidemiological comparison of Cryptosporidium spp. among different pig breeds in Tibet and Henan, China

Background

Cryptosporidium spp. are important zoonotic pathogens infecting a wide range of vertebrate hosts, and causing moderate to severe diarrhea in humans. Cryptosporidium infections are frequently reported in humans and animals worldwide, but little research has been done on local pig breeds such as Tibetan pigs and Yunan Black pigs and imported pig breeds such as Landrace pigs in China. Therefore, a total of 1089 pig fecal samples from four intensive farms in four areas of China, including Tibetan pigs from Gongbujiangda County (n = 180) and Mainling County (n = 434), Tibet, Yunan Black pigs from Sanmenxia, Henan Province (n = 246), and Landrace pigs from Kaifeng, Henan Province (n = 229), and were screened for the presence of Cryptosporidium with microscopy and nested PCR amplification of the small subunit rRNA gene.

Results

The total infection rate of Cryptosporidium in 1089 fecal samples of three different pig breeds was 2.11% (23/1089), and the infection rates of Tibetan pigs, Yunan Black pigs, and Landrace pigs were 0.49% (3/614), 0.41% (1/246), and 8.30% (19/229), respectively. The prevalence of Cryptosporidium infection was significantly higher in weaned piglets (1–2 months) (4.36%, 21/482) than in younger and older age groups (p < 0.01). Sequence analysis of positive samples revealed that there was no mixed infection in our study population, which included 12 cases of C. suis mono-infections (52.17%, 12/23) and 11 cases of C. scrofarum mono-infections (47.83%, 11/23). C. suis was identified in one pre-weaned piglet (< 1 month) and 11 weaned piglets (1–2 months), while C. scrofarum was only detected in 10 weaned piglets (1–2 months) and one finished pig (> 2 months).

Conclusions

This is the first report on the identification of Cryptosporidium spp. in Tibetan pigs, and our findings also elucidate the occurrence and distribution of Cryptosporidium in three different pig breeds in Tibet and Henan, China. More molecular epidemiological studies are required to better clarify the prevalence and public health significance of Cryptosporidium in different pigs.

Review of Cryptosporidium and Giardia in the eastern part of Europe, 2016

This paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results: Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.

Suidae and Tayassuidae

The Suidae and Tayassuidae live on all continents except Antarctica. True wild boars were indigenous to Europe and Asia and are the ancestors to the domestic pig; with whom they share the same scientific name Sus scrofa. Wild boars have been introduced to the Americas and many islands. Because of the close genetic relationship, in many areas they have interbred with domestic pigs and formed considerable populations of feral suids that represent wild boar and feral pig crosses. Wild suid populations are relatively hardy and most disease research has been focused on their potential as a reservoir for diseases of concern for commercial pig production. The Togian Island babirusa, pygmy hog, Visayan warty pig, Javan warty pig, and Chacoan peccary are endangered. For all species, hunting, habitat loss, and hybridization are important threats to conservation.

Molecular Epidemiology of Cryptosporidiosis in China

Molecular epidemiology of cryptosporidiosis is an active research area in China. The use of genotyping and subtyping tools in prevalence studies has led to the identification of unique characteristics of Cryptosporidium infections in humans and animals. Human cryptosporidiosis in China is exemplified by the high diversity of Cryptosporidium spp. at species and subtype levels, with dominant C. hominis and C. parvum subtypes being rarely detected in other countries. Similarly, preweaned dairy calves, lambs, and goat kids are mostly infected with non-pathogenic Cryptosporidium species (C. bovis in calves and C. xiaoi in lambs and goat kids), with C. parvum starting to appear in dairy calves as a consequence of concentrated animal feeding operations. The latter Cryptosporidium species is dominated by IId subtypes, with IIa subtypes largely absent from the country. Unlike elsewhere, rodents in China appear to be commonly infected with C. parvum IId subtypes, with identical subtypes being found in these animals, calves, other livestock, and humans. In addition to cattle, pigs and chickens appear to be significant contributors to Cryptosporidium contamination in drinking water sources, as reflected by the frequent detection of C. suis, C. baileyi, and C. meleagridis in water samples. Chinese scientists have also made significant contributions to the development of new molecular epidemiological tools for Cryptosporidium spp. and improvements in our understanding of the mechanism involved in the emergence of hyper-transmissible and virulent C. hominis and C. parvum subtypes. Despite this progress, coordinated research efforts should be made to address changes in Cryptosporidium transmission because of rapid economic development in China and to prevent the introduction and spread of virulent and zoonotic Cryptosporidium species and subtypes in farm animals.

Presence of zoonotic Cryptosporidium scrofarum, Giardia duodenalis assemblage A and Enterocytozoon bieneusi genotypes in captive Eurasian wild boars (Sus scrofa) in China: potential for zoonotic transmission

Background

Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi are the main causal pathogens of gastrointestinal disease. However, there are limited reports about the prevalence of these organisms in captive Eurasian wild boars worldwide. Therefore, we examined the occurrence and identified the species/assemblages/genotypes of these pathogens in captive Eurasian wild boars, and estimated the zoonotic potential.

Findings

Of 357 fecal samples collected from captive Eurasian wild boars in China, 155 (43.4%) were infected with Cryptosporidium, G. duodenalis and/or E. bieneusi. The infection rates significantly differed in different areas, but did not differ between wild boars kept indoors and outdoors. Three (0.8%), 11 (3.1%) and 147 (41.2%) fecal samples were positive for Cryptosporidium, G. duodenalis and E. bieneusi, respectively. Sequence analysis of SSU rRNA gene revealed that all of the Cryptosporidium strains belonged to C. scrofarum. Based on the sequence analysis of the β-giardia gene of G. duodenalis, assemblages E and A were characterized. Fourteen E. bieneusi genotypes comprising five novel (WildBoar 7–11) and eight known (EbpC, F, CHG19, CHC5, PigEBITS5, D, RWSH4, SC02) genotypes were identified by ITS sequencing. EbpC was the most frequent genotype, detected in 85 specimens. Phylogenetic analysis revealed that all 14 genotypes belonged to Group 1.

Conclusions

This first report on the occurrence of Cryptosporidium, G. duodenalis and E. bieneusi in captive wild boars in China indicates that the presence of zoonotic species/assemblages/genotypes poses a threat to public health. The findings suggest that wild boars could be a significant source of human infection and water pollution.

Prevalence and Diversity of Cryptosporidium and Giardia Identified Among Feral Pigs in Texas

The population size and geographic range of feral pigs in the United States are rapidly expanding. Nevertheless, the role of this invasive species in the ecology and transmission of zoonotic enteric pathogens is poorly understood. Our objectives were to describe the prevalence and diversity of Cryptosporidium and Giardia shedding among feral pigs throughout Texas and to identify risk factors for infection. Fecal samples were collected from feral pigs in Texas from February 2014 through May 2015. Cryptosporidium oocysts and Giardia cysts were detected using a direct immunofluorescence assay, and genotyping of positive samples was performed. The prevalence of Cryptosporidium shedding was 1.6% (6/370), and C. scrofarum and C. suis were identified. The prevalence of Giardia shedding was 4.3% (16/370), and assemblages A and E were identified. Cryptosporidium shedding was significantly more common among juvenile and subadult pigs than among adult pigs, but age group was not associated with Giardia shedding status. Feral pigs may serve as a source of Cryptosporidium and Giardia transmission to humans and livestock.

Public health significance of zoonotic Cryptosporidium species in wildlife: Critical insights into better drinking water management

Cryptosporidium is an enteric parasite that is transmitted via the faecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Human encroachment into natural ecosystems has led to an increase in interactions between humans, domestic animals and wildlife populations. Increasing numbers of zoonotic diseases and spill over/back of zoonotic pathogens is a consequence of this anthropogenic disturbance. Drinking water catchments and water reservoir areas have been at the front line of this conflict as they can be easily contaminated by zoonotic waterborne pathogens. Therefore, the epidemiology of zoonotic species of Cryptosporidium in free-ranging and captive wildlife is of increasing importance. This review focuses on zoonotic Cryptosporidium species reported in global wildlife populations to date, and highlights their significance for public health and the water industry.