A whole water catchment approach to investigating the origin and distribution of Cryptosporidium species

Cryptosporidium occultus in disguise

As data accumulate in GenBank, the difficulties of delineating species of Cryptosporidium based on nuclear small subunit ribosomal RNA (ssu rRNA) gene information alone becomes increasingly evident. Here, we summarize currently available evidence suggesting that several ssu rDNA sequences primarily referred to as Cryptosporidium suis (some of them from non-suid hosts) should be considered Cryptosporidium occultus.

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 and Molecular Diversity of Cryptosporidium spp. and Giardia duodenalis in the Endangered Iberian Lynx (Lynx pardinus), Spain

Cryptosporidium spp. and Giardia duodenalis are the main non-viral causes of diarrhoea in humans and domestic animals globally. Comparatively, much less information is currently available in free-ranging carnivore species in general and in the endangered Iberian lynx (Lynx pardinus) in particular. Cryptosporidium spp. and G. duodenalis were investigated with molecular (PCR and Sanger sequencing) methods in individual faecal DNA samples of free-ranging and captive Iberian lynxes from the main population nuclei in Spain. Overall, Cryptosporidium spp. and G. duodenalis were detected in 2.4% (6/251) and 27.9% (70/251) of the animals examined, respectively. Positive animals to at least one of them were detected in each of the analysed population nuclei. The analysis of partial ssu rRNA gene sequences revealed the presence of rodent-adapted C. alticolis (n = 1) and C. occultus (n = 1), leporid-adapted C. cuniculus (n = 2), and zoonotic C. parvum (n = 2) within Cryptosporidium, and zoonotic assemblages A (n = 5) and B (n = 3) within G. duodenalis. Subgenotyping analyses allowed for the identification of genotype VaA19 in C. cuniculus (gp60 locus) and sub-assemblages AI and BIII/BIV in G. duodenalis (gdh, bg, and tpi loci). This study represents the first molecular description of Cryptosporidium spp. and G. duodenalis in the Iberian lynx in Spain. The presence of rodent/leporid-adapted Cryptosporidium species in the surveyed animals suggests spurious infections associated to the Iberian lynx's diet. The Iberian lynx seems a suitable host for zoonotic genetic variants of Cryptosporidium (C. parvum) and G. duodenalis (assemblages A and B), although the potential risk of human transmission is regarded as limited due to light parasite burdens and suspected low excretion of infective (oo)cysts to the environment by infected animals. More research should be conducted to ascertain the true impact of these protozoan parasites in the health status of the endangered Iberian lynx.

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.

Zoonotic Cryptosporidium spp. in Wild Rodents and Shrews

There has been a significant increase in the number of reported human cryptosporidiosis cases in recent years. The aim of this study is to estimate the prevalence of Cryptosporidium spp. in wild rodents and shrews, and investigate the species and genotype distribution to assess zoonotic risk. Partial 18S rRNA gene nested-PCR reveals that 36.8, 53.9 and 41.9% of mice, voles and shrews are infected with Cryptosporidium species. The highest prevalence occurred in the Microtus agrestis (field vole) and Myodes glareolus (bank vole). Interestingly, bank voles caught in fields were significantly more often Cryptosporidium-positive compared to those caught in forests. The proportion of infected animals increases from over-wintered (spring and summer) to juveniles (autumn) suggesting acquired immunity in older animals. Based on Sanger sequencing and phylogenetic analyses, Apodemus flavicollis (yellow-necked mouse) is commonly infected with zoonotic C. ditrichi. Voles carry multiple different Cryptosporidium sp. and genotypes, some of which are novel. C. andersoni, another zoonotic species, is identified in the Craseomys rufocanus (grey-sided vole). Shrews carry novel shrew genotypes. In conclusion, this study indicates that Cryptosporidium protozoan are present in mouse, vole and shrew populations around Finland and the highest zoonotic risk is associated with C. ditrichi in Apodemus flavicollis and C. andersoni in Craseomys rufocanus. C. parvum, the most common zoonotic species in human infections, was not detected.

FIRST REPORT OF GENUS Cryptosporidium IN CERVIDS SPECIES: Mazama americana, Mazama nana AND Blastocerus dichotomus

We analyzed Cryptosporidium spp. in fecal samples of wild cervids (Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo) from many Brazilian regions, a fact unprecedented in the literature. Sniffer dogs were used to collect 936 fecal samples of cervids from 14 Brazilian localities. Cervids species were identified using polymerase chain reaction (PCR) performed from genomic DNA extracted from 563 fecal samples of Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo. Cryptosporidium spp. oocyst screening was performed using malachite green negative staining. Nested PCR (nPCR) protocols targeting the 18S rRNA and GP60 genes followed by genetic sequencing were performed for Cryptosporidium spp. detection and Cryptosporidium parvum subtyping, respectively. Nested PCR targeting actin gene and genetic sequencing were performed in samples with non-identified Cryptosporidium species by 18S rRNA amplicon sequencing. The association between the occurrence of Cryptosporidium and the presence of bovines in the same locality was evaluated using Fisher's exact test. The positivity rates of diagnostic methods were compared by McNemar test and the Kappa correlation coefficient. The prevalence rates of Cryptosporidium spp. in cervids were 1.42% (8/563) and 0.36% (2/563) by nPCR and malachite green negative staining, respectively. C. parvum IIaA16G3R1 isolate was identified in three fecal samples from M. americana, two from M. nana and one from B. dichotomus. Cryptosporidium ryanae were found in one sample from B. dichotomus. We identified a new Cryptosporidium genotype, named Cryptosporidium deer genotype BR, from one M. americana fecal sample.

Detection of Zoonotic Cryptosporidium ubiquitum in Alpine Wild Ruminants

Cryptosporidium is a widespread apicomplexan protozoan of major zoonotic importance, characterized by a wide host range, and with relevant economic implications and potential negative effects on livestock and wildlife population dynamics. Considering the recent strong demographic increase of alpine ungulates, in this study, carried out in the Italian Northwestern Alps, we investigated the occurrence of Cryptosporidium spp. in these species and their potential involvement in environmental contamination with Cryptosporidium spp. oocysts. The immune-enzymatic approach revealed a Cryptosporidium prevalence of 1.7% (5/293), 0.5% (1/196) and 3.4% (4/119) in alpine chamois (Rupicapra rupicapra), red deer (Cervus elaphus) and roe deer (Capreolus capreolus), respectively. Positive samples were subjected to polymerase chain reaction (PCR) amplification for the COWP and gp60 genes. The presence of Cryptosporidium was confirmed in one chamois and four roe deer. Sequences obtained clustered within Cryptosporidium ubiquitum, currently recognized as an emerging zoonotic species. This finding represents the first detection of zoonotic C. ubiquitum in chamois and in the Alpine environment. Despite the low observed prevalences, environmental contamination by oocysts could play a role as a potential source of infections for humans and livestock.

Small ruminants and zoonotic cryptosporidiosis

Sheep and goats are commonly infected with three Cryptosporidium species, including Cryptosporidium parvum, Cryptosporidium ubiquitum, and Cryptosporidium xiaoi, which differ from each in prevalence, geographic distribution, and public health importance. While C. parvum appears to be a dominant species in small ruminants in European countries, its occurrence in most African, Asian, and American countries appear to be limited. As a result, zoonotic infections due to contact with lambs and goat kids are common in European countries, leading to frequent reports of outbreaks of cryptosporidiosis on petting farms. In contrast, C. xiaoi is the dominant species elsewhere, and mostly does not infect humans. While C. ubiquitum is another zoonotic species, it occurs in sheep and goats at much lower frequency. Host adaptation appears to be present in both C. parvum and C. ubiquitum, consisting of several subtype families with different host preference. The host-adapted nature of C. parvum and C. ubiquitum has allowed the use of subtyping tools in tracking infection sources. This has led to the identification of geographic differences in the importance of small ruminants in epidemiology of human cryptosporidiosis. These tools have also been used effectively in linking zoonotic transmission of C. parvum between outbreak cases and the suspected animals. Further studies should be directly elucidating the reasons for differences in the distribution and public health importance of major Cryptosporidium species in sheep and goats.

Prevalence of Cryptosporidium spp. in water: a global systematic review and meta-analysis

Cryptosporidium spp., as a genus of protozoan intestinal parasites, is recognized as responsible for cryptosporidiosis. The present study was conducted to provide an overview of the prevalence of Cryptosporidium based on water. In this regard, some databases such as Scopus, PubMed, Embase, and Web of Science were screened in order to retrieve the related citations from 1 January 1983 to 10 September 2019. The pooled prevalence of Cryptosporidium spp. was calculated by using a random effect model (REM) based on defined subgroups, including countries, water type, treatment conditions (treated and untreated), economic condition, World Health Organization (WHO) regions, and method of detection. In contrast, this index for treated and untreated water was 25.7% and 40.1%, respectively. Also, the overall prevalence of Cryptosporidium spp. among all water types was defined as 36 (95% CI: 31.4-40.7). The rank order of prevalence of Cryptosporidium spp. based on water type was wastewater (46.9%) > surface water (45.3%) > raw water (31.6%) > drinking water (25.5%) > reservoirs water (24.5%) > groundwater (18.8%) > swimming pool water (7.5%) > marine water (0.20%). Identifying the key contributing factors to Cryptosporidium spp. survival can help provide solutions at both local and global scales.

Genetic Diversity of Cryptosporidium in Bactrian Camels (Camelus bactrianus) in Xinjiang, Northwestern China

Cryptosporidium species are ubiquitous enteric protozoan pathogens of vertebrates distributed worldwide. The purpose of this study was to gain insight into the zoonotic potential and genetic diversity of Cryptosporidium spp. in Bactrian camels in Xinjiang, northwestern China. A total of 476 fecal samples were collected from 16 collection sites in Xinjiang and screened for Cryptosporidium by PCR. The prevalence of Cryptosporidium was 7.6% (36/476). Six Cryptosporidium species, C. andersoni (n = 24), C. parvum (n = 6), C. occultus (n = 2), C. ubiquitum (n = 2), C. hominis (n = 1), and C. bovis (n = 1), were identified based on sequence analysis of the small subunit (SSU) rRNA gene. Sequence analysis of the gp60 gene identified six C. parvum isolates as subtypes, such as If-like-A15G2 (n = 5) and IIdA15G1 (n = 1), two C. ubiquitum isolates, such as subtype XIIa (n = 2), and one C. hominis isolate, such as Ixias IkA19G1 (n = 1). This is the first report of C. parvum, C. hominis, C. ubiquitum, and C. occultus in Bactrian camels in China. These results indicated that the Bactrian camel may be an important reservoir for zoonotic Cryptosporidium spp. and these infections may be a public health threat in this region.

Cryptosporidiosis and Giardiasis in Buffaloes (Bubalus bubalis)

Cryptosporidium spp. and Giardia duodenalis infect the gastrointestinal tracts of animals and humans. Both parasite groups are distributed worldwide and cause significant economic losses in animal productivity. Infected hosts presenting with and without clinical manifestations can eliminate infective forms of these protozoa, which are particularly important to One Health. Compared to the published research on cattle, relatively few studies have examined the epidemiology of cryptosporidiosis and giardiasis in buffaloes. This short review describes the global occurrence of Cryptosporidium spp. and G. duodenalis in buffaloes, including the molecular techniques employed for the identification of species/assemblages and genotypes of these protozoa. Genetic analyses of isolates of G. duodenalis and Cryptosporidium spp. from various sources (environmental, animal, and human) have been performed to investigate their epidemiology. In buffaloes, the species Cryptosporidium parvum, Cryptosporidium ryanae, Cryptosporidium bovis, and Cryptosporidium suis-like have been characterized, as well as assemblages A and E of G. duodenalis. We demonstrate that buffaloes can be infected by species of Cryptosporidium spp. and G. duodenalis assemblages with zoonotic potential. Epidemiological studies that utilize molecular biology techniques represent an important resource for efforts to control and prevent the spread of these protozoans.

Does land use affect pathogen presence in New Zealand drinking water supplies?

Four microbes (Campylobacter spp., Escherichia coli, Cryptosporidium spp. and Giardia spp.) were monitored in 16 waterways that supply public drinking water for 13 New Zealand towns and cities. Over 500 samples were collected from the abstraction point at each study site every three months between 2009 and 2019. The waterways represent a range from small to large, free flowing to reservoir impoundments, draining catchments of entirely native vegetation to those dominated by pastoral agriculture. We used machine learning algorithms to explore the relative contribution of land use, catchment geology, vegetation, topography, and water quality characteristics of the catchment to determining the abundance and/or presence of each microbe. Sites on rivers draining predominantly agricultural catchments, the Waikato River, Oroua River and Waiorohi Stream had all four microbes present, often in high numbers, throughout the sampling interval. Other sites, such as the Hutt River and Big Huia Creek in Wellington which drain catchments of native vegetation, never had pathogenic microbes detected, or unsafe levels of E. coli. Boosted Regression Tree models could predict abundances and presence/absence of all four microbes with good precision using a wide range of potential environmental predictors covering land use, geology, vegetation, topography, and nutrient concentrations. Models were more accurate for protozoa than bacteria but did not differ markedly in their ability to predict abundance or presence/absence. Environmental drivers of microbe abundance or presence/absence also differed depending on whether the microbe was protozoan or bacterial. Protozoa were more prevalent in waterways with lower water quality, higher numbers of ruminants in the catchment, and in September and December. Bacteria were more abundant with higher rainfall, saturated soils, and catchments with greater than 35% of the land in agriculture. Although modern water treatment protocols will usually remove many pathogens from drinking water, several recent outbreaks of waterborne disease due to treatment failures, have highlighted the need to manage water supplies on multiple fronts. This research has identified potential catchment level variables, and thresholds, that could be better managed to reduce the potential for pathogens to enter drinking water supplies.

Prevalence and Characterization of Cryptosporidium Species and Genotypes in Four Farmed Deer Species in the Northeast of China

Cryptosporidiosis is a major public health problem in humans and animals. Information on the prevalence and molecular diversity of Cryptosporidium in farmed deer in northeastern China is limited. In this study, the prevalence of these parasites was investigated in four farmed deer species, including 125 reindeer, 109 red deer, 86 sika deer, and 18 Siberian roe deer by nested PCR amplification of the partial small subunit of ribosomal RNA (SSU rRNA) gene. C. ubiquitum isolates were subtyped using nested PCR and sequence analysis of the 60-kDa glycoprotein (gp60) gene. The overall prevalence of Cryptosporidium was 7.1%, with 15.1% for sika deer, 4.0% for reindeer, 4.6% for red deer, and 5.6% for roe deer. C. ubiquitum (n = 4), C. xiaoi (n = 2), and Cryptosporidium deer genotype (n = 18) were identified. All four C. ubiquitum isolates belonged to the XIIa subtype (n = 4). This study confirms that Cryptosporidium deer genotype is widely occurring in deer in the investigated areas. Presence of zoonotic C. ubiquitum XIIa subtype indicates that farmed deer represent potential source of zoonotic cryptosporidia and might pose a threat to human health.

Prevalence and molecular characterization of Cryptosporidium spp. in Père David's deer (Elaphurus davidianus) in Jiangsu, China

Cryptosporidium is a zoonotic parasite that causes diarrhea in a broad range of animals, including deer. Little is known about the prevalence and genotype of Cryptosporidium spp. in Père David's deer. In this study, 137 fecal samples from Père David's deer were collected between July 2017 and August 2018 in the Dafeng Reserve and analyzed for Cryptosporidium spp. by nested-PCR based on the small subunit ribosomal RNA (SSU rRNA) gene, followed by sequence analyses to determine the species. The 60 kDa glycoprotein (gp60) gene was used to characterize Cryptosporidium spp. Among 137 samples, 2 (1.46%) were positive for Cryptosporidium spp. according to SSU rRNA gene sequencing results. Both samples belonged to the Cryptosporidium deer genotype, with two nucleotide deletions and one nucleotide substitution. The prevalence data and molecular characterization of this study provide basic knowledge for controlling and preventing Cryptosporidium infections in Père David's deer in this area.

A One Health Approach to Tackle Cryptosporidiosis

Cryptosporidiosis is a significant diarrhoeal disease in both people and animals across the world and is caused by several species of the protozoan parasite Cryptosporidium. Recent research has highlighted the longer-term consequences of the disease for malnourished children, involving growth stunting and cognitive deficits, and significant growth and production losses for livestock. There are no vaccines currently available to prevent the disease and few treatment options in either humans or animals, which has been a significant limiting factor in disease control to date. A One Health approach to tackle zoonotic cryptosporidiosis looking at new advances in veterinary, public, and environmental health research may offer several advantages and new options to help control the disease.

First report of Cryptosporidium viatorum and Cryptosporidium occultus in humans in China, and of the unique novel C. viatorum subtype XVaA3h

BACKGROUND

Cryptosporidium is a genus of common intestinal protozoa, members of which cause diarrhea in a wide variety of hosts. Previous studies on Cryptosporidium in China have mainly focused on diarrhea sufferers, children, and immunodeficient individuals such as HIV/AIDS patients. However, the epidemiological characteristics of Cryptosporidium in the population in rural areas remain unclear. Herein, we investigated the prevalence of, and risk factors for, Cryptosporidium in rural areas of Binyang County, Guangxi Zhuang Autonomous Region, China, and genetically characterized the Cryptosporidium isolates we obtained.

METHODS

From August to December 2016, two villages in Binyang County, Guangxi, were sampled using a random cluster sampling method. Fresh fecal samples were collected from all eligible residents (residence time > 6 months). Molecular characterization of Cryptosporidium was carried out based on its SSU rRNA, gp60, actin and hsp70 gene sequences. Fisher's exact test were conducted to assess the risk factors for Cryptosporidium infection.

RESULTS

A total of 400 fecal samples were collected from 195 males (48.8%) and 205 females (51.2%). Two samples (0.5%) were positive for Cryptosporidium and were identified as C. viatorum and C. occultus respectively. Moreover, a new C. viatorum subtype XVaA3h was identified based on the sequence of the gp 60 gene.

CONCLUSIONS

To our knowledge, this is the first report of C. viatorum and C. occultus infections in humans in China and of C. viatorum subtype XVaA3h. The findings provide important information on the prevalence of Cryptosporidium in the Chinese population, and expand the range of Cryptosporidium species known to infect people in China.

Molecular detection of Cryptosporidium and Enterocytozoon bieneusi in dairy calves and sika deer in four provinces in Northern China

The protistan pathogens Cryptosporidium and Enterocytozoon bieneusi can cause significant intestinal diseases in animals and humans. However, limited information is available regarding prevalence and molecular characterization of Cryptosporidium and E. bieneusi in ruminants in Northern China. In this study, the overall prevalence of Cryptosporidium and E. bieneusi was 19.3% (62/321) and 28.97% (93/321) in dairy calves and 1.10% (9/818) and 13.57% (111/818) in sika deer (Cervus nippon) in four provinces in Northern China, respectively. The prevalence of Cryptosporidium and E. bieneusi in different factor groups was various. Five Cryptosporidium species/genotypes were identified, of which C. parvum, C. ryanae, C. bovis, and C. andersoni were only found in dairy calves, and only Cryptosporidium deer genotype was found in sika deer. Moreover, J, I, and BEB4 ITS genotypes of E. bieneusi were found in dairy calves, and six known genotypes (JLD-III, JLD-IX, JLD-VII, EbpC, BEB6, and I) and ten novel genotypes (namely LND-I and JLD-XV to JLD-XXIII) were found in sika deer in this study. Cryptosporidium parvum and E. bieneusi genotype J were identified as the predominant species/genotypes in dairy calves, whereas the predominance of Cryptosporidium spp. and E. bieneusi in sika deer was Cryptosporidium deer genotype and BEB6, respectively. The present study reported the prevalence and genotypes of Cryptosporidium and E. bieneusi in dairy calves and sika deer in four provinces in northern China. The present findings also suggest that investigated dairy calves and sika deer may play an important role in the transmission of E. bieneusi and Cryptosporidium to humans and other animals, and also in an effort to better understand the epidemiology of these enteric pathogens in China.

Cryptosporidium Prevalence in Calves and Geese Co-Grazing on Four Livestock Farms Surrounding Two Reservoirs Supplying Public Water to Mainland Orkney, Scotland

The parasite Cryptosporidiumparvum represents a threat to livestock health and production, water quality and public health. Cattle are known to be significant reservoirs of C. parvum, but transmission routes are complex and recent studies have implicated the potential role of wildlife in parasite transmission to cattle and water sources. On the Orkney Isles, high densities of Greylag geese (Anser anser) cause widespread faecal contamination of cattle pastures, where cryptosporidiosis is known to be the main cause of neonatal calf diarrhoea and Cryptosporidium contamination frequently occurs in two reservoirs supplying Mainland Orkney’s public water. This study aimed to determine the Cryptosporidium species and subtypes present in geese and calves co-grazing on four farms surrounding two reservoirs on Mainland Orkney. Results indicated a high level of C. parvum prevalence in calves, geese and water samples. gp60 analysis illustrated that higher genotypic diversity was present in the goose population compared with calves, but did not yield sequence results for any of the water samples. It can be concluded that the high levels of C. parvum evident in calves, geese and water samples tested represents a significant risk to water quality and public health.

Molecular characterization of Cryptosporidium and Enterocytozoon bieneusi in Père David's deer (Elaphurus davidianus) from Shishou, China

Cryptosporidium and Enterocytozoon bieneusi are important intestinal pathogens that infect humans and various animals. Few reports are available regarding the infections of the two pathogens in Père David's deer. In this study, polymerase chain reaction (PCR) confirmed Cryptosporidium infection in two (1.6%) and E. bieneusi in 45 (35.2%) of 128 fecal samples collected from Père David's deer in the National Nature Reserve of Shishou, Hubei Province, China. C. parvum (n = 1) and Cryptosporidium deer genotype (n = 1) were identified using the small subunit rRNA (SSU rRNA) gene. The C. parvum was further subtyped as IIdA20G1 by sequencing analysis of the 60-kDa glycoprotein (gp60) gene. The identity of E. bieneusi was confirmed by an internal transcribed spacer (ITS) gene; the HLJD-V (n = 42) and MWC_d1 (n = 3) genotypes were identified, with the former clustering in group 2 and the latter in group 1. These data suggest that the Père David's deer were infected with host-specific and/or zoonotic genotypes of these pathogens, implicating Père David's deer could be a potential source of human Cryptosporidium infection.

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C. parvum subtype IIdA20G1 was firstly identified in Pere David's deer.

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Genotypes HLJD-V and MWC_d1 were detected from 45 E. bieneusi-positive samples.

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The present study implicated Père David's deer could be a potential source of human infection.

Giardia and Cryptosporidium in Red Foxes (Vulpes Vulpes): Screening for Coproantigens in a Population of Central Italy and Mini-Review of the Literature

Giardia and Cryptosporidium are common protozoan parasites affecting several animal species and humans. The aim of this survey was to investigate, for the first time, their prevalence in red fox (Vulpes vulpes) faecal samples in central Italy. Seventy-one red foxes of different ages and sexes were examined for antigenic detection of Giardia and Cryptosporidium in fecal samples by means of a commercial rapid immunochromatographic test. The sample was randomly selected from foxes culled during a population control program. They were divided into groups based on sex and age (≤1-year-old and >1-year-old). Five (7%) and one (1.4%) out of 71 fecal samples were positive for the Giardia or Cryptosporidium antigens by immunochromatographic assay, respectively, and no coinfections were observed. The present prevalence rates of Giardia and Cryptosporidium antigens in faeces from V. vulpes suggest that this host species is likely to play only a limited role in the spread of the two protozoa in the study area. A concise review of the literature related to Giardia and Cryptosporidium in V. vulpes is presented.

Understanding human infectious Cryptosporidium risk in drinking water supply catchments

Treating drinking water appropriately depends, in part, on the robustness of source water quality risk assessments, however quantifying the proportion of infectious, human pathogenic Cryptosporidium oocysts remains a significant challenge. We analysed 962 source water samples across nine locations to profile the occurrence, rate and timing of infectious, human pathogenic Cryptosporidium in surface waters entering drinking water reservoirs during rainfall-runoff conditions. At the catchment level, average infectivity over the four-year study period reached 18%; however, most locations averaged <5%. The maximum recorded infectivity fraction within a single rainfall runoff event was 65.4%, and was dominated by C. parvum. Twenty-two Cryptosporidium species and genotypes were identified using PCR-based molecular techniques; the most common being C. parvum, detected in 23% of water samples. Associations between landuse and livestock stocking characteristics with Cryptosporidium were determined using a linear mixed-effects model. The concentration of pathogens in water were significantly influenced by flow and dominance of land-use by commercial grazing properties (as opposed to lifestyle properties) in the catchment (p < 0.01). Inclusion of measured infectivity and human pathogenicity data into a quantitative microbial risk assessment (QMRA) could reduce the source water treatment requirements by up to 2.67 log removal values, depending on the catchment, and demonstrated the potential benefit of collating such data for QMRAs.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in deer in Henan and Jilin, China

Background

Little is known about the prevalence and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in deer in China. In this study, 662 fecal samples were collected from 11 farms in Henan and Jilin Provinces between July 2013 and August 2014, and were screened for the presence of Cryptosporidium and G. duodenalis with genotyping and subtyping methods.

Results

Cryptosporidium spp. and G. duodenalis were detected in 6.80% (45/662) and 1.21% (5/662) of samples, respectively. Six Cryptosporidium species/genotypes were identified based on the small subunit ribosomal ribonucleic acid (SSU rRNA) gene: C. parvum (n = 11); C. andersoni (n = 5); C. ubiquitum (n = 3); C. muris (n = 1); C. suis-like (n = 1); and Cryptosporidium deer genotype (n = 24). When five of the 11 C. parvum isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene, zoonotic subtypes IIaA15G2R2 (n = 4) and IIdA19G1 (n = 1) were found. According to a subtype analysis, three C. ubiquitum isolates belonged to XIIa subtype 2. In contrast, only assemblage E was detected in the five Giardia-positive samples with small subunit ribosomal ribonucleic acid (SSU rRNA) gene sequencing.

Conclusions

To our knowledge, this is the first study to report C. andersoni, as well as C. parvum zoonotic subtypes IIaA15G2R2 and IIdA19G1 in cervids. These data, though limited, suggest that cervids may be a source of zoonotic Cryptosporidium and Giardia. Cervids in the present study are likely to be of low zoonotic potential to humans, and more molecular epidemiological studies are required to clarify the prevalence and public health significance of Cryptosporidium and G. duodenalis in cervids throughout China.

Widespread Occurrence of Zoonotic Cryptosporidium Species and Subtypes in Dairy Cattle from Northeast China: Public Health Concerns

Bovine cryptosporidiosis constitutes a threat to the livestock industry and public health worldwide. In the present study we investigated dairy cattle of all ages in northeast China for the prevalence and genetic traits of Cryptosporidium. Nested polymerase chain reaction of the small subunit rRNA gene was used to identify Cryptosporidium species or genotype. The parasite was detected in 130 of 537 (24.2%) animals sampled from the cities of Harbin (35.2%, 69/196) and Qiqihar (32.1%, 61/190). Cryptosporidium parvum (87/130) was identified as the dominant species by sequence analysis followed by Cryptosporidium bovis (28/130), Cryptosporidium ryanae (5/130), Cryptosporidium andersoni (2/130), Cryptosporidium suis-like genotype (2/130), and mixed C. ryanae/ C. bovis (1/130). Subtyping of C. parvum isolates was based on the DNA polymorphisms of the 60-kDa glycoprotein gene. Subtyping of the C. parvum isolates recognized subtypes IIdA15G1 (24/87) in Harbin and IIdA20G1 (48/87) in Qiqihar. A diversity of Cryptosporidium species/genotype and subtypes was identified in cattle from northeast China. Widespread occurrence of human-pathogenic Cryptosporidium species and subtypes is of public health significance. This is the first study reporting C. parvum subtype IIdA20G1 in China. The findings improve the epidemiological knowledge of bovine cryptosporidiosis in China, highlighting the importance of ongoing Cryptosporidium surveillance.

Cryptosporidium in humans and animals-a one health approach to prophylaxis

Cryptosporidium is a major cause of moderate-to-severe diarrhoea in humans worldwide, second only to rotavirus. Due to the wide host range and environmental persistence of this parasite, cryptosporidiosis can be zoonotic and associated with foodborne and waterborne outbreaks. Currently, 31 species are recognized as valid, and of these, Cryptosporidium hominis and Cryptosporidium parvum are responsible for the majority of infections in humans. The immune status of the host, both innate and adaptive immunity, has a major impact on the severity of the disease and its prognosis. Immunocompetent individuals typically experience self-limiting diarrhoea and transient gastroenteritis lasting up to 2 weeks and recover without treatment, suggesting an efficient host antiparasite immune response. Immunocompromised individuals can suffer from intractable diarrhoea, which can be fatal. Effective drug treatments and vaccines are not yet available. As a result of this, the close cooperation and interaction between veterinarians, health physicians, environmental managers and public health operators is essential to properly control this disease. This review focuses on a One Health approach to prophylaxis, including the importance of understanding transmission routes for zoonotic Cryptosporidium species, improved sanitation and better risk management, improved detection, diagnosis and treatment and the prospect of an effective anticryptosporidial vaccine.

Cryptosporidium infecting wild cricetid rodents from the subfamilies Arvicolinae and Neotominae

We undertook a study on Cryptosporidium spp. in wild cricetid rodents. Fecal samples were collected from meadow voles (Microtus pennsylvanicus), southern red-backed voles (Myodes gapperi), woodland voles (Microtus pinetorum), muskrats (Ondatra zibethicus) and Peromyscus spp. mice in North America, and from bank voles (Myodes glareolus) and common voles (Microtus arvalis) in Europe. Isolates were characterized by sequence and phylogenetic analyses of the small subunit ribosomal RNA (SSU) and actin genes. Overall, 33·2% (362/1089) of cricetids tested positive for Cryptosporidium, with a greater prevalence in cricetids from North America (50·7%; 302/596) than Europe (12·1%; 60/493). Principal Coordinate analysis separated SSU sequences into three major groups (G1-G3), each represented by sequences from North American and European cricetids. A maximum likelihood tree of SSU sequences had low bootstrap support and showed G1 to be more heterogeneous than G2 or G3. Actin and concatenated actin-SSU trees, which were better resolved and had higher bootstrap support than the SSU phylogeny, showed that closely related cricetid hosts in Europe and North America are infected with closely related Cryptosporidium genotypes. Cricetids were not major reservoirs of human pathogenic Cryptosporidium spp.

Molecular identification of the Cryptosporidium deer genotype in the Hokkaido sika deer (Cervus nippon yesoensis) in Hokkaido, Japan

The protozoan Cryptosporidium occurs in a wide range of animal species including many Cervidae species. Fecal samples collected from the Hokkaido sika deer (Cervus nippon yesoensis), a native deer of Hokkaido, in the central, western, and eastern areas of Hokkaido were examined by polymerase chain reaction (PCR) to detect infections with Cryptosporidium and for sequence analyses to reveal the molecular characteristics of the amplified DNA. DNA was extracted from 319 fecal samples and examined with PCR using primers for small-subunit ribosomal RNA (SSU-rRNA), actin, and 70-kDa heat shock protein (HSP70) gene loci. PCR-amplified fragments were sequenced and phylogenetic trees were created. In 319 fecal samples, 25 samples (7.8 %) were positive with SSU-rRNA PCR that were identified as the Cryptosporidium deer genotype. Among Cryptosporidium-positive samples, fawns showed higher prevalence (16.1 %) than yearlings (6.4 %) and adults (4.7 %). The result of Fisher's exact test showed a statistical significance in the prevalence of the Cryptosporidium deer genotype between fawn and other age groups. Sequence analyses with actin and HSP70 gene fragments confirmed the SSU-rRNA result, and there were no sequence diversities observed. The Cryptosporidium deer genotype appears to be the prevalent Cryptosporidium species in the wild sika deer in Hokkaido, Japan.

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.

Cryptosporidium in small water systems in Puerto Rico: a pilot study

A pilot study was undertaken to investigate the occurrence of Cryptosporidium in four very small drinking water systems supplying communities in rural Puerto Rico. Water samples (40 L) were collected and oocysts were concentrated by calcium carbonate flocculation, recovered by immunomagnetic separation and detected by immunofluorescence microscopy. Cryptosporidium oocysts were identified in all four systems. This is the first report of evidence of the potential public health risk from this chlorine-resistant pathogen in Puerto Rican small water systems. Further work is warranted to fully assess the health risks that Cryptosporidium and other protozoa pose to populations served by community-managed small drinking water systems.

First Molecular Characterization of Cryptosporidium spp. Infecting Buffalo Calves in Brazil

With the aim of determining the occurrence of Cryptosporidium spp., 222 fecal samples were collected from Murrah buffalo calves aged up to 6 mo. Fecal DNA was genotyped with a nested polymerase chain reaction targeting the 18S rRNA gene and sequencing of the amplified fragment. Nested 18S PCR was positive for 48.2% of the samples. Sequence analysis showed that the most frequent species in these animals was Cryptosporidium ryanae, which was present in buffalo calves as young as 5 d. The zoonotic species Cryptosporidium parvum was detected in one animal. An uncommon Cryptosporidium 18S genotype was found in buffaloes.

Outbreak of Cryptosporidium hominis following river flooding in the city of Halle (Saale), Germany, August 2013

Background

During weeks 32–33, 2013, 24 cases of cryptosporidiosis were notified in the city of Halle (annual mean 2008–2012: 9 cases). We investigated the outbreak to identify the source and recommend control measures, considering that between weeks 23–25 the river Saale which flows through the city centre overflowed the floodplain, parts of the city centre and damaged sewage systems.

Methods

We defined a case as a resident of Halle with gastroenteritis, Cryptosporidium-positive stool and disease onset weeks 27 through 47. In a case–control study among kindergarten children, we compared cases and controls regarding environmental exposure, use of swimming pools, zoo visits and tap water consumption 14 days pre-onset or a corresponding 14-days-period (controls) and adjusted for residence. Stool specimens were tested by microscopy and PCR, and Cryptosporidium DNA was sequenced. Samples from public water system, swimming pools and river Saale were examined for Cryptosporidium oocysts (microscopy and PCR).

Results

Overall, 167 cases were detected, 40/167 (24%) were classified as secondary cases. First disease onsets occurred during week 29, numbers peaked in week 34 and started to decrease in week 36. Median age was 8 years (range: 0–77). Compared to controls (n = 61), cases (n = 20) were more likely to report visits to previously flooded areas (OR: 4.9; 95%-CI: 1.4-18) and the zoo (OR: 2.6; 95%-CI: 0.9-7.6). In multivariable analysis visits to the floodplain remained the sole risk factor (OR: 5.5; 95%-CI: 1.4-22). Only C.hominis of a single genotype (IbA9G2) was detected in stools. Oocysts were detected in samples from the river, two local lakes and three public swimming pools by microscopy, but not in the public water supply.

Conclusions

Evidence suggests that activities in the dried out floodplain led to infection among children. Secondary transmissions may be involved. Consequently, authorities recommended to avoid playing, swimming and having picnics in the flood-affected area. Health authorities should consider the potential health risks of long-term surviving parasites persisting on flooded grounds and in open waters even several weeks after the flooding and of bathing places close to sewage spill-overs. Preventive measures comprise water sampling (involving parasites), information of the public and prolonged closures of potentially contaminated sites.

Prevalence, species identification and genotyping Cryptosporidium from livestock and deer in a catchment in the Cairngorms with a history of a contaminated public water supply

Background

The apicomplexan parasite Cryptosporidium represents a threat to water quality and public health. An important zoonotic species involved in human cryptosporidiosis from contaminated water is Cryptosporidium parvum (C. parvum), the main reservoirs of which are known to be farm livestock particularly neonatal calves, although adult cattle, sheep, lambs and wildlife are also known to contribute to catchment loading of C. parvum. This study aimed to establish Cryptosporidium prevalence, species and genotype in livestock, deer and water in a catchment with a history of Cryptosporidium contamination in the public water supply.

Methods

A novel method of processing adult ruminant faecal sample was used to concentrate oocysts, followed by a nested species specific multiplex (nssm) PCR, targeting the 18S rRNA gene, to speciate Cryptosporidium. A multilocus fragment typing (MLFT) tool was used, in addition to GP60 sequencing, to genotype C. parvum positive samples.

Results

A very high prevalence of Cryptosporidium was detected, with speciation identifying a predominance of C. parvum in livestock, deer and water samples. Four GP60 subtypes were detected within C. parvum with the majority IIaA15G2R1 which was detected in all host species and on all farms. Multilocus fragment typing further differentiated these into 6 highly related multilocus genotypes.

Conclusion

The high prevalence of Cryptosporidium detected was possibly due to a combination of the newly developed sample processing technique used and a reflection of the high rates of the parasite present in this catchment. The predominance of C. parvum in livestock and deer sampled in this study suggested that they represented a significant risk to water quality and public health. Genotyping results suggested that the parasite is being transmitted locally within the study area, possibly via free-roaming sheep and deer. Further studies are needed to verify particular host associations with subtypes/MLGs. Land and livestock management solutions to reduce Cryptosporidium on farm and in the catchment are planned with the aim to improve animal health and production as well as water quality and public health.

Investigating source water Cryptosporidium concentration, species and infectivity rates during rainfall-runoff in a multi-use catchment

Protozoan pathogens present a significant human health concern, and prevention of contamination into potable networks remains a key focus for drinking water providers. Here, we monitored the change in Cryptosporidium concentration in source water during high flow events in a multi-use catchment. Furthermore, we investigated the diversity of Cryptosporidium species/genotypes present in the source water, and delivered an oocyst infectivity fraction. There was a positive and significant correlation between Cryptosporidium concentration and flow (ρ = 0.756) and turbidity (ρ = 0.631) for all rainfall-runoff events, despite variable source water pathogen concentrations. Cell culture assays measured oocyst infectivity and suggested an overall source water infectious fraction of 3.1%. No infectious Cryptosporidium parvum or Cryptosporidium hominis were detected, although molecular testing detected C. parvum in 7% of the samples analysed using PCR-based molecular techniques. Twelve Cryptosporidium species/genotypes were identified using molecular techniques, and were reflective of the host animals typically found in remnant vegetation and agricultural areas. The inclusion of molecular approaches to identify Cryptosporidium species and genotypes highlighted the diversity of pathogens in water, which originated from various sources across the catchment. We suggest this mixing of runoff water from a range of landuses containing diverse Cryptosporidium hosts is a key explanation for the often-cited difficulty forming strong pathogen-indicator relationships.

Molecular characterization of Cryptosporidium and Giardia occurring in natural water bodies in Poland

Cryptosporidium and Giardia protozoa are zoonotic parasites that cause human gastroenteritis and can be transmitted to human through the fecal-oral route and water or food. Several species belong to these genera and their resistant forms occur in water, but only some of them are infectious to human. Health risk depends on the occurrence of infectious Cryptosporidium and Giardia species and genotypes in water, and only molecular techniques allow detecting them, as well as enable to identify the contamination source. In this work, genotyping and phylogenetic analysis have been performed on the basis of 18S rDNA and ß-giardin genes sequences of Cryptosporidium and Giardia, respectively, in order to provide the molecular characterization of these parasites detected earlier in five natural water bodies in Poland and to track possible sources of their (oo)cysts in water. Genotyping revealed a high similarity (over 99 up to 100 %) of analyzed sequences to cattle genotype of C. parvum isolated from cattle and human and to G. intestinalis assemblage B isolated from human. The sequences obtained by others originated from patients with clinical symptoms of cryptosporidiosis or giardiasis and/or with the infection confirmed by different methods. The contamination of three examined lakes is probably human-originated, while the sources of contamination of two remaining lakes are wild and domestic animals. Obtained phylogenetic trees support suggestions of other authors that the bovine genotype of C. parvum should be a separate species, as well as A and B assemblages of G. intestinalis.

Occurrence and molecular characterization of Cryptosporidium spp. and Enterocytozoon bieneusi in dairy cattle, beef cattle and water buffaloes in China

Cryptosporidium spp. and Enterocytozoon bieneusi are important protists in a wide range of vertebrate hosts, causing diarrheal diseases. Cattle are considered potential reservoirs of Cryptosporidium infection in humans, although their role in the transmission of E. bieneusi is not clear. In the present work, 793 fecal specimens from dairy cattle, native beef cattle, and water buffaloes on 11 farms in China were examined for the presence of Cryptosporidium spp. and E. bieneusi using nested PCR targeting the small subunit (SSU) rRNA gene of Cryptosporidium spp. and the internal transcribed spacer (ITS) of E. bieneusi. For Cryptosporidium, 144/446 (32.3%) dairy cattle, 44/166 (26.5%) beef cattle, and 43/181 (23.8%) water buffaloes were PCR-positive. Sequence analysis was successful for 213 of the 231 Cryptosporidium-positive isolates; among them 94 had Cryptosporidium andersoni, 61 had Cryptosporidium bovis, 54 had Cryptosporidium ryanae, 2 had a Cryptosporidium suis-like genotype, and 2 had mixed infections of C. bovis and C. ryanae. In dairy and beef cattle, C. andersoni and C. bovis were the most common species, whereas C. ryanae was the dominant species in water buffaloes. The latter species produced SSU rRNA sequences different between cattle and water buffaloes. For E. bieneusi, the infection rate of E. bieneusi in dairy cattle, beef cattle and water buffaloes was 4.9%, 5.4% and 2.2%, respectively. All 35 E. bieneusi-positive specimens were successfully sequenced, revealing the presence of four genotypes: three Group 2 genotypes previously reported in cattle as well as humans (I, J and BEB4) and one Group 1 genotype recently reported in yaks (CHN11). Genotypes I and J were the most common genotypes in dairy and beef cattle, while genotype CHN11 was the only genotype seen in water buffaloes. Thus, the distribution of Cryptosporidium spp. and E. bieneusi in water buffaloes might be different from in dairy and beef cattle in China. These findings indicate that some of the Cryptosporidium species and all four E. bieneusi genotypes identified in bovine animals in the study areas may have zoonotic potential.

Enterocytozoon bieneusi, giardia, and Cryptosporidium infecting white-tailed deer

Despite a white-tailed deer (WTD) population in the United States of approximately 32 million animals extremely little is known of the prevalence and species of the protists that infect these animals. This study was undertaken to determine the presence of potential human protist pathogens in culled WTD in central Maryland. Feces from fawns to adults were examined by molecular methods. The prevalence of Enterocytozoon bieneusi, Cryptosporidium, and Giardia was determined by PCR. All PCR-positive specimens were sequenced to determine the species and genotype(s). Of specimens from 80 WTD, 26 (32.5%) contained 17 genotypes of E. bieneusi. Four genotypes were previously reported (I, J, WL4, LW1) and 13 novel genotypes were identified and named DeerEb1-DeerEb13. Genotypes I, J, and LW1 are known to infect humans. Ten (12.5%) specimens contained the Cryptosporidium deer genotype, and one (1.25%) contained Giardia duodenalis Assemblage A. The identification zoonotic G. duodenalis Assemblage A as well as four E. bieneusi genotypes previously identified in humans suggest that WTD could play a role in the transmission of those parasites to humans.

First molecular characterization of Cryptosporidium and Giardia from bovines (Bos taurus and Bubalus bubalis) in Sri Lanka: unexpected absence of C. parvum from pre-weaned calves

Background

The genetic characterization of Cryptosporidium and Giardia has important implications for investigating their epidemiology and underpins their control. We undertook the first molecular epidemiological survey of domestic bovids in selected regions of Sri Lanka to establish whether they excreted Cryptosporidium and/or Giardia with zoonotic potential.

Methods

Faecal samples were collected from dairy calves (n = 340; Bos taurus; < 3 months of age; weekly sampling for six weeks) and water buffaloes (n = 297; Bubalus bubalis; <6 months and ≥6 months of age; one sampling) from seven different farms in Sri Lanka. Genomic DNAs were extracted from individual faecal samples and then tested for the presence of parasite DNA using a PCR-based mutation scanning-targeted sequencing-phylogenetic approach, employing genetic markers within the small subunit of nuclear ribosomal RNA and 60 kDa glycoprotein genes (designated pSSU and pgp60, respectively) for Cryptosporidium, and within the triose phosphate isomerise (ptpi) gene for Giardia.

Results

Based on pSSU sequence data, C. bovis, C. ryanae and six new genotypes that were genetically similar but not identical to C. andersoni (n = 1), C. bovis (n = 1), C. ryanae (n = 3) and C. suis (n = 1) were recorded in cattle. For pSSU, two other, new genotypes were defined in water buffalo, which were genetically most similar to Cryptosporidium genotypes recorded previously in this host species in other countries including Australia. Consistent with the findings for pSSU, no species or genotypes of Cryptosporidium with zoonotic potential were detected using pgp60. Based on ptpi sequence data, G. duodenalis assemblages A and E were detected in four and 137 samples from cattle, respectively, and assemblage E in two samples from water buffaloes.

Conclusions

The present study showed that C. parvum, the most commonly reported zoonotic species of Cryptosporidium recognised in bovine calves globally, was not detected in any of the samples from pre-weaned calves tested in the present study. However, eight new genotypes were recorded. Future studies of different host species in various regions are required to investigate the molecular epidemiology of cryptosporidiosis and giardiasis in Sri Lanka and neighbouring countries in South Asia.

Assessing calves as carriers of Cryptosporidium and Giardia with zoonotic potential on dairy and beef farms within a water catchment area by mutation scanning

In the present study, we undertook a molecular epidemiological survey of Cryptosporidium and Giardia in calves on three dairy and two beef farms within an open drinking water catchment area (Melbourne, Australia). Faecal samples (n = 474) were collected from calves at two time points (5 months apart) and tested using a PCR-based mutation scanning-targeted sequencing phylogenetic approach, employing regions within the genes of small subunit (SSU) of ribosomal RNA (designated partial SSU), 60 kDa glycoprotein (pgp60) and triose phosphate isomerase (ptpi) as genetic markers. Using partial SSU, the C. bovis, C. parvum, C. ryanae and a new genotype of Cryptosporidium were characterised from totals of 74 (15.6%), 35 (7.3%), 37 (7.8%) and 9 (1.9%) samples, respectively. Using pgp60, C. parvum genotype IIa subgenotype A18G3R1 was detected in 29 samples. Using ptpi, G. duodenalis assemblages A and E were detected in totals of 10 (2.1%) and 130 (27.4%) samples, respectively. The present study showed that a considerable proportion of dairy and beef calves in this open water catchment region excreted Cryptosporidium (i.e. subgenotype IIaA18G3R1) and Giardia (e.g. assemblage A) that are consistent with those infecting humans, inferring that they are of zoonotic importance. Future work should focus on exploring, in a temporal and spatial way, whether these parasites occur in the environment and water of the catchment reservoir.

Spatial and temporal distribution of Cryptosporidium and Giardia in a drinking water resource: implications for monitoring and risk assessment

Because of their significant public health impact, waterborne Cryptosporidium and Giardia have been monitored in surface water in order to assess microbial quality of water bodies used for drinking water production and/or for recreational purposes. In this context, sampling strategy is of key importance and should be representative enough to appropriately assess the related microbial risk. This, however, requires sound knowledge on the behaviour of both pathogens in water. In the present study, the spatial and temporal distribution of Cryptosporidium and Giardia was explored in the rural Upper-Sûre watershed used for drinking water production in Luxembourg. By subdividing it into three compartments including (i) sub-catchments, (ii) the Sûre River fed by the sub-catchments and (iii) the Upper-Sûre reservoir fed by the Sûre River, parasite distribution was assessed using sampling designs adapted to the hydro-dynamic characteristics of the respective compartments. Results highlighted the high spatial and temporal variability in parasite distribution at watershed scale, as well as the prevalence of Giardia over Cryptosporidium. Besides land use features and catchment characteristics, hydro-climatology appeared to be a major driver of parasite behaviour in the watershed. It introduced a seasonal trend in their occurrence, highest densities being detected during the wet season. Peaks of contamination triggered out by rainfall-induced runoff were further observed in the three compartments. In the Sûre River, Cryptosporidium and Giardia fluxes peaked at 10(9) and 10(10) (oo)cysts.d(-1), respectively, and were discharged into the drinking water reservoir, where they underwent a 2 to 3 log10 removal rate. Despite this, parasite fluxes entering the drinking water treatment plant were still high (10(6) to 10(7) (oo)cysts.d(-1)) and stressed on the need for improved watershed management upstream the water treatment barrier. The catchment-wide analysis described here constitutes a valuable tool for assessment of catchment microbial dynamics, especially within the framework of Water Safety Plans.

A year-long study of Cryptosporidium species and subtypes in recreational, drinking and wastewater from the central area of Spain

A year-long longitudinal study was undertaken to evaluate the presence of Cryptosporidium spp. in drinking water treatment plants (DWTPs), wastewater treatment plants (WWTPs) and freshwater bathing beaches (FBBs) from the central area of Spain. Water samples were collected according to USEPA Method 1623, and concentrated by the IDEXX Filta-Max® system. Cryptosporidium species were detected based on PCR-restriction fragment length polymorphism and sequence analyses of the ssuRNA gene. C. hominis and/or C. parvum isolates were subtyped by DNA sequencing of the Gp60 gene. Among 150 samples, 23 (15.3%) were positive by IFAT and 40 (26.7%) by PCR. Cryptosporidium spp. was more frequent in WWTPs (26.2 and 50.8%) and FBBs (12.5 and 17.5%) by IFAT and PCR respectively. Effluent waters from DWTPs were negative for this parasite suggesting that they are suitable for public use. Tertiary treatment in the WWTPs demonstrated a high removal efficiency of Cryptosporidium in the samples evaluated. Cryptosporidium species identified included C. hominis, C. parvum, C. ubiquitum, C. andersoni and C. muris. Subtyping analysis revealed C. hominis IbA10G2 and IeA11G3T3 alleles, which is the first report of the latter in water samples. Cryptosporidium highest frequency was observed in winter and spring. Our data provide information about the occurrence and diversity of Cryptosporidium in water of human use from the central area of Spain.

Cryptosporidium from a free-ranging marsupial host: bandicoots in urban Australia

Expansion of human settlement has increased the interface between people and bandicoots with implications for the emergence and spread of zoonotic parasites. The host status of bandicoots inhabiting suburban areas and their potential role in Cryptosporidium transmission remains unresolved. Our study aimed to determine the prevalence and identity of Cryptosporidium in two sympatric bandicoot species. Cryptosporidium signatures were detected in twelve bandicoot faecal samples (n=98) through amplification of the 18S rRNA. Phylogenetic inference placed the isolates in a clade with Cryptosporidium parvum, a species with a broad host range and zoonotic potential, or loosely related to Cryptosporidium hominis. However, the identity of the bandicoot isolates was not fully resolved and whether they were infected or simply passively transmitting oocysts is unknown. This study revealed that free-ranging bandicoots of northern Sydney were shedding Cryptosporidium oocysts at a prevalence of 12.2% (95% CI [6.76, 20.8]), similar to marsupial species that act as reservoirs for Cryptosporidium. Our findings expand the range of hosts known to shed Cryptosporidium in urban areas.

First molecular characterisation of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) in Victoria, Australia

We conducted a molecular epidemiological survey of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) on two extensive farms (450 km apart) in Victoria, Australia. Faecal samples (n=476) were collected from different age groups of water buffalo at two time points (six months apart) and tested using a PCR-based mutation scanning-targeted sequencing-phylogenetic approach, employing markers within the small subunit of ribosomal RNA (designated pSSU) and triose phosphate isomerase (ptpi) genes. Based on pSSU data, Cryptosporidium parvum, Cryptosporidium bovis and Cryptosporidium genotypes 1, 2 (each 99% similar genetically to Cryptosporidium ryanae) and 3 (99% similar to Cryptosporidium suis) were detected in two (0.4%), one (0.2%), 38 (8.0%), 16 (3.4%) and one (0.2%) of the 476 samples tested, respectively. Using ptpi, Giardia duodenalis assemblages A and E were detected in totals of 56 (11.8%) and six (1.3%) of these samples, respectively. Cryptosporidium was detected on both farms, whereas Giardia was detected only on farm B, and both genera were detected in 1.5% of all samples tested. The study showed that water buffaloes on these farms excreted C. parvum and/or G. duodenalis assemblage A, which are consistent with those found in humans, inferring that these particular pathogens are of zoonotic significance. Future work should focus on investigating, in a temporal and spatial manner, the prevalence and intensity of such infections in water buffaloes in various geographical regions in Australia and in other countries.

Molecular-based investigation of Cryptosporidium and Giardia from animals in water catchments in southeastern Australia

There has been no large-scale systematic molecular epidemiological investigation of the waterborne protozoans, Cryptosporidium or Giardia, in southeastern Australia. Here, we explored, for the first time, the genetic composition of these genera in faecal samples from animals in nine Melbourne Water reservoir areas, collected over a period of two-years. We employed PCR-based single-strand conformation polymorphism (SSCP) and phylogenetic analyses of loci (pSSU and pgp60) in the small subunit (SSU) of ribosomal RNA and 60-kDa glycoprotein (gp60) genes to detect and characterise Cryptosporidium, and another locus (ptpi) in the triose-phosphate isomerase (tpi) gene to identify and characterise Giardia. Cryptosporidium was detected in 2.8% of the 2009 samples examined; the analysis of all amplicons defined 14 distinct sequence types for each of pSSU and pgp60, representing Cryptosporidium hominis (genotype Ib - subgenotype IbA10G2R2), Cryptosporidium parvum (genotype IIa - subgenotypes IIaA15G2R1, IIaA19G2R1, IIaA19G3R1, IIaA19G4R1, IIaA20G3R1, IIaA20G4R1, IIaA20G3R2 and IIaA21G3R1), Cryptosporidium cuniculus (genotype Vb - subgenotypes VbA22R4, VbA23R3, VbA24R3, VbA25R4 and VbA26R4), and Cryptosporidium canis, Cryptosporidium fayeri, Cryptosporidium macropodum and Cryptosporidium ubiquitum as well as six new pSSU sequence types. In addition, Giardia was identified in 3.4% of the samples; all 28 distinct ptpi sequence types defined were linked to assemblage A of Giardia duodenalis. Of all 56 sequence types characterised, eight and one have been recorded previously in Cryptosporidium and Giardia, respectively, from humans. In contrast, nothing is known about the zoonotic potential of 35 new genotypes of Cryptosporidium and Giardia recorded here for the first time. Future work aims to focus on estimating the prevalence of Cryptosporidium and Giardia genotypes in humans and a wide range of animals in Victoria and elsewhere in Australia. (Nucleotide sequences reported in this paper are available in the GenBank database under accession nos. KC282952-KC283005).

Assessment of polymorphic genetic markers for multi-locus typing of Cryptosporidium parvum and Cryptosporidium hominis

The use of high resolution molecular tools to study Cryptosporidium parvum and Cryptosporidium hominis intra-species variation is becoming common practice, but there is currently no consensus in the methods used. The most commonly applied tool is partial gp60 gene sequence analysis. However, multi-locus schemes are acknowledged to improve resolution over analysis of a single locus, which neglects potential re-assortment of genes during the sexual phase of the Cryptosporidium life-cycle. Multi-locus markers have been investigated in isolates from a variety of sampling frames, in varying combinations and using different assays and methods of analysis. To identify the most informative markers as candidates for the development of a standardised multi-locus fragment size-based typing (MLFT) scheme to integrate with epidemiological analyses, we examined the published literature. A total of 31 MLFT studies were found, employing 55 markers of which 45 were applied to both C. parvum and C. hominis. Of the studies, 11 had sufficient raw data, from three or more markers, and a sampling frame containing at least 50 samples, for meaningful in-depth analysis using assessment criteria based on the sampling frame, study size, number of markers investigated in each study, marker characteristics (>2 nucleotide repeats) and the combinations of markers generating all possible multi-locus genotypes. Markers investigated differed between C. hominis and C. parvum. When each scheme was analysed for the fewest markers required to identify 95% of all MLFTs, some redundancy was identified in all schemes; an average redundancy of 40% for C. hominis and 27% for C. parvum. Ranking markers, based on the most productive combinations, identified two different sets of potentially most informative candidate markers, one for each species. These will be subjected to technical evaluation including typability (percentage of samples generating a complete multi-locus type) and discriminatory power by direct fragment size analysis and analysed for correlation with epidemiological data in suitable sampling frames. The establishment of a group of users and agreed subtyping scheme for improved epidemiological and public health investigations of C. parvum and C. hominis will facilitate further developments and consideration of technological advances in a harmonised manner.

Enteric protozoa in the developed world: a public health perspective

Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control.