Prevalence and identity of Cryptosporidium spp. in pig slurry

Molecular Detection of Cryptosporidium spp. and Microsporidia in Human and Animal Stool Samples

Cryptosporidium spp. and Microsporidia are opportunistic microorganisms with remarkable zoonotic transmission potential due to their capacity to infect humans and animals. The aim of this study was to evaluate the prevalence of these microorganisms in stool samples of animal and human origin. In total, 369 stool samples (205 from human patients with diarrhea and 164 of animal origin) were included in the study. Cryptosporidium spp. and Microsporidia presence were determined by using multiplex nested PCR. Positive results were analyzed by using Sanger sequencing of the amplicon, utilizing BLASTN and ClustalX software to confirm identification. Cryptosporidium spp. were found in 0.97% and 4.26% of human and animal samples, respectively. Enterocytozoon bieneusi was detected in human and animal stools in 6.82% and 3.05% of the samples, respectively. No associations were found when analyzing the presence of Cryptosporidium spp. and E. bieneusi and the demographic and clinical variables of patients and animals. This study demonstrates the presence of these microorganisms in human and animal samples from different species, and the most interesting findings are the detection of Cryptosporidium spp. in pets (e.g., rodents) that are not usually included in this type of study, and the identification of E. bieneusi in patients with diarrhea without underlying disease.

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.

First Characterization and Zoonotic Potential of Cryptosporidium spp. and Giardia duodenalis in Pigs in Hubei Province of China

The zoonotic protozoa parasites Cryptosporidium spp. and Giardia duodenalis infect a wide range of hosts, including humans. Pigs are reservoir hosts for Cryptosporidium spp. and G. duodenalis, which can transmit cryptosporidiosis and giardiasis to humans and other animals. The current study sought to investigate the infection rates and species/genotypes of Cryptosporidium spp. and G. duodenalis in pigs in Hubei of China. The nested PCR and sequence analyses of the small ribosomal subunit RNA (SSU rRNA) gene for Cryptosporidium spp. and the β-giardin (bg) gene for G. duodenalis was utilized to screen for the infection of those parasites in a total of 826 fresh fecal samples. Both Cryptosporidium spp. and G. duodenalis infection rates were 0.97% (8/826). Of the genotyped positive isolates, 6/8 (75%) were C. scrofarum and 2/8 (25%) were C. suis, while two zoonotic species G. duodenalis assemblage E and assemblage A were also detected in 7/8 (87.5%) isolates and 1/8 (12.5%) isolates, respectively. The findings suggest that both of those parasites in pig in intensive farms of Hubei province, China, pose a potential public health risk.

Gastrointestinal parasites of indigenous pigs (Sus domesticus) in south-central Nepal

BACKGROUND

Intestinal parasites have a significant impact on productivity of pigs. Additionally, presence of zoonotic parasites in pig faeces used as fertilizer and ingestion of raw or undercooked pork products originated from parasite-infested pigs pose a risk to human health.

OBJECTIVES

The aim of the study was to estimate the prevalence and diversity of gastrointestinal (GI) parasites in indigenous pigs (Sus domesticus) maintained under traditional rearing system in Nepal.

METHODS

Fresh faecal samples (n = 100) were collected from the pigs of varying age and sex maintained in 18 small-scale farms in south-central Nepal. Samples were processed using various standard methods and examined for parasite eggs, cysts or oocysts.

RESULTS

Prevalence of GI parasites in indigenous pigs was 91%, comprising of 14 different genera of protozoans and helminths. Male pigs generally had a higher (97.5%) prevalence of GI parasites than females (87%). While 90% of the suckling and weaner piglets were positive for the GI parasites, all growers and 85% the adult pigs were infected with the parasites. Entamoeba spp. were the primary protozoans in all age groups. Strongyloides sp. was more prevalent helminths in suckling and weaner piglets, whereas Ascarid spp. were higher in both growers and adults. Triplet infection was higher (33.3%) in suckling and weaner piglets, while quadruplet and pentuplet infections were higher (p < .05) among growers (46.7%) and adults (30%), respectively.

CONCLUSIONS

The indigenous pigs harbour a higher prevalence and greater diversity of GI parasites. GI parasitism varies by sex and age of the pigs.

Detection of Cryptosporidium parvum in a Red-Eared Slider Turtle (Trachemys scripta elegans), a Noted Invasive Alien Species, Captured in a Rural Aquatic Ecosystem in Eastern Poland

Purpose

Little is known about cryptosporidiosis in turtles of invasive alien species (IAS) inhabiting European bodies of fresh water. In this article, we report an occurrence of Cryptosporidium parvum in a red-eared slider turtle (Trachemys scripta elegans) captured in a rural aquatic ecosystem in eastern Poland.

Methods

A pair of samples consisting of feces and scrapings of intestinal mucosa (taken during necropsy) were collected from 104 animals representing the four IAS turtle species red-eared slider, yellow-bellied slider, false map and Cumberland slider. The animals were trapped in running and standing freshwater ecosystems across the Lublin province. Parasite genomic DNA was extracted from samples using a modified alkali wash and a heat-lysis method and identification of the Cryptosporidium species was performed at the 18SSU rRNA and COWP loci.

Results

The presence of Cryptosporidium DNA was only detected in one sample of intestinal scraping collected from a red-eared slider. A phylogenetic analysis of a 18SSU rRNA gene fragment showed 100% sequence identity between the C. parvum strain isolated from the turtle and other C. parvum strains previously detected in cattle from the Lublin province.

Conclusions

There was no clinical evidence that the red-eared slider turtle was truly infected rather than being merely a mechanical parasite carrier. Sporadic detection of this protozoan parasite in the studied population of IAS turtles could be associated with low natural occurrence of Cryptosporidium infections in this animal species. The results provide evidence for possible transmission of zoonotic Cryptosporidium species by IAS turtles.

Molecular Characterization of Cryptosporidium spp. in Brandt's Vole in China

Cryptosporidium spp. are important intestinal parasites that infect humans and various animals, including wildlife. Currently, few epidemiological data in wild rodents, especially in voles, are available. In the present study, a total of 678 Brandt's vole feces samples were collected from Maodeng Livestock Farm and East Ujimqin, Inner Mongolia. The overall prevalence of Cryptosporidium spp. was 18.7%. Significant differences were not found between genders but between locations and weight groups. Moreover, three known species/genotypes, C. suis, Cryptosporidium environmental sequence and muskrat genotype II, and a novel Cryptosporidium species/genotypes of Brandt's vole was identified. To the best of our knowledge, this is the first report of Cryptosporidium spp. infection in Brandt's vole worldwide. These findings imply Brandt's voles might be a potential source of human cryptosporidiosis.

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.

Diversity of Cryptosporidium spp. in Apodemus spp. in Europe

The genetic diversity of Cryptosporidium spp. in Apodemus spp. (striped field mouse, yellow-necked mouse and wood mouse) from 16 European countries was examined by PCR/sequencing of isolates from 437 animals. Overall, 13.7% (60/437) of animals were positive for Cryptosporidium by PCR. Phylogenetic analysis of small-subunit rRNA, Cryptosporidium oocyst wall protein and actin gene sequences showed the presence of Cryptosporidium ditrichi (22/60), Cryptosporidium apodemi (13/60), Cryptosporidium apodemus genotype I (8/60), Cryptosporidium apodemus genotype II (9/60), Cryptosporidium parvum (2/60), Cryptosporidium microti (2/60), Cryptosporidium muris (2/60) and Cryptosporidium tyzzeri (2/60). At the gp60 locus, novel gp60 families XVIIa and XVIIIa were identified in Cryptosporidium apodemus genotype I and II, respectively, subtype IIaA16G1R1b was identified in C. parvum, and subtypes IXaA8 and IXcA6 in C. tyzzeri. Only animals infected with C. ditrichi, C. apodemi, and Cryptosporidium apodemus genotypes shed oocysts that were detectable by microscopy, with the infection intensity ranging from 2000 to 52,000 oocysts per gram of faeces. None of the faecal samples was diarrheic in the time of the sampling.

Genomics and molecular epidemiology of Cryptosporidium species

Cryptosporidium is one of the most widespread protozoan parasites that infects domestic and wild animals and is considered the second major cause of diarrhea and death in children after rotavirus. So far, around 20 distinct species are known to cause severe to moderate infections in humans, of which Cryptosporidium hominis and Cryptosporidium parvum are the major causative agents. Currently, ssurRNA and gp60 are used as the optimal markers for differentiating species and subtypes respectively. Over the last decade, diagnostic tools to detect and differentiate Cryptosporidium species at the genotype and subtype level have improved, but our understanding of the zoonotic and anthroponotic transmission potential of each species is less clear, largely because of the paucity of high resolution whole genome sequencing data for the different species. Defining which species possess an anthroponotic vs. zoonotic transmission cycle is critical if we are to limit the spread of disease between animals and humans. Likewise, it is unclear to what extent genetic hybridization impacts disease potential or the emergence of outbreak strains. The development of high resolution genetic markers and whole genome sequencing of different species should provide new insights into these knowledge gaps. The aim of this review is to outline currently available molecular epidemiology and genomics data for different species of Cryptosporidium.

Occurrence, Molecular Characterization, and Assessment of Zoonotic Risk of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in Pigs in Henan, Central China

Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are common gastrointestinal pathogens in humans and animals. Little is known about them and the range of species/assemblages/genotypes occurring in domestic pigs in China. Here, we present data on the occurrence and molecular diversity of these pathogens detected in the feces from farms in Henan, central China. Of 897 fecal samples tested, 28 (3.1%), 15 (1.7%), and 408 (45.5%) samples were positive for Cryptosporidium, G. duodenalis, and E. bieneusi, respectively. Cryptosporidium and G. duodenalis were most frequently detected in piglets, while E. bieneusi was markedly more prevalent in fattening pigs. Sequence analysis of SSU rRNA gene revealed that positive Cryptosporidium strains belonged to C. suis (n = 18) and C. scrofarum (n = 10). Giardia duodenalis assemblages E (n = 9), assemblages A (n = 3), and assemblages C (n = 3) were characterized based on the sequence analysis of tpi gene. Thirteen E. bieneusi genotypes comprising four novel (pigHN-I to pigHN-IV) and nine known (EbpC, EbpA, pigEbITS5, LW1, H, CM8, G, CHG19, and CHS5) genotypes were identified by ITS sequence analysis of a large proportion (n = 200) of E. bieneusi-positive samples. EbpC was the most frequent genotype, detected in 60 specimens. All 13 genotypes identified in this study clustered in zoonotic Group 1. The findings indicate that the presence of zoonotic species/assemblages/genotypes of these pathogens poses a threat to public health, suggesting that pigs in Henan province could be a significant source of human infection and water pollution.

Cryptosporidium occultus sp. n. (Apicomplexa: Cryptosporidiidae) in rats

Cryptosporidium parvum VF383 has been reported in humans, domesticated ruminants, and wild rats worldwide and described under several names including Cryptosporidium suis-like, based on its close phylogenetic relationship to C. suis. Unlike C. suis, however, it has never been detected in pigs. In the present work, C. parvum VF383 originating from wild brown rats was not infectious for piglets or calves but was infectious for laboratory brown rats, BALB/c mice, and Mongolian gerbils. The prepatent period was 4-5 days for all rodents. The patent period was longer for rats (>30 days) than other rodents (<20 days). None of the rodents developed clinical signs of infection. In all rodents, life cycle stages were detected in the colon by histology and electron microscopy. Oocysts were morphometrically similar to those of C. parvum and smaller than those of C. suis, measuring 5.20 × 4.94 μm. Phylogenetic analyses of 18S rRNA, actin, and HSP70 gene sequences revealed C. parvum VF383 to be genetically distinct from, C. suis, and other described species of Cryptosporidium. Morphological, genetic, and biological data support the establishment of C. parvum VF383 as a new species, and we propose the name Cryptosporidium occultus sp. n.

Diversity of Cryptosporidium species occurring in sheep and goat breeds reared in Poland

The aim of this study was molecular identification of Cryptosporidium species and assessment of their prevalence in different breeds of sheep and goat reared in Poland. In addition, the relationship between animal age, breed type, and the frequency of Cryptosporidium infections was determined. Fecal samples from 234 lambs and 105 goat kids aged up to 9 weeks, representing 24 breeds and their cross-breeds were collected from 71 small ruminant farms across Poland. The identification of Cryptosporidium species was performed at the 18 SSU ribosomal RNA (rRNA) and COWP loci followed by subtyping of C. parvum and C. hominis strains at GP60 gene locus. The presence of Cryptosporidium DNA at the 18 SSU rRNA locus was detected in 45/234 (19.2%) lamb feces samples and in 39/105 (37.1%) taken from goats. The following Cryptosporidium species: C. xiaoi, C. bovis, C. ubiquitum, C. parvum, and C. hominis were detected in small ruminants. Infections caused by C. xiaoi were predominant without favoring any tested animal species. Subsequent GP60 subtyping revealed the presence of C. parvum IIaA17G1R1 subtype in sheep and IIdA23G1 subtype in goats. IIdA23G1 subtype was detected in a goat host for the first time. There were no significant differences found in frequency of infections between the age groups (<3 and 3-9 weeks) of lambs (P = 0.14, α > 0.05) or goat kids (P = 0.06, α > 0.05). In addition, there was no correlation observed between the frequency in occurrence of particular parasite species and breed type in relation to native sheep breeds (F = 0.11; P = 0.990 > 0.05). In the case of goats, more breed-related differences in parasite occurrence were found. The results of this study improve our knowledge on the breed-related occurrence of Cryptosporidium infections in the population of small ruminants reared in Poland.

Cryptosporidium proliferans n. sp. (Apicomplexa: Cryptosporidiidae): Molecular and Biological Evidence of Cryptic Species within Gastric Cryptosporidium of Mammals

The morphological, biological, and molecular characteristics of Cryptosporidium muris strain TS03 are described, and the species name Cryptosporidium proliferans n. sp. is proposed. Cryptosporidium proliferans obtained from a naturally infected East African mole rat (Tachyoryctes splendens) in Kenya was propagated under laboratory conditions in rodents (SCID mice and southern multimammate mice, Mastomys coucha) and used in experiments to examine oocyst morphology and transmission. DNA from the propagated C. proliferans isolate, and C. proliferans DNA isolated from the feces of an African buffalo (Syncerus caffer) in Central African Republic, a donkey (Equus africanus) in Algeria, and a domestic horse (Equus caballus) in the Czech Republic were used for phylogenetic analyses. Oocysts of C. proliferans are morphologically distinguishable from C. parvum and C. muris HZ206, measuring 6.8–8.8 (mean = 7.7 μm) × 4.8–6.2 μm (mean = 5.3) with a length to width ratio of 1.48 (n = 100). Experimental studies using an isolate originated from T. splendens have shown that the course of C. proliferans infection in rodent hosts differs from that of C. muris and C. andersoni. The prepatent period of 18–21 days post infection (DPI) for C. proliferans in southern multimammate mice (Mastomys coucha) was similar to that of C. andersoni and longer than the 6–8 DPI prepatent period for C. muris RN66 and HZ206 in the same host. Histopatologicaly, stomach glands of southern multimammate mice infected with C. proliferans were markedly dilated and filled with necrotic material, mucus, and numerous Cryptosporidium developmental stages. Epithelial cells of infected glands were atrophic, exhibited cuboidal or squamous metaplasia, and significantly proliferated into the lumen of the stomach, forming papillary structures. The epithelial height and stomach weight were six-fold greater than in non-infected controls. Phylogenetic analyses based on small subunit rRNA, Cryptosporidium oocyst wall protein, thrombospondin-related adhesive protein of Cryptosporidium-1, heat shock protein 70, actin, heat shock protein 90 (MS2), MS1, MS3, and M16 gene sequences revealed that C. proliferans is genetically distinct from C. muris and other previously described Cryptosporidium species.

Cryptosporidium and Giardia in Danish organic pig farms: Seasonal and age-related variation in prevalence, infection intensity and species/genotypes

Although pigs are commonly infected with Cryptosporidium spp. and Giardia duodenalis, including potentially zoonotic species or genotypes, little is known about age-related infection levels, seasonal differences and genetic variation in naturally infected pigs raised in organic management systems. Therefore, the current study was conducted to assess seasonal and age-related variations in prevalence and infection intensity of Cryptosporidium and Giardia, evaluate zoonotic potential and uncover correlations between species/genotypes, infection intensity and faecal consistency. Shedding of oocysts and cysts ((oo-)cysts) was monitored at quarterly intervals (September 2011-June 2012) in piglets (n = 152), starter pigs (n = 234), fatteners (n = 230) and sows (n = 240) from three organic farms in Denmark. (oo-)Cysts were quantified by immunofluorescence microscopy; and 56/75 subsamples from Cryptosporidium infected pigs were successfully analysed by PCR amplification and partial sequencing of the small subunit (SSU) 18S rRNA and hsp70genes, while 13/67 Giardia subsamples were successfully analysed by amplification and partial sequencing of the 18S rRNA and the gdh genes. Altogether, Cryptosporidium or Giardia infections were observed in 40.9% (350/856) and 14.0% (120/856) of the pigs, respectively, including 8.2% (70/856) infected with both parasites. Prevalence, intensity of infections and presence of Cryptosporidium species varied significantly between age-groups; 53.3% piglets, 72.2% starter pigs, 40.4% fatteners and 2.9% sows were infected with Cryptosporidium, whereas 2.0% piglets, 27.4% starter pigs, 17.8% fatteners and 5.0% sows were infected with Giardia. The overall prevalence was stable throughout the year, except for dual-infections that were more prevalent in September and December (p < 0.05). The infection intensity was age-related for both parasites, and dual-infected pigs tended to excrete lower levels of oocysts compared to pigs harbouring only Cryptosporidium. Likewise, pigs infected with Cryptosporidium scrofarum excreted fewer oocysts (mean CPG: 54,848 ± 194,508CI: 9085-118,781) compared to pigs infected with Cryptosporidium suis (mean OPG: 351,035 ± 351,035CI: 67,953-634,117). No correlation between faecal consistency and (oo-)cyst excretion levels was observed. Of the successfully genotyped isolates, 38/56 (67.9%) were C. scrofarum and 18/56 (32.1%) were C. suis, while the livestock specific G. duodenalis Assemblage E was detected in 11/13 (84.6%) isolates and the potentially zoonotic Assemblage A was identified in 2/13 (15.4%) isolates. Piglets exclusively hosted C. suis, with one exception, while starter pigs and fatteners predominantly hosted C. scrofarum. As organic pigs are partly reared outdoors, environmental contamination with Cryptosporidium and Giardia is inevitable. Nevertheless, the present data indicate that the potential public health risk associated with both of these parasites in Danish organic pig production seems to be negligible.

Occurrence, source, and human infection potential of Cryptosporidium and Enterocytozoon bieneusi in drinking source water in Shanghai, China, during a pig carcass disposal incident

In March 2013, thousands of domestic pig carcasses were found floating in the Huangpu River, a drinking source water in Shanghai, China. To investigate the impact of the pig carcass incident on microbial water quality, 178 river water samples were collected from the upper Huangpu River from March 2013 to March 2014. Samples were concentrated by calcium carbonate flocculation and examined for host-adapted Cryptosporidium and Enterocytozoon bieneusi by ploymerase chain reaction (PCR). Positive PCR products were sequenced to determine Cryptosporidium species and E. bieneusi genotypes. A total of 67 (37.6%) and 56 (31.5%) samples were PCR-positive for Cryptosporidium and E. bieneusi, respectively. The occurrence rates of Cryptosporidium and E. bieneusi in March 2013 (83.3%; 41.7%) and May 2013 (73.5%; 44.1%) were significantly higher than rates in later sampling times. Among the 13 Cryptosporidium species/genotypes identified, C. andersoni and C. suis were the most common species, being found in 38 and 27 samples, respectively. Seventeen E. bieneusi genotypes were found, belonging to 11 established genotypes (EbpC, EbpA, D, CS-8, PtEb IX, Peru 8, Peru 11, PigEBITS4, EbpB, G, O) and six new ones (RWSH1 to RWSH6), most of which belonged to pig-adapted Groups 1d and 1e. EbpC was the most common genotype, being found in 37 samples. The distribution of Cryptosporidium species and E. bieneusi genotypes suggest that dead pigs contributed significantly to Cryptosporidium and E. bieneusi contamination in the Huangpu River. Although most Cryptosporidium species found in river water were not major human pathogens, the majority of E. bieneusi genotypes detected were endemic in China. Data from this study should be useful in the development of strategies in addressing future contamination events in drinking water supplies.

Cryptosporidiumspecies in humans and animals: current understanding and research needs

Cryptosporidiumis increasingly recognized as one of the major causes of moderate to severe diarrhoea in developing countries. With treatment options limited, control relies on knowledge of the biology and transmission of the members of the genus responsible for disease. Currently, 26 species are recognized as valid on the basis of morphological, biological and molecular data. Of the nearly 20Cryptosporidiumspecies and genotypes that have been reported in humans,Cryptosporidium hominisandCryptosporidium parvumare responsible for the majority of infections. Livestock, particularly cattle, are one of the most important reservoirs of zoonotic infections. Domesticated and wild animals can each be infected with severalCryptosporidiumspecies or genotypes that have only a narrow host range and therefore have no major public health significance. Recent advances in next-generation sequencing techniques will significantly improve our understanding of the taxonomy and transmission ofCryptosporidiumspecies, and the investigation of outbreaks and monitoring of emerging and virulent subtypes. Important research gaps remain including a lack of subtyping tools for manyCryptosporidiumspecies of public and veterinary health importance, and poor understanding of the genetic determinants of host specificity ofCryptosporidiumspecies and impact of climate change on the transmission ofCryptosporidium.

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

From 2011 to 2012, to identify Cryptosporidium spp. occurrence in Eurasian wild boars (Sus scrofa) 29 randomly selected localities (both forest areas and enclosures) across the Central European countries of Austria, the Czech Republic, Poland, and the Slovak Republic were investigated. Cryptosporidium oocysts were microscopicaly detected in 11 out of 460 faecal samples examined using aniline-carbol-methyl violet staining. Sixty-one Cryptosporidium infections, including the 11 infections that were detected by microscopy, were detected using genus- or species-specific nested PCR amplification of SSU rDNA. This represents a 5.5 fold greater sensitivity for PCR relative to microscopy. Combining genus- and species-specific PCR tools significantly changes the perspective on the occurrence of Cryptosporidium spp. in wild boars. While RFLP and direct sequencing of genus specific PCR-amplified products revealed 56 C. suis (20) and C. scrofarum (36) monoinfections and only 5 mixed infections of these species, species-specific molecular tools showed 44 monoinfections and 17 mixed infections with these species. PCR analysis of the gp60 gene did not reveal any other Cryptosporidium infections. Similar to domestic pigs, C. scrofarum was detected as a dominant species infecting adult Eurasian wild boars (Sus scrofa). Cryptosporidium infected wild boars did not show signs of clinical disease. This report is perhaps the most comprehensive survey of cryptosporidial infection in wild boars.

Cryptosporidiosis in Farmed Animals

Cryptosporidiosis was first identified as a disease of veterinary, rather than human medical, importance, and infection of farmed animals with different species of Cryptosporidium continues to be of veterinary clinical concern. This chapter provides insights into Cryptosporidium infection in a range of farmed animals – cattle, sheep, goats, pigs, cervids, camelids, rabbits, water buffalo and poultry – presenting not only an updated overview of the infection in these animals, but also information on clinical disease, infection dynamics and zoonotic potential. Although extensive data have been accrued on, for example, Cryptosporidium parvum infection in calves, and calf cryptosporidiosis continues to be a major veterinary concern especially in temperate regions, there remains a paucity of data for other farmed animals, despite Cryptosporidium infection causing significant clinical disease and also, for some species, with the potential for transmission of infection to people, either directly or indirectly.

Prevalence and genetic characterizations of Cryptosporidium spp. in pre-weaned and post-weaned piglets in Heilongjiang Province, China

Background

Cryptosporidium spp. are common intestinal protozoa of humans and animals. There have been few studies conducted on the molecular characterizations of pig-derived Cryptosporidium isolates worldwide, especially in China. Thus, the aim of the present study was to understand the prevalence, distribution and genotypes of Cryptosporidium in pigs in Heilongjiang Province, China.

Methodology/Principal Findings

A total of 568 fecal samples from pre-weaned and post-weaned piglets were collected from eight pig farms from four areas of Heilongjiang Province. The average infection rate of Cryptosporidium was 1.6% (9/568) by microscopy. 113 samples were subjected to PCR amplification of the small subunit (SSU) rRNA gene of Cryptosporidium, with 55.8% (63/113) being positive for Cryptosporidium. Cryptosporidium suis (n = 31) and C. scrofarumn (n = 32) were identified by DNA sequencing of the SSU rRNA gene. Three types of C. scrofarumn were found at the SSU rRNA locus, with one novel type being detected. Using species/genotype-specific primers for pig-adapted Cryptosporidium spp., 22 and 23 respectively belonged to C. suis and C. scrofarum mono-infections, with 18 co-infections detected. The infection peaks for C. suis (60%, 24/40) and C. scrofarum (51.2%, 21/41) were respectively found in the piglets of 5 to 8 weeks and more than 8 weeks.

Conclusion/Significance

The detection of C. suis and C. scrofarum in pre-weaned and post-weaned piglets has public health implications, due to the fact that the two species are both zoonotic Cryptosporidium. The novel C. scrofarum type detected may be endemic to China.

Occurrence of Cryptosporidium suis and Cryptosporidium scrofarum on commercial swine farms in the Czech Republic and its associations with age and husbandry practices

From 2009 to 2011, the occurrence of Cryptosporidium spp. was investigated on 22 farms in the Czech Republic. A total of 1,620 individual faecal samples of pigs of all age categories (pre-weaned, starters, pre-growers, growers, and sows) were evaluated for presence of Cryptosporidium spp. by standard microscopy and molecular tools. Genotyping was done through PCR amplification and characterization of the SSU rRNA (species-specific protocols) and GP60 loci. Cryptosporidium spp. was found on 16 of 22 farms with a range 0.9-71.4 %. Overall, 194 (12 %) specimens were positive by microscopy and 353 (21.8 %) by PCR. While RFLP and direct sequencing of the PCR-amplified products showed presence of Cryptosporidium suis (142), Cryptosporidium scrofarum (195), Cryptosporidium muris (3) and 13 samples had mixed infections with C. suis and C. scrofarum, species-specific molecular tools identified C. suis (224), C. scrofarum (208), Cryptosporidium parvum subtype IIa A16G1R1b (1), and C. muris (3). In addition, a total of 82 pigs had concurrent infections with C. suis and C. scrofarum. The analysis by age showed that C. suis was primarily detected among pre-weaned, whereas C. scrofarum was mostly detected among starters, especially those weaned at a younger age. Moreover, C. scrofarum never has been detected in animals younger than 6 weeks of age. Also, piglets weaned at 3 weeks of age were twice more likely to be infected with C. scrofarum than piglets weaned at an older age. Pigs raised on straw bedding were more likely to have Cryptosporidium than pigs raised on slats/slurry systems. The infections with different species were not associated with loose faeces or intensity of oocyst shedding, even when comparing different age groups.

Molecular characterization of Cryptosporidium in pigs in central Vietnam

Little information is available on the epidemiology of Cryptosporidium in pigs in central Vietnam. The aims of this study were to investigate the prevalence and to characterize the genotype distribution of Cryptosporidium isolates in pigs in this region. A total of 193 pig fecal samples were screened for the presence of Cryptosporidium oocysts using the modified Ziehl-Neelsen staining method, and 28 (overall prevalence 14.5 %) were identified as positive by microscopic observation. Positive samples were further analyzed by polymerase chain reaction amplification and sequencing. Genetic identification based on the 18S ribosomal RNA and 70 kDa heat shock protein genes revealed that pigs in Vietnam are infected with two species/genotypes (Cryptosporidium suis and Cryptosporidium pig genotype II). This study is the first molecular characterization of Cryptosporidium in pigs in Vietnam. The presence of these host-adapted species/genotypes suggests that pigs may not pose a significant public health risk in this area. More extensive studies are necessary to ascertain the zoonotic potential of Cryptosporidium in porcine hosts in Vietnam.

Cryptosporidium scrofarum n. sp. (Apicomplexa: Cryptosporidiidae) in domestic pigs (Sus scrofa)

We describe the morphological, biological, and molecular characteristics of Cryptosporidium pig genotype II and propose the species name Cryptosporidium scrofarum n. sp. to reflect its prevalence in adult pigs worldwide. Oocysts of C. scrofarum are morphologically indistinguishable from C. parvum, measuring 4.81-5.96 μm (mean=5.16)×4.23-5.29 μm (mean=4.83) with a length to width ratio of 1.07±0.06 (n=400). Oocysts of C. scrofarum obtained from a naturally infected pig were infectious for 8-week-old pigs but not 4-week-old pigs. The prepatent period in 8-week-old Cryptosporidium-naive pigs was 4-6 days and the patent period was longer than 30 days. The infection intensity of C. scrofarum in pigs was generally low, in the range 250-4000 oocysts per gram of feces. Infected pigs showed no clinical signs of cryptosporidiosis and no pathology was detected. Cryptosporidium scrofarum was not infectious for adult SCID mice, adult BALB/c mice, Mongolian gerbils (Meriones unguiculatus), southern multimammate mice (Mastomys coucha), yellow-necked mice (Apodemus flavicollis), or guinea pigs (Cavia porcellus). Phylogenetic analyses based on small subunit rRNA, actin, and heat shock protein 70 gene sequences revealed that C. scrofarum is genetically distinct from all known Cryptosporidium species.

Cryptosporidium species in Australian wildlife and domestic animals

Cryptosporidium is an important enteric parasite that is transmitted via the fecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Most species of Cryptosporidium are morphologically indistinguishable and can only be identified using molecular tools. Over 24 species have been identified and of these, 7 Cryptosporidium species/genotypes are responsible for most human cryptosporidiosis cases. In Australia, relatively few genotyping studies have been conducted. Six Cryptosporidium species (C. hominis, C. parvum, C. meleagridis, C. fayeri, C. andersoni and C. bovis) have been identified in humans in Australia. However, little is known about the contribution of animal hosts to human pathogenic strains of Cryptosporidium in drinking water catchments. In this review, we focus on the available genotyping data for native, feral and domestic animals inhabiting drinking water catchments in Australia to provide an improved understanding of the public health implications and to identify key research gaps.

Prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam

We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.1% (134/740) and 71.9% (64/89), respectively. Risk factors for the infection were identified using univariate and multivariate logistic regression analysis. The results revealed that age, sanitary condition and topography were significantly associated with oocyst shedding (P<0.05). Pre-weaned piglets were at the highest risk for infection, followed by post-weaners, sows and finishing pigs. Good sanitary conditions showed positive effects in decreasing oocysts shedding. Topographically, Cryptosporidium was more common in mountainous zone than that in coastal delta zone. There was an association between the occurrence of diarrhea and the level of Cryptosporidium oocyst excretion within infected pigs. This is the first epidemiological investigation of prevalence and risk factors of Cryptosporidium in pigs in Vietnam.

The first report on Cryptosporidium suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa) (Czech Republic)

A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).

Prevalence of the Cryptosporidium pig genotype II in pigs from the Yangtze River Delta, China

Background

Cryptosporidium spp. is prevalent globally, pigs are an important Cryptosporidium reservoir. In China, little data regarding rates of Cryptosporidium infections in pigs are available. The present study was therefore aimed at characterizing the distribution of Cryptosporidium species in pigs from two different cities, Shaoxing and Shanghai, from the Yangtze River delta.

Methodology/Principal Findings

Nested PCR to amplify the 18S rRNA locus on DNA extracted from fecal samples (n = 94) revealed the positive rate of Cryptosporidium in pigs from two cities was approximately 17.0%. The positive rates in Shanghai and Shaoxing were 14.3% and 25.0% respectively. Amplified sequences were verified by sequencing. The identified strain belonged to the C. pig genotype II using BLAST analysis in the NCBI database.

Conclusion/Significance

Our finding of Cryptosporidium pig genotype II in pigs in the Yangtze River delta area suggests that pig farms in this region must be considered a public health threat and proper control measures be introduced.

Estimated human health risks from exposure to recreational waters impacted by human and non-human sources of faecal contamination

This work was conducted to determine whether estimated risks following exposure to recreational waters impacted by gull, chicken, pig, or cattle faecal contamination are substantially different than those associated with waters impacted by human sources such as treated wastewater. Previously published Quantitative Microbial Risk Assessment (QMRA) methods were employed and extended to meet these objectives. Health outcomes used in the analyses were infection from reference waterborne pathogens via ingestion during recreation and subsequent gastrointestinal (GI) illness. Illness risks from these pathogens were calculated for exposure to faecally contaminated recreational water at the U.S. regulatory limits of 35 cfu 100 mL(-1) enterococci and 126 cfu 100 mL(-1)Escherichia coli. The probabilities of GI illness were calculated using pathogen dose-response relationships from the literature and Monte Carlo simulations. Three scenarios were simulated, representing a range of feasible interpretations of the available data. The primary findings are that: 1) GI illness risks associated with exposure to recreational waters impacted by fresh cattle faeces may not be substantially different from waters impacted by human sources; and 2) the risks associated with exposure to recreational waters impacted by fresh gull, chicken, or pig faeces appear substantially lower than waters impacted by human sources. These results suggest that careful consideration may be needed in the future for the management of recreational waters not impacted by human sources.

Concentrations, viability, and distribution of Cryptosporidium genotypes in lagoons of swine facilities in the Southern Piedmont and in coastal plain watersheds of Georgia

Waste lagoons of swine operations are a source of Cryptosporidium oocysts. Few studies, however, have reported on oocyst concentrations in swine waste lagoons; none have reported on oocyst viability status, nor has there been a systematic assessment of species/genotype distributions across different types of swine facilities. Ten swine waste lagoons associated with farrowing, nursery, finishing, and gestation operations were each sampled once a month for a year. Oocysts were extracted from triplicate 900-ml effluent samples, enumerated by microscopy, and assessed for viability by dye exclusion/vital stain assay. DNA was extracted from processed samples, and 18S ribosomal DNA (rDNA) genes were amplified by PCR and sequenced for species and genotype identification. Oocysts were observed at each sampling time at each lagoon. Annual mean concentrations of total oocysts and viable oocysts ranged between 24 and 51 and between 0.6 and 12 oocysts ml(-1) effluent, respectively. The species and genotype distributions were dominated (95 to 100%) by Cryptosporidium suis and Cryptosporidium pig genotype II, the latter of which was found at eight of the lagoons. The lagoon at the gestation facility was dominated by Cryptosporidium muris (90%), and one farrowing facility showed a mix of pig genotypes, Cryptosporidium muris, and various genotypes of C. parvum. The zoonotic C. parvum bovine genotype was observed five times out of 407 18S rDNA sequences analyzed. Our results indicate that pigs can have mixed Cryptosporidium infections, but infection with C. suis is likely to be dominant.

Molecular epidemiology of cryptosporidiosis: an update

Molecular tools have been developed to detect and differentiate Cryptosporidium at the species/genotype and subtype levels. These tools have been increasingly used in characterizing the transmission of Cryptosporidium spp. in humans and animals. Results of these molecular epidemiologic studies have led to better appreciation of the public health importance of Cryptosporidium species/genotypes in various animals and improved understanding of infection sources in humans. Geographic, seasonal and socioeconomic differences in the distribution of Cryptosporidium spp. in humans have been identified, and have been attributed to differences in infection sources and transmission routes. The transmission of C. parvum in humans is mostly anthroponotic in developing countries, with zoonotic infections play an important role in developed countries. Species of Cryptosporidium and subtype families of C. hominis have been shown to induce different clinical manifestations and have different potential to cause outbreaks. The wide use of a new generation of genotyping and subtyping tools in well designed epidemiologic studies should lead to a more in-depth understanding of the epidemiology of cryptosporidiosis in humans and animals.

Molecular characterization of Cryptosporidium isolates from pigs in Zaragoza (northeastern Spain)

A total of 142 stool specimens from pigs on 24 farms from the province of Zaragoza (northeastern Spain) were screened for Cryptosporidium spp. Samples were first analysed by routine techniques (formalin-ethyl acetate sedimentation method and modified Ziehl-Neelsen stain) selecting those microscopically positive for genetic characterization. Cryptosporidium species and genotypes were determined by a nested PCR-RFLP technique at the 18S ribosomal DNA locus and sequencing of the PCR-positive secondary products. Cryptosporidium oocysts were microscopically identified in the faeces of 32 pigs (22.5%) from 15 farms (62.5%). Infected animals included 23 weaned piglets (30.7%), 5 fattening pigs (11.9%) and 4 sows (16%). Diarrhoea was not detected in any of the infected pigs. The molecular characterization was successfully performed in 26 samples from 14 farms. Cryptosporidium suis was found in 10 specimens from 7 farms (nine weaned piglets and one sow) and the Cryptosporidium pig genotype II in 16 samples from 10 farms (13 weaned piglets and 3 fattening pigs). Both C. suis and the pig genotype II were concurrently detected on three farms.

Prevalence ofCryptosporidiumspecies in intensively farmed pigs in Ireland

NaturalCryptosporidiuminfections in pigs are widespread but generally apathogenic. This study was undertaken to determine the prevalence of zoonoticCryptosporidiumspp. in piggeries in Ireland, where the drinking water supply is particularly vulnerable to contamination with zoonotic species. Overall, infections were detected in 39 out of 342 animals (11·4%), with highest infection rates among weaners (15%) and sows (13·3%). Twenty-nine positive samples were genotyped based on SSU rRNA sequence analysis. Infections withCryptosporidium parvum, the most important zoonotic species were rare and are likely to be of greater concern to animal handlers than suppliers of drinking water. In addition toC. parvum,Cryptosporidium suis,Cryptosporidiumpig genotype II,Cryptosporidium murisand a previously undescribed genotype were identified. ABI-profiles indicated the presence of different alleles in at least 40% of all genotyped isolates. This was confirmed in 3 isolates by cloning of the PCR products. Since chronic mixed infections appear to be quite common in pigs they could be considered as models for mixed infections in immunocompromised humans.