Cryptosporidium infection in a veal calf cohort in France: molecular characterization of species in a longitudinal study

Frequency and Molecular Identification of Cryptosporidium in Adult Prim'Holstein Dairy Cattle Farms in the North of France

Cryptosporidium apicomplexan protozoa are ubiquitous intracellular agents affecting humans and animals. In particular, bovine cryptosporidiosis is recognized as endemic worldwide. However, epidemiological investigations remain limited in France regarding the burden of these parasites in cattle. To improve our understanding of the epidemiology of cryptosporidiosis, the main aim of this study was to determine the frequency and the genetic diversity of Cryptosporidium in adult Prim'Holstein dairy cattle farms in the north of France. Fecal specimens were collected from 1454 non-diarrheic and non-pregnant animals (nulli-, primi-, or multiparous) throughout 20 farms in an area of 110 km around Lille. For Cryptosporidium species identification, nested PCR followed by sequence and phylogenetic analyses were used. The overall frequency of Cryptosporidium spp. in-fection was 30.00% (C.I. 95%: 12.83-54.33) in farms and 0.89% (C.I. 95%: 0.498-1.57) at the individual level. In primi- or multiparous cows, only C. andersoni was found. C. ryanae, C. bovis/xiaoi and C. andersoni were detected in heifers. The phylogenetic tree confirmed that analyzed sequences were grouped with known reference sequences reported in dairy cattle. Further studies on the cumulative prevalence, risks factors and pathogenicity are needed to give a more accurate assessment of the impact of Cryptosporidium infection in dairy cattle in France.

Study of the economic impact of cryptosporidiosis in calves after implementing good practices to manage the disease on dairy farms in Belgium, France, and the Netherlands

Cryptosporidium spp. are widespread parasitic protozoans causing enteric infections in humans and animals. The parasites cause neonatal diarrhoea in calves, leading to a high mortality rate in the first three weeks. Losses are significant for farmers, but the cost of cryptosporidiosis remains poorly documented. In the absence of a vaccine, only preventive measures are available to farmers to combat the infection. This study, conducted between 2018 and 2021, aimed to evaluate the economic impact of Cryptosporidium spp. on European dairy farms and monitor changes in costs after implementing disease management measures. First, a field survey was carried out and questionnaires administered to 57 farmers in Belgium, France, and the Netherlands. The aim of the survey was to assess the losses associated with the occurrence of diarrhoea in calves aged between 3 days and 3 weeks. The economic impact of diarrhoea was calculated based on mortality losses, health expenditures, and additional labour costs. To refine the cost estimation specifically for Cryptosporidium spp., stool samples were collected from 10 calves per farm. The prevalence of Cryptosporidium spp. was determined, and the economic impact of diarrhoea was adjusted accordingly. The assumption was made that a certain percentage of costs was attributed to cryptosporidiosis based on the prevalence. These protocols were repeated at the end of the study to observe changes in costs. In the three years, the cost of diarrhoea for the 28 farms that stayed in the panel all along the study improved from €140 in 2018 to €106 on average per diarrhoeic calf in 2021. With a stable prevalence at 40%, the cost of cryptosporidiosis per infected calf decreased from €60.62 to €45.91 in Belgium, from €43.83 to €32.14 in France, and from €58.24 to €39.48 in the Netherlands. This represented an average of €15 saved per infected calf. The methodology employed in this study did not allow us to conclude that the improvement is strictly due to the implementation of preventive measures. However, with 11 million calves raised in the Interreg 2 Seas area covered by the study, it provided valuable insights into the economic burden of Cryptosporidium spp.

Prevalence, risk factors and molecular epidemiology of neonatal cryptosporidiosis in calves: The Argentine perspective

Cryptosporidium spp. are enteroparasitic protozoans that cause cryptosporidiosis in newborn calves. Clinical signs of the infection are diarrhoea and dehydration leading to decreased productivity and economic losses in cattle farms around the world. Additionally, cryptosporidiosis is a relevant zoonotic disease since the ingestion of oocysts can be fatal for children under five years of age, the elderly, and/or immunocompromised adults. This review aims to integrate existing knowledge on the epidemiological situation of calf cryptosporidiosis and associated risk factors in Argentina. In addition, the GP60 subtype diversity of the pathogen was analysed and related with the global distribution of corresponding GP60 subtypes. Depending on the study region and applied diagnostics, prevalence among calves up to 20 days of age varied between 25.2% and 42.5%, while a prevalence of 16.3-25.5% was observed at the age of 1-90 days. So far, molecular studies have determined exclusively Cryptosporidium parvum in preweaned calves. In addition, C. parvum infection was reported as the major cause of calf diarrhoea, followed by rotavirus A (RVA), while enteropathogens such as coronavirus, Escherichiacoli, and Salmonella sp. played a negligible role. Calf age of 20 days or less, incidence of diarrhoea, poorly drained soils, and large farm size were identified as risk factors for C. parvum-infection in Argentina. A total of nine GP60 subtypes (IIaAxxG1R1, xx = 16 to 24) were identified, showing a stepwise increase of the trinucleotide motif TCA, and including the zoonotic subtypes IIaA16G1R1, IIaA17G1R1, IIaA18G1R1, IIaA19G1R1, and IIaA20G1R1. We found that an increase in the A16→A24 trinucleotide repeat was accompanied by a gradual decrease in the global distribution of GP60 alleles, strongly suggesting that IIaA16G1R1 represents the primordial allelic variant of this group. Since identified GP60 alleles have a similar genetic background, we hypothesize that the continuous trinucleotide repeat array has been generated by stepwise repeat expansion of A16. The information gathered and integrated in this study contributes to an improved understanding of the epidemiological characteristics of bovine cryptosporidiosis in and beyond Argentina, which in turn can help to develop control strategies for this parasitosis of veterinary and medical relevance.

Dynamics of protozoal excretion in the faeces of calves during the first 28 days after arrival at the fattening farm indicate infection before regrouping and show poor temporal correlation with diarrhoea

BACKGROUND

Calves in dairy cattle production in Switzerland are transported to a fattening farm at the age of 3-5 weeks, and frequently suffer from diarrhoea within the first 14 days after arrival. To characterise the role of intestinal protozoa in this, we investigated the excretion dynamics of Eimeria, Cryptosporidium and Giardia during the first 28 days after the arrival and regrouping of calves at fattening farms.

METHODS

A total of 610 faecal samples from 122 calves (mean age 37.3 days; mean body weight 79.8 kg) were collected on seven different fattening farms during the first 28 days after the arrival and regrouping of the animals. The farms were visited between January and April (cold season; n = 4) and between June and August (warm season; n = 3). The samples were collected rectally on days 1, 4, 7, 14 and 28, assessed for consistency, and analysed using the McMaster method for quantitative determination of the number of Eimeria oocysts per gram of faeces (OPG), flotation for morphological differentiation of the unsporulated Eimeria oocysts, a concentration method for the semi-quantitative determination of Giardia cysts, and modified Ziehl-Neelsen staining for semi-quantitative determination of Cryptosporidium oocysts.

RESULTS

Overall, 50.8% (62/122) of the animals had diarrhoea during the study period. However, the faecal excretion of protozoal pathogens was neither associated with diarrhoea nor with body weight gain of the animals. Altogether, 90.2% (110/122) of the calves were Eimeria positive. Eimeria zuernii was excreted by 51 (41.8%) and Eimeria bovis by 68 (55.7%) animals. In the warm season more animals tested positive for Eimeria and OPGs were higher than in the cold season. There was no correlation between the age of the calves and the OPG values. Overall, 64.8% (79/122) of the calves excreted Eimeria oocysts within the first 7 days, indicating that they had been infected with the parasite on the dairy farm of origin. Eighty-nine calves (73.0%) excreted Giardia cysts, with more positive animals in the cold (80.3%) compared with the warm season (64.3%). Only Giardia duodenalis assemblage E was identified. Cryptosporidium oocysts were microscopically detected in 14 animals (11.5%) on five farms. Cryptosporidium spp. were present in a total of 12 animals, i.e. Cryptosporidium parvum in nine, Cryptosporidium ryanae in two, and Cryptosporidium bovis in one animal.

CONCLUSIONS

A better understanding of the temporal dynamics of protozoal infections in calves is helpful for the implementation of appropriate measures to protect the health of these animals at a critical phase in their lives. Our results indicate that factors other than those examined in the present study contributed to the onset of diarrhoea in the calves.

Follow-up investigation into Cryptosporidium prevalence and transmission in Western European dairy farms

Cryptosporidium parvum is an enteric parasite and a major contributor to acute enteritis in calves worldwide, causing an important economic burden for farmers. This parasite poses a major public health threat through transmission between livestock and humans. Our previous pilot study in Western Europe revealed a high prevalence of Cryptosporidium in calves of dairy farms. In the sequel study herein, 936 faecal samples were collected from the same 51 dairy farms across Belgium, France, and the Netherlands. Following DNA extraction, Cryptosporidium screening was carried out using nested-PCR amplification targeting the SSU rRNA gene. All positive samples were sequenced, and phylogenetic analyses were used to identify the Cryptosporidium spp. present. The 60 kDa glycoprotein (gp60) gene was also sequenced to determine the C. parvum subtypes present. Prevalence of Cryptosporidium ranged from 23.3% to 25%, across the three countries surveyed. The parasite was found in most of the farms sampled, with 90.2% testing positive. Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni were all identified, with the former being the most predominant, representing 71.4% of all infections. Cryptosporidium parvum was associated with pre-weaned calves, while other species were associated with older animals. Subtyping of gp60 gene revealed nine subtypes, eight of which have previously been reported to cause clinical disease in humans. Similarly to the first study, vertical transmission was not a major contributor to Cryptosporidium spread. Our study highlights the need for further investigation into cryptosporidiosis transmission, and future studies will require a One Health approach to reduce the impact of this disease.

First report of Cryptosporidium andersoni and risk factors associated with the occurrence of Cryptosporidium spp. in pre-weaned native Korean calves with diarrhea

Cryptosporidium spp. are important enteric protozoan parasites that infect humans and other animals throughout the world. Cryptosporidium infection in cattle industry leads to substantial economic losses due to diarrhea, growth retardation, weight loss, and possibly death. Most studies have focused on C. parvum, and studies on other Cryptosporidium spp. and calf diarrhea are limited. Therefore, this study aimed to investigate the occurrence of Cryptosporidium spp. in pre-weaned calves, to determine the risk factors for Cryptosporidium spp. infection such as age and season, and to identify subtypes of C. parvum circulating in the Republic of Korea (ROK). A total of 510 fecal samples were collected from calves with diarrhea and divided by age and season. Cryptosporidium spp. were first screened using PCR targeting the small subunit (SSU) rRNA gene and further the 60-kDa glycoprotein gene for subtyping of C. parvum. Out of 510 fecal samples, 71 (13.9%) were positive for Cryptosporidium spp. in pre-weaned calves with diarrhea. C. andersoni (2.8%), C. bovis (30.9%), C. parvum (29.6%), and C. ryanae (36.6%) were identified. C. ryanae was the most predominant in calves in the ROK. Calf age was a significant risk factor for C. bovis (χ² = 13.83, P = 0.001), C. parvum (χ² = 7.57, P = 0.023), and C. ryanae (χ² = 20.18, P = 0.000) occurrence. Additionally, C. parvum was detected 3.1-fold more frequently in pre-weaned calves with diarrhea in fall (95% CI: 1.23-7.81; P = 0.016) than in spring, whereas C. ryanae was 8.9-fold more frequently detected in summer (95% CI: 1.65-48.68; P = 0.011) than in spring. Three subtypes (IIaA17G4R1, IIaA18G3R1, and IIaA20G3R1) of C. parvum were identified. Of them, IIaA17G4R1 was the most common, whereas IIaA20G3R1 was not previously detected in calves in the ROK. To our knowledge, this is the first report of C. andersoni in pre-weaned calves in the ROK. The occurrence of Cryptosporidium spp. appears to be age-dependent in calves. Season had a significant effect on the occurrence of C. parvum and C. ryanae. Taken together, C. bovis and C. ryanae along with C. parvum are detected in pre-weaned calves with diarrhea and these two pathogens should not be overlooked in the diagnosis of calf diarrhea.

Evaluation of a novel multiplex qPCR method for rapid detection and quantification of pathogens associated with calf diarrhoea

AIMS

Diarrhoea is a common health problem in calves and a main reason for use of antimicrobials. It is associated with several bacterial, viral and parasitic pathogens, most of which are commonly present in healthy animals. Methods, which quantify the causative agents, may therefore improve confidence in associating a pathogen to the disease. This study evaluated a novel commercially available, multiplex quantitative polymerase chain reaction (qPCR) assay (Enterit4Calves) for detection and quantification of pathogens associated with calf-diarrhoea.

METHODS AND RESULTS

Performance of the method was first evaluated under laboratory conditions. Then it was compared with current routine methods for detection of pathogens in faecal samples from 65 calves with diarrhoea and in 30 spiked faecal samples. The qPCR efficiencies were between 84%-103% and detection limits of 100-1000 copies of nucleic acids per sample were observed. Correct identification was obtained on 42 strains of cultured target bacteria, with only one false positive reaction from 135 nontarget bacteria. Kappa values for agreement between the novel assay and current routine methods varied between 0.38 and 0.83.

CONCLUSION

The novel qPCR method showed good performance under laboratory conditions and a fair to good agreement with current routine methods when used for testing of field samples.

SIGNIFICANCE AND IMPACT OF STUDY

In addition to having fair to good detection abilities, the novel qPCR method allowed quantification of pathogens. In the future, use of quantification may improve diagnosis and hence treatment of calf diarrhoea.

Prevalence, risk factor and diversity of Cryptosporidium in cattle in Latvia

The epidemiology of Cryptosporidium spp. in Latvia was investigated by testing fecal samples from 926 animals aged from one day to 24 years for the presence of Cryptosporidium spp. oocysts. The samples were collected from 87 cattle farms and from four slaughterhouses, and analyzed by conventional and fluorescent microscopy, followed by Cryptosporidium species and C. parvum subtype differentiation. Moreover, using a questionnaire, we surveyed factors that could be relevant as risk factors of Cryptosporidium spp. infection on the farms. Cryptosporidium spp. were shed by 33.8% of the investigated cattle and at least one shedding animal was found on 77.8% of the farms. In the present study, all four Cryptosporidium species reported to commonly infect cattle and two additional Cryptosporidium species (C. scrofarum and C. ubiquitum) were identified. In addition, mix infections of C. parvum/C. bovis, C. bovis/C. ryanae, C. parvum/C. ryanae, C. parvum/C. andersoni and C. bovis/C. andersoni were observed. C. parvum and C. bovis was mostly prevalent in young animals (0-3 months old) and in addition, diarrhea associated with C. parvum infection was observed only in very young animals. Cryptosporidium andersoni and C. ryanae in age group 0-3 months was observed in low prevalence, while a higher proportion of animals with diarrhea associated with C. andersoni infection was observed in very young animals and with C. ryanae in animals age group 4-24 months. Eight previously described C. parvum subtypes were observed. The majority of the subtypes were in the IIa subtype family, while one subtype was identified from the IId subtype family. The most common subtype was IIaA15G2R1, which was found in 34.2% of the C. parvum successfully subtyped samples. The probability of Cryptosporidium spp. associated diarrhea in cattle decreased significantly with the age of the animals and a prolonged period during which calves were fed with milk.

Cross-Border Investigations on the Prevalence and Transmission Dynamics of Cryptosporidium Species in Dairy Cattle Farms in Western Mainland Europe

Cryptosporidium is an apicomplexan parasitic protist, which infects a wide range of hosts, causing cryptosporidiosis disease. In farms, the incidence of this disease is high in animals such as cows, leading to extensive economic loss in the livestock industry. Infected cows may also act as a major reservoir of Cryptosporidium spp., in particular C. parvum, the most common cause of cryptosporidiosis in these animals. This poses a risk to the trading of livestock, to other farms via breeding centres, and to human health. This study is a part of a global project aimed at strategies to tackle cryptosporidiosis. To reach this target, it was essential to determine whether prevalence was dependent on the studied countries or if the issue was borderless. Indeed, C. parvum occurrence was assessed across dairy farms in certain regions of Belgium, France, and the Netherlands. At the same time, the animal-to-animal transmission of the circulating C. parvum subtypes was studied. To accomplish this, we analysed 1084 faecal samples, corresponding to 57 dairy farms from all three countries. To this end, 18S rRNA and gp60 genes fragments were amplified, followed by DNA sequencing, which was subsequently used for detection and subtyping C. parvum. Bioinformatic and phylogenetic methods were integrated to analyse and characterise the obtained DNA sequences. Our results show 25.7%, 24.9% and 20.8% prevalence of Cryptosporidium spp. in Belgium, France, and the Netherlands respectively. Overall, 93% of the farms were Cryptosporidium positive. The gp60 subtyping demonstrated a significant number of the C. parvum positives belonged to the IIa allelic family, which has been also identified in humans. Therefore, this study highlights how prevalent C. parvum is in dairy farms and further suggests cattle as a possible carrier of zoonotic C. parvum subtypes, which could pose a threat to human health.

A single-cohort study of Cryptosporidium bovis and Cryptosporidium ryanae in dairy cattle from birth to calving

In order to investigate the infection dynamics of Cryptosporidium bovis and C. ryanae, a two-year prospective cohort study was performed on a dairy farm known to be free of C. parvum. Sixteen calves were recruited when newborn. Faecal samples were collected weekly until calves were nine weeks old, then monthly until calving or culling. Samples (n = 455) were examined by fluorescence microscopy, and when positive the species were determined by DNA sequencing. In calves up to nine weeks, C. bovis was found in 58.5% of the samples, C. ryanae in 9.2%, and both C. bovis and C. ryanae in 3.1%. The prevalence of shedding calves peaked at 87.5% in week five, which is earlier than many international studies have shown for C. bovis. The cumulative incidence of C. bovis reached 100% when the calves were five weeks old. In four calves, the species detected changed from C. bovis to C. ryanae or the other way around, and two samples were a combination of both species. Several individuals shed oocysts sporadically up to 16 months of age. The highest oocysts per gram faeces count was seen in week three (3.6 × 10⁶ OPG). Diarrhoea was not associated with oocyst shedding.

First identification of Cryptosporidium parvum zoonotic subtype IIaA15G2R1 in diarrheal lambs in France

To date, no information is available about the presence of Cryptosporidium spp. in French sheep, nor their potential role as zoonotic reservoirs. A total of 23 fecal samples were collected from diarrheic lambs (<11 days old) from seven randomly selected farms. Cryptosporidium-oocysts were detected microscopically with Direct Immunofluorescence Assays (DFA) in 23/23 (100%) of fecal samples. PCR-RFLP of the 18S rRNA gene was used to determine species in all samples, and only Cryptosporidium parvum was identified. Isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene. Two zoonotic subtypes within the IIa subtype family were identified, including IIaA15G2R1 (22/23) and IIaA16G3R1 (1/23). This study reports for the first time the identification and genotyping of zoonotic C. parvum subtypes from lambs in France. Sheep could thus play an important role as potential reservoirs for this zoonotic protist.

Cryptosporidium infections in terrestrial ungulates with focus on livestock: a systematic review and meta-analysis

Background

Cryptosporidium spp. are causative agents of gastrointestinal diseases in a wide variety of vertebrate hosts. Mortality resulting from the disease is low in livestock, although severe cryptosporidiosis has been associated with fatality in young animals.

Methods

The goal of this systematic review and meta-analysis was to review the prevalence and molecular data on Cryptosporidium infections in selected terrestrial domestic and wild ungulates of the families Bovidae (bison, buffalo, cattle, goat, impala, mouflon sheep, sheep, yak), Cervidae (red deer, roe deer, white-tailed deer), Camelidae (alpaca, camel), Suidae (boar, pig), Giraffidae (giraffes) and Equidae (horses). Data collection was carried out using PubMed, Scopus, Science Direct and Cochran databases, with 429 papers being included in this systematic analysis.

Results

The results show that overall 18.9% of ungulates from the investigated species were infected with Cryptosporidium spp. Considering livestock species (cattle, sheep, goats, pigs, horses and buffaloes), analysis revealed higher Cryptosporidium infection prevalence in ungulates of the Cetartiodactyla than in those of the Perissodactyla, with cattle (29%) being the most commonly infected farm animal.

Conclusions

Overall, the investigated domestic ungulates are considered potential sources of Cryptosporidium contamination in the environment. Control measures should be developed to reduce the occurrence of Cryptosporidium infection in these animals. Furthermore, literature on wild populations of the named ungulate species revealed a widespread presence and potential reservoir function of wildlife.

Molecular characterization of Cryptosporidium isolates from diarrheal dairy calves in France

Cryptosporidium is an obligate intracellular protist parasite infecting a wide range of vertebrate hosts and causes significant intestinal disease in both animals and humans, as some species are zoonotic. Cattle and especially calves have been identified as one of the most common reservoirs of this protist. However, little is known about the genetics of Cryptosporidium in calves in some regions of France. The aim of this study was to detect and isolate Cryptosporidium spp. in faecal samples from naturally infected pre-weaned calves (≤45 days-old) in France. A total of 35 diarrhoeic pre-weaned calf faecal samples were collected from 26 dairy cattle farms in six departments (French administrative provinces). Cryptosporidium presence was established by microscopically screening samples for oocystes with an immunofluorescent (DFA) staining method. DFA-positive samples were then analysed by PCR-RFLP and 18S rRNA gene sequencing to determine species. Cryptosporidium parvum-positive samples were subtyped via nested PCR analysis of a partial fragment of the 60 kDa glycoprotein (gp60) gene product. Data were then integrated into phylogenetic tree analysis. DFA revealed the presence of Cryptosporidium oocysts in 31 out of 35 (88%) samples. Combined with 18S rRNA gene analysis results, C. parvum was detected in 30 samples. Subtyping analysis in 27/30 samples (90%) of the C. parvum isolates revealed two zoonotic subtype families, IIa (24/27) and IId (3/27). Four subtypes were recognised within the subtype family IIa, including the hypertransmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (21/27), IIaA17G3R1 (1/27), IIaA17G1R1 (1/27), and IIaA19G1R1 (1/27). Two subtypes were recognised within the IId subtype family including IIdA22G1 (2/27) and IIdA27G1 (1/27). These findings illustrate the high occurrence of Cryptosporidium in calves in dairy herds and increase the diversity of molecularly characterised C. parvum isolates with the first description of IIaA17G3R1, IIaA19G1R1, and IId subtypes in France. The presence of zoonotic C. parvum subtype families (IIa, IId) in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, and highlights the importance of animal to human cryptosporidiosis transmission risk. Further molecular studies in calves and small ruminants from other French regions are required to better understand the epidemiology of cryptosporidiosis in France.

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Faecal samples from pre-weaned diarrheal calves were analysed

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Cryptosporidium spp. was detected in 30 samples out of 35.

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C. parvum was the only species identified

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Two zoonotic subtype families were identified: IIa and IId

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The hyper-transmissible IIaA15G2R1 was the dominant C. parvum subtype

Shedding of Cryptosporidium in calves and dams: evidence of re-infection and shedding of different gp60 subtypes

One of the most common causes of calf diarrhoea is the parasite Cryptosporidium parvum. Two longitudinal studies were carried out on a dairy farm Scotland to determine the prevalence of Cryptosporidium species and subtypes in a group of calves and to determine whether dams were a possible source of calfhood infection. Fecal samples were collected from 25 calves from birth to 12 months in the first year. In the second year, fecal samples were collected from pregnant cows (n = 29) and their calves (n = 30) from birth to 6 months. The samples were tested for Cryptosporidium and speciated. Cryptosporidium parvum-positive samples were subtyped by GP60 fragment analysis. All calves in both studies shed Cryptosporidium during the study period. Cryptosporidium parvum was the predominant species detected in calves ⩽6 weeks of age and at 6 months of age, C. bovis and C. ryanae were detected in calves older than 4 weeks of age but ⩽6 months of age. The prevalence of Cryptosporidium was higher in younger animals than in older animals. GP60 subtyping revealed two subtypes in calves on this farm (IIaA15G2R1 and IIaA19G2R1) that differed in frequency by age. Adult cattle also shed C. parvum, of four gp60 genotypes.

Prevalence, Molecular Identification, and Risk Factors for Cryptosporidium Infection in Edible Marine Fish: A Survey Across Sea Areas Surrounding France

Cryptosporidium, a zoonotic pathogen, is able to infect a wide range of hosts including wild and domestic animals, and humans. Although it is well known that some parasites are both fish pathogens and recognized agents of zoonosis with a public health impact, little information is available concerning the prevalence of Cryptosporidium in wild aquatic environments. To evaluate the prevalence of Cryptosporidium spp. in commercially important edible marine fish in different European seas (English channel, North sea, Bay of Biscay, Celtic sea and Mediterranean sea), 1,853 specimens were collected as part of two surveys. Nested PCR followed by sequence analysis at the 18S rRNA gene locus was used to identify Cryptosporidium spp. The overall prevalence of Cryptosporidium spp. in sampled fish reached 2.3% (35 out of 1,508) in a first campaign and 3.2% (11 out of 345) in a second campaign. Sequence and phylogenetic analysis of positive samples identified Cryptosporidium parvum (n = 10) and seven genotypes which exhibited between 7.3 and 10.1% genetic distance from C. molnari, with the exception of one genotype which exhibited only 0.5–0.7% genetic distance from C. molnari. Among 31 analyzed fish species, 11 (35.5%) were identified as potential hosts for Cryptosporidium. A higher prevalence of Cryptosporidium spp. was observed in larger fish, in fish collected during the spring-summer period, and in those caught in the North East Atlantic. Pollachius virens (saithe) was the most frequently Cryptosporidium positive species. In fish infected by other parasites, the risk of being Cryptosporidium positive increased 10-fold (OR: 9.95, CI: 2.32–40.01.04, P = 0.0002). Four gp60 subtypes were detected among the C. parvum positive samples: IIaA13G1R1, IIaA15G2R1, IIaA17G2R1, and IIaA18G3R1. These C. parvum subtypes have been previously detected in terrestrial mammals and may constitute an additional source of infection for other animals and in particular for humans. Microscopical examination of histological sections confirmed the presence of round bodies suggestive of the development of C. parvum within digestive glands. We report herein the first epidemiological and molecular data concerning the detection of Cryptosporidium in edible marine fish in European seas surrounding France broadening its host range and uncovering potential novel infection routes.

Distribution of Cryptosporidium parvum gp60 subtypes in calf herds of Saxony, Germany

Cryptosporidiosis is a common protozoan parasitic infection that causes diarrhoea in neonatal calves. The high shedding of environmentally resistant oocysts facilitates outbreaks of cryptosporidiosis in humans. In total, 58 farms (512 calves) in Germany (Saxony and Brandenburg) were visited three times each. Faecal samples of pre-weaned calves were microscopically examined for oocysts of Cryptosporidium spp. using Heine staining and were scored with regard to their consistency. Overall, 88.9% of calves tested microscopically positive for Cryptosporidium spp. in at least one sample, and the excretion of oocysts was significantly (P < 0.01) associated with a higher faecal score (diarrhoea). After DNA extraction from pooled farm isolates, 47 samples were successfully subtyped by sequence analysis of the 60 kDa glycoprotein gene (gp60). All isolates belonged to subtype family IIa. IIaA15G2R1 was the most common subtype (present on 66% of the farms), followed by IIaA16G3R1 (13%). Subtypes IIaA14G1R1, IIaA14G2R1, IIaA1612R1, IIaA16G2R1, IIaA17G1R1, IIaA17G2R1, IIaA17G4R1 and IIaA19G2R1 were found sporadically. This is the first description of gp60 subtype IIaA17G4R1 in cattle in Germany.

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 spp. and Giardia spp. in feces and water and the associated exposure factors on dairy farms

The aims of this study were to verify the prevalence of Cryptosporidium spp. and Giardia spp. in animal feces and drinking water on dairy farms and to identify a possible relation between the exposure factors and the presence of these parasites. Fecal samples from cattle and humans and water samples were collected on dairy farms in Paraná, Brazil. Analysis of (oo)cysts in the feces was performed by the modified Ziehl-Neelsen staining and centrifugal flotation in zinc sulfate. Test-positive samples were subjected to nested PCR amplification of the 18SSU ribosomal RNA gene for identification of Cryptosporidium and Giardia and of the gp60 gene for subtyping of Cryptosporidium. Microbiological analysis of water was carried out by the multiple-tube method and by means of a chromogenic substrate, and parasitological analysis was performed on 31 samples by direct immunofluorescence and nested PCR of the genes mentioned above. Identification of the species of Cryptosporidium was performed by sequencing and PCR with analysis of restriction fragment length polymorphisms. The prevalence of Giardia and Cryptosporidium was higher in calves than in adults. Among the samples of cattle feces, Cryptosporidium parvum was identified in 41 (64%), C. ryanae in eight (12.5%), C. bovis in four (6.3%), C. andersoni in five (7.8%), and a mixed infection in 20 samples (31.3%). These parasites were not identified in the samples of human feces. Thermotolerant coliform bacteria were identified in 25 samples of water (45.5%). Giardia duodenalis and C. parvum were identified in three water samples. The gp60 gene analysis of C. parvum isolates revealed the presence of two strains (IIaA20G1R1 and IIaA17G2R2) in the fecal samples and one (IIaA17G2R1) in the water samples. The presence of coliforms was associated with the water source, structure and degradation of springs, rain, and turbidity. The prevalence of protozoa was higher in calves up to six months of age. C. parvum and G. duodenalis were identified in the water of dairy farms, as were thermotolerant coliforms; these findings point to the need for guidance on handling of animals, preservation of water sources, and water treatment.

Molecular characterization of zoonotic pathogens Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in calves in Algeria

Little is known on the identity and public health potential of Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in farm animals in Algeria. In this study, 102 fecal specimens from pre-weaned dairy calves with or without diarrhea were collected from 19 dairy farms located in 6 provinces. PCR-restriction fragment length polymorphism analysis of the small subunit rRNA gene was used to detect and differentiate Cryptosporidium spp., whereas PCR-sequence analysis of the triosephosphate isomerase gene and ribosomal internal transcribed spacer were used to detect and genotype G. duodenalis and E. bieneusi, respectively. Cryptosporidium was found in 14 specimens, among which 7 had C. parvum, 4 had C. bovis, and 3 had mixed infection of C. parvum and C. bovis or C. bovis and C. andersoni. Subtyping of C. parvum by PCR-sequence analysis of the 60kDa glycoprotein gene identified two zoonotic subtypes IIaA16G2R1 and IIaA17G3R1. G. duodenalis was found in 28 specimens, with 6 having the host-specific assemblage E, 14 having the zoonotic assemblage A (all belonging to A2 subtype), and 8 having mixed assemblages. Six known genotypes of E. bieneusi belonging to Group 2, including I, J, BEB3, BEB4, BEB6 and PtEb XI, were identified in 11 specimens. Diarrhea was mostly associated with the occurrence of C. parvum. Data from this study suggest that human-pathogenic C. parvum subtypes and G. duodenalis and E. bieneusi genotypes are common on dairy farms in Algeria.

Molecular analysis of Cryptosporidium from cattle from five states of Peninsular Malaysia

Despite the importance of the cattle industry in Malaysia, there are very few studies of the diversity and public health significance of bovine cryptosporidiosis in this country. In the present study, we used a PCR-based approach to detect and genetically characterize Cryptosporidium DNA in faecal samples from a cohort of 215 asymptomatic cattle (of different ages) from six farms from five states of Peninsular Malaysia. Cattle on four of the six farms were test-positive for Cryptosporidium, with an overall prevalence of 3.2%. Cryptosporidium bovis and Cryptosporidium ryanae were detected in two (0.9%) and five (2.3%) samples tested; this low prevalence likely relates to the age of the cattle tested, as most (73%) of the samples tested originated from cattle that were ≥2 years of age. Future studies should investigate the zoonotic potential of Cryptosporidium in pre-weaned and weaned calves in rural communities of Malaysia.

Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France

Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the observation of edible fillet contamination.

Cryptosporidium infections in suckler herd beef calves

A study was carried out to investigate how common Cryptosporidium infections are in beef calves in Swedish suckler herds and to explore which species and subtypes that occur. We further aimed at identifying factors associated with shedding of Cryptosporidium oocysts in this type of calf management. The study was conducted in two regions in Sweden and included 30 herds. Faecal samples were collected from calves younger than 3 months. A brief clinical examination was done and a questionnaire was used to collect data on management routines. Faeces were cleaned and concentrated and oocysts identified by epifuorescence microscopy. Cryptosporidium positive samples were analyzed at the 18S rRNA and GP60 genes to determine species and Cryptosporidium parvum subtype, respectively. Logistic regression was used to identify factors associated with infection. Oocysts were detected in 122 (36·7%) calves from 29 (97%) herds, at 400 to 2·4 × 10⁷ OPG. The youngest positive calves were only 1 and 2 days old. There was no association between age and Cryptosporidium infection. Cryptosporidium bovis, Cryptosporidium ryanae, C. parvum and Cryptosporidium ubiquitum were identified, with C. bovis being the major species. Two C. parvum subtypes, IIaA16G1R1 and IIdA27G1 were identified. Routines for cleaning calf pens and number of cows in calving pens were associated with infection.

Cryptosporidium parvum infection and associated risk factors in dairy calves in western France

This study was conducted to determine the prevalence and risk factors for Cryptosporidium infection in calf neonates on dairy farms in Normandy.

Fecal samples were randomly collected between July 2010 and September 2011 from 968 calves (7–21 days old) on 97 farms. Up to 10 calves were selected and sampled per farm, and feces examined for oocysts by microscopy. C. parvum oocyst shedding was scored semi-quantitatively (0–5). A questionnaire about calf-level care and management was completed, and mortality rates were obtained from the French national registration database (BDNI). Bivariable and multivariable analyses of potential risk factors for C. parvum oocyst shedding were conducted using generalized estimating equation (GEE) models (family = Binomial).Overall, 402 out of 968 calves (41.5%) were positive for oocysts, and 25.1% of animals had a shedding score >2. Seven of the 97 farms (7%) were negative for oocysts in all fecal samples. At the time of collection, 375 calves (39%) had diarrhea, and its prevalence strongly correlated with the score for C. parvum oocyst shedding (p < 0.0001). The mortality rate at 90 days was significantly greater for calves with high combined scores of diarrhea and shedding. Factors associated with the shedding of C. parvum were the Normande breed (odds ratio = 1.49; 95% confidence interval (CI): 0.93–2.37), dispensing of colostrum using a bucket (odds ratio = 1.37; 95% CI: 1.00–1.89), treatment with halofuginone (odds ratio = 0.46; 95% CI: 0.19–1.15) and feeding with fermented milk (odds ratio = 0.32; 95% CI: 0.17–0.63).

C. parvum is widespread among calves under 21 days old in dairy herds of western France. Shedding of C. parvum is associated with a high incidence of diarrhea and increased risk of mortality in young calves. This study identified some associated calf-level factors, although further investigations are necessary to determine appropriate measures that farmers and veterinary practitioners should take to reduce the prevalence of C. parvum.

Prevalence and Genetic Characterization of Cryptosporidium Spp. In Diarrheic Children from Gonbad Kavoos City, Iran

BACKGROUND

Cryptosporidium is an intestinal protozean parasite causing waterborne and foodborne outbreaks of diarrheal diseases. The present study was performed in order to find prevalence and subtypes of Cryptosporidium among children with diarrhea in Gonbad Kavoos City, Northern Iran.

METHODS

Diarrheic samples were collected from 547 children. The initial parasitological diagnosis was made based on detection of oocysts using the modified Ziehl-Neelsen acid-fast staining method. The positive microscopically samples were selected for sequence analysis of partial 60 kDa glycoprotein (gp60) gene.

RESULTS

Out of 547 collected samples, 27 (4.94%) were positive for Cryptosporidium oocysts. Fifteen from 27 positive samples successfully amplified in PCR. Sequences analysis of gp60 gene in 15 Cryptosporidium isolates revealed that all of them (100%) were C. parvum. The results showed three subtypes of IIa subtype family (7 cases) including IIaA16G2R1, IIaA17G1R1, IIaA22G3R1 and one subtype of IId subtype family (8 cases). The most common allele was IId A17G1d (53.3%).

CONCLUSION

The predominance of zoonotic subtype families of C. parvum species (IIa, IId) in the present study is in concordance with previous studies in Iran and emphasizes the significance of zoonotic transmission of cryptosporidiosis in the country.

Optimization of a fragment size analysis tool for identification of Cryptosporidium species and Gp60 alleles infecting domestic ruminants

A capillary electrophoresis (CE)-based DNA fragment analysis tool was optimized to identify in a single capillary the most common Cryptosporidium species and Cryptosporidium parvum GP60 alleles infecting domestic ruminants. For this purpose, a panel of genomic DNA samples including six Cryptosporidium species (C. parvum, C. bovis, C. ryanae, C. andersoni, C. ubiquitum, and C. hominis) and 18 C. parvum GP60 subtypes belonging to the subtype families IIa and IId was used. All these samples had been characterized previously by sequencing of SSU rRNA and GP60 genes. Isolates were re-amplified by PCR at these loci using sets of newly designed primers and subjected to CE. Fragment sizes were adjusted after comparison with sizes obtained by sequence analysis. The optimized CE-based approach provided fragments of different size for most Cryptosporidium species, but did not differentiate C. bovis and C. ryanae. Many of the GP60 subtypes (11/18) were also readily differentiated by CE, although overlapping in fragment sizes between IIa and IId subtypes was noticed. The CE-based tool was subsequently used to analyze Cryptosporidium isolates from naturally infected calves (n: 123) and lambs (n: 113) from farms in northern Spain. All isolates provided fragments typical of C. parvum. Fragment analysis at the GP60 locus differentiated a total of 10 alleles within isolates from calves (6 alleles) and lambs (8 alleles), with all but three alleles being host-associated. These findings support the validity of the optimized CE approach as a discriminatory and time- and cost-saving alternative to sequencing for identification of Cryptosporidium species and GP60 alleles in domestic ruminants.

Molecular characterization of Cryptosporidium isolates from beef calves under one month of age over three successive years in one herd in western France

Cohorts of pre-weaned calves were studied for Cryptosporidium infection over three successive years (2010–2012) in one beef cattle herd in western France. Each year 25–34 calves were sampled weekly from 3 days to one month of age in order to characterize oocyst output, Cryptosporidium species and clinical features associated with infection. Faecal samples were screened for the presence of oocysts using immunofluorescence analysis. DNA was extracted from positive samples and a PCR SSU rRNA followed by RFLP or sequencing was performed. For the subtyping of C. parvum, a gp60 PCR was carried out. Regardless of the year, 92–100% of the animals excreted oocysts on at least one sampling date. Depending on the year of observation, the age of highest prevalence varied. In contrast, the peak of excretion was systematically observed almost at the same age (2nd–3rd week of life) with excretion levels ranging from between 100 and 1.7 × 10⁷ oocysts/g of faeces. Differences concerning clinical signs depending on the year of sampling were observed. Different species patterns were observed, with a predominance of C. bovis in the 1st year and a predominance of C. parvum in the last year. Moreover, two zoonotic subtypes of C. parvum, IIaA15G2R1 and IIaA18G2R1, were recorded in different years. This study shows that, in a given farm, the Cryptosporidium species and C. parvum subtypes identified as well as the prevalence of infection and level of excretion may vary greatly and show distinct patterns according to the year.

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.

Prevalence and genetic characterization of Cryptosporidium in yaks in Qinghai Province of China

The objective of this study was to determine the prevalence, species and subtypes of Cryptosporidium infecting yaks in the Qinghai Province of Northwestern China. The prevalence of Cryptosporidium spp. was detected by microscopy and nested-PCR. A total of 586 fecal samples were collected from yaks in 6 counties, of which 142 (24.2%) samples tested positive for Cryptosporidium. The small subunit (SSU) rRNA gene of fifty-five samples were amplified and sequenced successfully and demonstrated that Cryptosporidium bovis (31/55, 56.4%) was the most common species, followed by C. parvum (16/55, 29.1%) and C. ryanae (5/55, 9.0%). Mixed infections of C. parvum and C. bovis (n = 2), C. ryanae and C. bovis (n = 1) were also detected. All three species were found in yaks ranging in age from <1 year, 1–2 years, to >2 years. Cryptosporidium was most commonly detected in spring (28.4%), followed by summer (20.9%), then winter (17.5%). Cryptosporidium parvum positive samples were subtyped using the 60 kDa glycoprotein (gp60) gene. Subtypes IIaA15G2R1 (n = 8), IIaA16G2R1 (n = 2), IIaA14G1R1 (n = 1), IIaA14G2R1 (n = 1) and IIaA16G3R1 (n = 1) were detected. All of these subtypes are zoonotic, and may pose a potential threat to human health.

Molecular characterization of Cryptosporidium isolates from pre-weaned calves in western France in relation to age

Eighteen pre-weaned female calves from a single beef cattle herd in western France were sampled weekly from birth to 21/2 months of age in order to characterize Cryptosporidium oocyst output. 182 fecal samples were screened for the presence of oocysts after concentration using immunofluorescence analysis. DNA was extracted from positive samples and a PCR-RFLP protocol, with the restriction enzyme SspI and MboII, to amplify the partial SSU rRNA gene was performed. For the subtyping of Cryptosporidium parvum, a gp60 PCR was carried out. All animals excreted oocysts at at least one sampling date and 80% of the calves presented a mild diarrhea at at least one occasion, with no mortality. The prevalence of excretion reached 94% when calves were 17-23 days of age. The mean number of oocysts at the peak of excretion (10-16 days) was 5 × 10(5) oocysts per gram of feces. PCR-RFLP analysis was successful for 61 of 84 positive samples: 14 were identified as C. parvum, 15 as Cryptosporidium bovis, and 22 as Cryptosporidium ryanae. Ten mixed infections with all combinations of these species were also identified. Calves excreted the following Cryptosporidium species: C. parvum between 7 and 27 days of age, C. bovis between 11 and 38 days and C. ryanae from 19 to 72 days. The IIaA15G2R1 zoonotic subtype of C. parvum subtype was the only subtype identified. We observed the presence of different Cryptosporidium species depending on the age of the animals. This study showed that C. parvum and C. bovis can infect beef calf neonates at similar levels of oocyst excretion with or without clinical signs and that C. parvum isolates had zoonotic potential.

Dynamics of excretion and molecular characterization of Cryptosporidium isolates in pre-weaned French beef calves

Studies on excretion and molecular characterization of Cryptosporidium have been mostly conducted in dairy calves, both diarrhoeic and non-diarrhoeic. Little is known about Cryptosporidium in beef calves, especially in non-diarrhoeic ones. This study was conducted in a herd of Parthenais beef cattle (France) with no history of clinical cryptosporidiosis. Twenty-five calves were sampled once a week from birth to one month of age (age range: 5-34 days). At each sampling date, presence of clinical signs of cryptosporidiosis (diarrhoea) was recorded. Oocyst excretion was assessed using the Heine staining method and a direct immunofluorescence method (Merifluor(®) C/G) which allowed quantification (oocysts per gram of faeces, opg). All samples were subjected to a two-step nested PCR protocol to amplify the 18S rRNA gene and amplification products were sequenced. None of the calves presented diarrhoea. Twenty-three of them excreted oocysts at least one sampling date. Prevalence of excretion was maximal when calves were 27-34 days old, with a percentage of excretion of 85% in this age category [95% CI: 70; 100]. Mean excretion was maximal when calves were 20 to 26 days old, with a mean excretion of 7.6×10(5) opg (range: 0-8×10(6) opg). 32 isolates were successfully identified: 27 as Cryptosporidium bovis, 4 as Cryptosporidium ryanae and 1 as Cryptosporidium parvum. C. bovis was isolated from samples of calves between 11 and 33 days old. C. ryanae was isolated from samples of calves between 17 and 34 days old. C. parvum was isolated from one calf aged 13 days. This survey demonstrated the high infection rate of non-diarrhoeic beef calves by Cryptosporidium species other than C. parvum.