Asymptomatic Cryptosporidium infections in ewes and lambs are a source of environmental contamination with zoonotic genotypes of Cryptosporidium parvum

Molecular Epidemiology of Cryptosporidiosis on Lamb and Goat Kid Farms in Gran Canaria, Canary Islands (Spain)

The aim of this study was to analyse and characterise Cryptosporidium spp. in sheep and goats in Gran Canaria (Spain) and to identify the risks and economic factors related to the disease. During sampling, a semi-structured survey was conducted with farmers, and faecal samples were collected from lambs, goat kids, sheep, and adult goats from a total of 30 farms. Adult samples were examined microscopically for the presence of Cryptosporidium spp. oocysts, with only three positive samples being found in sheep and one in goats. The PCR of the SSU rRNA gene was performed on all juvenile and adult samples, and positive samples from lambs (8.3%), sheep (6.9%), goat kids (23.3%), and goats (2.5%) were subjected to sequencing, detecting three of the most important species in small ruminants: C. parvum, C. xiaoi, and C. ubiquitum. By sequencing the GP60 PCR products, two subtypes of C. parvum belonging to the IId family were identified, IIdA16G1 and IIdA23G1, with the latter being the most frequent. Although the prevalence of the disease was not very high, the zoonotic potential of C. parvum and the limited awareness of the parasite among farmers make surveillance and health education focused on the control of this member of Apicomplexa necessary.

Genetic diversity of Cryptosporidium species from diarrhoeic ungulates in the United Arab Emirates

Cryptosporidiosis has previously been reported in animals, humans, and water sources in the United Arab Emirates (UAE). However, most reports were only to the genus level, or generically identified as cryptosporidiosis. We aimed to investigate the genetic diversity of Cryptosporidium species occurring in diarrhetic ungulates which were brought to the Central Veterinary Research Laboratory (CVRL) in Dubai. Using a combination of microscopic and molecular methods, we identified five species of Cryptosporidium occurring among ungulates in the UAE, namely C. parvum, C. hominis, C. xiaoi, C. meleagridis, and C. equi. Cryptosporidium parvum was the most prevalent species in our samples. Furthermore, we identified subtypes of C. parvum and C. hominis, which are involved in both human and animal cryptosporidiosis. This is also the first reported occurrence of Cryptosporidium spp. in the Arabian Tahr, to our knowledge. Since the animals examined were all in contact with humans, the possibility of zoonotic spread is possible. Our study correlates with previous reports in the region, building upon the identification of Cryptosporidium sp. However, there is a need to further investigate the endemic populations of Cryptosporidium, including more hosts, sampling asymptomatic animals, and location data.

Cryptosporidium spp. in large-scale sheep farms in China: prevalence and genetic diversity

Cryptosporidium spp. are significant zoonotic intestinal parasites that induce diarrhea and even death across most vertebrates, including humans. Previous studies showed that sheep are important hosts for Cryptosporidium and that its distribution in sheep is influenced by geography, feeding patterns, age, and season. Environmental factors also influence the transmission of Cryptosporidium. Molecular studies of Cryptosporidium in sheep have been conducted in only a few regions of China, and studies into the effect of sheep-housing environments on Cryptosporidium transmission are even rarer. To detect the prevalence of Cryptosporidium in large-scale sheep-housing farms, a total of 1241 fecal samples were collected from sheep, 727 environmental samples were taken from sheep housing, and 30 water samples were collected in six regions of China. To ascertain the existence of the parasite and identify the species of Cryptosporidium spp., we conducted nested PCR amplification of DNA extracted from all samples using the small-subunit (SSU) rRNA gene as a target. For a more in-depth analysis of Cryptosporidium spp. subtypes, C. xiaoi-and C. ubiquitum-positive samples underwent separate nested PCR amplification targeting the 60 kDa glycoprotein (gp60) gene. The amplification of the Cryptosporidium spp. SSU rRNA gene locus from the whole genomic DNA of all samples yielded a positive rate of 1.2% (20/1241) in fecal samples, 0.1% (1/727) in environmental samples, and no positive samples were found in water samples. The prevalence of Cryptosporidium spp. infection in large-scale housed sheep was 1.7%, which was higher than that in free-ranging sheep (0.0%). The highest prevalence of infection was found in weaning lambs (6.8%). Among the different seasons, the peaks were found in the fall and winter. The most prevalent species were C. xiaoi and C. ubiquitum, with the former accounting for the majority of infections. The distribution of C. xiaoi subtypes was diverse, with XXIIIc (n = 1), XXIIId (n = 2), XXIIIe (n = 2), and XXIIIl (n = 4) identified. In contrast, only one subtype, XIIa (n = 9), was found in C. ubiquitum. In this study, C. xiaoi and C. ubiquitum were found to be the predominant species, and Cryptosporidium was found to be present in the environment. These findings provide an important foundation for the comprehensive prevention and management of Cryptosporidium in intensively reared sheep. Furthermore, by elucidating the prevalence of Cryptosporidium in sheep and its potential role in environmental transmission, this study deepens our understanding of the intricate interactions between animal health, environmental contamination, and public health dynamics.

Molecular Detection and Distribution of Giardia duodenalis and Cryptosporidium spp. Infections in Wild and Domestic Animals in Portugal

Enteric protozoan parasites Giardia duodenalis, Cryptosporidium spp., and, to a lesser extent, the ciliate Balantioides coli are responsible for severe human and animal intestinal disorders globally. However, limited information is available on the occurrence and epidemiology of these parasites in domestic, but especially wild species in Portugal. To fill this gap of knowledge, we have investigated G. duodenalis, Cryptosporidium spp., and B. coli occurrence, distribution, genetic diversity, and zoonotic potential by analyzing 756 fecal samples from several wild carnivores (n = 288), wild ungulates (n = 242), and domestic species (n = 226) collected across different areas of mainland Portugal. Overall, infection rates were 16.1% (122/756; 95% CI: 13.59-18.96) for G. duodenalis and 2.7% (20/756; CI: 1.62-4.06) for Cryptosporidium spp., while no ungulate sample analyzed yielded positive results for B. coli. Giardia duodenalis was found across a wide range of hosts and sampling areas, being most prevalent in the Iberian lynx (26.7%), the Iberian wolf (24.0%), and the domestic dog (23.9%). Cryptosporidium spp. was only identified in wild boar (8.4%), red fox (3.4%), Iberian lynx (3.3%), red deer (3.1%), and Iberian wolf (2.5%). Sequence analysis of G. duodenalis determined zoonotic assemblage A (subassemblage AI) in one roe deer sample, canine-specific assemblages C and D in Iberian wolf, red fox, and domestic dog, and ungulate-specific assemblage E in wild boar, sheep, cattle, and horse. Six Cryptosporidium species were identified: C. scrofarum in wild boar, C. canis in the Iberian wolf and red fox, C. ubiquitum in red deer and wild boar, C. felis in the Iberian lynx, and both C. ryanae and C. occultus in red deer. Giardia duodenalis and Cryptosporidium spp. coinfections were observed in 0.7% (5/756) of the samples. This is the first, most comprehensive, and largest molecular-based epidemiology study of its kind carried out in Portugal, covering a wide range of wild and domestic hosts and sampling areas. The detection of zoonotic Cryptosporidium spp. and G. duodenalis subassemblage AI demonstrates the role of wild and domestic host species in the transmission of these agents while representing a potential source of environmental contamination for other animals and humans.

Persistence and survival of Cryptosporidium parvum oocysts on lamb's lettuce leaves during plant growth and in washing conditions of minimally-processed salads

Cryptosporidium is the causative agent of cryptosporidiosis, which results, among others, in profuse diarrhoea. Transmission to humans occurs via the faecal-oral route directly by contact with infected hosts or indirectly by waterborne or foodborne routes. For the latter, parasite transmission is closely linked to the oocyst's ability to persist and survive in food matrices. In this study, we evaluated the persistence and survival of Cryptosporidium oocysts in lamb's lettuce: i) during plant growth and ii) in conditions mimicking the industrial washing process applied in minimally-processed vegetables (MPV). Results show that oocysts persisted during the growth of lamb's lettuce, i.e. two months from the 2-leaf stage until the 8-leaf harvest time (-0.89 Log10 of oocysts). However, their survival decreased from as early as one week (-0.61 Log10), and only 6 % of oocysts remained infective at the time of harvest. The washing process had a limited effect on parasite load (<0.5 Log10) and no effect on survival; chlorination of washing water did not improve the efficiency (removal and inactivation) of the process. The ability of C. parvum to persist and survive throughout the food chain may drive its transmission to humans through MPV products. Appropriate management measures should be implemented at each operational level to limit contamination and ensure food safety of fresh produce.

Cryptosporidium in human-animal-environment interphase at Adama and Asella areas of Oromia regional state, Ethiopia

Background

In Ethiopia, several studies have reported the occurrence of Cryptosporidium infection in young calves, lambs, and HIV positive patients. However, research on cattle and sheep of all ages, as well as humans, has been limited.

Methods

A cross-sectional study was conducted to investigate the occurrence of Cryptosporidium in dairy cattle, sheep, humans, and manure samples. Dairy cattle and sheep were stratified according to their age groups and randomly sampled. Stool samples from volunteered dairy farm workers and rural household members were collected purposefully. A semi-structured questionnaire was also used to collect information about manure handling practices and socio-demographic variables. All collected samples were processed with the sugar floatation technique and the modified Ziehl–Neelsen staining method. Logistic regression was used to analyze the association of risk factors with the occurrence of Cryptosporidium in study subjects (p < 0.05).

Results

The overall prevalence of Cryptosporidium in dairy cattle, sheep, humans, and manure samples was 20.5%, 14%, 16%, and 13.20%, respectively. Cryptosporidium infection was significantly higher in dairy cattle aged 1–12 months and 13–36 months with odds of 3.48 and 3.07 times higher, respectively, compared to others. Similarly, its occurrence was 2.69 times higher in sheep aged 1–6 months than those above 6 months. And also, a higher average oocyst count (above 10 oocysts) per-field was observed in cattle aged 1–12 months, followed by sheep aged 1–6 months. Furthermore, the likelihood of infection was 13 times greater in farm workers compared to household members of smallholder farmers. In addition, the occurrence of oocysts was 22.8 times higher in manures from dairy cattle than that of sheep. About 16.8% of the study respondents had manure disposal pit, 98.1% of them used manure as fertilizer for crop and vegetable production without any treatment.

Conclusions

The study revealed the occurrence of Cryptosporidium infection in all age groups of dairy cattle and sheep, humans engaged in animal production. Occurrence of Cryptosporidium in manure suggests it potential contamination of environment and water sources.

The global prevalence of Cryptosporidium in sheep: a systematic review and meta-analysis

Cryptosporidium spp. are important pathogens with some species causing diarrhoea in humans and animals. Sheep are one of the most common potential hosts for various Cryptosporidium spp. The prevalence of Cryptosporidium in sheep globally was evaluated from published information including molecular data via meta-analysis. In total, 126 datasets from 41 countries were included for final quantitative analysis. Sheep aged <3 months had a significantly higher prevalence (27.8%; 3284/11 938) than those at the age of 3–12 and >12 months. The prevalence of Cryptosporidium in sheep with diarrhoea of 35.4% (844/1915) was higher than in sheep that did not show diarrhoea (11.3%; 176/1691). Fourteen Cryptosporidium species/genotypes were detected in sheep globally. The proportion of subgenotype family XIIa of Cryptosporidium ubiquitum was 90.0% (216/240); the proportions of subgenotypes IIdA20G1 and IIaA15G2R1 of Cryptosporidium parvum were 15.4% (62/402) and 19.7% (79/402). The results indicate that C. parvum is the dominant species in Europe while Cryptosporidium xiaoi is the dominant species in Oceania, Asia and Africa and C. ubiquitum is the dominant species in North America and South America. Subgenotype family IIa of C. parvum is particularly widespread among sheep worldwide. The results highlight the role of sheep as a reservoir host for zoonotic cryptosporidia and the need for further study of prevalence, transmission and control of this pathogen in sheep.

Small ruminants and zoonotic cryptosporidiosis

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