Global prevalence and risk factors of Cryptosporidium infection in Equus: A systematic review and meta-analysis

Investigation of Cryptosporidium spp. and Enterocytozoon bieneusi in free-ranged livestock on the southeastern Qinghai-Xizang Plateau, China

BACKGROUND

Cryptosporidium spp. and Enterocytozoon bieneusi are zoonotic pathogens with global distribution, infecting humans and various livestock. For yaks, Tibetan sheep and horses, the traditional grazing models still hold a main position. After these animals become infected, it not only hinders the development of animal husbandry but also increases the risk of Cryptosporidium spp. and E. bieneusi transmission between livestock and herdsmen.

METHODS

In the present study, a total of 750 fecal samples were collected from yaks, Tibetan sheep and horses in Shiqu County, Sichuan Province, from July to August 2023, and were analyzed by nested Polymerase chain reaction (PCR) amplification of the small subunit ribosomal RNA (SSU rRNA) gene of Cryptosporidium spp. and internal transcribed spacer (ITS) gene of E. bieneusi.

RESULTS

The prevalence of Cryptosporidium spp., and E. bieneusi were 2.1% (16/750) and 1.5% (11/750), respectively. Mixed infections of Cryptosporidium spp. and E. bieneusi were detected in two samples. Among these positive fecal samples, one Cryptosporidium species (Cryptosporidium suis) was identified in the yaks (n = 11), Tibetan sheep (n = 1), and horses (n = 4). Three E. bieneusi genotypes, including a known genotype BEB4 and two novel ones SQY1 and SQY2, were identified in the yaks (n = 7), while in Tibetan sheep (n = 4) only the known genotype BEB4 was detected. The novel genotype SQY1 was grouped into the human-pathogenic Group 1, and the known genotype BEB4 and the novel genotype SQY2 were grouped into Group 2. Enterocytozoon bieneusi was not detected in horses.

CONCLUSIONS

Cryptosporidium suis was identified in yaks and horses while zoonotic E. bieneusi genotype BEB4 in Tibetan sheep for the first time, expanding their host ranges. These findings suggested that yaks, Tibetan sheep and horses could act as potential sources of human Cryptosporidium spp. and E. bieneusi infections, implying that the presence of zoonotic species/genotypes could pose a threat to public health.

Cryptosporidium in Rabbits: A Global Systematic Review and Meta-Analysis of Prevalence, Species/Genotypes Distribution and Zoonotic Significance

BACKGROUND

This systematic review and meta-analysis assessed the global prevalence, species/genotype distribution and zoonotic impact of Cryptosporidium in rabbits.

METHODS

A systematic search of PubMed, Scopus and Web of Science was performed for studies from 2000 to 25 October 2024 on Cryptosporidium spp. in rabbits. Data on publication/implementation years, prevalence rates, rabbit types, diagnostics, countries and species/genotypes were collected. A meta-analysis with random-effects models estimated overall prevalence and assessed heterogeneity using the I2 index. A sensitivity analysis evaluated the robustness of the results.

RESULTS

This systematic review included 26 studies with 6093 rabbits from 9 countries, revealing a pooled Cryptosporidium spp. prevalence of 9% (95% CI: 6%-13.4%). Three zoonotic species were found in rabbits: Cryptosporidium cuniculus in 18 studies and each of C. parvum and C. andersoni in 1 study. The isolates included 2 genotypes of C. cuniculus (Va, Vb) and 1 genotype of C. parvum (IIc), along with 18 subtypes of C. cuniculus (VaA16, VaA18, VaA31, VbA18, VbA19, VbA21, VbA22, VbA23, VbA24, VbA25, VbA26, VbA28, VbA29, VbA31, VbA32, VbA33, VbA35 and VbA36). Among these, 11 subtypes (VbA19, VbA22-VbA26, VbA28, VbA29 and VbA31-VbA33) are identified as zoonotic. Pet rabbits had the highest Cryptosporidium spp. pooled prevalence at 21.9% (95% CI: 14.7%-31.3%), followed by farmed rabbits at 9.7% (95% CI: 5.1%-17.8%), wild rabbits at 8.8% (95% CI: 4.8%-15.5%) and laboratory rabbits at 1% (95% CI: 0.3%-3.1%), with higher rates noted in Africa and the AFR WHO region.

CONCLUSIONS

This study assessed the global distribution of Cryptosporidium spp. in rabbits, highlighting its zoonotic implications. It serves as a key resource for researchers, veterinarians and public health officials for future studies and control strategies.

Global prevalence of Eimeria species in goats: a systematic review and meta-analysis

Background

Coccidiosis is a protozoal disease caused by Eimeria species, the main symptom of which is diarrhea. Eimeria spp. infection can cause weight loss and ill-thrift in goats, and in severe cases, it can lead to mortality in kids, resulting in economic losses for the goat industry. This study aimed to determine the global prevalence of Eimeria spp. in goats and to identify the possible predictors of heterogeneity among selected studies.

Methods

Data were retrieved from five databases of major global importance (PubMed, Web of Science, CAB Direct, Scopus, and Google Scholar), with 255 studies published between 1963 and 2022 being included. A random-effects model was used to calculate pooled prevalence estimates with 95% confidence intervals (CI), followed by subgroup meta-analysis and meta-regression analysis to identify factors contributing to high prevalence and explore sources of heterogeneity among studies.

Results

The estimated global prevalence of Eimeria spp. in goats was 62.9% (95% CI: 58.6-67.2). Our results indicated high inter-study variability (inconsistency index (I2) = 99.7%, p < 0.01). Among the variables analyzed, regions and quality of studies were the most significant predictors of heterogeneity. According to the region-based subgroup meta-analysis, North America had the highest estimated prevalence of Eimeria spp. (92.2, 95% CI: 82.7-98.2), followed by Europe (86.6, 95% CI: 79.8-92.3), while Asia had the lowest prevalence (52.0, 95% CI: 45.9-58.1). Most countries (n = 42/56) had an estimated prevalence above the overall pooled estimate (>62.9%). The subgroup of studies conducted in 2000 or later presented a lower prevalence of 59.6% (95% CI: 54.7-64.3). Studies with a score of 5-7 had a significantly higher prevalence (72.4, 95% CI: 66.2-78.2) than studies with low or medium scores (p < 0.01). The prevalence of Eimeria spp. in goats detected with conventional and molecular methods was 67.3% (95% CI: 47.0-84.7). Only 47% (119/255) of the studies provided details on identifying Eimeria at the species level. Overall, more than 26 Eimeria spp. have been identified in goats globally. Among these, the most frequently reported and pathogenic species were E. arloingi (115/119), E. ninakohlyakimovae (108/119), E. christenseni (94/119), and E. caprina (71/119). Other valid species that were reported less frequently include E. alijevi, E. hirci, E. caprovina, E. aspheronica and E. jolchijevi.

Conclusion

These findings suggest that the pathogenic Eimeria spp. are widespread in goats globally. Given the high prevalence and the extensive distribution of pathogenic Eimeria spp. in goats, it is recommended that integrated parasite management approaches be implemented for the effective control of coccidiosis in goats.

Prevalence and Molecular Characterization of Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in Donkeys of Inner Mongolia, Northern China

BACKGROUND

Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are important zoonotic pathogens. In Inner Mongolia, a single pathogen molecular epidemiological survey of these three protozoa was previously conducted on only 176 fecal samples donkeys. In this study, the purpose is to simultaneously evaluate the zoonotic potential of three protozoa.

METHODS

Small subunit ribosomal RNA (SSU rRNA) and gp60 from Cryptosporidium; SSU rRNA, gdh, tpi, and bg from G. duodenalis; and ITS of E. bieneusi were analyzed in 300 fecal samples collected from donkeys from two intensive farms in Inner Mongolia in 2022. Sample processing, nucleic acid extraction, polymerase chain reaction, sequencing, and sequence analysis were performed to determine the prevalence and genetic characteristics of the protozoans.

RESULTS

Our results revealed that 75.33% (226/300) of the samples were infected with at least one protozoan, whereas 2.33% (7/300) were simultaneously infected with all three genera. Mixed infection was observed in 20.67% (62/300; Cryptosporidium + G. duodenalis), 5.33% (16/300; Cryptosporidium + E. bieneusis), and 5.67% (17/300; G. duodenalis + E. bieneusis) of the samples. Overall prevalence of Cryptosporidium, G. duodenalis, and E. bieneusi was 56.33% (169/300), 36.33% (109/300), and 13.33% (40/300), respectively. Five Cryptosporidium species were identified, with C. andersoni being the predominant species. The C. parvum subtypes identified were IIdA20G1 (66.67%) and IIdA19G1 (33.33%). Three G. duodenalis assemblages were identified, with assemblage B being predominant. Seven isolates formed two different assemblage B MLGs, two different assemblage A MLGs, and two different assemblage B + E MLGs. Three known and eight novel sequences of E. bieneusis were identified in group 1 (including horse1 and NMG6-NMG8) and group 2 (including J, BEB6, and NMG1-NMG5), with horse1 being the predominant genotype.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate that donkeys can be infected with a combination of two or three protozoa, with C. andersoni being the most detected Cryptosporidium species. Meanwhile, assemblage B was predominant among G. duodenalis, whereas horse1 was the dominant genotype for E. bieneusi. Moreover, the prevalence of C. bovis, C. ryanae, C. suis, C. parvum subtype IIdA20G1 and eight novel sequences of E. bieneusis and new features of G. duodenalis assemblages were identified in donkeys for the first time. These findings reconfirmed that donkeys in Inner Mongolia are infected with these three protozoa, emphasizing the risk of disease transmission by these protozoans to humans.

Evaluating prevalence, risk factors, and diagnostic techniques for Cryptosporidium infection in goats and surrounding water sources

Background

Cryptosporidium spp. are protozoan parasites that infect the gastrointestinal tract of various animals, including goats, and can also contaminate water sources, posing a significant public health risk. Detecting Cryptosporidium oocysts in fecal and water samples is critical for understanding the epidemiology of cryptosporidiosis and implementing appropriate control measures. Various staining methods, such as the Modified Ziehl-Neelsen (ZN) and Kenyon's Acid-Fast (KAF) staining techniques, are employed to identify these oocysts. This study compared the effectiveness of these two staining methods in detecting Cryptosporidium oocysts in goat feces and water samples across different geographic regions in district of Mardan, Khyber Pakhtunkhwa, Pakistan, and other factors such as genders, age groups, diarrheal statuses, and feeding regimes.

Methods

A total of 300 fecal and 300 water samples were collected from goats and water sources in four geographic regions: Tehsil Katlang, Tehsil Takhtbhai, Tehsil Mardan, and Tehsil Lundkhwarh. Samples were categorized based on gender, age group (<1 year, 1-2 years, and >2 years), diarrheal status, and feeding regime (stall feeding, grazing). The two staining methods, ZN and KAF staining, were employed to detect Cryptosporidium oocysts. The detection rates were calculated, and statistical analyses were performed to compare the effectiveness of the two methods across different categories.

Results

The overall detection rates of Cryptosporidium oocysts for fecal samples were 61.00% (95% CI: 55.22-66.55%) using the ZN method and 63.33% (95% CI: 57.60-68.79%) using KAF method, with no significant difference (p > 0.05). The highest detection rate was observed in Tehsil Katlang (70.66%) with the ZN method and in both Tehsil Katlang and Takhtbhai (66.66%) with the KAF staining method, having no significant difference (p > 0.05). Gender-wise analysis in fecal samples showed similar detection rates for males and females, with no significant differences. Age-wise, the highest detection rates were found in the youngest age group (<1 year) using the ZN method, and in the oldest age group (>2 years) using KAF staining, with no significant differences between age groups. Diarrheal status analysis indicated higher detection rates in diarrheic goats for both methods, with the highest detection rate in the diarrheic group of Tehsil Katlang (84.61%) using the ZN method. Feeding regime analysis showed no significant differences between stall-fed and grazing goats. For water samples, the detection rates of Cryptosporidium oocysts were significantly different between the two methods. The ZN technique had a significantly higher overall detection rate of 16.00% (95% CI: 12.03-20.64%) compared to 1.00% (95% CI: 0.20-2.89%) for KAF staining (p < 0.001). The performance of the two staining methods for the detection of Cryptosporidium oocysts in contaminated water samples from different geographic regions was also presented.

Conclusion

Both ZN and KAF staining methods are effective for detecting Cryptosporidium oocysts in goat feces. However, in water samples, the ZN method showed a significantly higher detection rate compared to KAF staining method, suggesting its suitability for environmental surveillance. These findings highlight the importance of integrating reliable diagnostic techniques with public health interventions to mitigate the zoonotic risks of cryptosporidiosis.

Prevalence of Cryptosporidium spp. infection in rodents and chickens in Franceville, Gabon

Background and Aim

Cryptosporidium spp. members of the phylum Apicomplexa are obligate protozoan parasites capable of infecting various vertebrate hosts, including rodents and chickens. Infection caused by these parasites may lead to zoonotic diseases in humans. The aim of this study was to estimate the prevalence of Cryptosporidium spp. in rodents and domestic chickens sampled in Franceville, Gabon.

Materials and Methods

Two hundred and eighty-five samples were collected, of which 185 samples were from rodents and 100 from domestic chickens. Microscopy after modified Ziehl-Neelsen staining and nested polymerase chain reaction targeting the small subunit (SSU) rRNA gene were used to examine Cryptosporidium spp.

Results

The overall prevalence of Cryptosporidium oocysts was 55.8%, with a prevalence of 72.4% in rodents and 25.0% in domestic chickens. Molecular analysis showed that Cryptosporidium spp. were present in 4.0% of the samples. No significant correlation was observed between Cryptosporidium spp. carriage and sex or location in this study. These results indicate that Cryptosporidium spp. persist and circulate in the studied animal species in Franceville, Gabon.

Conclusion

Infection with Cryptosporidium is very common in rodents and chickens in Franceville. The potential risk of human contamination cannot be ruled out. More research should be conducted to characterize Cryptosporidium species circulating in rodents and chickens in Gabon. Such studies are essential to better understand the epidemiology of this protozoan and its potential impact on public health.

Prevalence and potential risk factors for Cryptosporidium spp. infection in horses from Egypt

Cryptosporidium is an intestinal protozoan that cause diarrhea in livestock all over the world and have zoonotic importance. The present study aimed to determine the prevalence of Cryptosporidium spp. in horses in Egypt and evaluate the associated risk factors. A total of 420 fecal samples were collected from three governorates (Giza, Kafr ElSheikh and Qalyubia) and examined microscopically using Ziehl-Neelsen staining method. The overall prevalence of Cryptosporidium spp. was 29% and Kafr ElSheikh governorate had the highest rate in comparison to other areas. The prevalence of Cryptosporidium spp. in examined horses had significant association with sex, age, type of management, absence of bedding and presence of dogs. The higher prevalence rate was observed in females (32.2%), age group less than two years (43.2%), mixed (grazing and stable) horses (36.1%), animals had history of diarrhea (33%), absence of bedding (35.1%) and contact with dogs (35.7%). These findings give baseline data for further research. It is necessary to establish control strategy for Cryptosporidium spp. infection in order to lower the risk of infection in animals and human.

Anti-Cryptosporidium oocysts polyclonal antibodies for cryptosporidiosis diagnosis and protection

Cryptosporidiosis is an intestinal infection that is triggered by the protozoan parasite Cryptosporidium spp. Cryptosporidium oocysts can spread from one host to another either through direct contact with infected hosts' faeces or through indirect means (consumption of contaminated water or food). Significant numbers of oocysts are produced as a result of the rapid growth of the parasite within the infected hosts. For proper care of cryptosporidiosis, a laboratory diagnosis is necessary. Therefore, this study aimed to produce anti-Cryptosporidium parvum (C. parvum) oocyst immunoglobulin (Ig)G polyclonal antibodies (pAbs). The produced pAbs were used in the detection of C. parvum oocysts antigens in stool and serum samples of infected calves. Moreover, pAbs were tested in protection of balb-c male mice from cryptosporidiosis infection. C. parvum oocysts were used in the preparation of antigens to be used in the immunization of New Zealand white rabbits. pAb was purified by ammonium sulphate precipitation method, caprylic acid purification method and diethylaminoethyl (DEAE) anion exchange chromatographic method. Sandwich enzyme-linked immunosorbent assay (ELISA) (using prepared pAb) scored higher sensitivity (85% and 95% for serum and stool samples) than that (80%) of microscopic examination of stool samples. Moreover, pAb significantly reduced the oocysts shedding, decreased inflammatory cytokines and enhanced the loss in the body weight of protected animals. The prepared pAb succeeded in the diagnosis of cryptosporidiosis in calves with high sensitivity either in the serum or stool samples. Our results indicated the usefulness of using the prepared pAb in protection against cryptosporidiosis.

Epidemiology of Cryptosporidium Infection in Romania: A Review

Since 1983, when the first report of a human Cryptosporidium spp. infection was published in Romania, and until now, many studies on cryptosporidiosis have been published in our country, but most of them are in the Romanian language and in national journals less accessible to international scientific databases. Although the infection was first recognized as a problem in children or immunocompromised people or more of a problem in low-income or underdeveloped global countries, we have shown in this review that it can also occur in people with normal immunological function and that the epidemiology of our country can provide a theoretical basis for the formulation of a Cryptosporidium spp. prevention strategy. In addition, 9.1% of healthy children and 73% of immunocompromised children were observed to have Cryptosporidium spp. infections. Higher rates have also been reported in immunocompromised adults (1.8-50%). Analyzing the prevalence of Cryptosporidium spp. infection in animals, we found values of 28.52% in cattle, 18% in buffalo calves, between 27.8 and 60.4% in pigs, 52.7% in dogs, and 29.4% in cats. Furthermore, in Romania, the burden of cryptosporidiosis, including acute infections and long-term sequelae, is currently unknown.