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

Epidemiological investigation of Cryptosporidium in children with diarrhea in middle Inner Mongolia, China

Cryptosporidia (Cryptosporidium) is a protozoan that is widely parasitic in the intestinal cells of humans and animals, and it is also an important zoonotic parasite. However, there is no epidemiological investigation on Cryptosporidium spp. infection in infants with diarrhea of Inner Mongolia, the largest livestock region in China. To investigate the prevalence of Cryptosporidium, 2435 fresh fecal samples were collected from children with diarrhea in Inner Mongolia Maternal and Child Health Care Hospital. Molecular characterization of Cryptosporidium was carried out based on its 18S rRNA and gp60 gene sequences. The overall prevalence was 12.85% (313/2435), and in Hohhot (12.15%), it was lower than that in the surrounding city (14.87%) (P < 0.05). Moreover, Cryptosporidium was detected in different seasons and sexes. Concerning the age of children with diarrhea, the prevalence of those age groups between 0 and 1 was obviously lower than others, and there were significant differences in the prevalence at different ages (P < 0.001). Analysis of the 18S rRNA gene sequence revealed that all the positive samples were Cryptosporidium parvum, and there were 5 subtypes (IIdA23G3, IIdA24G3, IIdA24G4, IIdA25G3, and IIdA25G4). To the best of our knowledge, the above subtypes have not been reported. Our results provide a relevant basis for control and education on food safety and foodborne illness prevention.

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

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

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

Longitudinal follow-up reveals occurrence of successive Cryptosporidium bovis and Cryptosporidium ryanae infections by different subtype families in dairy cattle

Cryptosporidium bovis and Cryptosporidium ryanae are common species causing cryptosporidiosis in cattle. Data accumulated thus far indicate that the infection patterns of the two species could be different between areas with and without Cryptosporidium parvum. To better understand the infection dynamics of these two species, cross-sectional and longitudinal studies of Cryptosporidium spp. were conducted using genotyping and subtyping tools. In the cross-sectional survey, analysis of 634 faecal samples from two farms identified only C. bovis and C. ryanae in pre-weaned calves. Two birth cohorts of 61 and 78 calves were followed longitudinally over a 12 month period, which revealed the shedding of C. bovis oocysts started at 1-2 weeks of age and peaked initially at 6-8 weeks of age. Altogether calves experienced four infections by six subtype families of C. bovis, with each infection caused by different subtype families. In contrast, the shedding of C. ryanae oocysts started at 2-4 weeks of age, and the two infections were caused by different subtype families. The cumulative incidence of C. bovis infection was 100% (58/58, 32/32) on both farms, compared with 84.4-98.3% (27/32 and 57/58) for C. ryanae infection. Overall, the mean duration of oocyst shedding in the cohort studies was 3.8-4.0 weeks for C. bovis compared with 2.1 weeks for C. ryanae. The oocyst shedding intensity was high (mean oocysts per gram of faeces was over 105) during the first infection with each species but became significantly lower in the later infections. Cryptosporidium ryanae was associated with the occurrence of diarrhea on one farm, while C. bovis was not. The data indicate that there is an early occurrence of C. bovis and C. ryanae in pre-weaned calves with high infection intensity in the absence of C. parvum. Calves infected with the same Cryptosporidium sp. multiple times could be associated with the presence of subtype-specific immunity.

Prevalence of Cryptosporidium infection in children from China: a systematic review and meta-analysis

Cryptosporidium is an important zoonotic pathogen that causes diarrhea in humans and animals, and a leading cause of diarrhea morbidity and mortality in children under 5 years old. However, the meta-analysis of Cryptosporidium infection in children in China has not been published. We searched the databases for articles published on the prevalence of Cryptosporidium infection in children in China since the inception of these databases to 31 October 2022. The prevalence of Cryptosporidium infection in children was estimated using a random effects model. The results showed that 111 datasets from 24 provinces were selected for the final quantitative analysis. The estimated pooled Cryptosporidium infection prevalence in children in China was 2.9% (3300/126,381). The highest prevalence rate was in southwestern China (4.8%, 365/7766). Subgroup analysis indicated that the Cryptosporidium infection rate in children aged < 3 years (4.9%, 330/8428) was significantly higher than that in children aged 3-6 years (2.5%, 609/26,080) and >6 years (2.6%, 647/27,586). Six Cryptosporidium species were detected in children in China from the selected studies. C. hominis was the dominant species (77.1%, 145/188) and the proportions of subgenotype IaA14R4 of C. hominis was highest (42.8%, 62/145). The findings suggest that Chinese children is in a low level of Cryptosporidium infection, however, the geographical distribution of the infection is extensive. We suggest that measures should be taken to ensure the healthy growth of Chinese children by improving the water environment, increasing public health facilities, strengthening children's health education, and developing sound Cryptosporidium infection control programs.

Molecular identification and genetic characteristics of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in human immunodeficiency virus/acquired immunodeficiency syndrome patients in Shanghai, China

BACKGROUND

Opportunistic infections are a ubiquitous complication in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are common opportunistic intestinal pathogens in humans. In China, despite the number of HIV/AIDS patients being extremely large, only a few studies have investigated opportunistic infections caused by intestinal pathogens in this patient population. The aims of this study were to elucidate the occurrence and genetic characteristics of Cryptosporidium spp., G. duodenalis, and E. bieneusi in HIV/AIDS patients.

METHODS

We collected fecal specimens from 155 HIV/AIDS patients (one from each patient). All of the specimens were examined for the presence of the pathogens by genotyping using polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene for Cryptosporidium spp.; the triosephosphate isomerase, β-giardin and glutamate dehydrogenase genes for G. duodenalis; and the internal transcribed spacer region of the rRNA gene for E. bieneusi. The Cryptosporidium-positive specimens were further subtyped by polymerase chain reacion and sequencing of the 60-kDa glycoprotein gene.

RESULTS

Six (3.9%), three (1.9%), and eight (5.2%) HIV/AIDS patients were positive for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. No statistical differences were observed in occurrence rate between the groups by gender, clinical symptom (diarrhea), and CD4⁺ cell count. Four Cryptosporidium species were identified: Cryptosporidium hominis (n = 2), Cryptosporidium parvum (n = 1), Cryptosporidium meleagridis (n = 1), and Cryptosporidium andersoni (n = 2). Furthermore, two C. hominis subtypes (IeA12G3T3 and IaA28R4) were detected. Three G. duodenalis-positive specimens were successfully amplified and sequenced at the triosephosphate isomerase and β-giardin loci, which led to the identification of assemblages C and B, respectively. Seven genotypes (D, Type IV, EbpC, Peru11, EbpD, A, and I) were identified in E. bieneusi-positive specimens.

CONCLUSIONS

Our findings should increase awareness of AIDS-related opportunistic intestinal pathogens, and indicate the need for routine examination in clinical practice for the detection of Cryptosporidium spp., G. duodenalis, and E. bieneusi. Homology analyses of the three intestinal pathogens at the nucleotide and/or amino acid levels indicated their zoonotic potential.

Genetic diversity of Cryptosporidium species in Njoro Sub County, Nakuru, Kenya

Cryptosporidium spp. cause cryptosporidiosis in humans through zoonotic and anthroponotic transmission. Previous studies illustrated the significance of domestic animals as reservoirs of this parasite. Cryptosporidium occurs in Njoro River; a main source of water to humans and animals. However, there is no information on the Cryptosporidium spp. and genotypes circulating in Njoro Sub County. A total of 2174 samples from humans, cattle, chickens, sheep and goats were assessed for the presence of Cryptosporidium spp. Thirty-three positive samples were subsequently successfully sequenced and compared to Cryptosporidium sequences in the GenBank repository using NCBI's (National Center for Biotechnology Information) online BLAST (Basic Local Alignment Search Tool) algorithmic program. Sequence alignment was done using the Clustal W program and phylogenetic analysis was executed in MEGA X (Molecular Evolutionary Genetics Analysis version X). The prevalence of cryptosporidiosis in Njoro Sub County is 6.99%. Cryptosporidium spp. present in the watershed showed great genetic diversity and nine Cryptosporidium species were recorded: Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium ubiquitum, Cryptosporidium meleagridis, Cryptosporidium andersoni, Cryptosporidium baileyi, Cryptosporidium muris, Cryptosporidium xiaoi and Cryptosporidium viatorum. This is the first study to report the presence of C. viatorum in Kenya. Cattle is the major reservoir of zoonotic Cryptosporidium spp. while goats harbored the lowest number of species. Humans and domestic animals drink the contaminated water from Njoro River, humans are therefore, exposed to a high cryptosporidiosis risk.

An Update on Zoonotic Cryptosporidium Species and Genotypes in Humans

The enteric parasite, Cryptosporidium is a major cause of diarrhoeal illness in humans and animals worldwide. No effective therapeutics or vaccines are available and therefore control is dependent on understanding transmission dynamics. The development of molecular detection and typing tools has resulted in the identification of a large number of cryptic species and genotypes and facilitated our understanding of their potential for zoonotic transmission. Of the 44 recognised Cryptosporidium species and >120 genotypes, 19 species, and four genotypes have been reported in humans with C. hominis, C. parvum, C. meleagridis, C. canis and C. felis being the most prevalent. The development of typing tools that are still lacking some zoonotic species and genotypes and more extensive molecular epidemiological studies in countries where the potential for transmission is highest are required to further our understanding of this important zoonotic pathogen. Similarly, whole-genome sequencing (WGS) and amplicon next-generation sequencing (NGS) are important for more accurately tracking transmission and understanding the mechanisms behind host specificity.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021)

The protozoan parasites Cryptosporidium and Giardia are significant causes of diarrhoea worldwide and are responsible for numerous waterborne and foodborne outbreaks of diseases. Over the last 50 years, the development of improved detection and typing tools has facilitated the expanding range of named species. Currently at least 44 Cryptosporidium spp. and >120 genotypes, and nine Giardia spp., are recognised. Many of these Cryptosporidium genotypes will likely be described as species in the future. The phylogenetic placement of Cryptosporidium at the genus level is still unclear and further research is required to better understand its evolutionary origins. Zoonotic transmission has long been known to play an important role in the epidemiology of cryptosporidiosis and giardiasis, and the development and application of next generation sequencing tools is providing evidence for this. Comparative whole genome sequencing is also providing key information on the genetic mechanisms for host specificity and human infectivity, and will enable One Health management of these zoonotic parasites in the future.

Prevalence and Characterization of Cryptosporidium Species in Tibetan Antelope (Pantholops hodgsonii)

Cryptosporidium is an enteric apicomplexan parasite, which can infect multiple mammals including livestock and wildlife. Tibetan Antelope (Pantholops hodgsonii) is one of the most famous wildlife species, that belongs to the first class protected wild animals in China. However, it has not been known whether Tibetan Antelope is infected with Cryptosporidium so far. The objective of the present study was to determine the prevalence and characterization of Cryptosporidium species infection in Tibetan Antelope and the corresponding species by using molecular biological method. In the current study, a total of 627 fecal samples were randomly collected from Tibetan Antelope in the Tibet Autonomous Region (2019–2020), and were examined by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene. Among 627 samples, 19 (3.03%, 19/627) were examined as Cryptosporidium-positive, with 7 (2.33%, 7/300) in females and 12 (3.67%, 12/327) in males. The analysis of SSU rRNA gene sequence suggested that only two Cryptosporidium species, namely, C. xiaoi and C. ubiquitum, were identified in this study. This is the first evidence for an existence of Cryptosporidium in Tibetan Antelope. These findings extend the host range for Cryptosporidium spp. and also provide important data support for prevention and control of Cryptosporidium infection in Tibetan Antelope.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.

The Age-Related Cryptosporidium Species Distribution in Asymptomatic Cattle from North-Western SPAIN

Simple Summary

An age-related distribution of Cryptosporidium species has been reported in cattle, with the pathogenic and zoonotic C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Unravelling the age-related species distribution pattern in cattle from a particular region will allow determining those age classes posing a higher risk to public and animal health. Thus, fecal samples from asymptomatic cattle were collected in north-western Spain. Cryptosporidium detection and species identification was performed by molecular methods. Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium andersoni, C. bovis, C. occultus, C. parvum, C. ryanae and C. xiaoi were identified. Cryptosporidium parvum was predominant in calves younger than 1 month and C. bovis was predominant in the rest of the age groups. The presence of C. parvum in all age groups implies animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are needed to identify those factors determining the species distribution.

Abstract

An age-related distribution of Cryptosporidium species has been reported in cattle, with C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Thus, fecal samples (n = 594) from asymptomatic cattle were collected in north-western Spain. Animals were classified as <1 month (G1), 1–2 months (G2), 2–12 months (G3), 12–24 months (G4) and >2 years (G5). Cryptosporidium detection and species identification were performed by SSU rRNA PCR. Individual Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium parvum was predominant in G1 and C. bovis was predominant in the rest of the age classes; C. bovis and C. ryanae were especially prevalent in G2 and G3. Cryptosporidium occultus was not found in suckling calves. Finally, C. andersoni and C. xiaoi were occasionally detected in G5. The presence of C. parvum in all age classes implies significant animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are still needed to identify those factors determining the species distribution.

Identification of Uncommon Cryptosporidium viatorum (a Novel Subtype XVcA2G1c) and Cryptosporidium andersoni as Well as Common Giardia duodenalis Assemblages A and B in Humans in Myanmar

Cryptosporidium and Giardia are two important zoonotic intestinal protozoa responsible for diarrheal diseases in humans and animals worldwide. Feces from infected hosts, water and food contaminated by Cryptosporidium oocysts and Giardia cysts as well as predictors such as poverty have been involved in their transmission. Myanmar is one of the world’s most impoverished countries. To date, there are few epidemiological studies of Cryptosporidium and Giardia in humans. To understand the prevalence and genetic characterization of Cryptosporidium spp. and Giardia duodenalis in humans in Myanmar, a molecular epidemiological investigation of the two protozoa was conducted in four villages of Shan State. 172 fecal specimens were collected from Wa people (one each) and identified for the presence of Cryptosporidium spp. and G. duodenalis by sequence analysis of their respective small subunit ribosomal RNA genes. 1.74% of investigated people were infected with Cryptosporidium spp.—C. andersoni (n = 2) and C. viatorum (n = 1) while 11.05% infected with G. duodenalis—assemblages A (n = 6) and B (n = 13). By sequence analysis of 60-kDa glycoprotein gene, the C. viatorum isolate belonged to a novel subtype XVcA2G1c. DNA preparations positive for G. duodenalis were further subtyped. Five of them were amplified and sequenced successfully: different assemblage B sequences (n = 2) at the triosephosphate isomerase (tpi) locus; sub-assemblage AII sequence (n = 1) and identical assemblage B sequences (n = 2) at the β-giardin (bg) locus. This is the first molecular epidemiological study of Cryptosporidium spp. and G. duodenalis in humans in Myanmar at both genotype and subtype levels. Due to unclear transmission patterns and dynamics of Cryptosporidium spp. and G. duodenalis, future research effort should focus on molecular epidemiological investigations of the two parasites in humans and animals living in close contact in the investigated areas, even in whole Myanmar. These data will aid in making efficient control strategies to intervene with and prevent occurrence of both diseases.

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

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

Epidemiology of Cryptosporidiosis in France from 2017 to 2019

Cryptosporidiosis is currently recognized worldwide as a leading cause of moderate to severe diarrhea. In Europe, large water- and foodborne outbreaks have been reported, highlighting the widespread distribution of the parasite and its important health impact. Surveillance networks have been progressively set up and the aim of this study was to present recent epidemiological data obtained in France from 2017 to 2019 by the National Reference Center-Expert Laboratory of cryptosporidiosis (Centre National de Référence-Laboratoire Expert cryptosporidioses CNR-LE). Data were obtained from online reports of volunteer network participants and stools were sent to the CNR-LE for species identification and GP60 genotyping. During this period, data from 750 online reports were available. Cryptosporidiosis occurred predominantly in young children (<5 years old) and in young adults, especially during late summer. Most patients were immunocompetent (60%), and deaths were reported only in immunocompromised patients. Cryptosporidium parvum was largely predominant (72% of cases) over C. hominis (24%) and some other uncommon species. C. parvum GP60 subtypes IIa and IId were the most represented, which suggests frequent zoonotic transmission. For C. hominis, subtypes IbA10G2 and IaA22R2 were predominant.