Proventriculitis Associated with Cryptosporidium baileyi in a Snowy Owl (Bubo scandiacus) and Its Epidemiological Investigation

Comprehensive molecular epidemiology of Cryptosporidium species in Japan

Cryptosporidium species, causing diarrheal illnesses in humans and animals worldwide, are under investigation for their molecular epidemiology in Japan. The study focuses on detecting Cryptosporidium species in humans, animals, water, and the environment, revealing three species in people: C. parvum, C. meleagridis, and C. hominis. Subtype IIa of the C. parvum gp60 gene is prevalent, indicating potential zoonotic transmission. Animal studies identified sixteen species, mainly cattle and pets, with C. parvum (subtype IIa) common in cattle and C. canis and C. felis prevalent in pets. Additionally, C. bovis and C. ryanae were found in cattle and sika deer. Knowledge gaps exist, particularly in water and environmental source typing, with limited research revealing five species and five genotypes, suggesting a significant role of water in transmission. Further research is needed to understand the molecular diversity and transmission dynamics across humans, animals, water, and the environment in Japan.

Cancerogenic parasites in veterinary medicine: a narrative literature review

Parasite infection is one of the many environmental factors that can significantly contribute to carcinogenesis and is already known to be associated with a variety of malignancies in both human and veterinary medicine. However, the actual number of cancerogenic parasites and their relationship to tumor development is far from being fully understood, especially in veterinary medicine. Thus, the aim of this review is to investigate parasite-related cancers in domestic and wild animals and their burden in veterinary oncology. Spontaneous neoplasia with ascertained or putative parasite etiology in domestic and wild animals will be reviewed, and the multifarious mechanisms of protozoan and metazoan cancer induction will be discussed.

Cryptosporidium and colorectal cancer: a review of epidemiology and possible association

Cryptosporidiosis is an important protozoan disease with serious public health implications. The contribution of Cryptosporidium to colorectal cancer is still vaguely studied, but little evidence from experimental and epidemiological studies has suggested a possible association. This review discusses the epidemiology of cryptosporidiosis and colorectal cancer and attempts to unravel the possible link between the two diseases using epidemiological, pathological, molecular, and immunological evidence. The review stressed the need to undertake more studies in this relatively neglected field.

Cryptosporidium and Colon Cancer: Cause or Consequence?

The number of cancers attributable to infectious agents represents over 20% of the global cancer burden. The apicomplexan intracellular parasite Cryptosporidium is currently considered one of the major causes of mild and severe diarrhea worldwide. However, less attention has been paid to its tumorigenic potential despite the high exposure of humans and animals to this ubiquitous parasite. Herein, we discuss the potential causal link between Cryptosporidium infection and digestive cancer, with particular emphasis on colon cancer, based on increasing clinical, epidemiological and experimental pieces of evidence supporting this association. In addition, we highlight the current knowledge about the potential mechanisms by which this parasite may contribute to cell transformation and parasite-induced cancer.

Free-ranging avifauna as a source of generalist parasites for captive birds in zoological settings: An overview of parasite records and potential for cross-transmission

Captive birds in zoological settings often harbor parasites, but little information is available about the potential for free-ranging avifauna to act as a source of infection. This review summarizes the gastrointestinal parasites found in zoo birds globally and in seven common free-ranging avian species [mallard (Anas platyrhynchos), Eurasian blackbird (Turdus merula), common starling (Sturnus vulgaris), Eurasian jackdaw (Corvus monedula), house sparrow (Passer domesticus), European robin (Erithacus rubecula), and rock dove (Columba livia)] to identify the overlap and discuss the potential for cross-species transmission. Over 70 references were assessed, and papers spanned over 90 years from 1925 to 2019. A total of 60 studies from 1987 to 2019 met the eligibility criteria. All examined free-ranging avifauna harbored parasite species that were also reported in zoo birds, except for the European jackdaw. Parasites reported in captive and free-ranging birds include nematodes (Capillaria caudinflata, Dispharynx nasuta, Ornithostrongylus quadriradiatus, Strongyloides avium, Syngamus trachea, and Tetrameres fissispina), cestodes (Dicranotaenia coronula, Diorchis stefanskii, Fimbriaria fasciolaris, and Raillietina cesticillus, Sobolevicanthus gracilis), trematode (Echinostoma revolutum), and protozoa (Cryptosporidium baileyi). Although no study effectively proved cross-transmission either experimentally or by genetic analysis, these parasites demonstrate low host specificity and a high potential for parasite sharing. There is potential for parasite sharing whenever determinants such as host specificity, life cycle, and husbandry are favorable. More research should be carried out to describe parasites in both captive and free-ranging birds in zoological settings and the likelihood of cross-infection. Such information would contribute to evidence-based control measures, enhancing effective husbandry and preventive medicine protocols.

Cryptosporidium species and cryptosporidiosis in Japan: a literature review and insights into the role played by animals in its transmission

Cryptosporidium species infect domestic animals, livestock, and humans. These protozoan parasites are frequently reported as major environmental contaminants in many countries despite their differing climatic, socioeconomic, and demographic factors. This review focuses on the research findings that relate to Cryptosporidium epidemiology, genetic diversity, and associated risk factors relating to animals, contaminated water sources, and humans in Japan. Adequate knowledge of these factors is essential for understanding the economic and public health importance of cryptosporidiosis in Japan so that effective control strategies against it are implemented. Cryptosporidium infections are highly prevalent in animals in Japan. Among the different animal species, cattle infections stand out because of their economic importance and zoonotic potential. Living circumstances in Japan restrain Cryptosporidium transmission between humans, but there is evidence to suggest that animals, especially those in close contact with humans, can be potential sources of human infections. Water sampling studies have provided clues about how environmental contamination with Cryptosporidium oocysts can cause infections in livestock and wild animals. There is some evidence of person-to-person transmission of cryptosporidiosis, but only occasionally and under certain circumstances. By identifying the major role played by animals in Cryptosporidium transmission to people in Japan, we highlight the urgent need for disease control against this pathogen.

A new avian Cryptosporidium genotype in a 1-month-old caged brown wood owl (Strix leptogrammica) with severe dehydration and diarrhea

A 1-month-old brown wood owlet (Strix leptogrammica) purchased from a wholesaler and housed as a companion bird by an individual owner in Japan showed severe dehydration and anorexia following a week of vomiting and severe diarrhea. A great number of approximately 5 × 4-μm-sized Cryptosporidium oocysts were found in the feces by microscopy. The owlet was administered subcutaneous fluid and intragastric tube feeding for 2 weeks, resulting in improvement of the condition with a decreased number of oocysts in the feces. At days 51 and 119, no oocysts were found in the feces by microscope and PCR detection. These results suggested that this parasite was a possible agent of severe diarrhea in the affected bird. Molecular analysis of DNA extracted from oocysts based on the 18SrRNA loci identified C. avium; however, analysis of actin and hsp (heat shock protein) genes identified a novel genotype indicating a mixed infection with C. avium and a novel genotype.

First detection of Cryptosporidium parvum in falcons (Falconiformes): Diagnosis, molecular sequencing, therapeutic trial and epidemiological assessment of a possible emerging disease in captive falcons

Cryptosporidiosis in raptors and falcons is well-known to be caused by Cryptosporidium baileyi and associated mainly with respiratory pathology. This report presents the diagnosis of an atypical cryptosporidiosis event caused by Cryptosporidium parvum, that to the authors' knowledge, is a case observed for the first time in falcons. Two falcons (Gyrfalcon x Peregrine hybrids) were presented for annual check without any clinical signs. Hematology, biochemistry, fecal and crop parasitology, radiographic and endoscopic examinations were performed. Endoscopy revealed microcystic formation of the caudal lung field in the two falcons, adhesions and air sac alterations. Sampling and subsequent cytology revealed fungal spores and acid fast stain organisms (identified as Cryptosporidium spp.). Feces and affected lung tissue was further send for Cryptosporidium spp.-DNA detection. Fecal samples and lung tissue tested positive for Cryptosporidium spp. gp60 gene by PCR. By sequence analysis of the gp60 gene locus, diagnosis of C. parvum was confirmed with 100% homology. Despite the fact that falcons didn't recover after 1 month of therapy, eight months after the initial examination they were clinically healthy and had satisfactory flying performance. No other falcons were observed with C. parvum infections in the facility so far. The possible source, infection route and implications are discussed.