Cryptosporidiosis

Cryptosporidiosis is an infection caused by protozoan parasites of the genus Cryptosporidium ^[3]. The provided sources identify Cryptosporidium parvum as the most common species found in dairy calves in the United States and describe it as an important zoonotic species ^[1]. The sources also note that at least 44 Cryptosporidium species and more than 120 genotypes have been recognised, but source-backed detail on the relevance of specific species to all human disease settings is not yet available ^[3].

The sources describe cryptosporidiosis as a common cause of diarrhoea among preweaned dairy calves ^[1]. In calves, diarrhoea generally starts 3 to 4 days after ingestion of oocysts, with shedding beginning as early as 2 days of age and peaking at 14 days of age ^[1]. Beyond diarrhoea, the provided material does not specify additional symptoms, severity patterns, complications, or recovery course in humans or animals ^[1][2][3].

Cryptosporidiosis is described as a significant cause of diarrhoea worldwide and as a contributor to numerous waterborne and foodborne outbreaks ^[3]. One source states that Cryptosporidium is responsible for more than 8 million cases of foodborne illness annually ^[2]. In dairy calves in the United States, Cryptosporidium parvum is reported as the most common species, and risk factors in that setting include large dairy farms, summer months, feeding of milk replacer, and early feeding of starter grain ^[1].

The provided sources state that cryptosporidiosis is spread by fecal-oral transmission ^[1]. They also indicate that the organism is well suited to foodborne transmission and is implicated in waterborne and foodborne outbreaks ^[2][3]. Source-backed detail on persistence, infectious dose, or other transmission nuances is not yet available in the supplied material ^[1][2][3].

The provided sources identify preweaned dairy calves as a key affected group and note specific farm-management exposures linked with increased risk in that setting, including large dairy farms, summer months, milk replacer feeding, and early starter grain feeding ^[1]. They also identify Cryptosporidium parvum as a zoonotic species in dairy calves, supporting the relevance of animal-to-human interfaces ^[1][3]. Source-backed detail on additional human high-risk groups is not yet available in the supplied snippets ^[1][2][3].

For foodborne cryptosporidiosis, the sources emphasize food safety management tools including Good Hygienic Practices, Hazard Analysis and Critical Control Points, and Quantitative Microbial Risk Assessment in industrialised settings, as well as Water, Sanitation, and Hygiene measures in developing countries ^[2]. In the dairy-calf setting, concrete flooring and appropriate cleaning of feeding utensils are reported to reduce disease risk ^[1]. The sources also mention that sensitive detection methods and molecular typing support outbreak investigations and source tracking, which may inform control efforts ^[2][3].

From a surveillance perspective, cryptosporidiosis should be interpreted as a pathogen with both zoonotic and outbreak-associated potential, especially in foodborne and waterborne contexts ^[1][2][3]. The literature provided highlights the value of improved detection and typing tools, including molecular assays used in case linkage and infection source tracking during outbreak investigations ^[2][3]. For the specific calf setting, shedding begins very early and peaks around 14 days of age, which may be useful when interpreting animal-health surveillance data ^[1].

1. 1 Adkins PRF et al. Cryptosporidiosis. Vet Clin North Am Food Anim Pract. 2022 Mar. PMID: 35219480. doi: 10.1016/j.cvfa.2021.11.009. PubMed: https://pubmed.ncbi.nlm.nih.gov/35219480/
2. 2 Ryan U et al. Foodborne cryptosporidiosis. Int J Parasitol. 2018 Jan. PMID: 29122606. doi: 10.1016/j.ijpara.2017.09.004. PubMed: https://pubmed.ncbi.nlm.nih.gov/29122606/
3. 3 Ryan UM et al. Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021). Int J Parasitol. 2021 Dec. PMID: 34715087. doi: 10.1016/j.ijpara.2021.08.007. PubMed: https://pubmed.ncbi.nlm.nih.gov/34715087/
4. 4 Cryptosporidiosis. Infectious Diseases Newsletter. 1984. doi: 10.1016/s0278-2316(84)80040-7. DOI: https://doi.org/10.1016/s0278-2316(84)80040-7
5. 5 Cryptosporidiosis. BMJ. 2009. doi: 10.1136/bmj.b4733. DOI: https://doi.org/10.1136/bmj.b4733
6. 6 Cryptosporidiosis. Archives of Internal Medicine. 1985. doi: 10.1001/archinte.1985.00360010090014. DOI: https://doi.org/10.1001/archinte.1985.00360010090014

ICD-10

ICD-11

Total cases

176K

Peak month

2024-03

Coverage

4 reporting countries · 2000-01-01 → 2026-06-20