Cryptosporidiosis is a diarrhoeal disease caused by Cryptosporidium, a microscopic protozoan parasite
- Cryptosporidium may infect humans and animals
- the parasite lives in the intestines of infected humans and animals
- an infected person or animal sheds a high quantity of Cryptosporidium oocysts in the feces
- Cryptosporidium hominis (previously known as C. parvum Type 1) and Cryptosporidium parvum (previously known as C. parvum Type 2) are primarily responsible for morbidity and outbreaks of disease
- in addition, HIV-infected patients may be affected by Cryptosporidium meleagridis, Cryptosporidium felis, and Cryptosporidium canis
In the UK:
- Cryptosporidium is the commonest protozoal cause of acute gastroenteritis
- C parvum infections peak in spring and C hominis peaks in late summer and autumn
- number of cases in the first half of the year have reduced while in the second half, the number remains high (2)
The infection is commonly seen in young children (especially under the age of 5 years) but may affect healthy person of any age. However majority of clinical problems are seen in those with advanced immunosuppression.
- substantial morbidity is seen in the developing world and with children who are malnourished (including those with apparently asymptomatic infection who may exhibit poor growth)
Asymptomatic carriage of the organism has also been reported (2).
- a study carried out in day care centres for young children reported that unusual genotypes of Cryptosporidium were found proportionately much more frequently in asymptomatic carriers than in patients with symptomatic disease (2)