Key findings
- Cryptosporidium parvum is a parasite which has been recognised as a human pathogen since 1976. Over the last decade, Cryptosporidium has also been recognised as an important cause of opportunistic illness in people with HIV infection.
- Cryptosporidium infection is acquired through ingestion of oocysts excreted in the faeces of infected humans and animals. Modes of transmission therefore include person to person transmission, contact with infected animals, and ingestion of faecally contaminated water or food.
- In people with HIV infection, the clinical presentation of Cryptosporidium infection varies considerably, and includes asymptomatic colonisation, self-limiting diarrhoea, and life-threatening intractable watery diarrhoea and biliary disease.
- Over the period 1983 through 1994, over 1,400 people with AIDS were cared for by the St Vincent’s Hospital HIV Unit in Sydney. In 1995, a review of patient medical records was undertaken to examine AIDS illness incidence trends. Among the 1,394 people with available information, 145 (10.4%) had developed Cryptosporidium infection. Of these 145, cryptosporidiosis was the AIDS-defining illness in 60 (41.3%).