Epidemiology of human cryptosporidiosis in Ireland, 2004-2006: analysis of national notification data

Cryptosporidium is a protozoal parasite which is of public health interest primarily due to its frequent association with drinking water. Since cryptosporidiosis became a notifiable human disease in 2004 in Ireland, evidence has been growing as to the national burden of illness caused by this pathogen. Nationally, crude incidence rates of between 8.7 and 13.4 per 100,000 were reported annually in the period 2004-2006. Rural areas reported more cases, with regional incidence rates as high as 31.4/100,000 per year. Over this time period, there has consistently been a peak in the number of notifications in springtime, contrasting with the reported seasonal distribution of cases elsewhere in Europe. Outbreak surveillance data suggest that drinking water is an important transmission route for general outbreaks, with person-to-person spread more common in family outbreaks. Cryptosporidium is an important gastrointestinal pathogen in Ireland, with much still to be learned about its epidemiology here.