A retrospective review of notified human cryptosporidiosis cases in the Waikato region of New Zealand, 2004 to 2011.

AIM

To retrospectively review notified human cryptosporidiosis cases in the Waikato region of New Zealand between 2004 and 2011 and to identify risk factors for human cryptosporidiosis infection.

METHOD

Waikato cryptosporidiosis notification data for the period 1 January 2004 to 31 December 2011 were analysed to identify any trends in the rates and distribution of key variables. A comparison was made between urban and rural dwelling cases.

RESULTS

Annual Waikato cryptosporidiosis notification rates were consistently higher than national rates. Analysis showed a seasonal peak centred around September with most cases having direct or indirect contact with cattle. Comparisons between urban and rural cases showed similar probable causes of infection and higher rates of infection in rural cases.

CONCLUSION

Those who have contact with animals continue to be at risk of infection from Cryptosporidium. The data suggests that children who live on rural properties and have contact with animal faeces, either directly or via a contaminated drinking water supply, are at the highest risk of infection.