Effect of precipitation on seasonal variability in cryptosporidiosis recorded by the North West England surveillance system in 1990–1999

Elena N. Naumova, John Christodouleas, Paul R. Hunter, Qutub Syed

Research output: Contribution to journalArticle


The goal of this study was to examine temporal and spatial variability of reported cryptosporidiosis in 15 health authorities in the North West of England using regression modelling. We also examined the role of precipitation as a driving factor for seasonal variation. We separated the time series of the reported cryptosporidiosis into two processes: an endemic process and an epidemic process, and examined the spatial variability of each of these processes. In the North West region of England we observed a strong seasonal pattern that consists of two waves, spring and autumn, during which the weekly rates exceeded the endemic level 3.5 and 3 times, respectively. Health authorities with the high endemic cryptosporidiosis incidence and well-pronounced seasonal patterns exhibited a significant increase in rates of cryptosporidiosis associated with increased precipitation. The endemic level and the magnitude of epidemic peaks were inversely related, which might be indicative of multiple exposures to the pathogen in these localities and the development of some partial immunity.
Original languageEnglish
Pages (from-to)185-196
Number of pages12
JournalJournal of Water and Health
Issue number2
Publication statusPublished - 2005

Cite this