title: Cryptosporidiosis Risk in New Zealand Children Under 5 Years Old is Greatest in Areas with High Dairy Cattle Densities.
abstract: The public health risks associated with dairy farming intensification are an emerging concern. We examine the association between dairy cattle density and cryptosporidiosis risk in children <5 years old in New Zealand from 1997 to 2008, a period of rapid intensification of the dairy industry. Multi-level Poisson regression was used to model reported cryptosporidiosis (N = 3869 cases) incidence in relation to dairy cattle densities across urban and rural areas separately, after controlling for microbiological quality of public drinking water supplies and neighbourhood socio-economic factors using the Census Area Unit of residence. Within urban areas, the risk of cryptosporidiosis in children less than 5 years old was significantly, positively associated with medium and high dairy cattle density IRR 1.3 (95% CI 1.2, 1.5) and 1.5 (95% CI 1.2, 1.9) respectively, when compared to areas with no dairy cattle. Within rural areas, the incidence risk of cryptosporidiosis in children less than 5 years old were significantly, positively associated with medium and high dairy cattle density: IRR 1.7 (95% CI 1.3, 2.3) and 2.0 (95% CI 1.5, 2.8) respectively, when compared to areas with no dairy cattle. These results have public health implications for children living on and in proximity to intensively stocked dairy cattle farms.
authors.affiliation: National Centre for Epidemiology and Population Health, Research School of Population Health, The Australian National University, Building 62, Acton, Canberra, ACT, 2601, Australia. aparna.lal@anu.edu.au.
authors.forename: Aparna
authors.initials: A
authors.lastname: Lal
authors.affiliation: National Centre for Epidemiology and Population Health, Research School of Population Health, The Australian National University, Building 62, Acton, Canberra, ACT, 2601, Australia.
authors.forename: Timothy
authors.initials: T
authors.lastname: Dobbins
authors.affiliation: Department of Health Service Research and Policy, Research School of Population Health, Australian National University, 63 Eggleston Rd, Canberra, 2601, Australia.
authors.forename: Nasser
authors.initials: N
authors.lastname: Bagheri
authors.affiliation: Department of Public Health, University of Otago School of Medical and Health Sciences, PO Box 7343, Wellington South, 6242, New Zealand.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Baker
authors.affiliation: mEpiLab, Hopkirk Research Institute, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand.
authors.forename: Nigel P
authors.initials: NP
authors.lastname: French
authors.affiliation: Department of Public Health, University of Otago School of Medical and Health Sciences, PO Box 7343, Wellington South, 6242, New Zealand.
authors.forename: Simon
authors.initials: S
authors.lastname: Hales
mesh_terms: D000383:Agriculture; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology*; D003612:Dairying; D006801:Humans; D015994:Incidence; D007223:Infant; D009520:New Zealand; D012307:Risk Factors
keywords: children; cryptosporidiosis; dairy cattle density