Associations between Serum Vitamin D and Genetic Variants in Vitamin D Pathways and Age-Related Macular Degeneration in the European Eye Study.

PURPOSE: To study associations between early and late age-related macular degeneration (AMD) and neovascular AMD (nvAMD) with serum 25-hydroxy vitamin D (25(OH)D) and genetic variants in vitamin D pathway genes. DESIGN: Population-based, cross-sectional study in a random sample aged 65 years or older from 7 European countries. PARTICIPANTS: Of 4753 participants, 4496 (2028 men and 2468 women), with a mean age of 73 years, provided a blood sample; 2137 had no signs of AMD, 2209 had early AMD, and 150 had late AMD, of whom 104 had nvAMD. METHODS: Participants were interviewed to determine smoking and alcohol use, sunlight exposure, and diet; underwent fundus photography. Fundus images were graded using the International Classification System for Age-Related Maculopathy. The 25(OH)D was measured by liquid chromatography-tandem mass spectrometry and categorized as deficient (<30 nmol/l), insufficient (30-50 nmol/l), or adequate (≥50 nmol/l). Genotyping was performed on a subsample of 1284 AMD cases and controls for 93 single nucleotide polymorphisms (SNPs) from 7 genes. Associations were investigated by linear or logistic regression adjusted for potential confounders. MAIN OUTCOME MEASURES: Adjusted odds ratio (OR) for 3 outcomes (early AMD, late AMD, nvAMD). RESULTS: No linear association was found with 25(OH)D and early or late AMD or nvAMD. There was no association between insufficient or deficient status with early or late AMD. Deficient status was associated with nvAMD (adjusted OR, 1.27; 95% confidence interval, 1.1-1.45; P < 0.0001). Significant (P < 0.05) associations with 25(OH)D were found for SNPs in genes GC, VDR, CYP2R1, and CYP27B1. Two SNPs (VDR) were associated with early AMD, 4 SNPs (RXRA) and 1 SNP (VDR) were associated with nvAMD, and 1 SNP (RXRA), 2 SNPs (VDR), and 1 SNP (CYP2R1) were associated with late AMD. After Bonferroni correction, no SNPs were associated with early AMD, late AMD, or nvAMD. CONCLUSIONS: Deficiency in 25(OH)D was associated with nvAMD, but the adjusted OR was small, and we cannot exclude residual confounding. The hypothesis of a causal association of vitamin D with AMD is not supported by clear evidence for an association of vitamin D SNPs with early AMD, late AMD, or nvAMD.

Association Between Myopia, Ultraviolet B Radiation Exposure, Serum Vitamin D Concentrations, and Genetic Polymorphisms in Vitamin D Metabolic Pathways in a Multicountry European Study.

IMPORTANCE: Myopia is becoming increasingly common globally and is associated with potentially sight-threatening complications. Spending time outdoors is protective, but the mechanism underlying this association is poorly understood. OBJECTIVE: To examine the association of myopia with ultraviolet B radiation (UVB; directly associated with time outdoors and sunlight exposure), serum vitamin D concentrations, and vitamin D pathway genetic variants, adjusting for years in education. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional, population-based random sample of participants 65 years and older was chosen from 6 study centers from the European Eye Study between November 6, 2000, to November 15, 2002. Of 4187 participants, 4166 attended an eye examination including refraction, gave a blood sample, and were interviewed by trained fieldworkers using a structured questionnaire. Myopia was defined as a mean spherical equivalent of -0.75 diopters or less. Exclusion criteria included aphakia, pseudophakia, late age-related macular degeneration, and vision impairment due to cataract, resulting in 371 participants with myopia and 2797 without. EXPOSURES: Exposure to UVB estimated by combining meteorological and questionnaire data at different ages, single-nucleotide polymorphisms in vitamin D metabolic pathway genes, serum vitamin D3 concentrations, and years of education. MAIN OUTCOMES AND MEASURES: Odds ratios (ORs) of UVB, serum vitamin D3 concentrations, vitamin D single-nucleotide polymorphisms, and myopia estimated from logistic regression. RESULT: Of the included 3168 participants, the mean (SD) age was 72.4 (5) years, and 1456 (46.0%) were male. An SD increase in UVB exposure at age 14 to 19 years (OR, 0.81; 95% CI, 0.71-0.92) and 20 to 39 years (OR, 0.7; 95% CI, 0.62-0.93) was associated with a reduced adjusted OR of myopia; those in the highest tertile of years of education had twice the OR of myopia (OR, 2.08; 95% CI, 1.41-3.06). No independent associations between myopia and serum vitamin D3 concentrations nor variants in genes associated with vitamin D metabolism were found. An unexpected finding was that the highest quintile of plasma lutein concentrations was associated with a reduced OR of myopia (OR, 0.57; 95% CI, 0.46-0.72). CONCLUSIONS AND RELEVANCE: Increased UVB exposure was associated with reduced myopia, particularly in adolescence and young adulthood. The association was not altered by adjusting for education. We found no convincing evidence for a direct role of vitamin D in myopia risk. The relationship between high plasma lutein concentrations and a lower risk of myopia requires replication.

Neighbourhood Influences on Children's Weight-related Behaviours and Body Mass Index.

INTRODUCTION: Neighbourhood contextual factors such as accessibility of food shops and green spaces are associated with adult bodyweight but not necessarily weight-related behaviours. Whether these associations are replicated amongst children is unknown. AIM: To understand which aspects of childrens' neighbourhoods are associated with unhealthy weight and weight-related behaviours. METHODS: Individual-level data for children from the 2006/7 New Zealand Health Survey (of Body Mass Index (BMI), dietary indicators and socioeconomic variables) were linked with geographic level data on neighbourhood deprivation, rural/urban status, percentage of community engaged in active travel, access to green space, food shops and sports/leisure facilities. Logistic regression models were fitted for measures of BMI and weight-related behaviours; sugar sweetened beverage (SSB) consumption; fast-food consumption; and television viewing. RESULTS: Increased community engagement in active transport was, counterintuitively, the only neighbourhood contextual factor associated with unhealthy weight amongst children. After adjustment for socioeconomic and environmental variables, greater access to green space appeared to have a protective effect on SSB consumption and neighbourhood deprivation was associated with all three unhealthy weight-related behaviours (SSB and fast-food consumption and television viewing). CONCLUSIONS: Although further research is needed, evidence from the current study suggests that a repertoire of health promotion interventions and policies to change unhealthy weight-related behaviours in high deprivation neighbourhoods may be required to address childhood obesity.

Associations between neighbourhood environmental characteristics and obesity and related behaviours among adult New Zealanders.

BACKGROUND: The prevalence of adult obesity is escalating in most wealthy and middle income countries. Due to the magnitude of this issue, research and interventions at the individual-level abound. However, the limited success and high costs of such interventions has led to a growing recognition of the potential role of environmental factors in reducing obesity and promoting physical activity and healthy diets. METHODS: This study utilised individual-level data from the 2006/7 New Zealand Health Survey on obesity, physical activity, diet and socio-economic variables linked to geographic information from other sources on potentially aetiologically-relevant environmental factors, based on the respondent's residential address. We fitted logistic regression models for eight binary measures of weight or weight-related behaviours: 1) overweight; 2) obesity; 3) overweight + obesity; 4) active at least 30 minutes a day for 5+ days per week; 5) active <30 minutes per week; 6) walk 150 minutes + per week; 7) walk <30 minutes per week; and 8) consumption of 5+ fruits and vegetables per day. We included a range of independent environmental characteristics of interest in separate models. RESULTS: We found that increased neighbourhood deprivation and decreased access to neighbourhood greenspace were both significantly associated with increased odds of overweight and/or obesity. The results for weight-related behaviours indicate that meeting the recommended level of physical activity per week was associated with urban/rural status, with higher activity in the more rural areas and a surprising tendency for less activity among those living in areas with higher levels of active travel to work. Increased access to greenspace was associated with high levels of walking, while decreased access to greenspace was associated with low levels of walking. There was also a significant trend for low levels of walking to be positively associated with neighbourhood deprivation. Results for adequate fruit and vegetable consumption show a significant urban/rural gradient, with more people meeting recommended levels in the more rural compared to more urban areas. CONCLUSION: Similar to findings from other international studies, these results highlight greenspace as an amenable environmental factor associated with obesity/overweight and also indicate the potential benefit of targeted health promotion in both urban and deprived areas in New Zealand.

Climate change and food security: health impacts in developed countries.

BACKGROUND: Anthropogenic climate change will affect global food production, with uncertain consequences for human health in developed countries. OBJECTIVES: We investigated the potential impact of climate change on food security (nutrition and food safety) and the implications for human health in developed countries. METHODS: Expert input and structured literature searches were conducted and synthesized to produce overall assessments of the likely impacts of climate change on global food production and recommendations for future research and policy changes. RESULTS: Increasing food prices may lower the nutritional quality of dietary intakes, exacerbate obesity, and amplify health inequalities. Altered conditions for food production may result in emerging pathogens, new crop and livestock species, and altered use of pesticides and veterinary medicines, and affect the main transfer mechanisms through which contaminants move from the environment into food. All these have implications for food safety and the nutritional content of food. Climate change mitigation may increase consumption of foods whose production reduces greenhouse gas emissions. Impacts may include reduced red meat consumption (with positive effects on saturated fat, but negative impacts on zinc and iron intake) and reduced winter fruit and vegetable consumption. Developed countries have complex structures in place that may be used to adapt to the food safety consequences of climate change, although their effectiveness will vary between countries, and the ability to respond to nutritional challenges is less certain. CONCLUSIONS: Climate change will have notable impacts upon nutrition and food safety in developed countries, but further research is necessary to accurately quantify these impacts. Uncertainty about future impacts, coupled with evidence that climate change may lead to more variable food quality, emphasizes the need to maintain and strengthen existing structures and policies to regulate food production, monitor food quality and safety, and respond to nutritional and safety issues that arise.

The impact of rainfall and school break time policies on physical activity in 9-10 year old British children: a repeated measures study.

BACKGROUND: The weather may be a driver of seasonal patterns in children's physical activity (PA). A better understanding of the relationships between weather and PA may help increase children's PA. This study aims to examine the association between PA and rainfall in 9-10 year old children, and how it may be modified by school policies. METHODS: 1794 participants in the SPEEDY study in Norfolk, UK recorded PA using ActiGraph accelerometers over up to six days in the summer term of 2007. Multilevel regression models were used to determine the day-by-day association between rainfall and minutes spent sedentary, in moderate-to-vigorous PA (MVPA), and average counts per minute (cpm) over the whole day (07:00-21:00) and the lunchtime period (12:00-14:00). School policies for break times in bad weather were fitted as interaction terms with rainfall. RESULTS: Relative to days with no rain, children spent 9.4 minutes (95%CI 7.0 to 11.9) fewer in MVPA, were sedentary for 13.6 minutes (8.8 to 18.4) more, and accumulated 85.9 cpm (66.2 to 105.5) fewer over the whole day on the wettest days. Children allowed to play outside in wet weather showed the lowest lunchtime PA levels on the wettest days, undertaking 9.8 minutes (6.2 to 13.5) fewer MVPA, 16.1 minutes (10.3 to 21.9) more sedentary, and accumulating 408.0 cpm (250.9 to 565.1) fewer than those allowed to be active indoors. CONCLUSIONS: Rainfall is negatively associated with PA in primary school children, but providing indoor physical activities in wet weather may help children maintain physical activity levels irrespective of rainfall.

Climate variability and dengue fever in warm and humid Mexico.

Multiple linear regression models were fitted to look for associations between changes in the incidence rate of dengue fever and climate variability in the warm and humid region of Mexico. Data were collected for 12 Mexican provinces over a 23-year period (January 1985 to December 2007). Our results show that the incidence rate or risk of infection is higher during El Niño events and in the warm and wet season. We provide evidence to show that dengue fever incidence was positively associated with the strength of El Niño and the minimum temperature, especially during the cool and dry season. Our study complements the understanding of dengue fever dynamics in the region and may be useful for the development of early warning systems.

Environmental correlates of adiposity in 9-10 year old children: considering home and school neighbourhoods and routes to school.

The rapid speed of the recent rise in obesity rates suggest environmental causes. There is therefore a need to determine which components of the environment may be contributing to this increase. In this cross-sectional study, we examined the associations between adiposity and the characteristics of areas around homes, schools and routes to school among 1995 9-10 year old boys and girls in Norfolk, UK. The relationships between Fat Mass Index (FMI, calculated as fat mass (kg)/height (m)(2)) and objectively computed environmental indicators describing access to food outlets and physical activity facilities, the safety and connectivity of the road network, and the mix of land uses present were investigated. Multivariable hierarchical regression models were fitted with log-transformed FMI as the outcome, and stratification by gender and mode of travel to school. Among girls, better access to healthy food outlets (supermarkets and greengrocers) in the home environment was associated with lower FMI while better access to unhealthy outlets (takeaways and convenience stores) around homes and schools was associated with higher FMI. Also in girls, a higher proportion of accessible open land and a lower mix of land uses around the school were associated with higher FMI. Among boys the presence of major roads in the home neighbourhood was associated with higher FMI among non-active travellers, while major roads in the school neighbourhood were associated with lower FMI among active travellers. No significant associations were seen between FMI and any of the route characteristics. While the relative paucity of associations provides few indicators for the design of effective interventions, there was some evidence that environmental characteristics may be more important among active travellers than non-active travellers, and among girls than boys, suggesting that future interventions should be sensitive to such differences.

School level correlates with adiposity in 9-10 year old children.

We examined the associations between the physical, social, and policy environments of schools and adiposity in 9-10 year old children in Norfolk, UK. The relationships between 56 school-level variables and Fat Mass Index (FMI; fat mass (kg)/height (m(2))) were investigated among 1724 well characterised children from 92 schools in this cross-sectional study. After stepwise removal of variables from multilevel linear regression models stratified by gender, only three variables were significantly associated with FMI. Among girls, attending a school with more pupils in the year group was associated with lower FMI, and attending a school with better cycle provision was associated with higher FMI. In boys being allowed to eat any food at break-time was associated with higher FMI. There was some evidence of moderation of the relationship between cycle provision and FMI by urban-rural location. These data suggest that few school factors are associated with FMI, and provide limited pointers to inform potential future school-based interventions to reduce obesity.

Local food outlets, weight status, and dietary intake: associations in children aged 9-10 years.

BACKGROUND: The rising prevalence of childhood obesity is a key public health issue worldwide. Limited evidence suggests that there may be interactions between environmental factors at a neighborhood level and the development of obesity, with the availability and accessibility of food outlets being potentially important. PURPOSE: To examine how the weight status and dietary intake of 1669 children aged 9-10 years was associated with neighborhood food outlets in a cross-sectional study. METHODS: Availability of food outlets was computed from GIS data for each child's unique neighborhood. Outlets were grouped into BMI-healthy, BMI-unhealthy, or BMI-intermediate categories according to food type sold. Weight status measurements were objectively collected, and food intake was recorded using 4-day food diaries. Data were collected in 2007 and analyzed in 2009. RESULTS: Availability of BMI-healthy outlets in neighborhoods was associated with lower body weight (1.3 kg, p=0.03); BMI (0.5 kg/m(2), p=0.02); BMI z-score (0.20, p=0.02); waist circumference (1.3 cm, p=0.02); and percentage body fat (1.1%, p=0.03) compared to no availability. In contrast, neighborhood availability of BMI-unhealthy outlets was inversely associated with body weight (1.3 kg, p=0.02); BMI (0.4 kg/m(2), p=0.05); BMI z-score (0.15, p=0.05); waist circumference (1.1 cm, p=0.04); and percentage body fat (1.0%, p=0.03). Unhealthy food intake (fizzy drinks 15.3%, p=0.04, and noncarbonated "fruit" drinks 11.8%, p=0.03) was also associated with availability of BMI-unhealthy food outlets. CONCLUSIONS: Features of the built environment relating to food purchasing opportunities are correlated with weight status in children.

Visual impairment and quality of life in the older European population, the EUREYE study.

PURPOSE: To determine the prevalence of visual impairment (VI) in populations 65 year or older from six European countries and describe the association with vision-related quality of life. VI was defined according to WHO as best corrected visual acuity <6/18/log MAR >0,48 (World Health Organization (1992): International Statistical Classification of Diseases and Related Health Problems, 10th revised ed. Vol 1. Geneva). METHODS: 4166 participants in The European Eye study, 65 years and older selected randomly from the general census in the participating centres, were interviewed for vision-related quality of life and underwent an eye exam including distance visual acuity, refraction and fundus photography. RESULTS: The prevalence of VI rose with increasing age and more so in women. There was a pattern of a higher prevalence of VI in the Mediterranean countries compared to Northern European countries with the exception of Tallinn (Estonia) which had higher VI prevalence rates than the other north European centres. The prevalence of low vision was 3% or less in all centres. Blindness prevalence varied from 2% to less than half a per cent. Vision-related quality of life was strongly associated with visual acuity and the presence of bilateral age-related macular degeneration. CONCLUSION: The prevalence of visual impairment in the examined ageing European populations shows a definite increasing trend from north to south.

Environmental risk factors for diarrhoea among male schoolchildren in Jeddah City, Saudi Arabia.

Diarrhoeal disease is still one of the major causes of mortality and morbidity of children in developing countries. Our objective was to assess the prevalence of diarrhoeal disease among male schoolchildren in Jeddah and to identify the associated risk factors, especially those related to drinking water and sanitation disposal. This cross-sectional study was conducted randomly where self-administered questionnaires were issued to parents through the schools. The data were collected from 1,064 respondents indicating that 14.9% of the children had diarrhoea during the previous month. The main risk factors were: the number of children under five years living in the same house (OR per child 1.34, 95% confidence intervals 1.15-1.56), being of Saudi nationality (OR 1.75, 1.08-2.84), reporting sewage spillage near the home (OR 1.69, 1.14-2.53), eating out after school hours (OR 1.74, 1.16-2.60), not drying hands after washing them (OR 1.66, 1.10-2.51), using reusable cloths or sponges to dry dishes (OR 1.70, 1.14-2.52).

Using infectious intestinal disease surveillance data to explore illness aetiology; a cryptosporidiosis case study.

Infectious intestinal disease (IID) surveillance data are an under-utilised information source on illness geography. This paper uses a case study of cryptosporidiosis in England and Wales to demonstrate how these data can be converted into area-based rates and the factors underlying illness geography investigated. Ascertainment bias is common in surveillance datasets, and we develop techniques to investigate and control this. Rural areas, locations with many livestock and localities with poor water treatment had elevated levels of cryptosporidiosis. These findings accord with previous research validating the techniques developed. Their use in future studies investigating IID geography is therefore recommended.

Sunlight exposure, antioxidants, and age-related macular degeneration.

OBJECTIVE: To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD). METHODS: Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data. RESULTS: Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level-vitamin C, zeaxanthin, vitamin E, and dietary zinc-with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD. CONCLUSIONS: Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular age-related macular degeneration.

BACKGROUND: Fish intake, the major source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may reduce the risk of age-related macular degeneration (AMD). OBJECTIVE: We investigated the association of oily fish and dietary DHA and EPA with neovascular AMD (NV-AMD). DESIGN: Participants aged >/=65 y in the cross-sectional population-based EUREYE study underwent fundus photography and were interviewed by using a food-frequency questionnaire. Fundus images were graded by the International Classification System for Age Related Maculopathy. Questionnaire data were converted to nutrient intakes with the use of food-composition tables. Survey logistic regression was used to calculate odds ratios (ORs) and 95% CIs of energy-adjusted quartiles of EPA or DHA with NV-AMD, taking into account potential confounders. RESULTS: Dietary intake data and fundus images were available for 105 cases with NV-AMD and for 2170 controls without any features of early or late AMD. Eating oily fish at least once per week compared with less than once per week was associated with a halving of the odds of NV-AMD (OR = 0.47; 95% CI: 0.33, 0.68; P = 0.002). Compared with the lowest quartile, there was a significant trend for decreased odds with increasing quartiles of either DHA or EPA. ORs in the highest quartiles were 0.32 (95% CI: 0.12, 0.87; P = 0.03) for DHA and 0.29 (95% CI: 0.11, 0.73; P = 0.02) for EPA. CONCLUSIONS: Eating oily fish at least once per week compared with less than once per week was associated with a halving of the OR for NV-AMD.

Case-control study of environmental and social factors influencing cryptosporidiosis.

We report on the first case-control study to investigate the role of wider environmental and socioeconomic factors upon human cryptosporidiosis. Using GIS the detailed locations of 3368 laboratory-confirmed cases were compared to the locations of an equal number of controls. All cases were genotyped enabling Cryptosporidium hominis and Cryptosporidium parvum to be examined separately. When all cryptosporidiosis cases were analyzed, several location variables were strongly associated with illness: areas with many higher socioeconomic status individuals, many individuals aged less than 4 years, areas with a high estimate of Cryptosporidium applied to land from manure, and areas with poorer water treatment. For C. hominis cases, the strongly significant risk factors were areas with many higher socioeconomic status individuals, areas with many young children and urban areas. Socioeconomic status and areas with many individuals aged less then 4 years had a greater impact for infection with C. hominis than for C. parvum. Policy implications are discussed.

Cryptosporidiosis decline after regulation, England and Wales, 1989-2005.

Since new drinking water regulations were implemented in England and Wales in 2000, cryptosporidiosis has been significantly reduced in the first half of the year but not in the second. We estimate an annual reduction in disease of 905 reported cases and approximately 6,700 total cases.

Prevalence of age-related maculopathy in older Europeans: the European Eye Study (EUREYE).

OBJECTIVE: To estimate the prevalence of age-related maculopathy in an older population from 7 European countries. METHODS: Randomly sampled people 65 years and older were invited to an eye examination in centers across 7 European countries (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain). Fundus images of each eye were graded at a single reading center. Prevalence rates were calculated for stage of age-related maculopathy with 95% confidence intervals (CIs) estimated for clustered data. RESULTS: Of 5040 participants (45% response rate), 4753 (2128 men and 2625 women) had gradable fundus images. The prevalences were grade 0, 47.59% (95% CI, 43.53%-51.65%); grade 1, 36.48% (95% CI, 32.66%-40.30%); grade 2, 10.14% (95% CI, 8.92% to 11.37%); grade 3, 2.46% (95% CI, 1.79%-3.13%); and grade 4 (age-related macular degeneration [AMD]), 3.32% (95% CI, 2.52%-4.13%) and large drusen only (> or = 125 microm), 15.41% (95% CI, 13.61%-17.21%). The prevalence of geographic atrophic AMD was 1.2% (95% CI, 0.8%-1.7%) and of neovascular AMD, 2.3% (95% CI, 1.7%-2.9%). The prevalence of bilateral AMD was 1.4% (95% CI, 1.0%-1.8%). CONCLUSION: Age-specific prevalences of age-related maculopathy in the European Eye Study (EUREYE) are similar to other population-based studies in Western populations.

Effects of weather and river flow on cryptosporidiosis.

Outbreaks of cryptosporidiosis have been linked to weather patterns such as heavy precipitation. However, outbreaks only account for a small percentage of all cryptosporidiosis cases and so the causes of the majority of cases are uncertain. This study assessed the role of environmental factors in all cases of cryptosporidiosis by using ordinary least-squares regression to examine the relationship between the monthly cryptosporidiosis rate, and the weather and river flows in England and Wales between 1989 and 1996. Between April and July the cryptosporidiosis rate was positively related to maximum river flow in the current month. Between August and November cryptosporidiosis was also positively linked to maximum river flows in the current month but only after accounting for the previous month's temperature, precipitation and monthly cryptosporidiosis rate. No associations were found between December and March. Through an understanding of the environmental processes at work, these relationships are all consistent with an animal to human transmission pathway especially as the relationships vary throughout the year. This study therefore indicates the importance of an animal to human transmission pathway for all cases of cryptosporidiosis.