To improve the ecologic quality of water bodies, it is essential that tools are available that permit effect assessments for mixtures of chemicals.
Other studies have reported that ST-45 is more widely distributed in terms of host and ecologic niche, including water, than other common sequence types (12, 14 ).
Ecologic approaches to water-related diseases have drawn from biology, epidemiology, and genetics, among other fields, to focus on environmental determinants of disease via natural and increasingly anthropogenic changes to the physical environment, which frequently result from shifts in (human) population, consumption, and technologic growth (UNEP 2007).
Their analysis relied on ecologic assignment of drinking water exposures based on residence location, census-level exposures for housing age, and other risk factors for lead exposure.
We analyzed descriptive epidemiologic data, including the geographic distribution of cases during the study period, and investigated if changes in distribution occurred and if disease was associated with particular ecologic regions and inland water.
Several factors have been suggested as underlying causes, such as unusually severe floods in 1998 (34 ), major ecologic transformations caused by water resource development (35 ), potential effects of climate change (36, 37 ), market and health sector reforms (38 ), and termination of the WBLP for schistosomiasis control and insufficient attention to control efforts until 2001 (29 ).
The health outcome and potential confounders were measured at the individual level, and the exposure measure is composed of an individual assessment (the participant's address in each year) and an ecologic component (district-level water quality measurements) assigned to the addresses.
Similar to schistosomiasis, malaria, food-borne trematodiasis, lymphatic filariasis, and dengue, one of the main reasons for the proliferation of JE is the ecologic transformation caused by water resources development and management that create suitable breeding sites for vectors and intermediate hosts, which in turn influence the frequency and transmission dynamics of these diseases (39 ).
Gram-negative bacteria grow in ecologic niches that provide sufficient water, nutrients, oxygen, and heat.
We believe that knowledge of ecologic region and proximity to water can be used to define areas within which tularemia exposure is more likely.
