Climate and Water Type as Indicators for Gastroenteric Infections

J.S. Jagai, A.A. Kosheleva, D.A. Castronovo, K.C. Chui, E.N. Naumova

Background

Gastroenteric infections (GI) of waterborne or foodborne etiology are shown to be associated with contaminated water sources and warmer temperatures.
Conducted a nationwide analysis of hospitalization rates for five GI among the elderly to examine associations with climate characteristics and watersheds.

To determine if increased rates will be seen in counties with warm, moist climates
or watersheds.

Abstracted data on GI for each county in the United States for a 5 year period (1998-2002).
Calculated annual rates for each of the 3108 counties.
Classified counties on the Koppen Climate classification scheme (13 climate categories).
Used GIS maps to assign watershed to a county.
Examined the rates across climate categories and watershed regions using ANOVA.

The average annual county-specific hospitalization rates per 100,000 elderly were: 7.81 ± 13.27 cases of salmonellosis, 2.53 ± 6.53 cases of campylobacteriosis, 1.79 ± 6.79 cases of giardiasis, 0.90 ± 4.96 cases of shigellosis, and 0.13 ± 1.12 cases of cryptosporidiosis.
Elevated rates of salmonellosis (10.26 ± 14.04) was seen in counties with humid subtropical climate, the southern US from the eastern part of Texas to Florida.
The highest rates of salmonellosis (24.18 ± 43.95), shigellosis (14.52 ± 42.18) and campylobacteriosis (3.85 ± 8.84) in the subartic counties of Minnesota and South Dakota.
The highest rates of salmonellosis disease in Lower Mississippi and Texas-Gulf watershed regions. The highest rate of shigellosis (6.07 ± 12.93) in the Lower Colorado Region and higher rate of campylobacteriosis (5.45 ± 11.94).

Each infection demonstrated a different relationship with climate categories and watershed region.
These preliminary results demonstrate that gasteroenteric infections could be climate-sensitive.