Geographical distribution and risk factors associated with enteric diseases in Vietnam.

In Vietnam, shigellosis, typhoid fever, and cholera are important enteric diseases. To determine their magnitude and geographical distribution, and explore associated risk factors, we examined national surveillance data from 1991 to 2001 and potential ecological determinants. Average annual incidence rates were calculated and mapped for each province. Bivariate and multiple regression analyses were used to explore associations with selected environmental and human risk factors. Overall, shigellosis rates per 100,000 population (median, 41; mean, 70) were higher and more widespread than rates for typhoid fever (median, 7; mean, 23) and cholera (median, 0.3; mean, 2.7). Shigellosis was highest in the Central Highlands and was significantly associated with rainfall and urban poverty; typhoid fever prevailed in the Mekong River Delta and was most associated with vapor pressure and river/stream drinking water; and cholera predominated along the Central Coastal regions and correlated positively with rainfall and public well drinking water. The distinct geographical patterns of each disease appear to be driven by a combination of different ecological factors.