The newly busy towns also seemed to experience a breakdown of traditional social structure and supports, leading to poorer sanitation, Eisenberg said. Borbn, the boom town at the hub of the new road network, has grown to more than 1,000 homes and has an ominous "fecal film" on its river.

"When the tide goes down and you look at the river bank, you can see a number of pipes leading from all sorts of buildings," Eisenberg said.

To gather these measures, the team's surveyors visited each village three times over the course of two years. During each 15-day visit, they stopped at every home daily, asking if anyone was sick and collecting stool samples to identify the organism causing the illness.

In addition to tracking the movement and identity of diarrheal diseases, they interviewed all the villagers about their social contacts and built a social network map as a way to measure social cohesion. Social cohesion affects the maintenance of infrastructure, which is relevant to disease transmission, Eisenberg said. "The higher social cohesion is, the cleaner the village," he said.

Numerous studies have linked infectious disease with roads and road construction, including HIV transmission in Uganda and malaria in Peru, but the effects of roads on diarrheal diseases, which are a leading cause of mortality among infants and children under age 5, are relatively unknown.

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Contact: Karl Leif Bates
batesk@umich.edu
734-647-1842
University of Michigan
4-Dec-2006