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Rainforest dwellers get on the road to illness
It's no surprise that roads through rainforests are bad news for the trees; deforestation often follows infrastructure. They could also be bad for people, though. A study from the thinning jungle of northern Ecuador suggests that where roads go, disease follows, in a way that echoes the spread of disease in the New World brought by 15th-century European colonisers.
Joseph Eisenberg of the University of Michigan, Ann Arbor, and colleagues visited 21 villages situated at varying distances from a newly built asphalt highway. Their aim was to test the effect roads had on spreading severe and sometimes deadly diarrhoea.
Villagers closest to the road were 8.4 times as likely to come down with an E. coli-caused upset stomach as those who lived furthest away. The combined risk of diarrhoea from E. coli plus two other common pathogens, rotavirus and Giardia, was about three times as high for people living near the road.
Karen Levy of the University of California, Berkeley, a co-author on the study, believes this is because new roads open up tightly knit communities to the outside world.
"Closer to the road, people come and go a lot more and they don't care as much about what village they're in," she says. In Africa, there is evidence that dengue fever and malaria increase as a result of deforestation, she adds.
From issue 2581 of New Scientist magazine, 13 December 2006, page 21
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