Migration

The migration of infected people and increased domiciliary habits of vinchucas have expanded Chagas’ disease to regions not environmentally considered optimal for this disease, which now is no longer limited to the natural environmental parameters for vinchucas. M. Goldbaum (1982) has shown the impact of migratory movements and Chagas’ disease in Sao Paulo, Brazil, and Ciesielski et al. (1993) found 2 percent seropositivity for Chagas’ disease among 138 Hispanic and Haitian migrant farmworkers in labor camps in eastern North Carolina.

Migrants spread Chagas’ disease in a number of ways. Migrants can transport vinchucas in their baggage to nonendemic areas; infected peasants transfer T. cruzi in their blood to uninfected vinchucas in new regions. Peasants sell their blood to unwary buyers, passing the disease through blood transfusions. Residentes (urbanites) visit relatives in rural areas, where they become infected and return as hosts for Chagas’ disease in the cities. Chagas’ disease also has been imported into France and the United States (Brisseu et al. 1988; Kirchhoff, Gam, and Gilliam 1987).

Peasants migrate because their land has been sold, worn out, or expropriated. Some are ignorant of principles of sustainable agriculture; others lack money to improve productivity. Some Bolivians travel from the Altiplano to agricultural zones of Chile to pick fruit during the dry season and to pick coca leaves in the sub‑Andean regions of the Yungas during the wet season. Many peasant families have daughters who work as maids for families in Cochabamba, Santa Cruz, and La Paz. Others migrate to cities to find employment in construction and domestic labor markets.

When peasants first settle an area they cut the brush and trees to farm the land. Vinchucas are forced out of their nests in bushes and trees where they have fed upon birds and rodents. They move into the corrals and huts of the invading peasants. The Department of Tarija, Bolivia, has suffered especially, with high percentages of vinchuca infestation reported in corrals (61.6 percent) and ovens (60.2 percent). This explains its high infestation rate (78.2 percent), infected vinchucas (50 percent), and people with Chagas’ disease (60.6 percent).