HIGH PREVALENCE OF HANTAVIRUS INFECTION IN INDIAN COMMUNITIES OF THE PARAGUAYAN AND ARGENTINEAN GRAN-CHACO

Serologic evidence of past infection with a Sin Nombre-like hantavirus (es) was demonstrated in 78 (40.4%) of 193 Indians living in western P araguay and in 38 (17.1%) of 222 Indians inhabiting the Salta province of northern Argentina. In both populations seroprevalence increased w ith age, with the most striking increase occurring at 18 years of age in the Paraguayan population and at 35 years of age in the Salta popul ation, The peak prevalences in both populations (66.6% and 44.0%, resp ectively) were seen in Indians > 53 years old. Although no sex differe nce was observed in the Paraguayan Indians, in the Salta population se roprevalence was greater in males than in females. Familiar clustering of the infection was observed. The data indicate that the Indian popu lations of the Gran Chaco are frequently exposed to and survive infect ion with a Sin Nombre-like virus(es). Possible explanations of this no vel epidemiology are discussed.