 In 1959 the first victims of a new and unknown epidemic appeared in Beni, Bolivia. By 1962 hundreds of people were dead, thousands sick and thousand more fled their homes. In 1963 a team of scientists from the US arrived to San Joaquin to investigate what was causing the epidemic. After a year over 1000 deaths (of a population of less than 5000) they traced the virus to a rat, the Callomys Callosus. The struggle to stop the spread of the disease began and continues until today.