[The new-world hantaviruses. Ecology and epidemiology of an emerging virus in Latin America]

The hantaviruses are a group of emerging rodent-borne pathogens (family Bunyaviridae; Genus Hantavirus) that are etiologic agents for hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia and hantavirus cardiopulmonary syndrome (HCPS) in the Americas. HFRS is associated with rodents of the family Muridae, subfamilies Murinae and Arvicolinae; HPS is associated with rodents of the subfamily Sigmodontinae. Since the identification of HCPS in USA in 1993, a large number of cases of HPS and an increasing number of hantaviruses and rodent reservoir hosts have been identified in Central and South America. Epidemiologic studies have demonstrated important differences in frequency of infection with hantaviruses in both human and rodent host populations. Antibody prevalences in rodent and human populations may vary from less than 1% to more than 40%. Currently, more than 1500 cases of HCPS have been reported and more than 15 genetically distinct variants of hantaviruses, all associated with sigmodontine rodents, have been identified throughout the Americas. Several characteristics distinguish Latin American HCPS cases from the classical HCPS described for the first time in the USA. These include a variation in severity of disease from moderate and self-limiting to severe, the demonstration of person-to-person transmission, and a somewhat higher incidence of extrapulmonary clinical manifestations in the South American form of HCPS. Nevertheless, our understanding of hantaviruses in the Americas is still far from complete. The factors involved in the dynamics of these viruses in nature, their establishment and transmission within host populations and from hosts to humans, and the variable pathology of these viruses in humans are complex. It is likely that more hantaviruses will be described in the future, and much more data will be required in order to describe the diversity and evolution of this group of pathogens. Latin America, as the center of diversity for Sigmodontine rodents and their hantaviruses is presented with the unique opportunity as well as the challenge of being center stage for continued studies of the dynamics of hantaviruses in natural host populations and the links of host and virus to human populations.