Hemorrhagic Fevers Caused by South American Mammarenaviruses: A Comprehensive Review of Epidemiological and Environmental Factors Related to Potential Emergence.

Abstract

South American hemorrhagic fevers (SHF), a group of zoonotic diseases caused by various virus families including Arenaviridae, Bunyaviridae, Filoviridae, and Flaviviridae, are primarily confined to geographic areas where their host species reside. Transmission to humans occurs through direct contact with infected animals, especially rodents, and when infected, humans can transmit diseases to other humans through person-to-person interactions and other means, leading to illnesses that range from mild to life-threatening conditions. Diseases such as Argentine hemorrhagic fever, caused by the Junin virus, Brazilian hemorrhagic fever, caused by the Sabia virus, Venezuelan hemorrhagic fever, caused by the Guanarito virus, and Chapare hemorrhagic fever, are responsible for most hemorrhagic fevers excluding hemorrhagic consequences of diseases such as those caused by dengue. These diseases were first described in the late 1950s, coinciding with environmental and agricultural changes that led to increased rodent populations and the expansion of urban areas into rural zones. Pathogenically, these viruses typically initiate infection in the lungs and subsequently disseminate to regional lymphatic vessels and other organs, resulting in severe vascular and coagulation dysfunction. Clinical manifestations start with a prodromal phase characterized by general malaise and fever, progressing to more severe neurological and hemorrhagic symptoms, and concluding with a convalescent phase that may result in long-term neurological conditions. We comprehensively reviewed the literature on these South American hemorrhagic fevers. The dynamics of these diseases highlight the complex interactions between environmental factors, human behavior, and viral pathogenicity that drive the epidemiology of hemorrhagic fevers in South America.