Spectrum of hantavirus infection: Hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome

Hantaviruses chronically infect rodents without apparent disease, but when they are spread by aerosolized excreta to humans, two major clinical syndro mes result: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pul monary syndrome (HPS). Both diseases appear to be immunopathologic, and inf lammatory mediators are important in causing the clinical manifestations. I n HPS, T cells act on heavily infected pulmonary endothelium, and it is sus pected that gamma interferon and tumor necrosis factor are major agents of a reversible increase in vascular permeability that leads to severe, noncar diogenic pulmonary edema. HFRS has prominent systemic manifestations. The r etroperitoneum is a major site of vascular leak and the kidneys suffer tubu lar necrosis. Both syndromes are accompanied by myocardial depression and h ypotension or shock. HFRS is primarily a Eurasian disease, whereas HPS appe ars to be confined to the Americas; these geographic distinctions correlate with the phylogenies of the rodent hosts and the viruses that coevolved wi th them.