[Hantavirus and pulmonary pathology]

The hantavirus pulmonary syndrome recognized in the United States in 1993 quickly brought the formerly little known virus into the limelight. Contrary to what has been written almost everywhere, this is not a "new" virus causing new "emerging" disease. Hantaviruses have been harbored in their natural hosts, three subfamilies of murine rodents, for millions of years. The phylogenetic classifications of these viruses follows that of their hosts, proving close adaptation and contradicting short-term emergence of American serotypes in Eurasia. Certain hantaviruses are the causal agents of renal diseases of variable severity grouped together under the term of hemorrhagic fever with a renal syndrome in Eurasia. Others cause acute respiratory distress syndrome, particularly in North America. Most cases occur in adults and the sex-ratio always favors men, probably due to exposure to airborne rodent ejections. No interhuman contamination is observed. A few dozen cases of hantavirus pulmonary syndrome are reported annually in North America and a few hundred cases in Europe. China is the only country were incidence has been high enough for hundreds of years to lead to an experimentation on vaccines. Hantaviruses are difficult to isolate and diagnosis in humans is based on serology. Improved diagnostic tools have led to a better assessment of the impact of this virus on public health. An epidemic in France in 1996 caused 230 cases while only 808 cases had been registered since 1977. Most of the cases occurred in Northeastern France and were focalized.