Influenza. More than mom and chicken soup.

Influenza is an epidemic respiratory illness caused by one of three viral subtypes: A, B, or C. Influenza A causes higher mortality than influenza B and C and is often responsible for pandemics and yearly epidemics of this common, infectious disease. Clinically, patients with influenza present with an abrupt onset of fever, malaise, headache, and a dry, hoarse cough. These symptoms usually last three to five days. Amantadine and rimantadine may be used to prevent and to treat influenza A infection, but not B or C. Ribavirin, however, may be effective treatment for severe influenza pneumonia caused by either A or B subtype, although it is not FDA approved for this application. Annual influenza vaccination should be administered between mid-October and mid-November to any person at increased risk for complications. Health-care workers, those in close contact with high-risk individuals, and personnel vital to community function should also be immunized.

Hantavirus: an old bug learns new tricks.

Hantaviruses are a diverse group of RNA arboviruses in the Bunyaviridae family. Although their role as the causative agents of HFRS has been well established, the recent outbreak of a new disease in the Southwest clearly demonstrates the protein clinical manifestations that this pathogen can produce. Furthermore, whereas hantaviruses have been characterized largely as focal agents in the production of geographically delimited diseases, recent trends indicate that endemic areas for the virus are expanding. Outbreaks often occur in clusters as a result of the epizoology of rodent hosts, but isolated cases of hantavirus-related disease also may be observed. Although hantaviruses have proven their pathogenic capability in other areas of the world, it was perceived widely that they were of little consequence to public health in the United States. However, as more is learned about the nature of this truly global infectious agent, its potential danger to mankind becomes increasingly apparent. It is hoped that continued research will elucidate all the facets of hantavirus-induced disease.