Update: influenza activity -- United States, 1997-98 season.

CDC conducts surveillance for influenza viruses and related disease activity in collaboration with the World Health Organization (WHO), its collaborating laboratories, and state and local health departments. This report summarizes influenza surveillance data in the United States from September 28, 1997, through the week ending November 8, and describes two recent cruise ship outbreaks of influenza. The findings indicate that, during this period, influenza activity in the United States was low and that influenza A predominated.