Update: Influenza Activity - United States and Worldwide, May 20-October 13, 2018.

What is already known about this topic? CDC compiles, collects, and analyzes data on influenza activity to monitor the timing and severity of each influenza season. What is added by this report? Reported Southern Hemisphere influenza activity was relatively low and fairly mild, with influenza A(H1N1) pdm09 viruses predominating in most regions. In the United States, influenza activity was low in all regions, typical for this time of year. Fourteen influenza variant virus infections were reported in the United States, and most were associated with exposure to swine. What are the implications for public health practice? Annual influenza vaccination is recommended for all persons aged >= 6 months who do not have a contraindication. Providers should encourage influenza vaccination now prior to the increase of influenza activity.