The MMWR for May 8, 2009/ Vol. 58 / No. 17, includes:

– Update: Novel Influenza A (H1N1) Virus Infections — Worldwide, May 6, 2009

– False-Positive Results with a Commercially Available West Nile Virus Immunoglobulin M Assay — United States, 2008

– Outbreak of Swine-Origin Influenza A (H1N1) Virus Infection — Mexico, March–April 2009

– Swine-Origin Influenza A (H1N1) Virus Infections in a School — New York City, April 2009