This situation report provides an update of the international situation as of July 28, 2009. As of July 27, WHO regions have reported 134,503 laboratory-confirmed cases of novel influenza A (H1N1) and 816 deaths. The lab-confirmed cases represent an underestimation of total cases in the world as many countries have shifted to strategies of clinical confirmation and prioritization of laboratory testing for only persons with severe illness and/or high risk conditions. Currently, the novel influenza A (H1N1) virus is the dominant influenza virus in circulation in New Zealand, Australia, Chile, Argentina and Brazil. Influenza viruses currently being detected in England and Canada are almost exclusively novel Influenza A (H1N1). Following a seasonal influenza season that was dominated by influenza A (H3N2) virus circulation, South Africa is now detecting novel influenza A (H1N1) through its routine surveillance system. However, currently influenza A (H3N2) remains the dominant virus in circulation in South Africa. Many seasonal influenza viruses from these countries have not been subtyped. Of those that have been subtyped in Australia, South Africa, and Argentina, the majority are influenza A (H3N2) viruses.