In 2009, 65 diseases and conditions were nationally notifiable in Australia. States and territories reported a total of 236,291 notifications of communicable diseases to the National Notifiable Diseases Surveillance System, an increase of 48% on the number of notifications in 2008. This increase was largely due to cases of influenza A(H1N1) pandemic 2009. In 2009, the most frequently notified diseases were vaccine preventable diseases (101,627 notifications, 43% of total notifications), sexually transmissible infections (73,399 notifications, 31% of total notifications), and gastrointestinal diseases (31,697 notifications, 13% of total notifications). There were 18,861 notifications of bloodborne diseases; 8,232 notifications of vectorborne diseases; 1,919 notifications of other bacterial infections; 552 notifications of zoonoses and 4 notifications of quarantinable diseases.