Centers for Disease Control

Novel Influenza A H1N1 Update

* Disease likely persists through summer in US, possible surge in late August when school returns
* Monitor closely for genetic and antigenic virus changes
* Expected higher attack rate (20-30%) than in spring (6-15%), notably affecting younger individuals
* Vaccine availability possibly mid October, Federal funds for distribution and administration are available
* Healthcare facility support in part from HPP grants
* SNS Antiviral stocks likely to be distributed
* Drifted H3N2 may co-circulate with novel H1N1

Update on pandemic influenza A(H1N1) activity, United States

• Oseltamivir (Tamiflu) and Zanamivir (Relenza)
• Randomized clinical trials (RCT): Reduced duration of influenza by 1-1.5 days when administered in 48 hours
• Pooled RCT analysis: Reduced lower respiratory tract complications, pneumonia, and hospitalization
• Observational studies*: Oseltamivir reduced mortality among hospitalized adults with lab-confirmed seasonal influenza A virus infections

Update on the epidemiology and clinical features of Novel H1N1

• January 2007 –“Novel influenza A” made a Nationally Notifiable Disease but CSTE –part of pandemic preparedness efforts
• RT-PCR for influenza capabilities developed by public health labs in U.S.
• Increasing numbers of swine influenza infections in humans being detected from improved surveillance
• Increasing efforts at states, CDC, and USDA to investigate human cases of swine influenza