CENTERS FOR DISEASE CONTROL AND PREVENTION(CDC)

Disease Characteristics
When the novel H1N1 flu outbreak was first detected in mid-April 2009, CDC began working with states to collect, compile and analyze information regarding the novel H1N1 outbreak. On July 24, 2009 official reporting of individual cases of confirmed and probable novel H1N1 infection was discontinued.
This situation report provides an update to the international situation as of August 14, 2009. World Health Organization (WHO) regions have reported 177,457 laboratory-confirmed cases of novel 2009-H1N1 influenza virus (new H1N1) with 1,462 deaths. The laboratory-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. The new H1N1 influenza virus is the dominant influenza virus in circulation in the world. According to a WHO Global Influenza Surveillance Network (GISN) report dated August 4th, 71% of all influenza viruses currently detected globally are the new H1N1. The new H1N1 accounts for 66% of influenza viruses in the Northern Hemisphere and 89% of influenza viruses in the Southern Hemisphere. There are indications that disease may be decreasing in South America and part of Australia. Disease associated with new H1N1 influenza is continuing to increase in southern Africa.
Selected Highlights
The new H1N1 influenza virus is the predominate influenza virus in circulation worldwide.
The epidemiology of the disease caused by the novel 2009-H1N1 influenza virus in the Southern Hemisphere is very similar to that described in the United States this past spring.
Isolates sequenced at WHO and CDC suggest that circulating novel 2009-H1N1 influenza viruses look similar to A/California/07/2009 (the reference virus selected by WHO as a potential candidate for the new H1N1 vaccine).

H1N1 Flu (Swine Flu): General Information
H1N1 Flu & YouWhat is novel H1N1 flu?
What To Do if You Get Flu-Like Symptoms
Antiviral Drugs
Taking Care of a Sick Person in Your Home
Novel H1N1 Vaccine: Q & A
Facemask & Respirators

Vaccination Recommendations
With the new H1N1 virus continuing to cause illness, hospitalizations and deaths in the US during the normally flu-free summer months and some uncertainty and about what the upcoming flu season might bring, CDC's Advisory Committee on Immunization Practices has taken an important step in preparations for a voluntary novel H1N1 vaccination effort to counter a possibly severe upcoming flu season. On July 29, ACIP met to consider who should receive novel H1N1 vaccine when it becomes available