Novel H1N1 Flu Situation Update
May 20, 2009, 11:00 AM ET

Map: Weekly Influenza Activity Estimates, Including Novel H1N1 Flu
May 20, 2009

Table. U.S. Human Cases of H1N1 Flu Infection
(As of May 20, 2009, 11:00 AM ET)

States*	Confirmed and Probable Cases	Deaths
Alabama	64 cases	0 deaths
Arizona	488 cases	2 deaths
Arkansas	3 cases	0 deaths
California	553 cases	0 deaths
Colorado	55 cases	0 deaths
Connecticut	59 cases	0 deaths
Delaware	88 cases	0 deaths
Florida	122 cases	0 deaths
Georgia	25 cases	0 deaths
Hawaii	26 cases	0 deaths
Idaho	8 cases	0 deaths
Illinois	794 cases	0 deaths
Indiana	105 cases	0 deaths
Iowa	71 cases	0 deaths
Kansas	34 cases	0 deaths
Kentucky**	20 cases	0 deaths
Louisiana	73 cases	0 deaths
Maine	9 cases	0 deaths
Maryland	39 cases	0 deaths
Massachusetts	175 cases	0 deaths
Michigan	171 cases	0 deaths
Minnesota	39 cases	0 deaths
Mississippi	5 cases	0 deaths
Missouri	20 cases	1 deaths
Montana	9 cases	0 deaths
Nebraska	28 cases	0 deaths
Nevada	33 cases	0 deaths
New Hampshire	22 cases	0 deaths
New Jersey	22 cases	0 deaths
New Mexico	68 cases	0 deaths
New York	284 cases	1 deaths
North Carolina	12 cases	0 deaths
North Dakota	5 cases	0 deaths
Ohio	13 cases	0 deaths
Oklahoma	43 cases	0 deaths
Oregon	94 cases	0 deaths
Pennsylvania	55 cases	0 deaths
Rhode Island	8 cases	0 deaths
South Carolina	36 cases	0 deaths
South Dakota	4 cases	0 deaths
Tennessee	86 cases	0 deaths
Texas	556 cases	3 deaths
Utah	72 cases	0 deaths
Vermont	1 cases	0 deaths
Virginia	23 cases	0 deaths
Washington	411 cases	1 death
Washington, D.C.	13 cases	0 deaths
Wisconsin	766 cases	0 deaths
TOTAL*(48)	5,710 cases	8 deaths
*includes the District of Columbia **one case is resident of KY but currently hospitalized in GA. This table will be updated daily Monday-Friday at around 11 AM ET. International Human Cases of Swine Flu Infection See: World Health Organization. NOTE: Because of daily reporting deadlines, the state totals reported by CDC may not always be consistent with those reported by state health departments. If there is a discrepancy between these two counts, data from the state health departments should be used as the most accurate number.

Summary of Situation

A New Influenza Virus

Novel influenza A (H1N1) is a new flu virus of swine origin that was first detected in April, 2009. The virus is infecting people and is spreading from person-to-person, sparking a growing outbreak of illness in the United States. An increasing number of cases are being reported internationally as well.

It’s thought that novel influenza A (H1N1) flu spreads in the same way that regular seasonal influenza viruses spread; mainly through the coughs and sneezes of people who are sick with the virus.

It’s uncertain at this time how severe this novel H1N1 outbreak will be in terms of illness and death compared with other influenza viruses. Because this is a new virus, most people will not have immunity to it, and illness may be more severe and widespread as a result. In addition, currently there is no vaccine to protect against this novel H1N1 virus. CDC anticipates that there will be more cases, more hospitalizations and more deaths associated with this new virus in the coming days and weeks.

Novel influenza A (H1N1) activity is now being detected through CDC’s routine influenza surveillance systems and reported weekly in FluView. CDC tracks U.S. influenza activity through multiple systems across five categories. The fact that novel H1N1 activity can now be monitored through seasonal surveillance systems is an indication that there are higher levels of influenza-like illness in the United States than is normal for this time of year. About half of all influenza viruses being detected are novel H1N1 viruses.

CDC Response

CDC continues to take aggressive action to respond to the outbreak. CDC’s response goals are to reduce the spread and severity of illness, and to provide information to help health care providers, public health officials and the public address the challenges posed by this new public health threat.

CDC is issuing updated interim guidance daily in response to the rapidly evolving situation.

Clinician Guidance

CDC has issued interim guidance for clinicians on identifying and caring for patients with novel H1N1, in addition to providing interim guidance on the use of antiviral drugs. Influenza antiviral drugs are prescription medicines (pills, liquid or an inhaler) with activity against influenza viruses, including novel influenza H1N1 viruses. The priority use for influenza antiviral drugs during this outbreak is to treat severe influenza illness, including people who are hospitalized or sick people who are considered at high risk of serious influenza-related complications.

Public Guidance

In addition, CDC has provided guidance for the public on what to do if they become sick with flu-like symptoms, including infection with novel H1N1. CDC also has issued instructions on taking care of a sick person at home. Novel H1N1 infection has been reported to cause a wide range of symptoms, including fever, cough, sore throat, body aches, headache, chills and fatigue. In addition, a significant number of people also have reported nausea, vomiting or diarrhea. Everyone should take everyday preventive actions to stop the spread of germs, including frequent hand washing and people who are sick should stay home and avoid contact with others in order to limit further spread of the disease.

Testing

CDC has developed a PCR diagnostic test kit to detect this novel H1N1 virus and has now distributed test kits to all states in the U.S. and the District of Columbia and Puerto Rico. The test kits are being shipped internationally as well. This will allow states and other countries to test for this new virus. This increase in testing will likely result in an increase in the number of confirmed cases of illness reported. This, combined with ongoing monitoring through Flu View should provide a fuller picture of the burden of disease in the United States over time.

See also the FluView Surveillance Report for the week ending May 9, 2009.

More on the Situation

• Guidance
• Reports & Publications
• Press Briefing
• Past Updates on the Situation