Early Reports of pH1N1-Associated Illnesses: Alert for New Hampshire Clinicians

December 26, 2013

On December 24, 2013, the Centers for Disease Control and Prevention (CDC) issued CDCHAN-00359 to all state public health jurisdictions regarding reports of severe respiratory illness among young and middle-aged adults, many of whom were identified as infected with influenza A (H1N1) pdm09 (pH1N1) virus. This nomenclature refers to the same influenza strain that caused the 2009 pandemic: CDC has not yet detected any significant changes in pH1N1 viruses to suggest increased virulence or transmissibility, but if pH1N1 virus continues to circulate widely, illness that disproportionately affects young and middle-aged adults may occur.

Clinicians should encourage all persons with influenzalike illness who are at high risk for influenza complications to seek care promptly to determine whether treatment with influenza antiviral medications is warranted.

Antiviral treatment is recommended as early as possible for any patient with confirmed or suspected influenza who is hospitalized; has severe, complicated, or progressive illness; or is at higher risk for influenza complications. Antiviral treatment should not be withheld from patients with suspected influenza, even if they test negative. Clinicians should recall that rapid influenza diagnostic tests (RIDTs) have limited sensitivities and predictive values for pH1N1; therefore, negative results of RIDTs do not exclude influenza virus infection in patients with signs and symptoms suggestive of influenza.

New Hampshire (NH) has not reported widespread flu activity to date. However, of the 89 specimens tested by the NH Public Health Laboratories through December 22, 2013, 19 were positive for influenza A pH1N1, 3 were positive for influenza B, and 65 specimens were negative (2 specimens had invalid/inconclusive results).

The NH Division of Public Health Services (NH DPHS) recommends:

  1. Review of the CDCHAN-00359 for the 2013-14 influenza season update.

  2. Clinicians should encourage all patients 6 months of age and older who have not yet received an influenza vaccine this season to be vaccinated against influenza.

  3. Continued monitoring of influenza activity and prompt reporting of any clusters, outbreaks, or cases of severe respiratory illness to NH DHHS, DPHS, Bureau of Infectious Disease Control at 1- 603-271-4496 (after hours, 1-800-852-3345, ext. 5300).

For more information on 2013-2014 influenza vaccine options, see:


All available vaccine formulations this season contain a pH1N1 component.

For NH weekly influenza activity reports see:


For any questions regarding the contents of this message, please contact NH Department of Health and Human Services, DPHS, Bureau of Infectious Disease Control at 1-603-271-4496 (after hours, 1-800-852-3345, ext. 5300).


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: