DELAWARE MONITORS FOR NEW FLU STRAINS

Delaware's Division of Public Health (DPH) has alerted health care providers statewide to an increase, elsewhere in the United States, in the number of detected human infections due to swine-origin strains of influenza A. This increase could be occurring for a number of reasons, including improved laboratory methods, increased surveillance, or a true increase in cases.

Specifically, two new sub-strains of swine influenza A have occurred across five states and have the potential to emerge in Delaware. The Centers for Disease Control and Prevention (CDC) report that there have been no deaths related to the new sub-strain known as H3N2; however, the sub-strain has been related to cases of severe illness and hospitalization. This sub-strain has been identified in 11 people nationwide as follows: West Virginia 1; Indiana 2; Pennsylvania 3; Maine 2; and Iowa 3. CDC has also confirmed that influenza in a Minnesota child was caused by a different sub-strain, known as H1N2.

According to the CDC, this year's flu vaccine may not provide protection against the H3N2 and H1N2 influenza subtypes. The H3N2 influenza subtype has similarities to viruses that circulated in the 1990s. For that reason, older individuals may have some existing partial immunity, but children of elementary school age and younger may be more likely to contract this strain. The epidemiology of the identified H3N2 subtype clusters suggests person-to-person transmission. The H1N2 influenza virus resembles a human strain that circulated as recently as 2007 and people with prior exposure may have some partial immunity.

CDC has confirmed that antiviral medications Oseltamivir (Tamiflu) and Zanamivir (Relenza) can be used to treat both H3N2 and H1N2 influenza subtype viruses.

Health care providers are advised to be more vigilant for these new influenza A strains, particularly in the following situations: 1) Outbreaks of influenza-like illness (ILI), especially among children or in day care or school settings; 2) Unusual or severe presentation of influenza illness, especially among children; and 3) ILI in children under 18 years of age who require medical attention.

Additionally, DPH continues to monitor the occurrence of influenza and influenza-like illness through its influenza surveillance network, which includes family and internal medicine practices, pediatricians, infectious disease physicians, child care centers, hospitals, long term care facilities, correctional institutions, and colleges/universities. These sentinels provide an early indication of the possible presence of flu by weekly reporting the number of occurrences of ILI. DPH also has asked healthcare providers in the surveillance network to submit to increase the number of specimens they submit each week from patients with ILI.

Delaware's only case of influenza for the 2011-2012 season was identified as a typical strain A/H3 occurring in an 11-year-old boy from Wilmington. To date, no documented illnesses from these influenza sub-strains have occurred in Delaware. Influenza subtypes known to have circulated in Delaware during the 2010-2011 influenza season were the expected, seasonal, vaccine-susceptible strains: 2009 H1N1, seasonal influenza A H 3, and influenza B.

Prevention is still the best medicine when it comes to influenza. Seasonal influenza strains are known to cause severe illness in some groups, such as people over 65 years of age. Everyone should get a flu shot and take simple everyday measures such as washing hands, using hand sanitizers, covering coughs and sneezes and staying at home when sick.

For more information, go to dhss.delaware.gov/dhss/dph/dpc/immunize-flu.html

Delaware Health and Social Services is committed to improving the quality of the lives of Delaware's citizens by promoting health and well-being, fostering self-sufficiency, and protecting vulnerable populations.