Posts Tagged "H1N1"

Despite the recent Advisory below, it is still important to get vaccinated against Influenza this year. We offer the Quadrivalent Influenza vaccine which protects against 4 Influenza viruses including partial protection against the H3N2 virus.

Influenza activity is currently low in the United States as a whole, but is increasing in some parts of the country. This season, influenza A (H3N2) viruses have been reported most frequently and have been detected in almost all states.

During past seasons when influenza A (H3N2) viruses have predominated, higher overall and age-specific hospitalization rates and more mortality have been observed, especially among older people, very young children, and persons with certain chronic medical conditions compared with seasons during which influenza A (H1N1) or influenza B viruses have predominated.

Influenza viral characterization data indicates that 48% of the influenza A (H3N2) viruses collected and analyzed in the United States from October 1 through November 22, 2014 were antigenically “like” the 2014–2015 influenza A (H3N2) vaccine component, but that 52% were antigenically different (drifted) from the H3N2 vaccine virus. In past seasons during which predominant circulating influenza viruses have been antigenically drifted, decreased vaccine effectiveness has been observed. However, vaccination has been found to provide some protection against drifted viruses. Though reduced, this cross-protection might reduce the likelihood of severe outcomes such as hospitalization and death. In addition, vaccination will offer protection against circulating influenza strains that have not undergone significant antigenic drift from the vaccine viruses (such as influenza A (H1N1) and B viruses).

Because of the detection of these drifted influenza A (H3N2) viruses, this CDC Health Advisory is being issued to re-emphasize the importance of the use of neuraminidase inhibitor antiviral medications when indicated for treatment and prevention of influenza, as an adjunct to vaccination.

The two prescription antiviral medications recommended for treatment or prevention of influenza are oseltamivir (Tamiflu) and zanamivir (Relenza). Evidence from past influenza seasons and the 2009 H1N1 pandemic has shown that treatment with neuraminidase inhibitors has clinical and public health benefit in reducing severe outcomes of influenza and, when indicated, should be initiated as soon as possible after illness onset. Clinical trials and observational data show that early antiviral treatment can:

• shorten the duration of fever and illness symptoms;
• reduce the risk of complications from influenza (e.g., otitis media in young children and pneumonia requiring antibiotics in adults); and
• reduce the risk of death among hospitalized patients.

Source: CDC

Nearly half of the United States is reporting widespread influenza activity, most of it attributed to the H1N1 virus that caused a worldwide pandemic in 2009. Thousands of people die every year from flu, which peaks in the United States between October and March. The flu is spreading quickly this season, with 25 states already reporting cases. “We are seeing a big uptick in disease in the past couple of weeks. The virus is all around the United States right now,” said Dr. Joe Bresee, chief of Epidemiology and Prevention in the CDC’s Influenza Division. In 2009-2010, the H1N1 virus, also known as swine flu, spread from Central Mexico to 74 other countries, killing an estimated 284,000 people. While younger people were more susceptible to H1N1 in 2009, Bresee said it is too early to tell whether the same will be true this year. This season’s virus has killed six children in the United States, according to CDC data. The agency does not track adult deaths, but dozens have been reported around the country. “There is still a lot of season to come. If folks haven’t been vaccinated, we recommend they do it now,” Bresee said. Texas has been one of the harder hit states, where at least 25 people have died this season from the flu. The Texas Department of State Health Services issued an “influenza health alert” on December 20, advising clinicians to consider antiviral treatment, even if an initial rapid-flu test comes back negative. Texas health officials also encouraged people to get a flu shot. “The flu is considered widespread in Texas,” a spokeswoman for the state’s health department said.

Source: Reuters

The CDC has received a number of reports of severe respiratory illness among young and middle-aged adults, many of whom were infected with influenza A (H1N1) pdm09 (pH1N1) virus. Multiple pH1N1-associated hospitalizations, including many requiring intensive care unit (ICU) admission, and some fatalities have been reported.  While it is not possible to predict which influenza viruses will predominate during the entire 2013-14 influenza season, pH1N1 has been the predominant circulating virus so far.  For the 2013-14 season, if pH1N1 virus continues to circulate widely, illness that disproportionately affects young and middle-aged adults may occur. In the 2012-13 influenza season, CDC estimates that there were approximately 380,000 influenza-associated hospitalizations. Although influenza activity nationally is currently at low levels, some areas of the United States are already experiencing high activity, and influenza activity is expected to increase during the next few weeks. The spectrum of illness observed thus far in the 2013-14 season has ranged from mild to severe and is consistent with that of other influenza seasons. While CDC has not detected any significant changes in pH1N1 viruses that would suggest increased virulence or transmissibility, the agency is continuing to monitor for antigenic and genetic changes in circulating viruses. CDC recommends annual influenza vaccination for everyone 6 months and older. Anyone who has not yet been vaccinated this season should get an influenza vaccine now. While annual vaccination is the best tool for prevention of influenza and its complications, treatment with antiviral drugs (oral oseltamivir and inhaled zanamivir) is an important second line of defense for those who become ill to reduce morbidity and mortality. 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.

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