Flu and other respiratory viruses increasing in Iowa

January 14, 2013

Flu and other respiratory viruses increasing in Iowa

The Iowa Department of Public Health says the number of reported influenza cases is increasing quickly in Iowa. All three strains of seasonal flu have been confirmed in the state and all are covered by the vaccine. The primary strain circulating in Iowa is influenza A (H3N2). IDPH strongly encourages all people over 6 months of age to get a flu shot if they have not already done so. Once vaccinated, it takes approximately two weeks to develop full immunity against the strains included in the influenza vaccine. In Iowa, influenza outbreaks can begin as early as October and last through March and beyond. For more information on flu, visit www.idph.state.ia.us/Cade/Influenza.aspx?pg=FluHome.

Flu vaccine availability in Iowa

While supplies of influenza vaccine remains adequate, spot shortages are being reported in Iowa. As of Thursday, January 10, the Vaccines for Children and Immunization programs have nearly 2,800 doses of influenza vaccine still available on a first-come, first-served basis. This vaccine is for use in VFC eligible children ages six months through 18 years. If interested in obtaining doses, please contact Tina Patterson at (800) 831-6293, Ext 4 as soon as possible.

Flu strains in Iowa are susceptible to antiviral medications

The currently circulating influenza viruses in Iowa are susceptible to the neuraminidase inhibitor antiviral medications oseltamivir and zanamivir; however, rare sporadic cases of oseltamivir-resistant 2009 H1N1 and A (H3N2) viruses have been detected worldwide.

Antiviral treatment with oseltamivir or zanamivir is recommended as early as possible for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at greater risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at www.cdc.gov/flu/antivirals/index.htm.

Updated confirmatory influenza test guidance

The prevalence of influenza in Iowa has increased to the level in which the positive predictive value of the rapid influenza screening tests is now acceptable. Thus, in most situations positive tests using rapid influenza screening will no longer need to be confirmed at SHL.

However, confirmatory testing at SHL is still recommended in the following situations:

  • Patients that are hospitalized (inpatient, not ER patient) with influenza-like illness (regardless of the rapid test result or if not tested).
  • When an influenza outbreak is suspected (especially in high-risk situations or a closed population such as a long-term care, schools, child care, hospitals, etc.). We recommend obtaining specimens from a few ill patients for testing to identify the microbe responsible. This can help target interventions such as anti-viral meds, quarantine and isolation, and prophylactic treatments.
  • Patients with influenza-like illness from designated influenza surveillance sentinel sites.
  • If confirmation is desired because of special circumstances (please note circumstances on the test request form when submitted to SHL).

It is also recommended to perform specific viral testing for high risk patients (hospitalized, immune-compromised, etc.) especially when influenza and RSV are in the differential diagnosis – so that antiviral agents can be appropriately used (or stopped as the case may be).

For more information on influenza testing at SHL, visit www.shl.uiowa.edu/services/influenza/. For influenza activity reports, visit www.idph.state.ia.us/IdphArchive/Archive.aspx?channel=FluReports.

FDA expands Tamiflu use for young children

The FDA has approved the expanded use of Tamiflu (oseltamivir) to treat children as young as two weeks old who have had symptoms of flu for less than two days. It is important to note that the drug is not approved for use in preventing influenza infection in this population. Note: the safety and efficacy of Tamiflu to treat influenza has not been established in children younger than two weeks old. For more information, visit: www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm333205.htm Children younger than two years are at high risk for developing complications from the influenza, and the highest rates of hospitalization are found in children less than six months of age.

Influenza and other respiratory viruses update

Current surveillance in Iowa shows that the majority of circulating influenza is the typical seasonal A(H3N2) which is a good match for the vaccine strain. Also being seen in Iowa is the A(H1N1) strain, which is also in the vaccine. Because the vaccine is not 100% effective (especially in the elderly, those with chronic diseases and who are immune-compromised), “cocooning” is recommended around these high-risk people and around babies who are too young to be vaccinated. Also recommended are the “Three C’s” – covering cough, cleaning hands and containing self at home when ill. Surveillance is also detecting parainfluenza virus types 2 and 3, RSV, rhinovirus and adenovirus. The influenza vaccine does not protect against any these other respiratory viruses.

Dual influenza type positive case report in Iowa

Last week, a seven-year-old patient (whose last influenza vaccination was in January 2011) presented for medical care because of a fever, cough, and headache. A rapid influenza test was positive. The specimen was then sent to SHL for confirmation testing, which detected both influenza A(H3) and influenza B. Dual infections are rare, but can occur during times when several influenza strains are circulating simultaneously. Currently, influenza A (H3), influenza A(H1N1) and influenza B are all circulating in Iowa, so potentially a person could be sick with all three flu viruses at the same time if they weren’t vaccinated.

Are vaccinated people getting influenza?

The efficacy of the influenza vaccine is high as it pertains to preventing serious illness (hospitalizations and death), but only about 60% to 85% effective in preventing all symptoms of the flu. The efficacy of the vaccine can also vary by patient’s age, health, previous vaccine/disease history, etc. And this is when the vaccine strains and the influenza strains in the community are well matched (this year they are well matched).

We do NOT expect everyone who is vaccinated to NEVER have any flu infections/flu symptoms (as is sometimes expected by the public). People who are healthy, young and been vaccinated in previous years will have about 90% protection against infection/symptoms and probably close to 100% protection from death after being vaccinated for that flu season. But those who are elderly, sick, and never been vaccinated in previous years, may have only a 40 - 60% protection from any symptoms, and about 70%- 80% protection from death. (Note - These are all rough estimates).

Bottom line: The flu vaccine is the best tool we have to prevent influenza. However, the answer is “yes”- we expect some people who have been vaccinated to get the flu and have some symptoms, but we don’t expect very many of them to have serious, life-threatening illnesses.

Pertussis

There were large numbers of pertussis cases both in Iowa and in the United States in 2012. Other European countries such as England, Estonia, Norway and the Netherlands also had high numbers. Sadly, England alone has reported 14 infant deaths from Pertussis in 2012.

Most of these countries had highest levels of illness in unvaccinated infants and adolescents. While it is recommended that everyone be up to date on their Pertussis vaccination, it is important that any adults traveling to Europe ensure that they have received their Tdap booster. For more information, visit www.cdc.gov/pertussis/countries.html.

Norovirus in Iowa

Norovirus outbreaks also have been reported in Iowa. These outbreaks have occurred among employees and residents of long-term care facilities, parties, and office get-togethers. Norovirus is the most common cause of vomiting and diarrheal outbreaks in Iowa. Those in certain high-risk occupations (i.e. food handlers, healthcare providers, childcare providers) should not work while ill. Note: people can remain infectious for a couple days after symptoms have resolved, so individuals in these occupations should not return to work until 48 hours after symptoms have ended.

While individual cases of Norovirus are not reportable in Iowa, all outbreaks must be reported. If an outbreak is suspected, please collect stool samples from patients and contact public health immediately. IDPH has guidance on how to clean and disinfect areas where outbreaks have taken place to prevent further transmission of the virus. For more information, visit: www.idph.state.ia.us/idph_universalhelp/main.aspx?system=IdphEpiManual and look for Norovirus under “Information on other diseases”.


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