Health Alert
SEASONAL INFLUENZA ACTIVITY AND TREATMENT OF PATIENTS WITH INFLUENZA IN DELAWARE

The Delaware Division of Public Health (DPH) is issuing this health advisory to advise health care providers of increased influenza (flu) activity in Delaware, what precautions can be taken and recommendations that can be made for patients experiencing flu-like symptoms.

Summary

The level of influenza activity in Delaware is at record levels in the state. DPH urges providers to continue to vaccinate their patients against the flu and to start patients who have a clinical picture consistent with influenza on neuraminidase inhibitor antivirals (such as oseltamivir) as soon as possible and without waiting for results of laboratory testing.

Due to the ongoing strain on the hospitals, providers are encouraged to direct to the emergency room (ER) only those patients experiencing serious or life-threatening symptoms. Patients with less serious symptoms related to influenza can be cared for by primary care providers or at walk-in clinics.

Providers should also consider calling in prescriptions for antivirals for patients with flu like symptoms without waiting for an office visit, and communicate to patients the importance of staying home from work, or in the case of children – school, while sick to prevent further spread of the disease.

Background

Influenza activity remains high

The number of Delaware laboratory-confirmed flu cases for the 2017-2018 season are at record high levels. Total laboratory-confirmed flu cases have now surpassed 4,100. The total for the entire 2016-2017 season was 4,590 laboratory-confirmed cases, which was a record high for the time. Additionally, for the week of Feb. 4 to Feb. 10, 2018, single week totals have exceeded 1,200 lab-confirmed cases, which is almost double the previous single week total record of 671 during the 2009-2010 flu season.

As of February 15, 2018, Delaware has seen 11 flu-related deaths for the 2017-2018 season, most of whom have been patients over 60 with chronic underlying health conditions. The latest reported death was to a 47-year old individual who had no underlying health conditions, and had not been vaccinated. To date, eight of the 11 deaths have been New Castle County residents and three have been Sussex County residents. There have not been any flu-related deaths in Kent County reported.

The age groups hit hardest with the flu this year have been persons aged 5 to 24 (875) – most of them in the 5 to 13 age range, as well as infants and children birth to 4 (461). To date, persons age 65 and older comprise 62.6 percent of the hospitalizations. 513 have been hospitalized this season due to flu complications – more than double the 199 at this time last year.

While there are signs that flu activity may be declining along the West coast, overall, influenza-like-illness increased again nationally. This is highest level of influenza-like illness recorded since the 2009 H1N1 pandemic

While H3N2 viruses continue to be predominant this season, the nation is seeing the proportion of H3N2 viruses begin to decline and an increase in the proportion of influenza B viruses and, to a lesser extent, H1N1 viruses as well.

Vaccine effectiveness estimates released

The Centers for Disease Control and Prevention (CDC) released the results of vaccine effectiveness studies for the 2017-18 season on Thursday Feb. 15, 2018. Over¬all adjusted vaccine effectiveness (VE) against medically attended influenza A and influenza B virus infection was 36%. VE was estimated to be 25% (CI = 13% to 36%) against illness caused by influenza A(H3N2) virus, 67% (CI = 54%–76%) against A(H1N1)pdm09 viruses, and 42% (CI = 25%–56%) against influenza B viruses.

Of note, VE was much higher in children 6 months through 8 years of age: overall VE against influenza A and B viruses was 59% (95% CI: 44%–69%) in this age group.

Children in this age group also had higher VE specifically against A(H3N2). VE against A(H3N2) viruses was 51% (95% CI: 29%—66%) in children 6 months through 8 years of age. This means the risk for A(H3N2) illness that required a doctor’s visit was reduced by more than half among this group of vaccinated children.

The interim estimate of 25% VE against A(H3N2) viruses this season indicates that vaccination provided some protection, in contrast to recently reported, interim estimates of 17% from Canada and 10% from Australia and is similar to final (32%) VE estimates in the United States against A(H3N2) viruses during 2016–17 season.

Vaccine and Antiviral Availability

While some individual medical providers are reporting spot shortages, the CDC indicates there is enough available. Individuals who need a shot, may have to be persistent in calling additional places to find it. They can also visit vaccinefinder.org to check availability. Providers and pharmacies who may be having an issue with their supply should check the influenza vaccine tracking availability system (IVATS) available at:  https://www.izsummitpartners.org/ivats/.

Regarding anti-virals, the CDC is aware that some manufacturers are reporting delays in filling orders and CDC is aware of spot shortages specifically for oseltamivir (Tamiflu) suspension. The CDC’s guidance is that pharmacists should consider compounding oseltamivir suspension by using oseltamivir capsules if suspension is not readily available.

The CDC has updated its antiviral drug supply web page with manufacturer information for inquires related to antiviral purchases/availability. Pharmacists can also visit the American Society of Health-System Pharmacists webpage for current updates on shortages and supply./

Recommendations

The Centers for Disease Control and Prevention (CDC) and DPH continue to recommend influenza vaccination because the vaccine can still prevent some infections with currently circulating influenza viruses, which are expected to continue circulating for several weeks. Even with current vaccine effectiveness estimates, vaccination will still prevent influenza illness, including thousands of hospitalizations and deaths.

Because emergency rooms are being overwhelmed by patients with influenza-like illnesses, DPH recommends primary care providers only direct patients to the ER if they have serious or life-threatening symptoms. If patients are calling and you do not have the ability to see them right away, direct them to urgent care or walk-in facilities, or consider calling in a prescription for antivirals for them if they report signs and symptoms consistent with influenza.

In addition, DPH recommends starting patients with a clinical picture consistent with influenza on antivirals without waiting for the results of laboratory testing for influenza. All hospitalized and severely ill and high-risk patients should be treated with antivirals.

DPH strongly encourages providers to communicate the following recommendations to all patients:

1.  If you are sick, stay home from work, and do not send children to school, unless you/they are free of fever - with a temperature less than 100 degrees F (37.8 degrees C) without the use of fever-reducing medications for at least 24 hours.
2.  Call your primary care provider to discuss treatment options as soon as possible.
3.  To prevent the spread of germs, wash your hands frequently with soap and water, or using alcohol-based hand sanitizers.
4.  Frequently wipe down often-touched surfaces with soap and water or disinfecting products.
5.  Cover sneezes and coughs with a tissue, and dispose of tissues immediately; if no tissue is available sneeze or cough into your inner elbow.

Those who become ill with the flu should also:

1.  Take antiviral medications as prescribed.
   1.  CDC recommends antiviral medications for treatment of influenza as an important adjunct to annual influenza vaccination. Treatment with neuraminidase inhibitors has been shown to have clinical and public health benefit in reducing illness and severe outcomes of influenza based on evidence from randomized controlled trials, meta-analyses of randomized controlled trials, and observational studies during past influenza seasons and during the 2009 H1N1 pandemic.
2.  Avoid close contact with well people in the household.
3.  Stay well-hydrated by drinking plenty of water and other clear liquids.

Reporting

Flu is a reportable disease in Delaware.

Communicable Disease Reporting in Delaware can be found at http://dhss.delaware.gov/dph/dpc/rptdisease.html and includes:

•  How to report
•  What to report
•  Notifiable diseases

Resources

•  For more information about flu surveillance in Delaware, read the weekly flu report at http://dhss.delaware.gov/dph/epi/influenzawkly.html
•  For the CDC Morbidity and Mortality Weekly Report, visit https://www.cdc.gov/mmwr/volumes/67/wr/mm6706a1.htm?s_cid=mm6706a1_w
•  Seasonal Influenza A (H3N2) Activity and Antiviral Treatment of Patients with Influenza health advisory: http://www.dhss.delaware.gov/dph/php/alerts/dhan380.html

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