Update: Novel Influenza A H1N1 Jeffrey S. Duchin, M.D., FACP, FIDSA Public Health- Seattle & King County Division of Allergy & Infectious Diseases University of Washington & Charissa Fotinos, MD August 31, 2009

What is influenza? Respiratory illness Mild to severe Symptoms: –fever and cough or sore throat –May include headache, extreme tiredness, runny nose, aches, vomiting, or diarrhea

What’s the difference between H1N1 and seasonal flu? H1N1 is new, so most people don’t have immunity H1N1 causes more serious illness among younger people

Why all the fuss? Influenza illness causes hospitalizations and death every year Most don’t have immunity to H1N1 and younger people are more vulnerable

Transmission

How does flu spread? Coughs and sneezes Most contagious during fever and 24 hours after fever has gone Not from eating pork or from pigs

Novel Influenza A H1N1- Transmission Limited data available indicate that this virus is transmitted in ways similar to other influenza viruses. Spread primarily through large-particle respiratory droplet transmission (e.g., when an infected person coughs or sneezes near a susceptible person). –Requires close contact between source and recipient persons because droplets do not remain suspended in the air and generally travel only a short distance (< 6 feet). Contact with contaminated surfaces is another possible source of transmission and transmission via droplet nuclei (also called “airborne” transmission). All respiratory secretions and bodily fluids (diarrheal stool) of novel influenza A (H1N1) cases should be considered potentially infectious.

Novel influenza A (H1N1) - Transmission Incubation and Infectious Period The estimated incubation period is estimated to range from 1-7 days, more likely 1-4 days. The estimated duration of viral shedding is based upon seasonal influenza virus infection. –Infected persons are assumed to be shedding virus from one day prior to illness onset until resolution of symptoms. In general, persons with novel influenza A (H1N1) virus infection should be considered potentially infectious from one day before to 7 days following illness onset. –Children, especially younger children, might be infectious for up to 10 days.

Where we’ve been.

Confirmed Cases of Novel Influenza A H1N1 by Illness Onset Date King County, WA, 2009

Confirmed cases through July 31, 2009

Hospitalized Patients By Age and ICU Status 2009, King County, WA

Who Seems to be at Higher Risk of Hospitalization?

Distribution by Age Group of Influenza Hospitalized Cases Emerging Infections Program - Pandemic H1N1 -14 JUL 2009 *April 12 – June 30 Draft: Not for distribution

Disparities Exist

What’s Happening Now?

Outpatient Visits for ILI in WA

Vaccination

Who should get flu vaccine Anyone over 6 months Priority groups: –Pregnant women –Caregivers of babies younger than 6 months –Age 6 months – 24 years –Age years with chronic health conditions –Healthcare and emergency medical services personnel Plenty for all later

Groups Recommended to Receive Novel H1N1 Influenza Vaccine – June, 2009 Pregnant women HH contacts and caregivers for children <6 mo. of age Healthcare and emergency medical services personnel All people from 6 months - 24 years of age Persons aged years who have health conditions associated with higher risk of medical complications from influenza.

Groups Recommended to Receive Novel H1N1 Influenza Vaccine First When Supply is Limited Pregnant women People who live with or care for children younger than 6 months of age Health care and emergency medical services personnel with direct patient contact Children 6 months through 4 years of age Children 5 through 18 years of age who have chronic medical conditions

Groups at Increased Risk for Seasonal Influenza Complications Children less than 5 years old Persons aged 65 years or older Children and adolescents (less than 18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection Pregnant women Adults and children who have chronic pulmonary, cardiovascular, hepatic, hematological, neurologic, neuromuscular, or metabolic disorders Adults and children who have immunosuppression (including immunosuppression caused by medications or by HIV) Residents of nursing homes and other chronic-care facilities

Treatment

A Word or Two About Protection Hand hygiene is key Cover your cough Stay Home when sick Surgical vs. N-95 masks Get vaccinated if you are able and OK with it

Antiviral Treatment Treatment with O or Z is recommended for all persons with suspected or confirmed influenza requiring hospitalization. Treatment with O or Z is recommended for persons with suspected or confirmed influenza who are at higher risk for complications –children, <5 years old –adults >64 years old –pregnant women, –persons with certain chronic medical or immunosuppressive conditions –and persons <19 years of age taking long-term aspirin therapy. Treatment generally is not recommended for persons who are not at higher risk for complications or do not have severe influenza requiring hospitalization.

Antiviral Treatment: Pregnant Women Oseltamivir and zanamivir are "Pregnancy Category C" medications, indicating that no clinical studies have been conducted to assess the safety of these medications for pregnant women. Pregnancy should not be considered a contraindication to oseltamivir or zanamivir use. Because of its systemic activity, oseltamivir is preferred for treatment of pregnant women. The drug of choice for chemoprophylaxis is less clear. Zanamivir may be preferable because of its limited systemic absorption; however, respiratory complications that may be associated with zanamivir because of its inhaled route of administration need to be considered, especially in women at risk for respiratory problems.

Antiviral Chemoprophylaxis Antiviral chemoprophylaxis generally should be reserved for persons at higher risk for influenza-related complications. Post-exposure antiviral chemoprophylaxis (PEP) with either oseltamivir or zanamivir can be considered for the following: –Persons who are at higher risk for complications of influenza and are a close contact of a person with confirmed, probable, or suspected influenza during that person’s infectious period. –Health care personnel, public health workers, or first responders who have had a recognized, unprotected close contact exposure to a person with confirmed, probable, or suspected influenza during that person’s infectious period.

Community Measures CDC recommends that people with influenza-like illness remain at home until at least 24 hours after they are free of fever (100° F [37.8°C]), or signs of a fever without the use of fever-reducing medications. –This is a change from the previous recommendation that ill persons stay home for 7 days after illness onset or until 24 hours after the resolution of symptoms, whichever was longer. –The new recommendation applies to camps, schools, businesses, mass gatherings, and other community settings where the majority of people are not at increased risk for influenza complications.

Messages For Clients

How you can protect yourself Wash your hands often Avoid touching your eyes, nose, and mouth Avoid close contact with sick people Stay healthy with sleep, exercise, stress management, and eating well

Why flu vaccine is important Best protection against flu Stimulates body’s immunity Need separate vaccinations for H1N1 and seasonal flu

H1N1 vaccine is safe Safe as seasonal flu vaccines Same process and testing as seasonal flu vaccines Most will not have side effects Any side effects will likely be mild (1-2 days): –Soreness, redness, or swelling –Mild fever, aches Don’t get vaccine if you are allergic to eggs

What to do if you are sick Stay home until at least 24 hours after fever is gone Drink liquids and rest Wash hands often Cover coughs and sneezes Avoid contact with other people

Free up doctors to help those who need it most Most won’t need to see doctor Testing is not needed unless seriously ill Call for advice before making an appointment Note from doctor not recommended to return to work, school, or childcare

When to seek medical care In a high risk group Ill person is a baby less than 1 year Having severe symptoms: ChildrenAdults Difficulty or fast breathing Bluish or grayish skin (call 911) Not able to drink Severe, persistent vomiting Not waking or interacting Not wanting to be held Flu symptoms improve then return with fever and worse cough Difficulty breathing Pain or pressure in chest/abdomen Sudden dizziness Severe, persistent vomiting Confusion Flu symptoms improve then return with fever and worse cough

Dealing with flu in the workplace Sick employees should stay home Encourage sick employees to go home Do not require doctor’s note to return to work Routinely clean areas used by employees Encourage hand washing and covering coughs and sneezes Guidance at

Parting Thoughts Many of your folks are at higher risk for hospitalization and serious illness Prevention, washing hands*, covering coughs is good The H1N1 vaccine is effective and safe, and folks at risk should be encouraged to get it If your clients develop symptoms and are at risk, early treatment, within 2 days, is important