ALI HASSOUN, MDALABAMA INFECTIOUS DISEASES CENTER

HUNTSVILLE, AL

H1N1 2009 pandemicWhat you need to Know

What is ‘the flu’?

An illness caused by influenza virusA sudden onset respiratory illness with fever

Affects nose, throat, air passages, and lung Yearly epidemics Occurs worldwide causing significant illness

How are viruses different from other germs?

Much smaller than animal cells or bacteriaViruses need to get a life!

Need to be inside our cells to live

Our cells become virus factoriesInfluenza virus kills cells in breathing

passages

What does an influenza virus look like?

Hemagglutinin protein Allows virus to stick to

cells of some animals and not others

Neuraminidase protein Helps release new virus

from cells

Genes (RNP) divided into 8 parts Allows 2 or more viruses

to mix and match genes

Fig.1 Electron micrograph

Fig.2 Schematic of influenza virus

Why are the numbered “H” and “N” important?

Used to subtype influenza A strains 16 different H’s 9 different N’s

Current human subtypes A(H1N1) and A(H3N2) primarily

Antibodies against H’s and N’s made by our immune system protect usH and N subtypes are basis for flu vaccines

How is influenza spread?

Patients with pandemic H1N1 influenza A virus infection are likely to be contagious from one day prior to the development of signs and symptoms until resolution of fever.

Incubation– Typically 2 days Range 1 to 4 days

Viral shedding Can begin 1 day before the onset of symptoms Peak shedding first 3 days of illness

Correlates with fever Subsides usually by 7 days

Can be 10+ days in children

Is flu only spread through the air?

Large droplet mostly Generated by coughing,

sneezing, talking “spitting distance”

Contact with contaminated hands or surfaces, sometimes

Microscopic droplets less common

Certain other bodily fluids (eg, diarrheal stool) should also be considered potentially infectious

the consequences of yearly epidemics in U.S.A?

> 36,000 die and 200,000 are hospitalized5 to 20% of general population infectedNursing home attack rates of up to 60%85% of flu-related deaths in ages > 65Over $10 billion lost

What about past flu pandemics?

A(H1N1) A(H2N2) A(H3N2)1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu”

20-40 m deaths

675,000 US deaths

1-4 m deaths

70,000 US deaths

1-4 m deaths

34,000 US deaths

Credit: US National Museum of Health and Medicine

H1N1 2009 pandemic

In March and April 2009, an outbreak of respiratory illnesses was first noted in Mexico, which was eventually identified as being related to H1N1 influenza A. The outbreak spread rapidly to the United States, Canada, and throughout the world as a result of airline travel

As of July 31, 2009, over 162,000 laboratory-confirmed cases had been reported in over 160 countries

In the United States, as of July 24, 2009, over 43,000 confirmed cases had been reported from 55 states and territories.

In Alabama as of August 19, 1587 confirmed cases and madison county had 115 cases

Novel H1N1 Confirmed and Probable Case Rate in the United States, By Age Group

What are symptoms of H1N1 flu?

Fever, usually > 101oF, and chillsSore throatNasal congestion and runny noseHeadacheBody and muscle achesDry coughTiredness and weaknessNausea, vomiting, diarrhea. gastrointestinal

manifestations appear to be more common

the most common risk factors for influenza complications

1.Chronic lung disease (asthma or chronic obstructive pulmonary disease)

2.Immunosuppressive conditions 3.Cardiac disease 4.Pregnancy 5.Diabetes mellitus 6.Obesity

Who is at risk for severe infection with H1N1 virus?

Treatment is mostly supportive with rest, fluids, cough medicine, and antipyretics such as Tylenol. Aspirin should be avoided.

It can be treated with antivirals. Mainly for at risk population and hospitalized patients with more than mild symptoms. Oseltamivir (Tamiflu)–

capsules and oral liquid Zanamivir (Relenza)–

Inhaled powder

How is H1N1 influenza treated?

No protection from current flu vaccine H1N1 vaccine will be available mid October,

initially will be indicated:1. Pregnant women,2. People who live with and care for children younger

than 6 months of age,3. Healthcare and emergency medical services

personnel,4. People between the ages of 6 months and 24 years5. People ages 25–64 years of age who have chronic

health conditions (such as asthma, heart disease, or diabetes) or compromised immune systems.

Will a regular flu vaccine protect me?

When should I call my healthcare provider?

Call if you get concerned about your symptoms especially if you or a family member are high risk.

If you have a fever and two or more other flu symptoms especially if symptoms are severe Your provider may recommend tests or treatment with

antivirals

If unable to drink fluids, have dark urine, or feel dizzy when standing (signs of dehydration)

If you have a fever for more than 3 to 5 days even if you have already been treated

If you start to recover from the flu symptoms and you get fever again.

When to Seek Emergency Medical Care

has difficulty breathing or chest pain has purple or blue discoloration of the lips is vomiting and unable to keep liquids down has signs of dehydration such as dizziness

when standing, absence of urination, or in infants, a lack of tears when they cry

has seizures (for example, uncontrolled convulsions)

is less responsive than normal or becomes confused

What should I do if I’m exposed to someone with H1N1 influenza?

Anti-viral prophylaxis is recommended for certain groups of people.

Household close contacts who are at high-risk of complications of a confirmed or probable case Your healthcare provider can tell you if you need

preventative medication If you are not in a high-risk group you should:

Limit your contact with others in the community Stay home at the earliest sign of flu symptoms

For updates see: http://www.cdc.gov/h1n1flu/recommendations.htm

What should People with novel H1N1 flu do ?

Check with their health care provider about whether they should take antiviral medications

Keep away from others as much as possible. Do not go to work or school while ill

Stay home for at least 24 hours after fever is gone, except to seek medical care or for other necessities. (Fever should be gone without the use of a fever-reducing medicine.)

Drink clear fluids (such as water, broth, sports drinks, electrolyte beverages for infants) to keep from being dehydrated

Cover coughs and sneezes. Clean hands with soap and water or an alcohol-based hand rub often and especially after using tissues and after coughing or sneezing into hands

Wear a facemask – if available and tolerable – when sharing common spaces with other household members to help prevent spreading the virus to others.

be watchful for emergency warning signs that might indicate you need to seek medical attention.

Placement of the sick person

Keep the sick person in a room separate from the common areas of the house. Keep the sickroom door closed.

Unless necessary for medical care or other necessities, people who are sick with an influenza-like-illness should stay home and keep away from others as much as possible

If possible, sick persons should use a separate bathroom. This bathroom should be cleaned daily with household disinfectant.

Protect other persons in the home

The sick person should not have visitors other than caregivers. If possible, have only one adult in the home take care of the sick person. If you are in a high risk group for complications from influenza, you should

attempt to avoid close contact (within 6 feet) with household members who are sick with influenza.

Avoid having sick family members care for infants and other groups at high risk for complications of influenza.

All persons in the household should clean their hands frequently, including after every contact with the sick person or the person’s room or bathroom.

Use paper towels for drying hands after hand washing or dedicate cloth towels to each person in the household. For example, have different colored towels for each person.

If possible, consideration should be given to maintaining good ventilation in shared household areas (e.g., keeping windows open in restrooms, kitchen, bathroom, etc.).

Antiviral medications can be used to prevent the flu, so check with your health care provider to see if some persons in the home should use antiviral medications.

What about masks in a pandemic?

Masks outside a healthcare setting can be considered in some circumstances.

Facemasks considered for crowded settings (avoid if possible and minimize time) Protect wearer from others’ cough and protect others from

wearer’s cough Single use

Respirators (N95) considered when close contact with infected person is unavoidable Care of sick person at home Requires fit-testing to be effective Single use

What about household cleaning, laundry, and waste disposal?

Throw away tissues and other disposable items used by sick person in the trash (wash hands)

Keep surfaces clean by wiping down with a household disinfectant according to label

Eating utensils and dishes of sick person Do not need to be cleaned separately; wash thoroughly in

dishwasher or with soap and waterLinens and towels

Household laundry soap and tumble dry on hot Avoid “hugging” laundry prior to washing to prevent

contaminating yourself Clean hands with soap and water or alcohol-based hand

rub right after handling dirty laundry

THANK YOU