# Presentation: 399876

## Larry D. Jecha MD MPHHealth Officer

## Pandemic Influenza

**Notes:**
Every year you hear “Get Your Flu Shot”.  So why are we concerned now?  This is different.  There’s something new out there.  

Pandemic Influenza refers to any type of influenza that spreads easily and quickly from person to person worldwide.  This influenza is a new type of virus that people have no immunity to, because we haven’t been exposed to it before. 

I’m here today because we need to be working together to plan and prepare for the next flu pandemic.  

## Why The Concern About Pandemic Influenza?

- Influenza pandemics are inevitable:  naturally recur at more-or-less cyclical intervals
- Can cause:
- High levels of sickness and death
- Drastic disruption of critical services
- Severe economic losses
- There will be little warning time between the onset of spread of a pandemic and its arrival in the U.S.

## Why The Concern About Pandemic Influenza?

- Outbreaks occur simultaneously in many areas
- Impacts will last for weeks to months
- Pandemics disproportionately affect younger, working-age people
- Current avian influenza outbreak in Asia

## Influenza

- Disease of swine, birds, horses and man
- Orthomyxoviridae (single strand RNA)

**Notes:**
So, what is ‘the flu’

It is a virus, like a cold, but a virus that can infect not only people, but also pigs, birds, horses and other animals.

It is in the family orthomyxoviridae, I mention this only because this family uses RNA as its means to reproduce, and viral RNA is notoriously fickle about swapping genetic material with other RNA that it meets

## Typical Flu Symptoms

- Fever (>102o F)
- Muscle and Joint Aches and Pains
- Dry Cough
- Runny Nose
- Sore throat
- GI symptoms in children and infants

**Notes:**
Once you are ill, you experience the normal fever, aches, pains, cough and other symptoms associated with the regular flu.
It is important to point out that typically the flu does not involve nausea, vomiting or diarrhea.  ‘Stomach flu’ is not influenza. 
However to confuse things, kids can have diarrhea or vomiting as their only symptom of influenza

## Spreading the Flu

- Droplet spread
- Infectious
- Adults: 1 day prior to symptoms to about 5 days after onset
- Children and immunocompromised much longer
- Incubation
- 1 to 4 days

- Image Source: *Human Biology*, Starr and McMillan

**Notes:**
Once the pandemic flu strain has established itself in humans, it is spread like any other flu.
Droplets are produced and spread by coughs and sneezing.
These droplets are infectious in adults from 1 day prior to the onset of symptoms to about 5 days after onset
Children and those who are immunocompromised can shed the virus for much longer
Once the flu is in you, it takes about 1 to 4 days to become ill.

## Death from Flu

- Viral Pneumonia
- Rapid destruction of lung tissue
- Secondary bacterial pneumonia
- Disrupted lung tissue
- Body’s defense mechanisms impaired
- Encephalitis
-  36-thousand Americans die each year

**Notes:**
In regular flu, you do run a chance of death, but this is far more likely in the pandemic strain.
Death can occur from a viral pneumonia where the lung is rapidly liquefied or can occur when a secondary bacterial pneumonia happens in the disrupted lung tissue when the body’s immune response is impaired
Another less frequent cause of death is a viral infection of the brain – an encephalitis

## Influenza A (H5N1) Pneumonia

- Hien. NEJM 2004;350:1179

## Avian Flu

- Two types common in birds
- Low pathogenic
- Mild symptoms
- Ruffled feathers, poor egg laying
- High pathogenic
- Deadly – 90-100% mortality rate
- Surviving birds shed virus in their droppings for 10 days after recovery
- Subtype H5N1

**Colorized transmission electron micrograph of Avian influenza A H5N1 viruses (seen in gold) grown in MDCK cells (seen in green).** http://phil.cdc.gov/phil/quicksearch.asp - #1841

## Avian Flu (H5N1)

- Since 2003, there have been small clusters of avian flu in SE Asia.
- Millions of birds have been killed in an attempt to control the disease.
- As of December 30, 2005
- 		142 human cases, 74 deaths

## Avian Flu

- Majority of human cases have been linked to close contact
- Home slaughter, de-feathering, butchering and preparation for cooking
- Traditionally slaughter and eat birds when signs of illness appear

## Avian Flu Concerns in SE Asia

- Barnyard flocks are kept close to the family home.
- Domestic flocks often mingle freely with wild birds.
- Flocks often scavenge for food, entering households or sharing areas where children play.

## Avian Flu Concerns in SE Asia

- Pigs also kept close to families
- Pigs are transported and sold in open markets where exposure to the bird flu and human flu could occur
- Pigs in Indonesia have been found carrying H5N1, but did not show signs of illness

## A’s and B’s, H’s and N’s

- Flu is classified by the RNA core
- Type A or Type B influenza
- Further classified by surface protein
- Hemagluttin (H) – 15 subtypes known
- Neuraminidase (N) – 9 subtypes known
- Only Type A had pandemic potential

**Notes:**
You have probably heard of types of flu and about H5N1, well what does that mean?
Flu is named based on the RNA material that allows it to reproduce, this decides whether it is an A or B (or even C). 
Flu is then further classified by two proteins that are on the surface of the virus.  Type A flu is know to have all subtypes, whereas Type B flu has only H1N1.
Only A can cause a pandemic, as it is the only type that is found in both animals and man and is less genetically stable than B

## Antigenic Drift

- Natural mutation of surface proteins over time to evade the immune system.
- Occurs in all types of viruses.
*Guessing* what the changes will be, to allow for vaccination of public.

## Potential Source of “Shift”

**Human**
** ****virus**

**Reassortant**
**virus**

**Non-human**
**virus**

**15 HAs**
**9 NAs**

- Source: CDC Influenza Branch

**Notes:**
This graphic demonstrates the potential mechanisms of shift.
We used to think the predominant cause of shifting was an avian flu strain and a human flu strain mixing in an intermediary, such as a pig to produce the reassortant virus.  
In 1997, in Hong Kong, we learned that the ‘shift’ can occur directly when an avian influenza strain infects a human who also a human virus at the same time.
And while we typically thing of this scenario playing out in Asia, it can occur anywhere these species come together – in the last few years, this has meant Delaware, the Netherlands and the Fraser Valley of British Columbia.

## Pandemic Influenza

_*Any*_ new type of flu with the ability to:
- Infect humans
- The avian virus apparently has this ability.
- Cause serious illness in humans
- Be easily spread among the human population.
- So far, the bird virus lacks this vital talent.
**Not seasonal **– it can occur at any time.
- Currently, there is no pandemic flu.

## Pandemic Influenza

- Reassortment of RNA
- Two flu strains swap RNA
- A “Shift” occurs that allows the transmission from Avian to Human populations
- A Novel Virus in a Naïve Population

**Notes:**
This unpredictable nature of RNA allows it to reassort –one strain of flu swaps RNA with another flu virus. 
If this occurs between a strain of bird flu and human flu, this causes a ‘shift’, a new genetic code that allows for avian influenza to be transmitted in a human population
What this leads to is a new virus in a naïve population that has not been exposed to it before.  Our bodies will not know how to respond to this threat

## Worse than WW II?

- The “Spanish” flu of 1918-1920
- At least 20 million deaths world wide
- At least 500,000 deaths in the US
- One of the reasons the “War to End all Wars” ended
- Unique ‘W’ Shaped Age Distribution

**Notes:**
Shifting the view from the individual to the population, the impact of a pandemic flu can be extensive
The Spanish flu pandemic 1918-1919 caused at least 20 million deaths over a two year period
At least five hundred thousand deaths occurred in the United States, and about 1600 deaths occurred in Seattle
There were so many casualties in the trenches on the western front from flu that this is one of the reasons the Germans pursued peace talks
The Spanish Flu was particularly devastating because it not only killed those who were infants and elderly, but also killed a large percentage of those in their 20’s and 30’s, causing a middle spike in the epidemic curve.
Some of theorized that this increased death rate in this age group may be due to an enhanced immune response.  In essence, the body killed itself in attempt to eliminate the flu virus.
Others have suggested that this strain of flu had previously occurred in the 1880’s and that in reality there were fewer deaths in the older ages due to existing immunity.

## US Infectious Disease Mortality:The Impact of Influenza and AIDS

- Armstrong. JAMA 1999;281:61

## More Flu Pandemics

- Other Flu Pandemics in the 20th Century
- Asian Flu of 1957-58
- 70K US Dead
- Hong Kong Flu of 1968-69
- 40K US Dead

**Notes:**
In addition to the 1918-1920 pandemic, there were two other pandemics in the last 100 years.
Both of these were relatively minor in comparison.
The Asian flu caused 70,000 deaths, or about twice the normal year
Whereas the Hong Kong flu of 1968-69 caused 40 thousand excess deaths, which is only 10% more than 36 thousand that we see in a typical flu year

## Projected Impact

- Typical Pandemic attack rate 15 – 35 % of the population
- More death than usual under 65 years old
- Strains all aspects of the health care system

**Notes:**
If pandemic influenza were to strike tomorrow, we can estimate the numbers affected throughout the country.

The Centers for Disease Control and Prevention model predicts that 15 to 35 percent of the population will become ill.  Fifty percent of the population had  influenza in the Spanish Flu of 1918-19.

The model predicts that there would be much more death and disability among middle aged adults than there is in a normal flu season.

A pandemic flu in Washington State would severely strain all aspects of the health care delivery system throughout the state.  

## Ways to Stop Pan Flu

- When there is a Novel virus
- Culling/vaccinating the bird flocks
- When there is person to person spread
- Quarantine/Isolation
- Antiviral medications
- Development of vaccine
- When there is widespread dissemination
- Antiviral medications
- Vaccine

**Notes:**
So, when a novel virus arises, we can look at ways of stopping the spread of the flu

These mechanisms are keyed to specific events as the pandemic unfolds.

The first steps occur when the novel virus is noted in poultry flocks – this is the mass culling of chickens and other poultry.  In 1997, the Hong Kong was depopulated of all avian life to stop H5 N1 at that time.  In addition, vaccination of poultry has been proposed as an alternate mechanism to control the spread

When person to person spread starts to occur this is the point where quarantine and isolation may be effective.  Antiviral medications may be also be useful at this juncture.  Both this are intended to delay the further spread of the pandemic influenza strain while a vaccine is being developed
Finally, when there is widespread dissemination, isolation and quarantine may offer little reduction in the number of cases, so efforts largely turn to the administration of antivirals and the pandemic vaccine

## Containment Strategies

- Infection Control
- HICPAC Practice Guidelines
- Possibility of Designated Hospitals
- Isolation/Quarantine
- DOH in Advisory Role
- LHO in Counties
- DGMQ at International Ports of Entry

## Antiviral Medication

**Tamiflu will be the drug of choice**
- Prophylaxis
- Daily dosing for length of pandemic
- Not recommended option by CDC
- Treatment
**Must Start Within 2 Days Of Onset**
- Twice daily dosing for 5 days

**Notes:**
Given the long time required for vaccine development, the neuraminidase inhibitor tamiflu will be a drug in demand
It can be used as a preventative drug, taken daily for the length of the pandemic
This is not recommended by the CDC at present given simulations that show that the numbers of deaths avoided would be minimal
It can also be used as a treatment, but to be effective it must be started within 2 days of the onset of symptoms.
For treatment it is a single pill twice daily.

## Problems in Creating a Vaccine

- Isolate the virus
- The virus has not mutated yet to the form that affects humans easily
- Convert it to a vaccine
- Produce enough vaccine for 300M people
- Current egg method not sufficient
- 300 M doses of vaccine requires 3.5 M eggs
- Avian flu strains are lethal to chicken embryos requiring genetic modification
- Do it in 6 months
- Virus continues to mutate

- A scientist uses eggs in the laboratory to cultivate bird flu vaccine at CSL's flu facility.

- http://www.smh.com.au/news/national/race-for-a-vaccine/2005/10/21/1129775959991.html

## Public Health Goals in a Pandemic: Protecting the Public’s Health

- Limit death and illness
- Preserve continuity of essential government and business functions
- Minimize social disruption
- Minimize economic losses

**Notes:**
In Public Health, we share the same goals you have in a pandemic:

 Limit death and illness

 Preserve continuity of essential government and business functions

 Minimize social disruption and

 Minimize economic loss

None of this can be achieved without a lot of planning and coordination BEFORE a pandemic influenza arrives.

## Public Health’s Role in a Pandemic

- Leadership Role in Emergency Response
- Disease Tracking and Control
- Health System Coordination
- Community Education
- Communications

**Notes:**
The Benton Franklin Health District has broad responsibilities in responding to a pandemic flu:

 Disease Tracking and Control means collecting and analyzing data from across the region to help determine the cause, location, and spread of the disease

 Environmental Health Response means that we assess potential impacts, advise partner agencies, and implement protective measures 

 Health System Coordination means we are working with our health care partners to triage and treat the greatest number of patients

Communications means that we have and share the most up to date information about the pandemic, its spread, and the community response

## The New WHO Pandemic Phases

| Phase 1
Interpandemic Period | Epidemic influenza viruses circulate |
| --- | --- |
|  Phase 2
Interpandemic Period | Animal influenza subtype circulating |
| Pandemic Phase 3
Pandemic Alert Period | Humans infected with subtype  |

## The New WHO Pandemic Phases

| Pandemic Phase 4
Pandemic Alert Period | Clusters of Human infections suggesting person to person spread |
| --- | --- |
| Pandemic Phase 5
Pandemic Alert Period | Localized, but larger human to human clusters |
| Pandemic Phase 6
Pandemic Period | Increased and sustained transmission in humans  |

## National Influenza Plan

- Intended to provide national, state and local guidance
- Acknowledges, but does not address
- Vaccine Manufacture and Distribution
- Antiviral Manufacture and Distribution
- Priority Group for Vaccine and Antivirals

## Surveillance

- Priority in any Pandemic Response
- Surveillance Intensifies throughout pandemic stages
- Novel Flu made a reportable disease
- Surveillance Year Round
- Increased Lab Testing

## Pandemic Impact: Health Care System

- Extreme staffing shortages
- Shortage of beds, facility space
- Shortage of key supplies (ventilators, drugs)
- Hospital morgues, Medical Examiner and mortuary services overwhelmed
- Extreme demands on social and counseling services
- Demand will outpace supply for months

**Notes:**
The very system we’ll need to triage, diagnose and treat our residents will be severely strained in a pandemic outbreak:

 25-35% of our health care workforce will be personally affected by the disease and unable to work

We will not have sufficient hospital beds to take the number of patients who should be admitted

Our current supplies of items like ventilators and drugs may be insufficient

Our residents will have a very high need for social and mental health services; and that need will outstrip supply

## Health Care Systems

- Alternate Care Sites
- Triage/Referral Points
- Neighborhood Emergency Health Centers
- Points of Distribution
- Staffing
- Sustained Operations and Surge Capacity
- Volunteers, Retirees, etc.

## Pandemic Impact: Infrastructure

- Significant disruption of transportation, commerce, utilities, public safety and communications
- Limited to no assistance from State and Federal governments due to nation-wide impact

**Notes:**
Our regional infrastructure will be disrupted. We’ll see disruptions to transportation (buses, planes, trains, road work), commerce, utilities, public safety services, and communications.

This pandemic outbreak will be nationwide. Unlike other types of emergencies, we won’t be able to rely on State or Federal assistance. We’ll be on our own.

## Pandemic Impact: Businesses

- High absenteeism
- Psychological impacts on workforce will be extreme
- Social distancing efforts may dramatically change hours of operation or close businesses temporarily
- Economic losses – small businesses at greatest risk

**Notes:**
With 25-35% of the population affected, business will have a very high level of absenteeism. Employees will be ill,  taking care of sick family members, or caring for children if schools are closed. 

Staff who do come to work may be traumatized and unable to focus.

You may have to change your hours of operation due to absenteeism, low business volumes, or requests for implementing social distancing measures.

A pandemic means economic losses for everyone – from personal, to public, to private businesses. Small family owned businesses are likely to be hit the hardest.

## Business Planning

- Start planning now
- Identify essential functions
- Consider telecommuting and flexible work hours
- Promote Cough Etiquette
- Encourage people to stay home when sick
- Get your annual flu shots

## Protecting Yourself and Others

**The single best way to protect against the flu is to get vaccinated each fall.**
- There are two types of vaccines:
**The "flu shot"**—an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm.
**The nasal-spray flu vaccine**—a vaccine made with live, weakened flu viruses that do not cause the flu.

## Protect yourself and others!

- To help stop the spread of germs,
- Cover your mouth and nose with a tissue when you cough or sneeze.
- If you don't have a tissue, cough or sneeze into your upper sleeve, not your hands.
- Put your used tissue in the waste basket.

- Clean your hands after coughing or sneezing
- Wash with soap and water.or
- Clean with alcohol-based hand cleaner.

## Be Prepared

- Have an emergency plan for your family
- Have an emergency survival kit
- Include supplies for at least three days
- Follow social distancing recommendations

*Courtesy King County Office of Emergency Management*

## What We Need From You

- Engage in business continuity planning
- Share resources and capabilities
- Share information about absenteeism to support tracking of disease
- Cooperate with social distancing measures
- Partner with us

**Notes:**
Being a prepared community means we need your expertise and help. Here’s what we need from you:
Make a continuity plan for your business. Do it now. 
Share your resources and capabilities with each other, and with the community at large. Do you have supplies, transport vehicles, communication capabilities, or large facilities that can be used during a pandemic? Can offer to post informational posters in your storefronts?
Help us track and monitor disease outbreaks by sharing information with us about absenteeism and reports of illness.
Reduce the risk of infection among your workforce by sending sick people home, and cooperate with social distancing measures requested by others.  That may mean that schools are closed, church services not held, movie theaters close.

 Partner with us. Join us in planning for reducing the health and economic impacts of a pandemic flu on our region.