A worldwide epidemic of a disease Epidemic = increased number of cases

from a disease Pandemics have occurred from

› Bacteria – cholera, Tuberculosis, Typhus, Bubonic plague

› Viruses – smallpox, influenza

The smallest of the microbes

Contain genetic material (DNA or RNA or both)

Nuclear material contained within a capsid

Parasitic, hijack host cell and replicate

New strains of virus Take advantage when herd immunity is

low Transmissible Limited treatment options

Influenza takes advantage of all of these to cause pandemics

Virus first described by Hippocrates in 412 BC

Influenza pandemics occur every 10-30 years

RNA virus

Disease characterized by fever, headache, malaise, myalgias

Respiratory symptoms include sore throat, cough, nasal congestion

May include GI symptoms Onset 3-6d after exposure Symptoms last 4-7 days

• results from RNA mutations

•changes surface proteins so they are not recognized by existing antibodies

Can occur in 3 ways

A)Genetic mixing in an intermediate hostB)Direct transmission to a new hostC)Direct transmission to an intermediate host and then on to humans

First reported in Russia May1889 Hit North America by December 1889 By February 1890 it had travelled to

South America Later reaching India and Australia High mortality rate Estimated one million deaths

Started in the fall of 1918 and rapidly spread across the globe

Killed 20-40 million people by end of 1919

Mortality approximately 2-3% Most deadly for 20-40 year olds Avian H1N1

Feb. 1957, new influenza identified in the far east, H2N2

Vaccine available Aug. 1957 Milder illness than Spanish flu (0.2-0.5%

mortality) Most disease in children and young adults Most deaths Sept 1957-Mar 1958 Estimated 2 million deaths worldwide

1968/9 pandemic 2 peaks Milder disease, H3N2 Vaccine available in US one month

after first cases identified Estimated one million deaths

worldwide Mortality rate 0.1%

Jan 1976 respiratory outbreak Fort Dix Identified as swine H1N1 influenza Fear that this virus may case pandemic

as H1 and N1 had not circulated in humans in 50 years

In the end 13 ill, 1 dead, 500 others exposed

Did not spread beyond Fort Dix

Began in China in May 1977, identified in Russia in Nov.

Affected those < 23yo Disease mild and mortality low Mortality = seasonal influenza H1N1 virus

Another pandemic was imminent Lots of work done in Pandemic planning Identify a team of “experts” Plan for high absentee rates (10-50%) Protect staff in the workplace Communication and knowledge

management

Identify a team of “experts” Plan for high absentee rates (10-50%) Protect staff in the workplace Communication and knowledge

management

H1N1 virus has previously been identified in humans

New strain with genetic elements from North American and European swine influenza, North American avian influenza and human influenza

Never previously seen in humans

Initial cases identified in Mexico Initial reports showed high mortality WHO began actively tracking cases Once virus identified, track of spread

Phase 1 – no animal influenza known to be circulating in humans

Phase 2 – a circulating animal influenza known to infect human posses a threat

Phase 3 – animal or human-animal virus has caused sporadic disease but no human-human transmission sufficient to cause pandemic

Prepare pandemic plans, surveillance systems, communication systems and plan to scale up as needed

Phase 4 – human-human transmission of animal or animal-human virus able to sustain community level outbreak

Implement containment protocols to prevent spread, increase surveillance, communicate protection plan to population and activate contingency plans

Phase 5 – virus as in phase 4 causes sustained community outbreaks in 2 or more countries in one WHO region

Pandemic – implement pandemic plans, active surveillance and monitoring, update public health and other stakeholders on ways to mitigate risk

WHO declared phase 5 on April 29, 2009

Phase 6 – same criteria as phase 5 with spread to one other WHO region

WHO declared phase 6 in June 2009

April 12, 2009-March 27, 2010 1,843 hospitalizations 319 ICU admissions 128 death March 21-28 8,759 lab confirmed cases

of H1N1

PHAC FluWatch 2009-2010, Ontario Influenza Bulletin

April 12, 2009-March 27, 2010 8,677 hospitalizations 1,473 ICU admissions 428 deaths Hospitalization rate 25:100 000, death

rate 1.3:100 000 (0.0013%)

Only 13 hospitalizations and 2 deaths since 2010

PHAC FluWatch 2009-2010

9 April 2010 -- As of 4 April 2010, worldwide more than 213 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza

H1N1 2009, including over 17700 deaths. WHO Most activity in Southeast Asia, West

Africa Mortality rate 0.01-0.03%

Access to supplies Access to reliable information Communication within organizations

Arepanrix (adjuvanted) Contains split, inactivated influenza virus Single dose of vaccine is effective AE – pain, redness, swelling at inject. Site,

myalgias and fatigue Jan30/10 – 25.143 million doses administered 6,131 AE (24.4/100,000) – 250 “serious”

(0.99/100,000)– of these 131 anaphylaxis(0.52/100,000) – all within acceptable range for vaccines

Vaccine supply chain in Canada› Vaccine comes from supplier to

government› Supply is reviewed› Customer service determines distribution› Vaccine is repackaged› Shipments prepared in warehouse› Vaccine delivered to PH units› Vaccine delivered to public

Health Canada

Federal government purchased 50 .4 million doses if vaccine for distribution to provinces and territories

Excess vaccine estimated at 25-30 million doses

Many reasons for this Initial estimates were that 25% of

population received H1N1 vaccine 37% US HCP received the H1N1 vaccine

4 Canadian studies Monitoring of flu found those who had

seasonal flu vaccine were 68% more likely to get H1N1 infection

Case control studies in Canada and Quebec and transmission study in Quebec showed risk increased by 1.4-5X

PLoS Medicine, April 6, 2010

Antivirals – recommended for age < 1, severe illness, immunocompromised, pregnant

Should be started within 48hr of symptom onset

Oseltamavir (Tamiflu) – oral Zanamivir (Relenza) - inhaled