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CHOTANI 2009.

Rashid A. Chotani, MD, MPH, DTM

Adjunct Assistant ProfessorUniformed Services University of the Health Sciences(USUHS)[email protected]

Just-in-Time LectureInfluenza A(H1N1) (Swine Flu): A Global Outbreak(Version 11, first JIT lecture issued April 26)

Tuesday, May 26, 2009 (01:30 AM EST)


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CHOTANI 2009.

Credit: L. Stammard, 1995

RNA, enveloped

Viral family: Orthomyxoviridae

Size:80-200nm or .08 0.12 m

(micron) in diameter

Three types A, B, C

Surface antigens H (haemaglutinin) N (neuraminidase)

irus


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H1 N1

H2 N2

H3 N3

H4 N4H5 N5

H6 N6

H7 N7

H8 N8

H9 N9

H10H11

H12

H13

H14

H15

H16

Haemagglutinin subtype Neuraminidase subtype


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HAmonomer. Sites A-E are immunodominant epitopes (From Fields Virology, 2nd ed, Fields &

Knipe, eds, Raven Press, 1990, Fig.40-4)

Structure of the influenza hemagglutinin monome


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HA trimer. (From Fields Virology, 2nd ed, Fields & Knipe, eds, Raven Press, 1990, Fig.39-6)

Structure of the influenza hemagglutinin trimer


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CHOTANI 2009.

Influenza replication

Replication of influenza A virus. After inding (1) to sialic acid-containing receptors, influenza is endocytosed and fuses (2) ith the

vesicle mem rane. Unli e for most other RNA viruses, transcription (3) and replication (5) of the genome occur in the nucleus. Viral

proteins are synthesized (4), helical nucleocapsid segments form and associate (6) ith the 1 protein-lined mem ranes containing

2 and the HA and NA glycoproteins. The virus uds (7) from the plasma mem rane ith 11 nucleocapsid segments. (-), Negative

sense; (+), positive sense;E

R, endoplasmic reticulum. (From edical icro iology, 5th

ed., urray, Rosenthal & Pfaller, os y Inc.,2005, Figure 60-2.)


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CHOTANI 2009.

Pathogenesis of influenza A virus. The symptoms of influenza are caused y viral pathologic and immunopathologic

effects, ut the infection may promote secondary acterial infection. CNS, Central nervous system. (From edical

icro iology, 5th ed., urray, Rosenthal & Pfaller, os y Inc., 2005, Figure 60-3.)

Influenza pathogenesis


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CHOTANI 2009.

Epidemic a located cluster of cases

Pandemic worldwide epidemic

Antigenic drift Changes in proteins by genetic point mutation & selection

Ongoing and basis for change in vaccine each year

Antigenic shift

Changes in proteins through genetic reassortment

Produces different viruses not covered by annual vaccine

DefinitionsGeneral


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CHOTANI 2009. Source: Bean B, et al. JID 1982;146:47-51

Survival of Influenza VirusSurfaces and Affect of Humidity & Temperature*

Hard non-porous surfaces 24-48 hours

Plastic, stainless steel

Recoverable for > 24 hours

Transferable to hands up to 24 hours

Cloth, paper & tissue Recoverable for 8-12 hours

Transferable to hands 15 minutes

Viable on hands


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CHOTANI 2009.

Swine Influenza A(H1N1)Introduction

Swine Influenza (swine flu) is a respiratorydisease of pigs caused by type A influenzathat regularly cause outbreaks of influenzaamong pigs

Most commonly, human cases of swine fluhappen in people who are around pigs

Swine flu viruses do not normally infecthumans, however, human infections withswine flu do occur, and cases of human-to-human spread of swine flu viruses havebeen documented


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CHOTANI 2009.

Swine Influenza A(H1N1)History in US

A swine flu outbreak in Fort Dix, New Jersey,USA occurred in 1976 that caused morethan 200 cases with serious illness in severalpeople and one death More than 40 million people were vaccinated However, the program was stopped short

after over 500 cases of Guillain-Barresyndrome, a severe paralyzing nerve disease,

were reported 30 people died as a direct result of thevaccination

In September 1988, a previously healthy 32-year-old pregnant woman in Wisconsin washospitalized for pneumonia after beinginfected with swine flu and died 8 days later.

From December 2005 through February2009, a total of 12 human infections withswine influenza were reported from 10 statesin the United States


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CHOTANI 2009.

Swine Influenza A(H1N1)Transmission to Humans

Through contact with infected pigs orenvironments contaminated withswine flu viruses

Through contact with a person withswine flu

Human-to-human spread of swine fluhas been documented also and isthought to occur in the same way as

seasonal flu, through coughing orsneezing of infected people


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CHOTANI 2009.

Swine Influenza A(H1N1)Transmission Through Species

Avian Virus

Human Virus

S ine Virus

Avian/Human

Reassorted Virus

Reassortment in Pigs


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CHOTANI 2009.

Swine Influenza A(H1N1) March 2009Timeline

In March and early April 2009, Mexico experiencedoutbreaks of respiratory illness and increasedreports of patients with influenza-like illness (ILI) inseveral areas of the country

April 12, the General Directorate of Epidemiology(DGE) reported an outbreak of ILI in a smallcommunity in the state of Veracruz to the Pan

American Health Organization (PAHO) in

accordance with International Health Regulations April 17, a case of atypical pneumonia in Oaxaca

State prompted enhanced surveillance throughoutMexico

April 23, several cases of severe respiratory illnesslaboratory confirmed as influenza A(H1N1) virusinfection were communicated to the PAHO

Sequence analysis revealed that the patients wereinfected with the same strain detected in 2 childrenresiding in California Samples from the Mexico outbreak match swine

influenza isolates from patients in the United States

Source: CDC


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CHOTANI 2009.

Swine Influenza A(H1N1) March 2009Facts

Virus described as a new subtype ofA/H1N1 not previously detected inswine or humans

CDC determines that this virus iscontagious and is spreading fromhuman to human

The virus contains gene segments from4 different influenza types: North American swine North American avian North American human and Eurasian swine


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CHOTANI 2009.

i I fl z A(H N )USR sp s

Th tr t gic N tio l tockpil ( N ) isr l si g o -q rt r of its Anti-viral drugs Personal protective equipment and Reparatory protection devices

President Obama today asked Congress for

an additional 1.5 billion to fight the swine flu On April 27, 2009, the CDC issued a travel

advisory that recommends against all non-essential travel to Mexico

Source: CDC


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CHOTANI 2009.

Swine Influenza A(H1N1)Global esponse

The WHO raised the alert level to Phase 5 WHOs alert system was revised after Avian influenza began to spread in 2004, and April 27 was the first time it

was raised above Phase 3 and on April 29 to Phase 5.

European Union (EU) issued a travel advisory to the 27 EU member countries recommending thatnon-essential travel to affected parts of the U.S. and Mexico be suspended

Source: WHO


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CHOTANI 2009.

Swine Influenza A(H1N1) May 25, 2009Status Update

MEXICO: March 01-May 22, a total of 4,174 Laboratory confirmed cases, with 80

deaths and 1311 hospitalizations (forpneumonia) reported in 32 of 32 States

UNITED STATES: March 28-May 25, atotal of

6,764 Laboratory confirmed cases, with 10deaths (Arizona 3; Missouri 1; New York 1;Texas 3; Utah 1 and; Washington 1) from48 States (including District of Columbia)

Over 100 Hospitalizations Most cases mild

CANADA: As of May 25, a total of 921 Laboratory confirmed cases, with one

deaths (1 Alberta) from 10 of 13 States 116 new Laboratory confirmed cases May

25 Most cases mild

Source: Secretaria de Salud, Mexico, CDC, Public Health Agency of Canada, European CDC, WHO


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CHOTANI 2009.

Swine Influenza A(H1N1) May 25, 2009Status Update

EUROPEAN UNION & EFTACOUNTRIES: April 27- May 25, a total of 360 Laboratory confirmed cases, with no

deaths from 19 countries 11 confirmed cases reported on May 24 130 in-country transmissions Vast majority of cases reported between

20-49 years of age Most cases (except 1) report mild disease

GLOBALLY: March 1-May 25, a total of 12,727 Laboratory confirmed cases, from

46 countries 92 Deaths among laboratory confirmed

cases from 4 countries Mexico: 80 deaths US: 10 deaths Canada: 01 death Costa Rica: 01 death

Source: Secretaria de Salud, Mexico, CDC, Public Health Agency of Canada, European CDC, WHO


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CHOTANI 2009.

Swine Influenza A(H N )MMRWR p rt, pril

MMWR, April 30, 2009 / 58(Dispatch); -3 Illness onset dates ranged from April 20 toApril 24

10 (23%) of the patients had illness onset onApril 22, and 28 (64%) had illness onset on April23 (Figure).

Among 35 patients who reported a maximumtemperature, the mean was 102.2rF (39.0rC)(range: 99.0-104.0rF [37.2--40.0rC])

In total, 42 (95%) patients reported subjectivefever plus cough and/or sore throat, meeting theCDC definition for influenza-like illness (ILI)

At the time of interview on April 27, 37 patients(84%) reported that their symptoms were stableor improving, three (7%) reported worseningsymptoms (two of whom later reportedimprovement), and four (9%) reported completeresolution of symptoms

Only one reported having been hospitalized for

syncope and released after overnightobservation

Symptoms Number (n=44)

%

Cough 43 98%

Fever 42 96%

Fatigue 39 89%

Headache 36 82%

Sore throat 36 82%

Runny nose 36 82%

Chills 35 80%

uscle aches 35 80%

Nausea 24 55%

Stomach ache 22 50%

Diarrhea 21 48%

Shortness of breath 21 48%

Joint pain 20 46%

Source: CDC. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0428a2.htm


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CHOTANI 2009.

Laboratory-Confirmed Cases of New InfluenzaA(H1N1) by Countries, May 25, 2009

2 16 1 7

8

15 13 28 4 1 10 6 2 16 17 1 4 1 1 1 1 8 19345

3 18 2

4174

3 9 4 76 25 1 3 1 1 133 3 3 2 2 122

6764

0

1000

2000

3000

4000

5000

6000

7000

Argentina

A

tralia

A

tria

Belgi

Brazil

anada

hile

hina

olo

bia

osta

i

a

ba

Den

ark

Ecuador

ElSal

ado

r

inland

rance

Ger

any

Greece

Guate

ala

Honduras

Iceland

India

Ireland

Israel

Italy

Japan

orea,

e

publicof

uwait

alaysia

exico

etherlan

ds

ewZealand

orway

Pana

a

Peru

Philippine

s

Poland

Portugal

ussia

Spain

Sweden

Switzerlan

d

hailand

urkey

nited

ingdo

nitedSta

tesofA

erica

ountries

No.

onfir

ed

ases

1

1

80

10

Chinese aipei has reported1confir edcaseof influenza A (H1N1)with0deaths. Casesfro Chinese aipei are

included inthecumulati etotalsprovided inthetableabove.

12,727 Cases & 92 Deaths


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CHOTANI 2009.

Global Distributionof eportedCumulati e robableCasesof

wineInfluenza A(H1N1) byCountries, May25, 2009 (08 00GM )

Source: WHO

12, 27Cases 92 Deaths

Total

12,727 Cases

92deaths

U

6,767

cases

10deaths


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CHOTANI 2009.

Swine Influenza A(H1N1)US Case Definitions

A confirmed case of swine influenza A (H1N1) virus infection is defined as aperson with an acute febrile respiratory illness with laboratory confirmed swineinfluenza A (H1N1) virus infection at CDC by one or more of the following tests: real-time RT-PCR

viral culture

A probable case of swine influenza A (H1N1) virus infection is defined as aperson with an acute febrile respiratory illness who is:

positive for influenza A, but negative for H1 and H3 by influenza RT-PCR, or positive for influenza A by an influenza rapid test or an influenza

immunofluorescence assay (IFA) plus meets criteria for a suspected case

A suspected case of swine influenza A (H1N1) virus infection is defined as aperson with acute febrile respiratory illness with onset within 7days of close contactwith a person who is a confirmed case of swine

influenza A (H1N1) virus infection, or

within 7days of travel to community eitherwithin the United States orinternationallywhere there are one or more confirmed swine influenza A(H1N1)cases, or

resides in a communitywhere there are one or more confirmed swine influenzacases.

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)US Case Definitions

Infectious periodfor a confirmed case of swine influenza A(H1N1)virus infection is defined as 1 day prior to the cases illness onset to 7days after onset

Close contactis defined as: within about 6 feet of an ill person whois a confirmed or suspected case of swine influenza A(H1N1) virusinfection during the cases infectious period

Acute respiratory illness is defined as recent onset of at least twoof the following: rhinorrhea or nasal congestion, sore throat, cough(with or without fever or feverishness)

High-risk groups:A person who is at high-risk for complications ofswine influenza A(H1N1) virus infection is defined as the same forseasonal influenza (see Reference)

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Guidelines for Clinicians

Clinicians should consider the possibility of swineinfluenza virus infections in patients presenting withfebrile respiratory illness who live in areas where human cases of swine influenza A(H1N1)

have been identified or have traveled to an area where human cases of swine influenza

A(H1N1) has been identified or have been in contact with ill persons from these areas in the 7

days prior to their illness onset

If swine flu is suspected, clinicians should obtain arespiratory swab for swine influenza testing and

place it in a refrigerator (not a freezer) once collected, the clinician should contact their state or

local health department to facilitate transport and timelydiagnosis at a state public health laboratory

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Guidelines for Clinicians

Signs and Symptoms Influenza-like-illness (ILI)

Fever, cough, sore throat, runny nose, headache, muscle aches. Insome cases vomiting and diarrhea. (These cases had illness onsetduring late March to mid-April 2009)

Cases of severe respiratory disease, requiring hospitalizationincluding fatal outcomes, have been reported in Mexico The potential for exacerbation of underlying chronic medical

conditions or invasive bacterial infection with swine influenza virusinfection should be considered

Non-hospitalized ill persons who are a confirmed or

suspected case of swine influenza A (H1N1) virusinfection are recommended to stay at home (voluntaryisolation) for at least the first 7 days after illness onsetexcept to seek medical care

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Biosafety Guidelines for LaboratoryWorkers

Diagnostic work on clinical samples from patients who are suspectedcases of swine influenza A (H1N1) virus infection should be conducted ina BSL-2 laboratory All sample manipulations should be done inside a biosafety cabinet (BSC)

Viral isolation on clinical specimens from patients who are suspectedcases of swine influenza A (H1N1) virus infection should be performed ina BSL-2 laboratory with BSL-3 practices (enhanced BSL-2 conditions)

Additional precautions include: recommended personal protective equipment (based on site specific risk

assessment) respiratory protection - fit-tested N95 respirator or higher level of protection shoe covers closed-front gown double gloves

eye protection (goggles or face shields)

Waste all waste disposal procedures should be followed as outlined

in your facility standard laboratory operating procedures

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Biosafety Guidelines for LaboratoryWorkers

Appropriate disinfectants 70per cent ethanol

5per cent Lysol

10per cent bleach

All personnel should self monitor for fever and anysymptoms. Symptoms of swine influenza infection

include diarrhea, headache, runny nose, and muscleaches

Any illness should be reported to your supervisorimmediately

For personnel who had unprotected exposure or aknown breach in personal protective equipment toclinical material or live virus from a confirmed case ofswine influenza A (H1N1), antiviral chemoprophylaxiswith zanamivir or oseltamivir for 7 days after exposurecan be considered

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Guidelines for General Population

Covering nose and mouth with atissue when coughing or sneezing Dispose the tissue in the trash after

use.

Handwashing with soap and water Especially after coughing or sneezing.

Cleaning hands with alcohol-basedhand cleaners

Avoiding close contact with sickpeople

Avoiding touching eyes, nose or

mouth with unwashed hands If sick with influenza, staying home

from work or school and limitcontact with others to keep frominfecting them


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CHOTANI 2009.

Swine Influenza A(H1N1)Treatment

No vaccine available

Antivirals for the treatment and/or prevention of infection: Oseltamivir (Tamiflu) or Zanamivir (Relenza)

Use of anti-virals can make illness milder and recovery faster

They may also prevent serious flu complications

For treatment, antiviral drugs work best if started soon after gettingsick (within 2 days of symptoms)

Warning! Do NOTgive aspirin (acetylsalicylic acid) or aspirin-containing products (e.g. bismuth subsalicylate Pepto Bismol) to

children or teenagers (up to 18 years old) who are confirmed orsuspected ill case of swine influenza A (H1N1) virus infection; thiscan cause a rare but serious illness called Reyes syndrome. Forrelief of fever, other anti-pyretic medications are recommended suchas acetaminophen or non steroidal anti-inflammatory drugs.

Source: C C


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CHOTANI 2009.

Swine Influenza A(H1N1)Treatment

Source: C C

Oseltamivir (Tamiflu) Zanamivir (Relenza)

Treatment Prophylaxis Treatment Prophylaxis

Adults 75 mg capsule twiceper day for 5 days

75 mg capsule onceper day

Two 5 mg inhalations(10 mg total) twice perday

Two 5 mg inhalations(10 mg total) once perday

Children 15 kg or less: 60 mgper day divided into 2

doses

30 mg once per day Two 5 mg inhalations(10 mg total) twice per

day (age, 7 years orolder)

Two 5 mg inhalations(10 mg total) once per

day (age, 5 years orolder)

15 23 kg: 0 mg perday divided into 2doses

5 mg once per day

2 0 kg: 120 mg per day divided into 2doses

60 mg once per day

> 0 kg: 150 mg perday divided into 2doses

75 mg once per day

osing recommendations for antiviral treatment of children younger than 1 year using oseltamivir. Recommended treatmentdose for 5 days. 3 months: 12 mg twice daily; 3-5 months: 20 mg twice daily; 6-11 months: 25 mg twice daily

osing recommendations for antiviral chemoprophylaxis of children younger than 1 year using oseltamivir. Recommendedprophylaxis dose for 10 days. 3 months: ot recommended unless situation udged critical due to limited data on use in thisage group; 3-5 months: 20 mg once daily; 6-11 months: 25 mg once daily


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CHOTANI 2009.

Swine Influenza A(H1N1)Other Protective Measures

Defining Quarantine vs. Isolation vs. Social-Distancing Isolation: Refers only to the sequestration ofsymptomatic

patents either in the home or hospital so that they will not infectothers

Quarantine: Defined as the separation from circulation in the

community ofasymptomaticpersons that may have beenexposed to infection

Social-Distancing: Has been used to refer to a range of non-quarantine measures that might serve to reduce contact betweenpersons, such as, closing of schools or prohibiting largegatherings

Source: C C


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CHOTANI 2009.

Swine Influenza A(H N )Ot r r t ctiv Meas res

Personnel Engaged in Aerosol Generating Activities

CDC Interim recommendations:

Personnel engaged in aerosol generating activities (e.g., collection ofclinical specimens, endotracheal intubation, nebulizer treatment,bronchoscopy, and resuscitation involving emergency intubation or

cardiac pulmonary resuscitation) for suspected or confirmed swineinfluenza A (H1N1) cases should wear a fit-tested disposable N95respirator

Pending clarification of transmission patterns for this virus, personnelproviding direct patient care for suspected or confirmed swine influenza

A (H1N1) cases should wear a fit-tested disposable N95respirator

when entering the patient room

Respirator use should be in the context of a complete respiratoryprotection program in accordance with Occupational Safety and Health

Administration (OSHA) regulations.

Source: C C


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CHOTANI 2009.

Infection Control of Ill Persons in a Healthcare Setting

Patients with suspected or confirmed case-status should be placedin a single-patient room with the door kept closed. If available, anairborne infection isolation room (AIIR) with negative pressure airhandling with 6 to 12 air changes per hour can be used. Air can beexhausted directly outside or be recirculated after filtration by a high

efficiency particulate air (HEPA) filter. For suctioning, bronchoscopy,or intubation, use a procedure room with negative pressure airhandling.

The illperson should wear a surgical mask when outside of thepatient room, and should be encouraged to wash hands frequentlyand follow respiratory hygiene practices. Cups and other utensils

used by the ill person should be washed with soap and water beforeuse by other persons. Routine cleaning and disinfection strategiesused during influenza seasons can be applied to the environmentalmanagement of swine influenza.


Source: C C


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CHOTANI 2009.

Infection Control of Ill Persons in a Healthcare Setting Standard, Droplet and Contactprecautions should be usedfor all

patient care activities, and maintained for 7 days after illness onsetor until symptoms have resolved. Maintain adherence to handhygiene by washing with soap and water or using hand sanitizerimmediately after removing gloves and other equipment and after

any contact with respiratory secretions. Personnel providing care to or collecting clinical specimens from

suspected or confirmed cases should wear disposable non-sterilegloves, gowns, and eye protection (e.g., goggles) to preventconjunctival exposure.


Source: C C


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CHOTANI 2009.

Surgical masks Easily available and commonly used for routine surgical and examination

procedures

High-filtration respiratory mask Special microstructure filter disc to flush out particles bigger than 0.3 micron.

These masks are further classified: oil proof oil resistant not resistant to oil

The more a mask is resistant to oil, the better it is The masks have numbers beside them that indicate their filtration efficiency.

For example, a N95 mask has 95% efficiency in filtering out particles greaterthan 0.3 micron under normal rate of respiration.

The next generation of masks use Nano-technologywhich are capable ofblocking particles as small as 0.027 micron.

Types of Protective Masks


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CHOTANI 2009.

Summary

WHO raised the alert level to Phase 5 on April 29, 2009

There is a disparity between the % case-fatality-rate between Mexico (1.91%), Canada(0.11%) and USA (0.15%)

The overall global case-fatality (12,727 cases and 92 deaths) is 0.72%

1,500 cases worldwide (reported) needed hospitalization Majority in Mexico

Epidemiological Data

US Median Age 16 years (range: 1-81 years) Over 80% of the cases in


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CHOTANI 2009.

Timeline of EmergenceInfluenza A Viruses in Humans

1918 1957 1968 1977 1997

1998/9

2003

H1

H1

H3H2

H7

H5H5

H9

Spanish

Influenza

H1N1

Asian

Influenza

H2N2

Russian

Influenza

Avian

Influenza

Hong

Kong

Influenza

H3N2

2009

H1

Reassorted Influenza

virus (Swine Flu)

1976Swine

FluOut reak,

Ft. ix


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Lessons Learned formPast Pandemics

First outbreaks March 1918 in Europe, USA Highly contagious, but not deadly Virus traveled between Europe/USA on troop

ships Land, sea travel to Africa, Asia Warning signal was missed

August, 1918 simultaneous explosiveoutbreaks in in France, Sierra Leone, USA 10-fold increase in death rate Highest death rate ages 15-35 years

Cytokine Storm?

Deaths from primary viral pneumonia, secondarybacterial pneumonia

Deaths within 48 hours of illness Coincident severe disease in pigs

20-40 million killed in less than 1 year World War I 8.3 million military deaths over 4

years

25-35% of the world infected


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CHOTANI 2009.

Pandemics are unpredictable Mortality, severity of illness, pattern of spread

A sudden, sharp increase in the need for medical carewill always occur

Capacity to cause severe disease in nontraditionalgroups is a major determinant of pandemic impact

Epidemiology reveals waves of infection Ages/areas not initially infected likely vulnerable in future

waves Subsequent waves may be more severe

1918- virus mutated into more virulent form 1957 schoolchildren spread initial wave, elderly died in

second wave

Public health interventions delay, but do not stoppandemic spread Quarantine, travel restriction show little effect

Does not change population susceptibility Delay spread in Australia later milder strain causes

infection there Temporary banning of public gatherings, closing schools

potentially effective in case of severe disease and highmortality

Delaying spread is desirable Fewer people ill at one time improve capacity to cope with

sharp increase in need for medical care

Lessons Learned formPast Pandemics


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CHOTANI 2009.

Conclusion/Recommendations

1. Past experience with pandemics have taught us that the second waveis worse than the first causing more deaths due to: Primary viral pneumonia, Acute Respiratory Distress Syndrome (ARDS),

& Secondary bacterial infections, particularly pneumonia

Fortunately compared to the past now we have anti-virals and antibiotics(to treat secondary bacterial infections)

Though difficult, there is likelihood that there will be a vaccine for this

strain by the emergence of the second wave In the US each year 35,000 deaths are attributed to influenza resulting in

>200,000 hospitalizations, costing 37.5 billion in economic cost(influenza & pneumonia) and > 10 billion in lost productivity

Based upon past experience and the way the current H1N1 outbreakis acting (currentwave is contagious, spreading rapidly and inMexico and Canada based upon preliminary data affecting thehealthy), there is a likelihood that come fall there might be a secondwave which could be more virulent


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CHOTANI 2009.


2. At present four death due to H1N1 strain has been reported outsideMexico.

The disease, though spreading rapidly across the globe, is of a mild form(exception Mexico)

Most people do not have immunity to this virus and, as it continues tospread. More cases, more hospitalizations and some more deaths areexpected in the coming days and weeks

Disease seems to be affecting the healthy strata of the population basedupon epidemiological data from Mexico and EU

60 years and above age group seems to show some protection againstthis strain suggesting past exposure and some immunity

3. Each locality/jurisdiction needs to Have enhanced disease and virological surveillance capabilities

Develop a plan to house large number of severely sick and provide careif needed to deal with mildly sick at home (voluntary quarantine)

Healthcare facilities/hospitals need to focus on increasing surge capacityand stringent infection prevention/control

General population needs to follow basic precautions


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CHOTANI 2009.


4. In the Northern Hemisphere influenza viral transmission traditionallystops by the beginning of May but in pandemic years (1957) sporadicoutbreaks occurred during summer among young adults Likelihood that

This wave will fade in North America within the next 1-3 weeks (influenzavirus cannot survive high humidity or temperature)

Will reappear in autumn in North America with the likelihood of being a highlypathogenic second wave

Will continue to circulate and cause disease in the Southern Hemisphere

5. Border Closure and Travel Restrictions: The disease has already crossed borders and continents, thus, border

closure or travel restrictions will not change the course of the spread ofdisease Most recently, the 2003 experience with SARS demonstrated the

ineffectiveness of such measures In China, 14 million people were screened for fever at the airport, train

stations, and roadside checkpoints, but only 12 were found to have probableSARS

Singapore reported that after screening nearly 500,000 air passengers, nonewere found to have SARS

Passive surveillance methods (in which symptomatic individuals report illness)can be important tools


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CHOTANI 2009.


6. School Closures: Preemptive school closures will merely delay the spread of disease Once schools reopen (as they cannot be closed indefinitely), the disease

will be transmitted and spread Furthermore, this would put unbearable pressure on single-working

parents and would be devastating to the economy (as children cannot beleft alone)

Closure after identification of a large cluster would be appropriate asabsenteeism rate among students and teachers would be high enough tojustify this action

7. High priority should be given to develop and include the presentNorth American (swine) influenza A(H1N1) virus in next yearsvaccine. A critical look at manufacturing capacity is called for

8. It is imperative to appreciate that times-have-changed Though this strain has spread very quickly across the globe and seems tobe highly infectious, today we are much better prepared than 1918. Thereis better surveillance, communication, understanding of infection control,anti-virals, antibiotics and advancement in science and resources toproduce an affective vaccine

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