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Just-in-Time Lecture
Swine “North American” Influenza A (H1N1) Outbreak :
Potential for a Pandemic
(Version 5, first JIT lecture issued April 26; Lecture Updated Daily)
Thursday, April 30, 2009
Rashid A. Chotani, MD, MPH, DTM
Adjunct Assistant Professor
Uniformed Services University of the Health Sciences
(USUHS)
240-367-5370
[email protected]
CHOTANI © 2009.
Acknowledgement
The Author acknowledges the efforts, hard work and diligence for
hosting this lecture, web-management & translations and thanks the
entire Supercourse Team, specially the following.
Dr. Ronald E. LaPorte, University of Pittsburgh, USA
Dr. Faina Linkov, University of Pittsburgh, USA
Dr. Eugene Shubnikov, Institute of Internal Medicine, Russia
Dr. Nicolás Padilla Raygoza, Universidad de Guanajuato, México
Dr. Ali Ardalan, Tehran University of Medical Sciences, Iran
Dr. Mehrdad Mohajeri, Tehran University of Medical Sciences, Iran
Dr. Seyed Amir Ebrahimzadeh, Tehran University of Medical Sciences, Iran
Dr. Nasrin Rahimian. Tehran University of Medical Sciences, Iran
•It is truly a global effort
•http://www.pitt.edu/~super1/
CHOTANI © 2009.
OUTLINE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Influenza Virus
Definitions
Introduction
History in the US
Current Situation in the US
Current Situation in Mexico
Current Situation Globally
Spread/Transmission
Case-Definitions
Guidelines
•
•
•
11.
12.
13.
14.
CHOTANI © 2009.
Clinicians
Laboratory Workers
General Population
Treatment
Other Protective Measures
Summary
Conclusion & Recommendations
Virus
• RNA, enveloped
• Viral family: Orthomyxoviridae
• Size:
80-200nm or .08 – 0.12 μm
(micron) in diameter
• Three types
• A, B, C
• Surface antigens
• H (haemaglutinin)
• N (neuraminidase)
CHOTANI © 2009.
Credit: L. Stammard, 1995
Haemagglutinin subtype
H1
H2
H3
H4
H5
H6
H7
H8
H9
H10
H11
H12
H13
H14
H15
H16
Neuraminidase subtype
N1
N2
N3
N4
N5
N6
N7
N8
N9
Definitions: General
• 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
CHOTANI © 2009.
Survival of Influenza Virus on Surfaces
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 <5 minutes only at high viral titers
• Potential for indirect contact transmission
*Humidity 35-40%, Temperature 28C (82F)
CHOTANI © 2009.
Source: Bean B, et al. JID 1982;146:47-51
Swine Flu: Introduction
• Swine Influenza (swine flu) is a respiratory
disease of pigs caused by type A influenza
that regularly cause outbreaks of influenza
among pigs
• Swine flu viruses do not normally infect
humans, however, human infections with
swine flu do occur, and cases of human-tohuman spread of swine flu viruses has
been documented
• Most commonly, human cases of swine flu
happen in people who are around pigs but
it’s possible for swine flu viruses to spread
from person to person also
CHOTANI © 2009.
Swine Flu: History in US
•
A swine flu outbreak in Fort Dix, New Jersey,
USA occurred in 1976 that caused more
than 200 cases with serious illness in several
people and one death
•
•
More than 40 million people were vaccinated
However, the program was stopped short
after over 500 cases of Guillain-Barre
syndrome, a severe paralyzing nerve disease,
were reported
• 30 people died as a direct result of the
vaccination
•
In September 1988, a previously healthy 32year-old pregnant woman in Wisconsin was
hospitalized for pneumonia after being
infected with swine flu and died 8 days later.
•
From December 2005 through February
2009, a total of 12 human infections with
swine influenza were reported from 10 states
in the United States
CHOTANI © 2009.
Swine Flu: Current Situation in the US
• Since March 2009, 91 of confirmed
human cases with one death from 10
States have been reported.
• 1st death reported in a child (22 months)
that had came from Mexico who died in a
hospital in the Houston area
• 5 cases (3 in CA & 2 in TX) hospitalized
• All have the same genetic pattern based
on preliminary testing
• Virus is being described as a new
subtype of A/H1N1 not previously
detected in swine or humans
• Samples from the Mexico outbreak match
swine influenza isolates from patients in
the United States
CHOTANI © 2009.
Source: CDC
Swine Flu: Current Situation in the US
•
CDC has determined that this virus is
contagious and is spreading from human to
human
•
The virus contains gene segments from 4
different influenza types:
•
•
•
•
•
North American swine,
North American avian,
North American human, and
Eurasian swine
The Strategic National Stockpile (SNS) is
releasing one-quarter 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 nonessential travel to Mexico
CHOTANI © 2009.
Source: CDC
Swine Flu: US Human Cases
As of April 28, 2009
• MMWR, April 28, 2009 / 58(Dispatch);1-3
• 47 patients reported to CDC with known ages (out of 64),
the median age was 16 years (range: 3-81 years),
• 38 (81%) were aged <18 years;
• 51% of cases were in males.
• Of the 25 cases with known dates of illness onset, onset
ranged from March 28 to April 25
• five patients hospitalized.
• Of 14 patients with known travel histories,
• 3 had traveled to Mexico;
• 40 of 47 patients (85%) had not been linked to travel or to
another confirmed case.
CHOTANI © 2009.
Source: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0428a2.htm
Swine Flu: US Human Cases
As of April 29, 2009
Total Number of Confirmed Cases = 91; 1 Death
No. of Confirmed Cases
60
40
20
0
Arizona
California
Indiana
Kansas
1
14
1
2
Massachu
Michigan
setts
Navada
New York
Ohio
Texas
1
51
1
15
1
Deaths
No. of laboratory confirm ed cases
2
2
US States
CHOTANI © 2009.
Source: CDC
Swine Flu: Current Situation in Mexico
• A total of approximately 2,498 suspected cases,
159 deaths and 1311 hospitalizations (for
pneumonia) have been reported in 31 of 32
States in Mexico (April 28, Ministry of Health)
• 26 Laboratory confirmed
• First case in Oaxaca, April 13, 2009
• Woman died of pneumonia
• Mexico City: Over 854 cases of pneumonia, 59
of them fatal
• San Luis Potosi: 24 cases with 3 deaths
• Mexicali (near the US border): 4 cases with no
deaths
• The illness outbreak in Mexico City prompted
the country's health minister to cancel classes in
Mexico City and advised students and adults to
avoid crowded public places and large events
CHOTANI © 2009.
Source: WHO, CDC, PAHO & ProMED
Swine Flu: Current Situation in Mexico
•
The virus in Mexico has primarily struck otherwise
healthy young adults, (20-50 years) which is a
departure from seasonal influenza, which typically
affects the very young and very old
•
CDC's laboratory analyzed 14 samples from
severely ill Mexican patients and found that 7 of
them had the same swine flu mix as the virus that
infected the US patients (preliminary report)
•
Canada's national laboratory has confirmed swine
flu A/H1N1 in 18 isolates from Mexican patients, 12
of which were genetically identical to the swine flu
viruses from California
CHOTANI © 2009.
Source: WHO, CDC & ProMED
Country
Lab Confirmed
Death in Lab Confirmed
Suspected
Suspected Dead
Australia
0
0
91
Austria
1
0
5
Argentina
0
0
Bolivia
0
Brazil
0
Belgium
TOTAL
TOTAL Dead
0
91
0
0
6
0
10
0
10
0
0
2
0
2
0
0
22
0
22
0
0
0
7
0
7
0
Canada1
13
0
19
0
32
0
Chile
0
0
24
0
24
0
Columbia
0
0
42
0
42
0
Costa Rica
1
0
21
0
22
0
France
0
0
32
0
32
0
Germany
3
0
5
0
8
0
Guatemala
0
0
1
0
1
0
Greece
0
0
1
0
1
0
Honduras
0
0
1
0
1
0
Hong Kong
0
0
5
0
5
0
Israel
2
0
1
0
3
0
Italy
0
0
1
0
1
0
Ireland
0
0
4
0
4
0
Mexico
33
7
2498
152
1311
2531
159
New Zealand
11
0
57
0
0
68
0
Norway
0
0
1
0
1
0
Peru
0
0
2
0
2
0
Poland
0
0
3
0
3
0
Russia
0
0
1
0
1
0
Slovakia
0
0
1
0
1
0
South Korea
0
0
6
0
6
0
Spain
4
0
35
0
39
0
Sweden
0
0
24
0
24
0
Switzerland
0
0
5
0
5
0
Uruguay
0
0
2
0
USA
91
1
0
0
UK
5
0
20
Venezuela
0
0
3
164
8
2952
152
TOTAL
CHOTANI © 2009.
Hospitalized
2
2
0
91
1
0
25
0
0
3
0
3116
160
5
1318
5:00 AM April 30
Swine Flu: Current Situation Globally
•
The WHO raised the alert level to Phase 5,
meaning there are large clusters (e.g., 25-50
cases lasting 2 to 4 weeks), but human-tohuman spread is still localized.
•
•
164 confirmed cases worldwide with 8 deaths
(Mexico & US)
•
•
WHO’s 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.
Case-fatality ~ 5%
2,952 suspected cases worldwide with 160
deaths (Mexico & US)
•
Case-fatality ~ 5%
•
1,318 hospitalized
•
European Union (EU) Health Commissioner
Androulla Vassiliou issued a travel advisory to
the 27 EU member countries recommending
that “non-essential” travel to affected parts of
the U.S. and Mexico be suspended
CHOTANI © 2009.
Inter-Pandemic
Phase
New Virus in
Animals, NO
Human Cases
Pandemic ALERT
New Virus Causes
Human Cases
PANDEMIC
Low Risk of Human Cases
1
High Risk of Human Cases
2
No or Very Limited Human-toHuman Transmission
3
Evidence of Increased Human-toHuman Transmission
4
Evidence of Significant Humanto-Human Transmission
5
Efficient & Sustained Human-toHuman Transmission
6
Swine Flu: Transmission Through Species
Reassortment in Pigs
Human Virus
Avian Virus
Avian/Human
Reassorted Virus
Swine Virus
CHOTANI © 2009.
Swine Flu: Transmission to Humans
• Through contact with infected pigs or
environments contaminated with
swine flu viruses
• Through contact with a person with
swine flu
• Human-to-human spread of swine flu
has been documented also and is
thought to occur in the same way as
seasonal flu, through coughing or
sneezing of infected people
CHOTANI © 2009.
Swine Flu: US Case Definitions (Updated)
•
A confirmed case of swine influenza A (H1N1) virus infection is defined as a
person with an acute febrile respiratory illness with laboratory confirmed swine
influenza A (H1N1) virus infection at CDC by one or more of the following tests:
•
•
•
A probable case of swine influenza A (H1N1) virus infection is defined as a
person with an acute febrile respiratory illness who is:
•
•
•
real-time RT-PCR
viral culture
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 a
person with acute febrile respiratory illness with onset
•
•
•
CHOTANI © 2009.
within 7 days of close contact with a person who is a confirmed case of swine
influenza A (H1N1) virus infection, or
within 7 days of travel to community either within the United States or internationally
where there are one or more confirmed swine influenza A(H1N1) cases, or
resides in a community where there are one or more confirmed swine influenza
cases.
Source: CDC
Swine Flu: US Case Definitions
• Infectious period for a confirmed case of swine influenza A (H1N1)
virus infection is defined as 1 day prior to the case’s illness onset to 7
days after onset
• Close contact is defined as: within about 6 feet of an ill person who is
a confirmed or suspected case of swine influenza A (H1N1) virus
infection during the case’s infectious period
• Acute respiratory illness is defined as recent onset of at least two of
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 of
swine influenza A (H1N1) virus infection is defined as the same for
seasonal influenza (see Reference)
CHOTANI © 2009.
Source: CDC
Swine Flu: Guidelines for
Clinicians
• Clinicians should consider the possibility of swine
influenza virus infections in patients presenting with
febrile 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 a
respiratory 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 timely diagnosis at
a state public health laboratory
CHOTANI © 2009.
Source: CDC
Swine Flu: Guidelines for
Clinicians
• Signs and Symptoms
• Influenza-like-illness (ILI)
• Fever, cough, sore throat, runny nose, headache, muscle aches. In
some cases vomiting and diarrhea. (These cases had illness onset
during late March to mid-April 2009)
• Cases of severe respiratory disease, requiring hospitalization
including fatal outcomes, have been reported in Mexico
• The potential for exacerbation of underlying chronic medical
conditions or invasive bacterial infection with swine influenza virus
infection should be considered
• Non-hospitalized ill persons who are a confirmed or
suspected case of swine influenza A (H1N1) virus
infection are recommended to stay at home (voluntary
isolation) for at least the first 7 days after illness onset
except to seek medical care
CHOTANI © 2009.
Source: CDC
Swine Flu: Guidelines for
Clinicians
FDA Issues Authorizations for Emergency Use (EUAs) of Antivirals
•
On April 27, 2009, the U.S. Food and Drug Administration (FDA) issued
EUAs in response to requests by the Centers for Disease Control and
Prevention (CDC) for the swine flu outbreak
•
One of the reasons the EUAs could be issued was because the U.S.
Department of Health and Human Services (HHS) declared a public health
emergency on April 26, 2009
•
The swine influenza EUAs aid in the current response:
CHOTANI © 2009.
•
Tamiflu: Allow for Tamiflu to be used to treat and prevent influenza in children
under 1 year of age, and to provide alternate dosing recommendations for
children older than 1 year. Tamiflu is currently approved by the FDA for the
treatment and prevention of influenza in patients 1 year and older.
•
Tamiflu and Relenza: Allow for both antivirals to be distributed to large segments
of the population without complying with federal label requirements that would
otherwise apply to dispensed drugs and to be accompanied by written
information about the emergency use of the medicines.
Swine Flu: Biosafety Guidelines for
Laboratory Workers
•
Diagnostic work on clinical samples from patients who are suspected
cases of swine influenza A (H1N1) virus infection should be conducted in
a BSL-2 laboratory
•
All sample manipulations should be done inside a biosafety cabinet (BSC)
•
Viral isolation on clinical specimens from patients who are suspected
cases of swine influenza A (H1N1) virus infection should be performed in
a 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
•
CHOTANI © 2009.
all waste disposal procedures should be followed as outlined
in your facility standard laboratory operating procedures
Source: CDC
Swine Flu: Biosafety Guidelines for
Laboratory Workers
• Appropriate disinfectants
• 70 per cent ethanol
• 5 per cent Lysol
• 10 per cent bleach
• All personnel should self monitor for fever and any
symptoms. Symptoms of swine influenza infection
include diarrhea, headache, runny nose, and muscle
aches
• Any illness should be reported to your supervisor
immediately
• For personnel who had unprotected exposure or a
known breach in personal protective equipment to
clinical material or live virus from a confirmed case of
swine influenza A (H1N1), antiviral chemoprophylaxis
with zanamivir or oseltamivir for 7 days after exposure
can be considered
CHOTANI © 2009.
Source: CDC
Swine Flu: Guidelines for
Laboratory Workers
FDA Issues Authorizations for Emergency Use (EUAs) of Diagnostic
Tests
•
On April 27, 2009, the U.S. Food and Drug Administration (FDA) issued
EUAs in response to requests by the Centers for Disease Control and
Prevention (CDC) for the swine flu outbreak
•
One of the reasons the EUAs could be issued was because the U.S.
Department of Health and Human Services (HHS) declared a public health
emergency on April 26, 2009
•
The swine influenza EUAs aid in the current response:
•
CHOTANI © 2009.
Diagnostic Test: Allow CDC to distribute the rRT-PCR Swine Flu Panel
diagnostic test to public health and other qualified laboratories that have the
equipment and personnel to perform and interpret the results.
Swine Flu: Guidelines for
General Population
• Covering nose and mouth with a tissue 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-based hand cleaners
• Avoiding close contact with sick people
• Avoiding touching eyes, nose or mouth with unwashed
hands
• If sick with influenza, staying home from work or school
and limit contact with others to keep from infecting them
CHOTANI © 2009.
Source: CDC
Swine Flu: 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 getting sick
(within 2 days of symptoms)
•
Warning! Do NOT give 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 or suspected ill case of
swine influenza A (H1N1) virus infection; this can cause a rare but serious
illness called Reye’s syndrome. For relief of fever, other anti-pyretic
medications are recommended such as acetaminophen or non steroidal
anti-inflammatory drugs.
CHOTANI © 2009.
Source: CDC
Swine Flu: Other Protective Measures
Defining Quarantine vs. Isolation vs. Social-Distancing
• Isolation: Refers only to the sequestration of symptomatic
patents either in the home or hospital so that they will not infect
others
• Quarantine: Defined as the separation from circulation in the
community of asymptomatic persons that may have been
exposed to infection
• Social-Distancing: Has been used to refer to a range of nonquarantine measures that might serve to reduce contact between
persons, such as, closing of schools or prohibiting large
gatherings
CHOTANI © 2009.
Source: CDC
Swine Flu: Other Protective Measures
Personnel Engaged in Aerosol Generating Activities
• CDC Interim recommendations:
• Personnel engaged in aerosol generating activities (e.g., collection of
clinical specimens, endotracheal intubation, nebulizer treatment,
bronchoscopy, and resuscitation involving emergency intubation or
cardiac pulmonary resuscitation) for suspected or confirmed swine
influenza A (H1N1) cases should wear a fit-tested disposable N95
respirator
• Pending clarification of transmission patterns for this virus, personnel
providing direct patient care for suspected or confirmed swine influenza
A (H1N1) cases should wear a fit-tested disposable N95 respirator when
entering the patient room
• Respirator use should be in the context of a complete respiratory
protection program in accordance with Occupational Safety and Health
Administration (OSHA) regulations.
CHOTANI © 2009.
Source: CDC
Swine Flu: Other Protective Measures
Infection Control of Ill Persons in a Healthcare Setting
• Patients with suspected or confirmed case-status should be placed
in a single-patient room with the door kept closed. If available, an
airborne infection isolation room (AIIR) with negative pressure air
handling with 6 to 12 air changes per hour can be used. Air can be
exhausted 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 air
handling.
• The ill person should wear a surgical mask when outside of the
patient room, and should be encouraged to wash hands frequently
and follow respiratory hygiene practices. Cups and other utensils
used by the ill person should be washed with soap and water before
use by other persons. Routine cleaning and disinfection strategies
used during influenza seasons can be applied to the environmental
management of swine influenza.
CHOTANI © 2009.
Source: CDC
Swine Flu: Other Protective Measures
Infection Control of Ill Persons in a Healthcare Setting
• Standard, Droplet and Contact precautions should be used for all
patient care activities, and maintained for 7 days after illness onset
or until symptoms have resolved. Maintain adherence to hand
hygiene by washing with soap and water or using hand sanitizer
immediately 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-sterile
gloves, gowns, and eye protection (e.g., goggles) to prevent
conjunctival exposure.
CHOTANI © 2009.
Source: CDC
Types of protective masks
•
Surgical masks
•
•
High-filtration respiratory mask
•
•
•
•
CHOTANI © 2009.
Easily available and commonly used for routine surgical and examination
procedures
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 greater
than 0.3 micron under normal rate of respiration.
The next generation of masks use Nano-technologywhich are capable of
blocking particles as small as 0.027 micron.
Summary
•
There is evidence of circulation of a strain previously undetected in pigs and humans
•
WHO raised the alert level to Phase 5, meaning there are large clusters (e.g., 25-50 cases lasting 2 to
4 weeks), but human-to-human spread is still localized.
•
164 confirmed cases worldwide (10 countries) with 8 deaths (Mexico & US); Case-fatality ~ 5%
•
2,952 suspected cases worldwide (34 countries) with 160 deaths (Mexico & US); Case-fatality ~ 5%
•
1,318 hospitalized
•
In the US epidemiological data on one study reported
•
•
•
47 patients (out of 64), the median age was 16 years (range: 3-81 years),
38 (81%) were aged <18 years;
51% of cases were in males.
•
In Mexico, healthy young adults, (20-50 years) affected by the disease
•
Huge disparity of mortality seen between Mexico and other countries such as US
•
No vaccine is available
•
Anti-virals available:
•
•
Oseltamivir (Tamiflu) or
Zanamivir (Relenza)
•
EU issues a travel advisory to the 27 EU member countries recommending “non-essential” travel to
affected parts of the U.S. and Mexico be suspended
•
US issued a travel advisory that recommends against all non-essential travel to Mexico
CHOTANI © 2009.
Conclusion/Recommendations
1. At present, there are cases in Canada and the United States who do not
have a history of travel to Mexico, so there are now 3 countries reporting
human to human spread of the virus – the virus should be renamed
“North American” H1N1 influenza
2. Most people do not have immunity to this virus and, as it continues to
spread, more cases, more hospitalizations and more deaths are
expected in the coming days and weeks.
•
Each locality/jurisdiction needs to
• have enhanced disease and virological surveillance capabilities
• develop a plan to house large number of severely sick and provide care if needed &
to deal with mildly sick at home (voluntary quarantine)
• healthcare facilities/hospitals need to focus on stringent infection prevention and
control
3. In the Northern Hemisphere influenza viral transmission traditionally
stops by the beginning of May but in pandemic years (1957) sporadic
outbreaks occurred during summer among young adults
•
Likelihood that
• this wave will fade in North America within the next 3-5 weeks (influenza virus
cannot survive high humidity or temperature)
• will reappear in autumn in North America as a highly pathogenic second wave
• will continue to circulate and cause disease in Australia & New Zealand
CHOTANI © 2009.
Conclusion/Recommendations
4. 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 of
disease
• 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 probable SARS
• Singapore reported that after screening nearly 500,000 air passengers, none were
found to have SARS
• passive surveillance methods (in which symptomatic individuals report illness) can
be important tools
5. School Closures:
• Preemptive school closures will just delay the spread of disease, once they
reopen (as they cannot be closed indefinitely), the disease will spread again.
Furthermore, this would put unbearable pressure on single-working parents
and would be devastating to the economy
• Closure after identification of a large cluster would be appropriate as the
absenteeism rate among students and teachers would be high enough to
justify this action
6. High priority should be given to include the present “North American” (swine)
influenza A/H1N1 virus in next years vaccine
CHOTANI © 2009.