Presentation on Influenza facts, prevention, swine flu for non medical audience ( Rotaract Club) Given on October 2010 in egypt

1. Influenza: Facts and
prevention
By
Dr. Moustapha A. Ramadan

2. Objectives of the session
 Epidemiology of influenza
 Difference between influenza and
common cold
 Virulence of influenza
 Prevention of influenza

3. Influenza Virus Strains
 Type A- moderate to severe illness
- all age groups
- humans and other animals
 Type B- milder disease
- primarily affects children
- humans only
 Type C- rarely reported in humans
- no epidemics

4. Influenza Epidemiology
 Reservoir Human, animals (type
A only)
 Transmission Contact (Direct-indirect-
droplet)
Airborne
 Temporal pattern Peak December – March
in temperate climate
May occur earlier or later
 Incubation period 1-3 days
 Communicability 1 day before to 5 days
after onset (adults)

5. Influenza Virus
A/Fujian/411/2002 (H3N2)
Neuraminidase
Hemagglutinin
Type of nuclear
material
Virus
type
Geographic
origin
Strain
number
Year of
isolation
Virus
subtype

6. Species Infected by Influenza A,
HA and NA Subtypes
H15,16
H14
H13
H12
H11
H10
H3
H2
H1
H9
H8
H7
H6
H5
H4
N9
N8
N7
N6
N5
N3
N4
N2
N1

7. Influenza Antigenic Changes
 Antigenic Shift
◦ major change, new subtype
◦ caused by exchange of gene segments
◦ may result in pandemic
 Example of antigenic shift
◦ H2N2 virus circulated in 1957-1967
◦ H3N2 virus appeared in 1968 and completely
replaced H2N2 virus

8. Influenza Antigenic Changes
 Antigenic Drift
◦ minor change, same subtype
◦ caused by point mutations in gene
◦ may result in epidemic
 Example of antigenic drift
◦ in 2002-2003, A/Panama/2007/99 (H3N2)
virus was dominant
◦ A/Fujian/411/2002 (H3N2) appeared in late
2003 and caused widespread illness in 2003-
2004

9. Influenza Type A Antigenic Shifts
Year
1889
1918
1957
1968
1977
Subtype
H3N2
H1N1
H2N2
H3N2
H1N1
Severity of
Pandemic
Moderate
Severe
Severe
Moderate
Mild

12. What are the symptoms of
influenza in humans?
The symptoms of different forms of influenza in people
tend to be similar and include
*Fever > 37.8°C
*Sore throat
*Cough
*Runny nose
*Chills
*Headache and body aches
*Fatigue
Some people have reported nausea, vomiting and
diarrhea.

13.  How is swine flu different from avian (bird)
flu?
Avian flu so far has had difficulty infecting humans unless
they are exposed intensely to birds, because the virus
has not mutated in a way that makes it transmissible by
humans to other humans. Swine virus has origins
genetically from both pigs and birds, and the big
difference from the avian flu is that the swine virus can
be transmitted readily from human to human.

14.  Is this just another scare that will go
away like bird flu?
Bird flu is a theoretical threat and will need a
mutation to be able to be transmitted among
humans to become a serious threat.
There is logical concern that swine flu might
re-emerge next flu season.

15.  Can influenza kill me?
Morbidity tends to be high and mortality low (1–
4%).
3-5 millions are affected yearly, 250 000-500 000
deaths yearly
We do not know all the factors geographically
and demographically that may contribute to the
mildness or severity of this flu.

16. What is the morbidity and mortality?
Avian flu H5 N1
Worldwide Total 505 Death 300 (59.4%)
Egypt Total 112 Death 36 ( 32.14%)
Swine flu H1 N1
Worldwide Total 8753967 Death 14346 (0. 16%)
Egypt Total 12230 Death 195 (1. 59%)

17.  What are the preventive methods for me
and contacts?
Proper hand hygiene
Coughing etiquette
Avoid overcrowded places
Avoid bad ventilated places
If you are ill, stay home.
Immunization
Surveillance by health authorities of the extent
and progress of the outbreak and reporting of
findings to the community is important.

19. What are the types of influenza vaccine
available?
 There are two forms for influenza vaccine
Inactivated Form and Live attenuated Form.
 During any outbreak the influenza vaccine is
made using the same process and facilities that
are used to make the currently licensed seasonal
influenza vaccines.
 During outbreak people willing to have the
vaccine should have both
 The vaccine is usually available at fall.

20. Who will be covered by the vaccine ?
 WHO currently estimates worldwide production capacity
for pandemic vaccines at approximately 3 billion doses
per year
 These supplies will still be inadequate to cover a world
population of 6.8 billion people in which virtually
everyone is susceptible to infection
 Vaccine supplies in low and middle income countries will
largely depend on donations from manufacturers and
other countries

21. Who is recommended to receive the
vaccine?
 Infants younger than 6 months of age ;
 Persons aged 65 years or older
 Pregnant women
 Persons of any age with certain chronic medical or
immunosuppressive conditions and ,
 Persons younger than 19 years of age who are
receiving long-term aspirin therapy .
 Healthcare personnel and emergency medical
services personnel.

22. What are the side effects of vaccine?
 In almost all vaccine recipients, symptoms are mild, self-
limited and last 1-2 days.
 Side effects are expected to be similar to those observed
with seasonal influenza vaccines :
 Local reaction at the injection site ( soreness, swelling,
redness)
 Systemic reaction (fever, headache, muscle or joint
aches)

23.  What medications are available for
influenza infections treatment/
chemoprophylaxis in humans?
There are four different antiviral drugs that are licensed
for use in the US for the treatment of influenza:
Amantadine, Rimantadine, Oseltamivir and
Zanamivir.

24. To whom chemoprophylaxis is
recommended?
 Persons who are at higher risk for complications of
influenza and are at close contact of a person with
confirmed, probable, or suspected influenza during
person’s infectious period.
 Health care personnel, public health workers, or first
responders who have had a recognized, unprotected
close contact exposure to a person with confirmed,
probable, or suspected influenza during person’s
infectious period.

25. When chemoprophylaxis is not
considered?
 Antiviral agents should not be used for post exposure
chemoprophylaxis in healthy children or adults based on
potential exposures in the community, school, camp or
other settings .
 Chemoprophylaxis generally is not recommended if
more than 48 hours have elapsed since the last contact
with an infectious person .
 Chemoprophylaxis is not indicated when contact
occurred before or after, but not during, the period of
communicability.

26. What are the treatment
recommendations?
Early empiric treatment with antiviral drugs should be
considered for persons with suspected or confirmed
influenza who are at higher risk for complications
including:
 Children younger than 2 years old ;
 Persons aged 65 years or older
 Pregnant women
 Persons of any age with certain chronic medical or
immunosuppressive conditions and ,
 Persons younger than 19 years of age who are receiving long-
term aspirin therapy .
Treatment with antiviral drugs is recommended for all
persons with suspected or confirmed influenza
requiring hospitalization.

27. What are the treatment
recommendations?
 Treatment, when indicated, should be initiated as early
as possible (i.e., within 48 hours of illness onset) is more
likely to be benefit .
 Treatment should not wait for laboratory confirmation of
influenza because laboratory testing can delay treatment
and because a negative rapid test for influenza does not
rule out influenza .

28. What is the antiviral dosage?
 Oseltamivir
Treatment: 75-mg capsule twice per day for 5 days
Chemoprophylaxis: 75-mg capsule once per day for 10
days
 Zanamivir
Treatment :10 mg (two 5-mg inhalations) twice daily for 5
days
Chemoprophylaxis :10 mg (two 5-mg inhalations) once
daily for 10 days

29. What are the antiviral agents side
effects?
 Oseltamivir
Nausea, vomiting( less severe if taken with food)
Transient neuropsychiatric event ) self injury, delirium) have
been reported in adults living in Japan
 Zanamivir
Diarrhea, nausea, sinusitis, bronchitis, cough, headache,
dizziness
Each of these symptoms was reported by less than 5%
Is not recommended for patients with underlying airway disease

30.  References:
World Health Organization (WHO)
Centre for disease control (CDC)
Control of communicable diseases manual
Infection control today