SWINE FLU

1. SWINE FLU
Dr.vijay

2. VIROLOGY OF INFLUENZA
Spherical
Enveloped ,
Segmented
Negative Sense
8 SINGLE Straded
RNA Virus

3. TAXONOMY

4. Anitgenic Drift
Mutation That Take Place Within The Genome
Causes Changes In Hemagglutinin And Neuraminidase Of
Influenza Virus Due To Point Mutations
This Involves No Change In Serotype; There Is Merely An
Alteration In Amino Acid Sequence Of HA Or NA Leading To
Change In Antigenicity.
Drift Variants Can Cause Epidemics And Lasts For 2 To 5 Years,
Before Being Replaced By A Different Strain.

5. ANTIGENIC SHIFT
Re-assortment (mixing of genetic
meterial ) among the genetic materials
of subtypes resulting in A new virus.
Involves major antigenic changes in
which a new HA or NA subtype is
introduced into the human population.
Caused by reassortment, typically between
human , avian and swine strains.
•Double reassortment
•Triple reassortment.(2009-
swineflu(H1N1))
§ Antigenic shift may result in a new virus
easily transmissible from man to man for
which the population has no immunity :
 results in pandemics
.

6. PATHOGENESIS

7. PATHOGENESIS
High affinity for the tracheal cells with sialic acid receptors. HA
ataches to Sialic acid receptors. Preferentially binds to the N-
acetylneuraminic acid attatched to the penultimate glucose sugar
by α 2,6 linkage. (2,3 linkage for avian flu)
the virus multiplies in bronchial epithelium within 16 hr of
infection and causes
focal necrosis of the bronchial epithelium,
focal atelectasis, and gross hyperemia of the lungs.
Epithelial cell damage
Airway plugging
Peribronchial and perivascular mononuclear infiltrates.

8. TRANSMISSION
Short incubation period, usually 1-4 days.
Source of infection -Case or sub-clinical case
 Reservoir of Infection - Human
 Spread by respiratory droplets
Person to person,
Direct contact, rare aerosol
Highly contagious
INFECTIOUS PERIOD:
üAdults: 1 day prior to symptoms & 5 days post illness starts
üChildren: >10 days
üImmune compromised shed virus for weeks to months
Virus is detectable just before symptom onset.
Usually not detectable after 5-10 days
People with flu can spread it to others up to about 6 feet away

9. SWINE FLU SYMPTOMS
SWINE FLU is a contagious respiratory illness caused
by flu viruses. It can cause mild to severe illness, and at
times can lead to death. The flu is different from a
cold. The flu usually comes on suddenly.
People who have the flu often feel some or all of these
symptoms:
Fever* or feeling feverish/chills
Cough
Sore throat
Runny or stuffy nose
Muscle or body aches
Headaches
Fatigue (tiredness)
Some people may have vomiting and diarrhea, though
this is more common in children than adults.
* It's important to note that not everyone with flu
will have a fever.

10. Symptoms
Symptoms Number (n=268) %
Fever 249 93%
Cough 223 83%
Shortness of breath 145 54%
Fatigue/Weakness 180 40%
Chills 99 37%
Myalgias 96 36%
Rhinorrhea 96 36%
Sore throat 84 31%
Headache 83 31%
Vomiting 78 29%
Wheezing 64 24%
Diarrhea 64 24%
Source: CDC. http://www.cdc.gov/h1niflu/surveillanceqa.htm

11. Emergency Warning Signs
. In adults:
•
Difficulty breathing or shortness of
breath
•
Pain or pressure in the chest or
abdomen
•
Sudden dizziness
•
Confusion
•
Severe or persistent vomiting
•
Flu-like symptoms improve but then
return with
fever and worse cough

12. SYMPTOMS IN CHILDREN

•
Fast breathing or trouble breathing
•
Red or grey rash on skin
•
Not drinking enough fluids
•
Not waking up or not interacting
•Being so irritable that the child does not want to
be held
•
Flu-like symptoms improve but then return with
fever and worse cough
•
Fever with a rash

13. Emergency warning signs in
children

 Fast breathing or trouble breathing
 Bluish or gray skin color
 Not drinking enough fluids
 Severe or persistent vomiting
 Not waking up or not interacting
 Irritable, the child does not want to be held
 Flu-like symptoms improve but then return
with fever and worse cough

14. HIGH RISK CASES
Adults 65 years and older
Children younger than 5 years old, but especially children
younger than 2 years old
Pregnant women and women up to 2 weeks after the end of
pregnancy
Asthma , Chronic lung disease (COPD] and cystic fibrosis
DIABETES
congestive heart failure and coronary artery disease)
Morbid obesity
Kidney disorders
Liver disorders
Weakened immune system due to disease or medication
(such as people with HIV or AIDS, or cancer, or those on chronic steroids)
Neurological and neurodevelopment conditions
Metabolic disorders (such as inherited metabolic disorders and mitochondrial
disorders)
Blood disorders (such as sickle cell disease
People younger than 19 years of age on long-term aspirin therapy

15. Smoking and Influenza
Some research studies show an increase in influenza
infections among smokers compared to nonsmokers.
There is a higher mortality rate for smokers than
nonsmokers from influenza.

16. Diagnostic Tests
Influenza
Diagnostic
Tests
Method AvailabilityTypical
Processing
Time2
Sensitivity3
for
H1N1
influenza
Distinguishes
H1N1
influenza
from other
influenza A
viruses?
Rapid influenza
diagnostic tests
(RIDT)4
Antigen detection Wide 0.5 hour 10 – 70% No
Direct and indirect
Immunofluorescence
assays (DFA and
IFA)5
Antigen detection Wide 2 – 4 hours 47–93% No
Viral isolation in
tissue cell
culture
Virus isolationLimited 2 -10 days - Yes 6
Nucleic acid
amplification
tests
(including rRT-
PCR) 7
RNA detection Limited8  48 – 96
hours
[6-8 hours to
perform test]
86 – 100% Yes
Source: CDC

17. SAMPLE COLLECTION.
Respiratory specimens including:
v bronchoalveolar lavage,
vtracheal aspirates,
vnasopharyngeal or oropharyngeal aspirates as washes, and
vnasopharyngeal or oropharyngeal swabs.
 Swab specimens should be collected only on swabs with a synthetic tip
(such as polyester or Dacron) and aluminium or plastic shaft.
Swabs with cotton and wooden shafts are not recommended. Specimens
collected with swabs made of calcium alginate are acceptable.
BEST TIME TO TAKE SAMPLE
Sample need to be collected within the first 4 to 5 days of illness (when an
infected person is most likely to be shedding virus).
• However, some persons, especially children, may shed virus for 10 days or
longer.
•Before antiviral medications are administered

18. Throat Swab
•
Highest yield in detecting H1N1
influenza in suspected cases
•
Have the patient open his/her mouth
wide open.
•
Sample should be collected from
back of the throat near the tonsils.

19. Nasal / Nasopharyngeal Swab
Insert dry swab into nostril and back to
nasopharynx
Leave in place for a few seconds. Slowly remove
swab while slightly rotating it.
 Use a different swab for the other nostril. Put
tip of
swab into vial containing VTM
Nasal Swab is collected from the anterior
turbinate.

21. ANTIVIRAL TREATMENT
There are two flu antiviral drugs recommended
Oseltamivir or Zanamivir

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)
Source: CDC

24. Source: CDC
OSELTAMIVIR (TAMIFLU)
ZANAMIVIR (RELENZA)
Treatment Prophylaxis Treatment Prophylaxis
ADULTS
75 mg capsule
twice per day for
5 days
75 mg OD
for 7-10 days
Two 5 mg
inhalations (10
mg total) BD
Two 5 mg
inhalations (10
mg total) OD
CHILDREN
15 kg or less: 30
mg BD
30 mg OD Two 5 mg
inhalations (10
mg total) BD
(age, 7 years or
older)
Two 5 mg
inhalations (10
mg total) OD
(age, 5 years
or older)
15–23 kg: 45 mg
BD
45 mg OD
24–40 kg: 60mg
BD
60 mg OD
>40 kg: 75mg
BD
75 mg OD
ANTIVIRAL PROTECTION

25. OSELTAVIR(PRODRUG)
MECHANISM OF ACTION
in the LIVER  it is hydrolyzed to its active metabolite - the free Oseltamivir
carboxylate.Oseltamivir is a competitive neuramidase inhibitor. By blocking the
activity of the enzyme, oseltamivir prevents new viral particles from being released
through the cleaving of terminal sialic acid on glycosylated hem agglutinin and thus fail to
facilitate virus release.
PHARMACOKINETICS
Its Oral bioavailability is over 80% and is extensively metabolised to its active form upon
first-pass through the liver.[
Its half-life is about 1–3 hours and its active metabolite has a half-life of 6–10 hours.
It is predominantly ELIMINATED IN THE URINE as the active carboxylate metabolite
(>90% of oral dose)
MOST COMMON SIDE EFFECTS :
Nausea, vomiting, abdominal pain, ear disorder, and diarrhea
DRUG INTERACTIONS :
Co administration of oseltamivir and probenecid resulted in reduced clearance of
Oseltamivir carboxylate by approximately 50% and a corresponding approximate two-fold
increase In the plasma levels of oseltamivir carboxylate

26. Oseltamivir, zanamivir, rimantadine, and
amantadine are “Pregnancy Category C” few
adverse events have been reported occasionally in
pregnant women who took these medications, no
causal relation between the use of these medications
and these adverse events has been established . In
addition, fever can cause adverse fetal outcomes, and
reducing fever, whether directly by using antipyretics,
or indirectly by reducing the duration and severity of
symptoms with antiviral medications, might reduce
this risk
. One retrospective cohort study found no evidence of
an association between oseltamivir use during
pregnancy and a variety of adverse events, including
preterm birth, premature rupture of membranes,
increased duration of hospital stay for mother or
neonate, malformations, or fetal weight .
Oseltamivir is preferred for
treatment of pregnant women.
.
PREGNANT WOMEN

27. PREVENTION
 Recent studies* by CDC researchers and other experts
indicate that flu vaccine reduces the risk of doctor visits due
to flu by approximately 60% among the overall population
when the vaccine viruses are like the ones spreading in the
community.

28. Live Attenuated (Human) Influenza Vaccine
NASOVAC-S, Influenza Vaccine, (Human), freeze dried is a live
trivalent vaccine for administration by intranasal spray
COMPOSITION
[Propagated in Embryonated hen eggs]
Each vial of single dose (0.5 ml) contains:
A(H1N1) Strain –

A/17/California/2009/38 (H1N1)* Not less than 107 EID 50
A(H3N2) Strain
 - A/17/Texas/2012/30 (H3N2)*     Not less than 107 EID 50
B Strain
 - B/60/Massachusetts/2012/10*       Not less than 106.5 EID 50

29. Reconstitute with Sterile Water for Inhalation USP
Dose: 0.5 ml intranasal (spray 0.25 ml per nostril)
The diluent supplied is specially designed for use with the vaccine.
Only this diluent must be used to reconstitute the vaccine. Do not
use diluents from other types of vaccine or from other
manufacturers.
Using an incorrect diluent may result in damage to the vaccine
and/or serious reactions to those receiving the vaccine. Diluent
must not be frozen, but should be kept cool.
ADVERSE REACTIONS
Local : Nasal discomfort, stuffy nose, sneezing, runny nose, loss of
smell, red eyes, chills, facial swelling.
Systemic : Fever, headache, fatigue, myalgia, arthralgia, irritability,
loss of appetite, sore throat, cough, wheezing, nausea.

30. Nasal Spray Flu Vaccine

The nasal spray vaccine is approved for use in people 2 years
through 49 years of age.

CONTRAINDIACTED IN :
Children younger than 2 years & Adults 50 years and older
People with a history of severe allergic reaction to any
component of the vaccine or to a previous dose of any
influenza vaccine
People who are allergic to eggs
Children or adolescents (2 years through 17 years of age) on
long-term aspirin treatment.
Pregnant women
Children 2 years through 4 years who have asthma or who
have had a history of wheezing in the past 12 months.
People who have taken influenza antiviral drugs within
the previous 48 hours.
severely immunocompromised persons

31. STORAGE
2 - 8ºC (35-46ºF)
Difference in the efficacy of intranasal and
injectable flu vaccines ?
Several studies have proved that the clinical efficacy
of intranasal vaccine is superior to that of injectable
vaccine.

Injectable vaccines protect only at the level of the
blood by producing antibodies. While the intranasal
vaccine offers protection at two levels viz the local
level mucosal immunity (the nasal tract) and the
blood by producing antibodies. Due to this, when the
disease virus attacks it gets neutralized at its points of
entry i.e. the nasal tract. If it does manage to pass the
first line of defense, it gets neutralized in the blood.
If a person is protected with an injectable vaccine and
the virus attacks, then the virus will enter through
nose, initially multiply, infect and then its gets
neutralized when it reaches the blood. The person
will be protected overall but may spread the disease
in the initial period.

32. VACCINATE EVERY YEAR ?

The flu viruses are constantly changing .Generally new
influenza virus strains circulate every flu season. Each
Year, before flu season, the most recent circulating
viruses are identified by the World Health
Organization [WHO] and included in a new vaccine
formula order to offer the best protection.

33. FLU COMPLICATIONS
Most people who get influenza will recover in a few days
to less than two weeks, but some people will develop
complications (such as pneumonia) as a result of the flu,
some of which can be life-threatening and result in death.
Pneumonia, bronchitis, sinus and ear infections are
examples of complications from flu. The flu can make
chronic health problems worse.
 For example, people with asthma may experience
asthma attacks while they have the flu, and people with
chronic congestive heart failure may experience worsening
of this condition that is triggered by the flu.

34. COMPLICATIONS.
Pulmonary complications
Primary viral pneumonia
Combined viral bacterial pneumonia
Secondary bacterial pneumonia.
ARDS
Extra pulmonary complications.
Viremia
Myositis
Cardiac involvement
Reye’s syndrome
CNS involvement
Toxic shock syndrome.

35. N95 masks do
not
provide complet
e protection,
they are a
valuable layer of
defense.
Influenza
viruses are
usually
transmitted in
two ways, direct
transmission
(touching an
infected surface)
or droplet
transmission.
The influenza
virus does not
transmit across
long distances
and doesn't
survive well
when exposed to
air (single
influenza viruses
don't just float
around by
themselves).
"N95" is a
NIOSH
standard,
meaning that
the mask stops
95% of
particles 3
microns or
larger in size.
The average
influenza virus
is about 0.12
microns in size.
The average
sneezed/coughe
d droplet is over
10 microns in
size.
The average
droplet nucleus
size is 5-10
microns in size.
N95 masks and the H1N1 virus.

36. Why The Flu Virus Is More Infectious In
Cold Winter Temperatures
At winter temperatures, the virus's outer covering, or
envelope, hardens to a rubbery gel that could shield the
virus as it passes from person to person, the researchers
have found. At warmer temperatures, however, the
protective gel melts to a liquid phase. But this liquid
phase apparently isn't tough enough to protect the virus
against the elements, and so the virus loses its ability to
spread from person to person.

37. OTHER REASONS
 During the winter, people spend more time indoors with the
windows sealed, so they are more likely to breathe the same air
as someone who has the flu and thus contract the virus .
Days are shorter during the winter, and lack of sunlight leads
to  low levels of vitamin D and melatonin, both of which
require sunlight for their generation. This compromises our
immune systems, which in turn decreases ability to fight the
virus .
 The influenza virus may survive better in colder, drier
climates, and therefore be able to infect more people .
Cold temperatures lead to drier air, which may dehydrate
mucous membrane preventing the body from effectively
defending against respiratory virus infections.
The virus may linger longer on exposed surfaces (doorknobs,
countertops, etc.) in colder temperatures.
A seasonal decline in the amount of ultraviolet radiation may
reduce the likelihood of the virus being damaged or killed by
direct radiation damage or indirect effects (i. e. ozone
concentration) increasing the probability of infection.

38. Source: Bean B, et al. JID 1982;146:47-51
Survival of Influenza Virus 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)

39. Swine flu H1N1 BIRD FLU H5N1
Swine flu spreads quickly as comparison
to bird flu, but casualty rate not much
high
Bird flu spreads very slowly, but has a
high casualty rate.
Swine flu virus affects only the respiratory
system.
The bird flu virus affects all systems of
human body
 The main symptoms of swine influenza
are vomiting and diarrhea. Apart from
cough, fever, sore throat
Bird flu patients suffer from eye
infections, pneumonia, and other
severe problems.
Where as swine flu is transmitted from
direct contact with pigs, waste matter
contaminated by infected people
Bird flu is transmitted by direct contact
with birds, their excretory products
contaminated by infected people.
Pregnant women, persons with chronic
medical conditions are most vulnerable
target for swine influenza,
Small children and rural workers are
soft target to get infected from bird flu.
Spread from person to person Less spread from person to person

40. 
SAFTEY MEASURES TO PREVENT INFECTION
Wear Glouses

Use Protective Eye Wear (Goggles)/Face Shields

Person Must Wash Their Hands Often – Especially After Handling
Infectious Materials And , Before Leaving The Laboratory Working Areas,
And Before Eating.
Appropriate Disinfectants
70 % Ethanol
5 % Lysol
10 % Bleach
.

41. Hand Washing
Wet hands with clean (not hot)
water
Apply soap
Rub hands together for at least
20 seconds
Rinse with clean water
Dry with disposable towel or
air dry
Use towel to turn off faucet

42. Good Health Habits Can Help
Stop flu
1. Avoid close contact.
2. Stay home when you are sick.
 3. Cover your mouth and nose.
4. Clean your hands. WITH
alcohol-based hand rub.
5. Avoid touching your eyes,
nose or mouth..
Clean and disinfect frequently
touched surfaces at home, work
or school, especially when
someone is ill.
Get plenty of sleep, be
physically active, manage your
stress, drink plenty of fluids, and
eat nutritious food.

43. Summary
•WHO raised the alert level to Phase 6 on June 11, 2009
•Influenza transmission remains active in much of western and central Asia and
there is evidence of pandemic virus circulation in most regions of Africa
•The overall global case-fatality is ~1%
•Symptoms mimic seasonal flu
•1:1 Male:Female Ratio
•Globally
–Number of deaths being reported is rising
•Vaccine
–Total Adverse Events: 5.4% (0.3% fatal)
•Anti-virals (oseltamivir and zanamivir)
–Oseltamivir resistance reported recently in immunocompromised patents

44. …….Thank u