Influenza current updates H3 N2 2023 by Dr. T.V.Rao MD

1. INFLUENZA
CURRENT UPDATES
H3 N2
2023
Dr.T.V.Rao MD
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 1
4/20/2023

2. Current infections with Influenza
H3 N2
• A sharp rise in H3N2 influenza cases has been
reported in India. The virus leads to respiratory
symptoms including persistent cough and many
more. A quick change in weather from extremely cold
to warm has been identified as one of the major
reasons behind this rapid increase in flu symptoms
among people. This virus can also infect birds and
mammals. According to WHO, H3N2 is a subtype of
Influenza A virus which majorly affects humans. A
report by the Centers For Disease Control And
Prevention (CDC), this virus was first identified
in pigs in the US in 2010. Later in 2012, 12
infections were detected in humans followed
by several H3N2 outbreaks in the same year.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 2
4/20/2023

3. WHAT IS H3 N2
• H3N2 is a non-human influenza
virus that normally circulates in
pigs and has infected humans,
according to the US Centre for
Disease Control and Prevention
(CDC). Symptoms are similar to
those of seasonal flu viruses
and can include fever and
respiratory symptoms such as
cough and runny nose, and
possibly other symptoms,
including body ache, nausea,
vomiting or diarrhoea.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 3
4/20/2023

4. Basics on Influenza virus
Mycovirus
•Classified into
1 Influenza virus
2 Parainluenza virus
A Mumps virus
B Parainluenza virus
C Measles virus
D Respiratory syncytial virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 4
4/20/2023

5. Influenza Virus belong to
Myxovirus
• Enveloped RNA virus
• Absorb to mucoprotein receptors
• Many viruses are included in this group
Influenza
Mumps
Measles.
Newcastle disease
Parainluenza virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 5
4/20/2023

6. Historically Speaking
• Influenza can be
traced as far back as
400 BC
• In Hippocrates’ Of
the Epidemics, he
describes a cough
outbreak that
occurred in 412 BC in
modern-day Turkey
at the turn of the
autumn season
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 6
4/20/2023

7. Early Recognized Pandemics
• The first recognized pandemic
occurred in July and August of
1510 when an outbreak of
“gasping oppression” appeared
nearly everywhere at once. It was
described as a “‘gasping
oppression’ with cough, fever, and
a sensation of constriction of the
heart and lungs”, leaving an
impression strong enough for
people to write of it decades later
(Morens et al, 2010). At least
seven contemporary and near-
contemporary reports exist of the
1510 pandemic (Morens, North &
Taubenberger, 2010).
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 7
4/20/2023

8. 1918 Spanish Flu
A great Memorable Event
• Mortality was greater than the 4-year “Black
Death” Bubonic Plague
• Mortality rate was 2.5%, other epidemics
had been 0.1%
• Unusually, most deaths associated with
young, healthy adults
• Researchers isolated a wide selection of
bacteria – virus for influenza unknown
• Years later, H1NI strain found responsible for infection
• However, bacteria responsible for the severe secondary
complications of pneumonia causing death
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 8
4/20/2023

9. Circulating Seasonal InfluenzaA Sub-Types
from Pandemics of the 20th Century
1920 1940 1960 1980 2000
H1N1 Seasonal Flu H1N1 Seasonal Flu
H2N2
H3N2 Seasonal Flu
1918/19 1957/58 1968/69
40-100 million deaths ~2 million deaths ~1 million deaths
4 pandemics since 1889, with 11 to 39 years (average ~30 years) between
each = ~3.3% annual risk of pandemic onset (but likely higher now)
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 9
4/20/2023

10. Camp Funston, Kansas, March 1918: Sadly, the comparatively
benign first wave was not at all predictive of what was to come
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 10
4/20/2023

11. INFLUENZA
• Cause of the
infection of the
Respiratory tract.
• Occurs as
Sporadic
Epidemic
Pandemic
Major pandemic in 1918
– 1919
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 11
4/20/2023

12. Scientific contributions
• Shoppe ( 1931 ) Isolated the Swine
influenza
1933 Smith, Andrews, Laidlaw identifies
Etiological agent
Land mark in advances of Medical
virology
• 1935 Burnet developed chick embryo techniques
• 1941 McClelland and Hare influenza virus tests
showing agglutination of fowl erythrocytes
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 12
4/20/2023

13. WHO defines Influenza
•Influenza is a viral infection
that affects mainly the nose,
throat, bronchi and,
occasionally, lungs. Infection
usually lasts for about a
week, and is characterized
by sudden onset of high
fever, aching muscles,
headache and severe
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 13
4/20/2023

14. Spread of Influenza
•The virus is
transmitted easily
from person to
person via
droplets and
small particles
produced when
infected people
cough or sneeze.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 14
4/20/2023

15. Most recover few Suffer
• Most infected
people recover
within one to two
weeks without
requiring medical
treatment. However,
in the very young,
the elderly, and
those with other
serious medical
conditions.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 15
4/20/2023

16. Origin of Pandemics Influenza
Migratory water birds
H 1-16
N 1-9
Domestic pig
Domestic birds
(All human flu
pandemics come
from bird flu by 1
of 2 mechanisms)
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 16
4/20/2023

17. 17
Where do “new” HA and NA
come from?
• >13 types HA
• 9 types NA
• all circulate in birds
• pigs
• avian and human
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza
4/20/2023

18. 18
Where do “new” HA and NA
come from?
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza
4/20/2023

19. Current incidence of Influenza
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 19
4/20/2023

20. Pandemics and Pandemic Threats of
the 20th Century
• 1918-19 “Spanish flu” H1N1
• 1957 “Asian flu” H2N2
• 1968 “Hong Kong flu” H3N2
• 1976 “Swine flu” episode H1N1
• 1977 “Russian flu” H1N1
• 1997 “Bird flu” in HK H5N1
• 1999 “Bird flu” in HK H9N2
• 2003 “Bird flu” in Netherlands H7N7
• 2004 “Bird flu” in SE Asia H5N1
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 20
4/20/2023

21. Structure of Virion
M1 protein
helical nucelocapsid (RNA plus
NP protein)
HA - hemagglutinin
polymerase complex
lipid bilayer membrane
NA - neuraminidase
100 n m
Influenza virions are SMALL. The average eukaryotic cell diameter is 10,000 nm
(10 microns), which is 100 times bigger than the influenza virion diameter.
http://www.med.sc.edu:85/pptvir2002/INFLUENZA-2002.ppt
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 21
4/20/2023

22. Influenza Virus
•Virus are
spherical in
shape
•Size is 80 -120
nm
•Pleomorphism is
common with
variant forms
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 22
4/20/2023

23. Viral structure
A negative sense
Single stranded
RNA genome is
segmented into 8
segments
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 23
4/20/2023

24. Viral structure
• The nucelocapsid is
surrounded by an
envelope with inner
membrane protein
layer and outer lipid
• From the envelop
there are projections of
two types
• 1 Hem agglutinins
• 2 Neuraminidase
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 24
4/20/2023

25. Resistance of Virus
•Inactivated by heating at 500c for 30
mt
•Survive for 1 week at 0 – 40c for 1
week
•Virus preserved at – 700c
•Survive in the blankets for 2 weeks
•Ether, formaldehyde, Phenol destroy
the virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 25
4/20/2023

26. Prominent Characters of the
Virus
• Haemagglutination Important character, when
mixed with Fowl erythrocytes virus absorbed onto
mucoprotein receptors on the cell surface
Links other cells produce Haemagglutination
• Elution Detachment of virus from cell surface
resisting Haemagglutination is called elution.
Caused by enzyme neuraminidase
Act on cell receptor splits off N –
Acetylneuraminiase
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 26
4/20/2023

27. Haemagglutination defines the nature of the Virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 27
4/20/2023

28. HN terminology
•H refers to Haemagglutinnins types
and each is given a number H1, H2
etc,
•Neuraminidase is designated N and
different forms are available as well
e.g. H5N1 (avian) and H1N1.
•Different combinations of H and N
glycoproteins give rise to different
strains
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 28
4/20/2023

29. Haemagglutination
• Act with red cells of
different species
• Type A and B – RBC’s of Fowl, Human and
guinea pigs
• Type C only RBC’s of Fowl at 40c
• Haemagglutination titer - Highest titer of virus
with fixed quantity of RBC
• Haemagglutination Inhibition titers convenient
way of measuring quantity o antibodies to
virus.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 29
4/20/2023

30. Types of
Haemagglutinnins
• Haemagglutination is
strain specific
• Great variation
• H A there are 15
subtypes H 1 to H15
in avian influenza
• But only 4 variants in
humans
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 30
4/20/2023

31. Neuraminidases
• Neuraminidase are glycoprotein's
• Destroys cell receptors by hydrolysis cleavage
• Anti neuraminidase antibodies are produced
following infection and immunization
• Not protective as Antihemagglutinin antibodies
• Helps to inhibit the release and spread of
progeny
• Strain specific exhibit variation, There are nine
different subtypes N 1 – N9.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 31
4/20/2023

32. Antigenic Variation
• Unique feature of this virus lies with
antigenic variation.
• High in type A virus
• Less in type B virus
• Not in type C virus
• RNP and Matrix proteins are stable
• Haemagglutination and Neuraminidase are
independent of the variations.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 32
4/20/2023

33. Influenza prominent 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
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 33
4/20/2023

34. 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
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 34
4/20/2023

35. Antigenic Variations
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 35
4/20/2023

36. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 36
4/20/2023

37. Antigenic Shift
• It is abrupt and Drastic
• Discontinuous variation
in structure in antigens
• Results in novel virus
and unrelated to
previous strains causing
infections
• Involves –
Haemagglutinnins,
Neuraminidase or both
• Subtypes depends only
on antigenic shifts,
occurs on
Haemagglutinnins
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 37
4/20/2023

38. Antigenic shift initiates
Pandemics
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 38
4/20/2023

39. Terminology by WHO
• Ao A1 A2 ( Asian ) A2 ( H K )
• Ho H1 H2 H3
Designated on the Basis of
Type, Place of Origin, Serial Number,
Year of isolation – Followed by Antigenic subtypes of
H and NA
A /Hong Kong / 1/68 ( H3 N2 )
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 39
4/20/2023

40. Host Range
•Experimented in Animals
•Spread through respiratory shredding
•Respiratory disease in Ferrets
•Intranasal passage in Mice
•Infect the amniotic cavity of Allantois
and Amniotic fluids
•Virus can be grown in primary
monkey kidney and in continuous cell
lines
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 40
4/20/2023

41. Life cycle of the ‘flu virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 41
4/20/2023

42. Pathogenesis
• Infects the respiratory tract
• Even 3 or few viral particles can infect
• Neuraminidase facilitates infection reducing
the viscosity of Mucous
• Ciliated cells are infected in the Respiratory
tract - site of viral infection
• When superficial layers are damaged
exposes the basal layers
• And exposure of the basal layer causes the
bacterial infections.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 42
4/20/2023

43. Reservoirs of Virus
• Virus harbored as
Asymptomatic infection
• All isolates from Non
human hosts harbor
type A virus
• Types B and C are
exclusively common to
Humans, Not identified
in animals or birds
• Plays a great role in
emerging pandemics
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 43
4/20/2023

44. 44
TRANSMISSION
• AEROSOL
• 100,000 TO 1,000,000
VIRIONS PER
DROPLET
• 18-72 HR
INCUBATION
• SHEDDING
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza
4/20/2023

45. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 45
4/20/2023

46. Pathogenesis – Viral Pneumonia
•Thickening of the Alveolar cells
•Intestinal infiltration with leucocytes
with capillary thrombosis of
Leucocytic exudates
•Hyaline membrane is formed
occupying alveolar ducts and alveoli
•In late stages infiltration with
Macrophages
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 46
4/20/2023

47. Clinical features
• Incubation 1 to 3 days
• Present with mild cold lead to
fulminating rapidly fatal Pneumonia
• Can abruptly present with head ache
malign
• Can also present with abdominal pain
with type B in children
• Bacteria superinfect
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 47
4/20/2023

48. 48
SYMPTOMS
•FEVER
•HEADACHE
•MYALGIA
•COUGH
•RHINITIS
•OCULAR SYMPTOMS
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza
4/20/2023

49. 49
CLINICAL FINDINGS
•SEVERITY
• VERY YOUNG
• ELDERLY
• IMMUNO-
COMPROMISED
• HEART OR
LUNG DISEASE
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza
4/20/2023

50. Complications of Influenza
• Bacterial super infections
• Cardiac complications
• Congestive heart failure
• Myocarditis
• Neurological involvement
• Encephalitis
• Type B virus can produce Reye’s syndrome
• Degenerative changes in the Brain and Liver
• Gastric flu with type B virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 50
4/20/2023

51. Viral Pneumonia is Leading cause of
Death
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 51
4/20/2023

52. Complications in Influenza
•Pneumonia
• secondary bacterial
• primary influenza viral
•Reye’s syndrome
•Myocarditis
•Death 0.5-1 per 1,000 cases
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 52
4/20/2023

53. Immunity in Influenza
• After infection immunity
lasts 1 to 2 years
• Immunity lasts short
duration due antigenic
variants infecting at
intervals.
• Antibodies produced
locally are effective IgA
immunoglobulin.
• Anti Hemagglutinins and
Antinerumanidase are
effective in prevention of
infection.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 53
4/20/2023

54. Epidemiology
• Virus enters through respiratory route
• In 3 – 4 days majority manifest
• Many are subclinical infections
• Type A produce pandemics
• Type B sporadic cases, epidemics
• Dangerous in the Temperate regions
• Higher mortality in aged and patients with
existing cardiopulmonary involvement
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 54
4/20/2023

55. RECENT MAJOR
PANDEMICS
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 55
4/20/2023

56. New strain Hon Kong
H5 N1 strain
• Originated in Hong
Kong
• 18 confirmed 6
dead
• Can spread from
Chicken to Humans
• Wild aquatic birds
spread.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 56
4/20/2023

57. What is Bird Flu
•Avian Influenza in Animals
•Only birds get infected
•Less common Pigs
•Avian influenza is species specific
•Less common in Humans
•Can spread from poultry to Humans
can produce sever disease
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 57
4/20/2023

58. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 58
4/20/2023

59. BIRD FLU
• Birds, just like
people, get the flu.
Bird flu viruses
infect birds,
including chickens,
other poultry and
wild birds such as
ducks. Most bird flu
viruses can only
infect other birds.
However, bird flu
can pose health
risks to people.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 59
4/20/2023

60. Bird flu can spread from Birds to Humans
• The first case of a
bird flu virus
infecting a person
directly, H5N1, was
in Hong Kong in
1997. Since then,
the bird flu virus
has spread to
birds in countries
in Asia, Africa and
Europe
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 60
4/20/2023

61. Wild Birds Migrate and spread the Disease
Globally
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 61
4/20/2023

62. Influenza Diagnosis
• Clinical and
epidemiological
characteristics
• Isolation of influenza
virus from clinical
specimen (e.g.,
nasopharynx, throat,
sputum)
• Significant rise in
influenza IgG by
serologic assay
• Direct antigen testing
for type A virus
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 62
4/20/2023

63. Be familiar with Importance of
Throat Swab in Diagnosis
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 63
4/20/2023

64. Isolation of Virus
• In the first 2 -3 days from gargle samples
• Specimens inoculated into eggs, and Monkey kidney
cells.
• Eggs are inoculated into Amniotic and Allantoic cavity
Grows at 370 C in 3 days
• The virus causes Haemagglutination of Guinea pig
and Fowl erythrocytes at 370 C
• Type A and B agglutinate guinea pig and fowl red cells
• Type C Hem agglutinates only Fowl cells
• Cytopathic effects on Monkey Kidney and Continuous
cell lines
• RNA detection by RT – PCR
• Immuno florescence – surface of Nasopharyngeal
cells
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 64
4/20/2023

65. Serology
• Compliment fixation
test
• Haemagglutination
Inhibition testing
• Testing on paired
sera
• Detection of
Haemagglutination
Inhibition testing
• Radial
Immunodiffusion
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 65
4/20/2023

66. SWINE FLU 2009
• Swine influenza (also
called H1N1 flu, swine
flu, hog flu, and pig
flu) is an infection by
any one of several
types of swine
influenza virus. Swine
influenza virus (SIV)
is any strain of the
influenza family of
viruses that is endemic
in pigs
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 66
4/20/2023

67. 2009 H1N1 Flu
• H1N1 (sometimes called “swine flu”) is a new
influenza virus causing illness in people. This
new virus was first detected in people in the
United States in April 2009. This virus is
spreading from person-to-person worldwide,
probably in much the same way that regular
seasonal influenza viruses spread. On June
11, 2009, the World Health Organization
(WHO) declared that a pandemic of 2009
H1N1 flu was underway.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 67
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68. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 68
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69. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 69
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70. Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 70
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71. Pigs infect Humans
• Pigs can pass
mutated viruses
back to humans,
and these can be
passed from human
to human.
Transmission
among humans is
thought to occur in
the same way as
with seasonal flu.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 71
4/20/2023

72. Tamiflu!
(oral)
Ralenza
(inhaled)
(Older
drugs)
(Viral resistance to these is more common)
(Injectable
Peramivir has
completed
phase-1 trials)
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 72
4/20/2023

73. Chemotherapy
•Tamiflu (oseltamivir) – inhibits the
neuraminidase and thus prevents the
spread of the virus in the body
•Tamiflu can therefore be used to
reduce the length of illness and its
transmission within a household
•Resistance of H1N1 strain to
oseltamivir has been reported at 25%
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 73
4/20/2023

74. Prevention
• WHO monitors the
events on Influenza
• Identifies the
subtypes circulating
all over the world.
• Vaccine
Cocktail vaccine
contains one or
two types of A and
type B virus of the
previous winter
months.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 74
4/20/2023

75. Influenza Vaccines
• Inactivated subunit
(TIV) vaccine
• intramuscular
• trivalent
• split virus and subunit
types
• duration of immunity 1
year or less
• Live attenuated
vaccine (LAIV)
• intranasal
• trivalent
• duration of immunity at
least 1 year
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 75
4/20/2023

76. Influenza Vaccine
Recommendations
• Healthcare
providers,
including home
care*
• Employees of long-
term care facilities
• Household contacts
of high-risk persons
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 76
*LAIV should not be administered to healthcare workers who have
contact with severely immunosuppressed persons who require
hospitalization and care in a protective environment
4/20/2023

77. Indication to Vaccinate Patents ?
• To all high risk groups
1 Elderly,
2 Chronic heart and
Lung disease
patients,
3 Asthmatic patients
4 Metabolic and,
renal disease patients.
5 HIV patients.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 77
4/20/2023

78. Inactivated Influenza Vaccine
Contraindications and Precautions
• Severe allergic reaction
to a vaccine component
(e.g., egg) or following a
prior dose of vaccine
• Moderate or severe
acute illness
• History of Guillian Barre’
syndrome within 6
weeks following a
previous dose of TIV
(precaution)
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 78
4/20/2023

79. Emerging trends in Vaccines
•A live
attenuated Cold
adopted
temperature
sensitive used
as nasal spray
on major trails.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 79
4/20/2023

80. Newer Vaccines are available
• The 2011-2012 vaccine
will protect against an
influenza A H3N2 virus,
an influenza B virus and
the H1N1 virus that
emerged in 2009 to
cause a pandemic.
Everyone 6 months of
age and older should get
a flu vaccine as soon as
the 2011-2012 vaccines
are available.
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 80
4/20/2023

81. HIV Infection and Inactivated Influenza
Vaccine
• Persons with HIV at
increased risk of
complications of
influenza
• TIV induces protective
antibody titers in many
HIV infected persons
• TIV will benefit many
HIV-infected persons
• Do not administer LAIV
to persons with HIV
infection
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 81
4/20/2023

82. Prevention is the Best option
•Covering your
nose and mouth
with a tissue
when you cough
or sneeze.
Throw the tissue
in the trash after
you use
Dr.T.V.Rao MD @ Current updates on H3 N2 Influenza 82
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83. Hand washing a Top priority
•Washing your
hands often with
soap and water,
especially after
you cough or
sneeze. You can
also use alcohol-
based hand
cleaners.
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84. Influenza is a Global Concern
Be Familiar with Facts
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85. UPDATES ON H3 N2
2023
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86. What is H3N2 virus?
• It is an influenza virus that causes respiratory
infection. The virus can also infect birds and
mammals. In bird and other animals, it has
mutated into many strains.
• H3N2 is a subtype of Influenza A virus, which
is an important cause of human influenza,
according to Centres for Disease Control
(CDC) and World health Organization (WHO).
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87. WHAT ARE THE SYMPTOMS
According to WHO, avian, swine and other zoonotic influenza infections
in humans may cause disease ranging from mild upper respiratory
infection (fever and cough) to rapid progression to severe pneumonia,
acute respiratory distress syndrome, shock and even death. Some of
the common symptoms of H3N2 virus are:
Chills
Coughing
Fever
Nausea
Vomiting
Throat ache/sore throat
An ache in muscles and body
In some cases, diarrhoea
Sneezing and runny nose
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88. WHEN TO CONSULT A DOCTOR
• If a person
experiences difficulty
in breathing, pain or
discomfort in chest,
continuous fever and
pain in throat while
gulping down the
food, it is very
important to see a
doctor.
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89. Diagnosis
• Laboratory tests are required to diagnose human
infection with zoonotic influenza. WHO, through its
Global Influenza Surveillance and Response System
(GISRS), periodically updates technical guidance
protocols for the detection of zoonotic influenza in
humans using molecular e.g. RT-PCR and others
methods.
• Rapid influenza diagnostic tests (RIDTs) have lower
sensitivity compared to PCR and their reliability depends
largely on the conditions under which they are used.
Commercially available RDTs in general cannot provide
subtype information. RIDTs are sometimes used in clinical
settings, but their use in detection of zoonotic viruses is
limited.
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90. Treatment Guidelines
As per suggestions of WHO
Evidence suggests that
some antiviral drugs,
notably neuraminidase
inhibitor (oseltamivir,
zanamivir), can reduce
the duration of viral
replication and improve
prospects of survival,
however ongoing clinical
studies are needed.
Emergence of oseltamivir
resistance has been
reported.
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91. Treatment Guidelines
As per suggestions of WHO
• In suspected and confirmed cases, neuraminidase
inhibitors should be prescribed as soon as possible
(ideally, within 48 hours following symptom onset) to
maximize therapeutic benefits. However, given the
significant mortality currently associated with A(H5)
and A(H7N9) subtype virus infections and evidence of
prolonged viral replication in these diseases,
administration of the drug should also be considered
in patients presenting later in the course of illness.
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92. As per suggestions of WHO
Current suggestions
• Treatment is recommended for a minimum of 5 days, but can
be extended until there is satisfactory clinical improvement.
• Corticosteroids should not be used routinely, unless indicated
for other reasons (eg: asthma and other specific conditions); as
it has been associated with prolonged viral clearance,
immunosuppression leading to bacterial or fungal
superinfection.
• Most recent A(H5) and A(H7N9) viruses are resistant
to adamantane antiviral drugs (e.g. amantadine and
rimantadine) and are therefore not recommended for
monotherapy.
• Presence of co-infection with bacterial pathogens can
be encountered in critically ill patients.
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93. PREVENTION
As per suggestions of WHO
• Apart from antiviral treatment, the public health
management includes personal protective
measures like:
Regular hand washing with proper drying of the
hands
• Good respiratory hygiene – covering mouth and
nose when coughing or sneezing, using tissues
and disposing of them correctly
• Early self-isolation of those feeling unwell,
feverish and having other symptoms of influenza
• Avoiding close contact with sick people
• Avoiding touching one’s eyes, nose or mouth
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94. As per suggestions of WHO
• Health care workers preforming aerosol generating procedures
should use airborne precautions. Standard contact and droplet
precautions and appropriate personal protective equipment
(PPE) should be made available and used during epidemics.
• Travelers to countries and people living in countries with known
outbreaks of avian influenza should, if possible, avoid poultry
farms, contact with animals in live poultry markets, entering
areas where poultry may be slaughtered, and contact with any
surfaces that appear to be contaminated with faeces from
poultry or other animals. Good food safety and food hygiene
practices e.g. hands washing with soap and water should be
followed. Travelers returning from affected regions should
report to local health services if respiratory symptoms
suspecting zoonotic influenza virus infection.
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95. Is there a Vaccine for H3 N2
• During a season where
influenza A(H3N2) was
antigenically different from
the vaccine virus,
vaccination was
associated with a reduced
risk of influenza
hospitalization in younger
immunocompetent adults.
However, vaccination did
not provide protection in
adults ≥65 years of age.
Improvements in vaccines,
antivirals, and prevention
strategies are warranted.
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96. For current Treatment and Vaccination
do consult your physician
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97. Programs Today
Influenza program focuses on three main areas:
strengthening the Influenza Surveillance Network,
public health research, and pandemic
preparedness. CDC collaborations with GOI
partners aim to increase capacity of influenza
sentinel surveillance sites and laboratory services
for the timely detection and characterization of
respiratory viruses with pandemic potential. The
public health research helps assess influenza
burden (e.g., hospitalizations, mortality, and
estimated cost) and informs critical preventive and
control measures through improved
understanding of the epidemiology of respiratory
pathogens.
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98. Major References
• WHO current issues on Influenza
• CDC Literature on facts, and prevention
• Open resources from Google
• National Institute on Health USA
• Public information resources
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99. To know more about articles of current Interest
on Infectious diseases follow me ..
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100. •Programme Created by Dr.T.V.Rao
MD for ‘ e ‘ learning resources for
Medical and Paramedical Students
Globally
• Email
• doctortvrao@gmail.com
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