INTRODUCTION
• Influenza isan acute respiratory tract infection
caused by influenza virus, of which there are three
types- A, B and C.
• The disease is characterized by sudden onset of
chills, malaise, fever, muscular pain and cough.
3.
EPIDEMIOLOGICAL DETERMINANTS
• Agent:-Influenza virus
• Reservoir of infection:- It has become increasingly
evident that a major reservoir of influenza virus
exists in animal and birds.
AGENT FACTORS:
Reservoir means a place where something is kept in
store
4.
Conti…
• Source ofinfection:- The secretions of the
respiratory tract are infective.
• Period of infectivity:- The virus is present in the
nasopharynx from 1 to 2 days before and 1 to 2
days after onset of symptoms.
5.
HOST FACTORS:
• Ageand sex:- The
influenza affects all ages
and both sexes.
• Human mobility:- this is
an important factors in the
spread of infection.
6.
• In Indiaepidemics occurs in summer season
• Overcrowding areas
ENVIRONMENTAL FACTORS:
7.
MODE OF TRANSMISSION:
•Influenza is spread mainly
from person to person by
droplet infection created by
sneezing, coughing or
talking.
• The portal of entry of the
virus is respiratory tract.
8.
Incubation period
• 18-72Hours.
The incubation period is
the time between first
exposure to a pathogen,
chemical, or radiation
and when the first
symptoms or signs of
illness become
apparent.
9.
PATHOGENESIS:
• The virusenters the respiratory tract and causes
inflammation and necrosis of superficial epithelial
of the trachea and bronchial mucosa, followed by
secondary bacterial invasion.
• There is no viranemia
10.
Conti..
• Both theviruses cause much the same symptoms-
fever, chills, ache and pain. Coughing and
generalized weakness.
• Fever last from 1-5 days, averaging 3 days in adult
• The most dreaded complication is pneumonia
13.
INVESTIGATIONS
• Molecular tests.These tests look for genetic material from
the flu virus. Polymerase chain reaction tests, shortened to
PCR tests, are molecular tests. also may hear this type of test
called an NAAT test, short for nucleic acid amplification
test.
Molecular tests analyze the molecular components
of cells, like DNA, RNA, and proteins, to diagnose
diseases, assess risk, or guide treatment.
14.
Conti….
• Antigen tests.These tests look for viral proteins
called antigens. Rapid influenza diagnostic tests are
one example of antigen tests.
PREVENTIVE MEASURES
• Aninfluenza
vaccine, or flu
shot/jab, is a
yearly vaccine that
protects against
seasonal flu viruses
by using
inactivated or
weakened viruses
• The vaccine is
administered
subcutaneously or
intramuscular
route. 0.5 ml for
adult and 0.25 ml
for children from 6
months to 36
months.