Influenza and parainfluenza. Acute respiratory illnesses.

Question 1

what are the CHARACTERISTICS OF INFLUENZA ?

Answer 1

Influenza A,B and C viruse

highly contagious human pathogenic viruses
causing flu

// have a tropism to the mucoprotein
substances of the cell = so = group ofMyxoviruses

Influenza B is infects only humans.
-
Influenza C is isolated mainly from humans,
rarely from swines in China

Question 2

TRANSMISSION OF INFLUENZA VIRUS ?

Answer 2

person-to-person via respiratory secretion

contagious from approximately 24 hours before the onset of clinical symptoms until
approximately 48 hours after the onset of symptoms.

Question 3

PATHOGENESIS OF INFLUENZA VIRUS ?

Answer 3

virus entry is the upper respiratory tract,
attaches to the mucosal epithelial cells.
-
Systemic symptoms are caused by the interferon
and cytokine response to the virus.
-
Local symptoms result from epithelial cell damage,including ciliated and mucus-
secreting cells.
-
Infected people are predisposed to bacterial superinfection because loss of
natural barriers and exposure of binding sites on epithelial cell

Question 4

what are the CLINICAL INCUBATION PERIOD OF INFLUENZA ?

Answer 4

1-3 days

Question 5

what are the CLINICAL MANIFESTATIONS OF INFLUENZA ?

Answer 5

may range from asymptomatic to severe.

acute :
sudden onset of fever , 
chills , 
 headache, 
arthralgia, myalgia

Patients often develop acute bronchitis with prominent dry cough

Hypotension and bradycardia

Question 6

what are the COMPLICATIONS OF INFLUENZA ?

Answer 6

primary influenza pneumonia

secondary bacterial pneumonia - strep pneumonia

myositis,
and Reye syndrome

Question 7

DIAGNOSIS OF INFLUENZA ?

Answer 7

usually all clinical

If we want to isolate the exact serotype:
-
Materials:
sputum,
nasopharyngeal swabs and secrets ,
 tracheal
aspirate,
bronchoalveolar lavage,
serum
viral culture 

RT-PCR: preferred diagnostic tool for the detection of influenza virus

Rapid antigen test: should only be used if more sensitive diagnostics (e.g., RT-PCR) are not available
this is also Used for early diagnosis

///// Serological testing (e.g., via complement fixation)
Used to diagnose an infection after it has resolved; should not be used for primary diagnosis
Infection is likely if serum antibody titers increase 4-fold within 1–2 weeks after acute illness

Question 8

what is the TREATMENT OF INFLUENZA?

Answer 8

rehydration
antipyretics and analgesia to decrease fever
antitussives relieve dry cough

====

antivirals - Patients with severe disease or patients at risk of developing complications

///(Amantadine is no longer recommended for treating influenza! It used to be an option for treating influenza A. But during the 2008/2009 flu season, the CDC found that 100% of seasonal H3N2 and 2009 pandemic viruses were resistant to amantadine.)////

Neuraminidase inhibitors: inhibit the release of viruses from the host cell.
Inhalative zanamivir
Oral oseltamivir
IV Peramivir

These drugs are
effective for prohylaxis and treatment during the first 24 to 48 hours after the onset
of influenza A illnes

Question 9

epc of influenza ?

Answer 9

Seasonal pattern: Most infections occur during the fall and winter.

Question 10

WHAT ARE THE HIGH RISK GROUP FOR COMPLICATIONS ?

Answer 10

above 65 years
and below 5 years
pregnant women
chronic diseases - asthma , heart , DM

====

most server and dangerous complications

primary influenza pneumonia
- hemorrhagic pneumonia with poor prognosis

secondary bacterial bronchitis/ pneumonia
Streptococcus pneumoniae,

Question 11

what are the PREVENTION METHODS FOR INFLUENZA ?

Answer 11

Annual flu shot for all aged 6 months and older every flu season as soon as the vaccine becomes available

Inactivated vaccine (more common)
 combining three different strains
whole virions(older generation) 

or purified two glycoproteins of the influenza virus membrane, hemagglutinin (HA) and neuraminidase (NA)
(Vaxigrip,Influvac,Fluarix).
-
The vaccine is prepared from virus grown in embryonated eggs and chemically
inactivated

=========

Live attenuated: intranasally administered

========

Hand hygiene

Adhere to standard precautions
Surface cleaning with alcohol- or aldehyde-based agents

Face mask

Gloves and gown for contact with potentially infectious material

========

Chemoprophylaxis
Antiviral medications may be considered in patients with exposure to an infected person under certain circumstances

Question 12

CHARACTERISTICS OF PARAINFLUENZA VIRUS ?

Answer 12

belong to the family of paramyxoviridae (together with mumps, measles and
respiratory syncytial viruses)

main features of all paramyxoviridae:
Virus replicate in the cytoplasm

penetrate the cell by fusion with the plasma membrane and exit by budding
from the plasma mem
brane.
-
Viruses induce cell-to-cell fusion,causing multinucleated giant cells.

Question 13

TRANSMISSION PARAINFLUENZA ?

Answer 13

respiratory droplets

person to person

Question 14

what are the DIFFERENT TYPES OF PARAINFLUENZA?

Answer 14

Parainfluenza virus types 1 and 2 usually affects infants and children, and tend to cause every other year epidemics.

Parainfluenza virus type 3 infects infants younger than 2 years and cause more severe diseases than type 1 or 2.

Parainfluenza type 4 causes mild disease.

Question 15

what is the PATHOGENESIS OF PARAINFLUENZA?

Answer 15

infection is limited to the respiratory tract,

Question 16

what is the EPIDEMIOLOGY OF PARAINFLUENZA?

Answer 16

Parainfluenza viruses are ubiquitous and infection is common.

it is seasonal

Question 17

what are the CLINICAL MANIFESTATION PARAINFLUENZA ?

Answer 17

Parainfluenza viruses 1, 2 and 3 may cause respiratory tract syndromes:
-
1.
A mild coldlike URT infection (coryza,
pharyngitis,
mild bronchitis,
wheezing,
and fever).
-
2.
Bronchiolitis
-
3.
Pneumonia
-
4.
Laryngotracheobronchitis
(croup-subglottal swelling,
which may close the
airway.)
Differential diagnosis is epiglottitis caused by H.influenzae.

-

Older children and adults usually experience milder infections than those seen in young children

Question 18

what is the DIAGNOSIS OF PARAINFLUENZA ?

Answer 18

Parainfluenza viruses are isolated from nasal washings and respiratory secretions.

• PCR
• ELIZA

isolation and identification through virus culture

serology
Human Para influenza -specific IgG antibodies

Question 19

who are at MOST RISK FROM PARAINFLUENZA VIRUS ?

Answer 19

Children are at risk for mild disease or croup

Question 20

is there a VACCINATION FOR PARAINFLUENZA VIRUS ?

Answer 20

NO!!!!!