pathophysiologic approach and therapeutic details

1. INFLUENZAINFLUENZA
-BY S.SANDHOSHINI MEENA-BY S.SANDHOSHINI MEENA

2. THANK YOUTHANK YOU

3. INFLUENZAINFLUENZA
DEFINITION:-DEFINITION:-
• Influenza is an infectious diseases caused byInfluenza is an infectious diseases caused by
RNA virusesRNA viruses of the familyof the family orthomyxoviridaeorthomyxoviridae
(the influenza virus).(the influenza virus).
• It attacks the respiratory system-the nose, throatIt attacks the respiratory system-the nose, throat
and lungs.and lungs.

4. EPIDEMOLOGY:-EPIDEMOLOGY:-
Influenza is a viral illness associated with highInfluenza is a viral illness associated with high
mortality and high hospitalization rates among personsmortality and high hospitalization rates among persons
younger than age 65 years.younger than age 65 years.
Seasonal influenza epidemics result in 25 million to 50Seasonal influenza epidemics result in 25 million to 50
million influenza cases, approx. 2,00,000million influenza cases, approx. 2,00,000
hospitalizations, and more than 30,000 deaths each yearhospitalizations, and more than 30,000 deaths each year
in the United States. Overall, more people die ofin the United States. Overall, more people die of
influenza than of any other vaccine-preventable illness.influenza than of any other vaccine-preventable illness.

5. TRANSMISSON:-TRANSMISSON:-
The route of influenza transmission is person-to-personThe route of influenza transmission is person-to-person
via inhalation of respiratory droplets, which can occurvia inhalation of respiratory droplets, which can occur
when an infected person coughs or sneezes.when an infected person coughs or sneezes.
The incubation period for influenza ranges between 1The incubation period for influenza ranges between 1
and 7 days, with an average incubation of 2 days.and 7 days, with an average incubation of 2 days.

6. RISK FACTORS:-RISK FACTORS:-
Age:Age: It tends to target young children (under 5 years) and OlderIt tends to target young children (under 5 years) and Older
Adults (older than 65 years)Adults (older than 65 years)
Weakened Immune System:Weakened Immune System: Cancer Treatments, Anti-rejectionCancer Treatments, Anti-rejection
drugs, Corticosteroids and HIV/AIDS can weaken the immunedrugs, Corticosteroids and HIV/AIDS can weaken the immune
system.system.
Chronic Illnesses:Chronic Illnesses: Such as Asthma, Diabetes or Heart Problems.Such as Asthma, Diabetes or Heart Problems.
Pregnancy:Pregnancy: Pregnant women are more likely to developPregnant women are more likely to develop
influenza complications particularly in the second and thirdinfluenza complications particularly in the second and third
trimesters.trimesters.

7. SIGNS AND SYMPTOMS:-SIGNS AND SYMPTOMS:-
Fever over 100.4 F (38Fever over 100.4 F (38°C)°C)
Aching muscles, especially in the back, arms and legsAching muscles, especially in the back, arms and legs
Chills and SweatsChills and Sweats
HeadacheHeadache
Dry, persistent coughDry, persistent cough
Fatigue and weaknessFatigue and weakness
Nasal congestionNasal congestion
Nausea and vomitingNausea and vomiting
MalaiseMalaise
Sore throatSore throat

8. TYPES:-TYPES:-
Influenza virus AInfluenza virus A
Influenza virus BInfluenza virus B
Influenza virus CInfluenza virus C
Influenza virus DInfluenza virus D

9. DIAGNOSIS:-DIAGNOSIS:-
The goldern standard for diagnosis of influenza isThe goldern standard for diagnosis of influenza is viralviral
culture.culture.
Rapid antigenRapid antigen andand point-of-care tests, direct fluorescenepoint-of-care tests, direct fluorescene
antibody test,antibody test, and theand the reverse transcription polymerasereverse transcription polymerase
chain reaction assaychain reaction assay may be used for rapid detection of virus.may be used for rapid detection of virus.
Chest radiographChest radiograph should be obtained if pneumonia isshould be obtained if pneumonia is
suspected.suspected.
Rapid tests have allowed for prompt diagnosis and initiation ofRapid tests have allowed for prompt diagnosis and initiation of
antiviral therapy and decreased inappropriate use ofantiviral therapy and decreased inappropriate use of
antibiotics.antibiotics.

10. PATHOPHYSIOLOGY:-PATHOPHYSIOLOGY:-
Influenza virusInfluenza virus
↓↓
Enters the respiratory system from an infected individualEnters the respiratory system from an infected individual
through respiratory dropletsthrough respiratory droplets
↓↓
The virus attaches to and replicates in columnar epithelialThe virus attaches to and replicates in columnar epithelial
cellscells
↓↓
The virus replicates in cells of both upper and lowerThe virus replicates in cells of both upper and lower
respiratory tractrespiratory tract
↓↓
The viral replication combines with the immune responseThe viral replication combines with the immune response
(both humoral and cell mediated )to infection(both humoral and cell mediated )to infection

11. Leads to destruction and loss of cells lining of theLeads to destruction and loss of cells lining of the
respiratory tractrespiratory tract
↓↓
Release of cytokinesRelease of cytokines
↓↓
Symptoms such as sore throat , runny nose, cough.Symptoms such as sore throat , runny nose, cough.

12. COMPLICATIONS:-COMPLICATIONS:-
► SinusitisSinusitis
► BronchitisBronchitis
► Primary viral pneumoniaPrimary viral pneumonia
► Secondary bacterial pneumoniaSecondary bacterial pneumonia
► Asthma flare-upsAsthma flare-ups
► Otitis mediaOtitis media
► EncephalopathyEncephalopathy
► Transverse myelitisTransverse myelitis
► MyositisMyositis
► MyocarditisMyocarditis
► PericarditisPericarditis
► Reye syndromeReye syndrome

13. TREATMENT:-TREATMENT:-
ANTI-INFLUENZA DRUGS:-ANTI-INFLUENZA DRUGS:-
► AmantadineAmantadine
► RimantadineRimantadine
► OseltamivirOseltamivir
► ZanamivirZanamivir
► peramivirperamivir

14. The neuraminidase inhibitors are the only antiviral drugsThe neuraminidase inhibitors are the only antiviral drugs
available for treatment and prophylaxis of influenza andavailable for treatment and prophylaxis of influenza and
are oseltamivir and zanamivir.are oseltamivir and zanamivir.
IV peramivir is another NA inhibitor underIV peramivir is another NA inhibitor under
investigation for treatment of influenza.investigation for treatment of influenza.
The adamantanes (amantadine and rimantadine) are noThe adamantanes (amantadine and rimantadine) are no
longer recommended due to high resistance amonglonger recommended due to high resistance among
influenza viruses. They prevent the release of infectiousinfluenza viruses. They prevent the release of infectious
viral nucleic acids.viral nucleic acids.

15. DOSE:-DOSE:-
Oseltamivir -75mg capsule twice daily for 5 daysOseltamivir -75mg capsule twice daily for 5 days
Zanamivir – 2 inhalations twice daily for 5 daysZanamivir – 2 inhalations twice daily for 5 days
Rimantadine -200mg/day for 7 daysRimantadine -200mg/day for 7 days
Amantadine -200mg/day for 2 days.Amantadine -200mg/day for 2 days.