Influenza virus symptoms influenza treatment

 # What is Influenza ?

# Causes of Influenza ?

Influenza is a highly contagious viral infection of respiratory tract caused by Influenza viruses. Influenza is caused by Orthomixo virus RNA single stranted, it is of 3 sub type- A, B, & C

Influenza virus structure

‌Type A: responsible for epidemic in every

2-3 years & pandemic in every 10-15 years 

Antigenic variation is most common in

‌Type B: epidemic in every 4-7 year

‌Type C: currently not circulating

# What Types of Virus is Influenza:

1. H1N1: Swine flue (pig-man-man) Dangerous

2. H5N1: Avian influenza/Bird flue (bird-man)

3. H7N9: Asian influenza

4. H2N2: East Asian influenza

# Incubation period: 18-72 Hours

# Influenza Virus Symptoms:

• ‌Fever, Headache, Backache (sudden onset)

• ‌Fever lasting from 1-5 days

• ‌Generalised weakness

• ‌>5 days fever: Suspected pneumonia

• ‌Multi-organs failure

Influenza virus symptoms

# Complications of influenza:

• ‌Pneumonia-most dreaded

• ‌Sinusitis

• ‌Otitis media

• ‌Reye syndrome: rare but severe

• ‌Purulent bronchitis

Influenza virus

# Management:

A. Diagnosis

• ‌Swab culture

• ‌Serological

• ‌Rapid antigen test

• ‌RT-PCR

• ‌Immunofluorescence assay

• ‌Rapid molecular assays

B. Influenza Treatments Influenza Treatment And Prevention

Influenza is treated by symptomatically, not specific treatment

• Chemoprophylaxis of influenza A ,B Oseltamivir (DOC) & Alternative is Zanamavir

• Others: Amantadine, Rimantadine

Influenza virus treatment

# Extra Notes on Influenza virus:

• ‌MOT: Droplet infection & droplet nuclei

• ‌Major antigenic variation in type A

• ‌Type C-antigenically stable

• ‌Period of infectivity: 1-2 days before and after onset of symptoms

• ‌Virus route-Respiratory tract

• ‌Source of infection- Clinical & subclinical

• ‌No viraemia in influenza

• ‌Influenza shows cyclic trend

• ‌Killed vaccine- Most commonly used

• ‌Influenza can be prevented either by vaccination or by chemoprophylaxis