This document discusses avian influenza in both poultry and humans. It describes the geographic distribution and pathogenicity of low pathogenicity avian influenza (LPAI) and high pathogenicity avian influenza (HPAI) in birds worldwide. It also summarizes the transmission, clinical signs, prevention, and control of avian influenza in poultry, as well as the transmission, diagnosis, treatment, and prevention of avian influenza infections in humans.

1. History

2. Geographic Distribution
LPAI HPAI
worldwide Eradicated from developed
nations
Wild birds and poultry Epidemic ongoing in parts of
Asia, the Pacific, Middle East, and
Africa

3. Pathogenicity
High pathogenicity avian influenza (HPAI)
Causes severe disease in poultry
Contains subtypes H5 or H7
Low pathogenicity avian influenza (LPAI)
Contains other H subtypes
Causes mild disease in poultry includes non-HPAI
H5 and H7

4. Antigenic Drift and Shift
Antigenic drift
Small changes in influenza virus due to point mutations
accumulated during virus replication
Antigenic shift
Abrupt change in virus subtype
Genetic reassortment between subtypes
Direct transfer of virus
Re-emergence of virus

5. Species Affected
 Wild birds
Waterfowl
Shorebirds
 Cage birds
 Poultry
 Mammals
Pigs, horses, mink, cats, dogs, ferrets, stone martens, palm civets,
and others

6. Avian
Influenza
in
Poultry

7. Transmission
In an infected flock, virus can spread in multiple ways:
Fecal-oral
Aerosol
Fomites
Mechanical vectors
Virus introduction:
Migratory birds
Infected poultry, pet birds

8. Clinical Signs
 Sudden death
 Combs swollen, cyanotic(bluish)
 Systemic disease
 Drop in egg production
 Neurological signs
 Depression, anorexia,
ruffled feathers
 Conjunctivitis and respiratory signs
 Most birds in an affected flock die

9. Post Mortem Lesions
Chickens and turkeys
Swollen sinuses
Edematous comb and wattle
Subcutaneous edema
Petechial hemorrhage
Trachea
Lungs
Proventriculus

10. Prevention
All-in/all-out flock management
Prevent contact with wild birds or their water sources
Do not allow birds to return to the farm from live
markets
Practice strict hygiene
Biosecurity measures

11. Differential
Diagnosis

12. • Virulent Newcastle disease
• Avian pneumovirus
• Infectious laryngotracheitis
• Infectious bronchitis
• Chlamydia
• Mycoplasma
• Acute bacterial diseases
• Fowl cholera, E. coli infection

13. Avian
Influenza
in
Human

14. •Inhalation:
Contaminated dust
Fine water droplets generated during slaughtering,
defeathering, eviscerating and preparing
•Contact with oral/nasal mucus membrane or conjunctiva:
Hand-transplantation of virus from contaminated surface
(poultry feces, respiratory secretions or other contaminated
products)
•Consumption of raw products:
Duck blood pudding & internal organs
Transmission

15. Cont….

16. Incubation Period
 Difficult to determine
2-17 days possible
 Symptoms usually appear in 2-5 days
World Health Organization
Recommends using incubation period of seven days for field investigations
and monitoring patient contact

17. Clinical Signs

18. Diagnosis
 RT-PCR
Primary test to identify H5N1
 Antigen detection
 Virus isolation
WHO Reference Laboratories
 Serology
Microneutralization

19. Treatment
 Antiviral drugs
Amantadine
Rimantadine
Zanamivir
Oseltamivir
 Currently circulating H5N1 viruses may be resistant to amantadine,
rimantadine

20. Prevention
 People working with infected poultry
Follow good hygiene practices
Wear protective clothing (gloves, masks)
Consider antiviral prophylaxis
Be vaccinated against human influenza
Do not have contact with sick birds if experiencing symptoms of influenza
 Avoid wild bird contact
 Wear gloves while handling or cleaning wild birds
 Wash hands
 Cook game thoroughly

21. Control
 Biosecurity
Quarantine
Intensify disinfecting measures
 Monitoring/Surveillance
 Stamping Out / Depopulation
 DIVA Vaccination - only for LPAI and not for HPAI because it might prolong
the shedding of the virus
 Proper Disposal