Avian Influenza (AI) is a viral influenza of birds including chickens, turkeys, guinea fowls, and other avian species. There are three main types of Influenza (A,B & C). Influenza Type-A Multiple species Influenza Type-B Human Influenza Type-C Human & swine

1. Chapter #06
AVIAN INFLUENZA
Amjad Khan Afridi

2. • BIRD FLU
• AVIAN FLU
• FOWL PLAGUE
SYNONYM

3. DEFINATION
 Avian Influenza (AI) is a viral influenza of birds
including chickens, turkeys, guinea fowls, and other
avian species.
 There are three main types of Influenza (A,B & C).
 Influenza Type-A
• Multiple species
 Influenza Type-B
• Human
 Influenza Type-C
• Human & swine

4. ETIOLOGY
• Causative agent is Avian Influenza (Type-A).
• AI viruses are Negative sense, Single stranded RNA Virus
in the family Orthomyxoviridae, genus Influenza A .
• Also called Influenza-A virus or Type a Influenza Virus.
• Further categorized into Haemagglutinin (H1-16) and
Neuraminidase (N1-9) subtypes.

5. TYPES
 Low pathogenicity avian influenza (LPAI)
by H1-4, H6, H8-16
 Low pathogenicity notifiable avian
influenza (LPNAI) only by H5 and H7
 Highly pathogenicity or highly pathogenic
notifiable avian influenza (HPAI) only by
mutated forms of H5 and H7

6. Symptoms
 Symptoms vary in severity from asymptomatic
infections to mild respiratory and reproductive diseases
to an acute , highly fatal systemic diseases.
 Some symptoms are;
 Sudden death
 Loss of appetite
 Depression
 Nasal & ocular discharge
 Coughing
 Dehydration
 Hemorrhage
 Paralysis

7. EPIDEMIOLOGY
Avian Influenza is present in wild-water birds.
First recorded in Italy in 1878.
Distributed worldwide and are recovered frequently from
shorebirds and migrating waterfowl.
 Infrequently recovered from
• Imported pet birds.
• Viruses may be present in village or backyard flocks
• Birds sold through live-poultry markets

8. • The most serious outbreaks in recent times have
been reported in;
• Hong Kong 1997-1998 and 2003.
• In Netherlands 2003 In South East Asia 2004-2006.
• Pathogenic strains could emerge and cause disease
in domestic poultry in any country at any time
INCIDENCES

9. INCUBATION
The incubation period is highly
variable and ranges from a few days
in individual birds to 2 week in the
flock.

10. TRANSMISSION
Transmission can occur by;
 Inhalation or ingestion
 Direct Contact
 Poultry faeces
 Indirectly through bio-aerosol / Fomites
 Consumption of uncooked poultry products
 Inhalation of aerosolized material (e.g., poultry faeces)
containing infectious HPAI H5N1 virus is a likely
route of transmission from poultry to humans.

11. PATHOGENESIS
• Exhibits severe lethargy, fever, weight loss,
transient lymphopenia (reduced amount of
lymphocytes in blood, and replication in the
upper and lower respiratory tract.

12. • High and prolonged HPAI H5N1 viral replication in the
lower respiratory tract induces pro-inflammatory
cytokines and chemokines, resulting in pulmonary
capillary leak, diffuse alveolar damage, and acute lung
injury, and can lead to development of ARDS (Acute
respiratory distress syndrome). HPAI H5N1 viraemia
has been reported in fatal cases, and dissemination of
HPAI H5N1 virus to infect brain tissue; isolation from
cerebrospinal fluid, gastrointestinal infection,

13. CLINICAL FINDINGS ANDLESIONS
•Clinical signs, severity of disease,
and mortality rates vary
depending on AI virus strain
and host species.

14. Low Pathogenicity Avian Influenza
Viruses:
Respiratory signs such as
 Sneezing
 Coughing
 Ocular and nasal discharge
Swollen infraorbital sinuses
in poultry
 Sinusitis is common
Fig-Sinusitis
CLINICAL FINDINGS ANDLESIONS Cont…
CLINICAL FINDINGS ANDLESIONS Cont…

15. Lesions in the respiratory tract includes
congestion and inflammation of the trachea and
lungs.
Decreased egg production or fertility.
Acute renal failure and
Visceral urate deposition (visceral gout)
Morbidity and mortality is usually low
Fig- Inflammation of Trachea
CLINICAL FINDINGS ANDLESIONS Cont…

16. • High Pathogenicity Avian
Influenza Viruses:
severe, systemic disease
with high mortality in
chickens, turkeys, and poultry.
Mortality can be as high as 100%
In peracute cases, clinical signs
or gross lesions may be lacking
before death
In acute cases - edema of the
head, comb, wattle, and snood
(turkey);
Blood-tinged oral and nasal
discharges.
CLINICAL FINDINGS ANDLESIONS Cont…

17. • Edema and haemorrhagic lesions in the feet,
comb.
Fig-Hemorrhagic skin
visible on the unfeathered
head regions
Fig- Hemorrhagic skin
visible on the
unfeathered regions
CLINICAL FINDINGS ANDLESIONS Cont…

18. CLINAL SIGNS IN HUMAN

19. • LP and HP AI viruses can be readily isolated
from oropharyngeal and cloacal swabs. AI
viruses grow well in the allantoic sac of 9- to 11-
day-old embryonating chicken eggs, and they
agglutinate RBCs.
DIAGNOSIS

20. DIAGNOSIS (Contd.)
• rRT- PCR (Real Time Reverse Transcriptase
PCR)is the preferred diagnostic test which gives
result in 3 hours.

21. TREATMENT AND CONTROL
• There is NO vaccine currently
available.
• However, good husbandry (farming), proper
nutrition, and broad spectrum antibiotics
may reduce losses from secondary infections.
It must be remembered that recovered flocks
continue to intermittently shed the virus.

22. • Destroying birds carrying or suspected of
carrying the virus.
Prevention

23. PREVENTION
•Disinfecting farm
equipment, clothing, and boots.
Prevention

24. • Limiting, restricting, or banning the shipment
of live birds within and between countries that
have had bird flu.
Prevention

25. Further STEP….
• Farm Biosecurity
• Food Security
• Personal Biosecurity

26. • Small capacity at a time to installed for 21 days.
• Samples are to be collected at 0th , 15th and 21st
day.
• Upon found negative rest stock to be installed.
RESTOCKING PRECAUTION

27. Thank You