Avian influenza

AVIAN INFLUENZA (AI) is a viral influenza of birds including chickens, turkeys, guinea fowls, and other avian species.

1. AVIAN INFLUENZA BY- CHANDRANI GOSWAMI

2. SYNONYM BIRD FLU AVIAN FLU FOWL PLAGUE

3. DEFINATION AVIAN INFLUENZA (AI) is a viral influenza of birds including chickens, turkeys, guinea fowls, and other avian species. Symptoms vary in severity from asymptomatic infections to mild respiratory and reproductive diseases to an acute , highly fatal systemic diseases.

4. EPIDEMIOLOGY Distributed worldwide and are recovered frequently from shorebirds and migrating waterfowl . Occasionally recovered from Imported pet birds. Viruses may be present in village or backyard flocks birds sold through live-poultry markets

5. EPIDEMIOLOGY (Contd.) INCIDENCES 1 st detected in 1997 during a poultry outbreak in Hong Kong, China . Later on again re emerged in China in March 2013. In India the first reports of bird flu came from the village of Navapur in the Nandurbar district of Maharashtra on 19 February 2006. Assam 1 st detected the disease on November 27 , 2008, in Rajabazar village, Kamrup district.

6. TRANSMISSION The incubation period is highly variable and ranges from a few days in individual birds to 2 wk in the flock .

7. ETIOLOGY 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 (H 1-16) and Neuraminidase (N1-9) subtypes.

8. 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 (HPNAI) only by mutated forms of H5 and H7

9. PATHOGENESIS Exhibits severe lethargy, fever, weight loss, transient lymphopenia , and replication in the upper and lower respiratory tract, as well as multiple systemic organs, including the brain.

10. CLINICAL FINDINGS AND LESIONS Clinical signs, severity of disease, and mortality rates vary depending on AI virus strain and host species.

11. CLINICAL FINDINGS AND LESIONS (Contd.) 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

12. CLINICAL FINDINGS AND LESIONS (Contd.) Lesions in the respiratory tract includes congestion and inflammation of the trachea and lungs. In layers and breeders, Decreased egg production or fertility. Acute renal failure and Visceral urate deposition (visceral gout) Morbidity and mortality is usually low Fig- Inflammation of Trachea

13. CLINICAL FINDINGS AND LESIONS (Contd.) 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 - cyanosis and edema of the head, comb, wattle, and snood (turkey); Blood-tinged oral and nasal discharges.

14. CLINICAL FINDINGS AND LESIONS (Contd.) Edema and haemorrhagic lesions in the shanks, feet, comb. Fig-Hemorrhagic skin visible on the unfeathered head regions Fig- Hemorrhagic skin visible on the unfeathered regions

15. CLINICAL FINDINGS AND LESIONS (Contd.) In severe cases Greenish diarrhea is common. Birds that survive the peracute infection may develop CNS involvement evident as Torticollis Opisthotonus Incoordination Paralysis Drooping wings

16. MICROSCOPIC LESIONS Highly variable and may consist of edema, hemorrhage, and necrosis in parenchymal cells of multiple visceral organs, skin, and CNS. Subcutaneous ecchymotic hemorrhages; petechial hemorrhages on visceral organs and in muscles.

17. CLINAL SIGNS IN HUMAN

18. DIAGNOSIS 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.

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

20. TREATMENT AND CONTROL There is NO vaccine currently available in India, although one is under development. Drugs includes amantadine , rimantadine and neuraminidase inhibitors (e.g., oseltamivir , zanamivir )

21. PREVENTION Destroying birds carrying or suspected of carrying the virus.

22. PREVENTION Disinfecting farm equipment, clothing, and boots.

23. PREVENTION Limiting, restricting, or banning the shipment of live birds within and between countries that have had bird flu epidemics.

24. Further STEP…. National Biosecurity Farm Biosecurity Food Security Personal Biosecurity

25. Fig- Steps toward Personal Biosecurity

26. CONTROL AND CONTAINMENT PROGRAMME

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