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Status of Bird Flu in Pakistan

What is Bird Flu ?Bird Flu (Avian influenza) Virus Group A belongs to (Orthomyxoviridae family)Virus Group B & C cause Human Flu (Influenza)

Bird Flu

Basically a viral disease in many exotic and domestic birds throughout the worldSingle stranded RNA virus, also share infection in human and other mammals including pigs and horses

Threat of Bird FluRecent outbreaks of Bird Flu in Asia, African and European countries including Pakistan rendered 200 millions of poultry deaths resulting in huge economic losses of poultry industry & posses a threat of Human Influenza

Disaster Avian Influenza A disaster and a notifiable disease and a great Public Health Significance There is a background on human Influenza and Bird Flu outbreaks

Spread (Transmission)Migratory Birds-waterfowl (Murgabi) and Geese are well known reservoir / vector in spreading the disease among domestic poultry flocks. The pathogenic virus has been recovered from lakes and pounds water

Risk FactorsThere are A, B, and C Influenza virus groups. B and C viruses infect human only. However, A Influenza virus has the ability to cross the species barrier and infect both people and birds. The other mammals such as pigs and horses are also show infections

Symptoms in humanIn mild cases patients manifest fever, cough, sore throat, conjunctivits (Tunica conjunctiva), excessive nasal discharge. In severe cases pneumonia, fever, acute respiratory distress and fatal outcome

Human Flu History (Influenza)Flu is an old disease recorded in human historyPandemic threats (severe outbreaks in the world) has been well documented from last four centuries. However, since 1900, three pandemic have occurred:Spanish Flu (1918)Asian Flu including Indo-Pak (1957)Hong Kong Flu (1968)

Bird Flu HistoryRecorded as Fowl Plague in 1878 (100% deaths of birds)Shown to be a filterable in 1901, a virus was isolated and identified in 1930, Recognized relationship to: Mammalian Influenza A virus in 1955

Recent outbreaks (Epidemiology) Well documented during:USA (1983-84) of H5N2 Italy (1999-2001) of H7N1, The LPAI virus become HPAI virus and took more than 17 millions birds.There is always Swine Flu threat in pig rearing countriesRecent outbreaks (2004-07) with transmissible to human in Canada, Vietnam, Iraq, China, Russia, Ukrane and Pakistan

Economic losses in PakistanAI killed over 0.8 millions breeding flocks in 1994-95 causing losses Rs:320 millions (Akram Muneer). In recent outbreaks the losses has gone to ten folds. Various strains of AI, H7N2 and H5N1 has been isolated in Pakistan. AI is posing a havoc in poultry industry for the last seven years. Experienced farmers are leaving their business and new comers are getting losses

Economic losses in Pakistan (continue)AI outbreak of 2006 in broiler, layer and breeder poultry farms involved 66 breeder and 33400 commercial farms. and engulfed 280,000 birds. Ministry of Food Agriculture and Livestock has monitored the situation. In order to mitigate the losses, a sum of Rs:100 millions has been compensated (Economic Survey 2006-07)

Bird Flu FactsLabile / instable virusAI is constantly mutating virus, change as they grow in human and birds. Small genetic change (mutation) is known as Drift and Shift

Genetic Drift & ShiftThe virus can swap and merge into a novel virus. This shift have long been thought to involve human living in close contact with poultry and pigs. Pigs are quite susceptible and can serve as mixing vessel for human and avian infections. For novel (new) virus there is not already any immunity against infection

WHO Global ProgramThe changing nature and its odd consequences necessitates a constant monitoring of the global Influenza situation and constant adjustment in the composition of Influenza vaccines

Bird Flu PotentialsInfluenza A virus can spread form birds to human and can spread from person to person. There is no immune protection against human infection. Human Influenza pandemic could begin from avian disease

WHO Safety and Contingency Guidelines for the WorldElimination of H5N1 virus from birds and mammals is essential for prevention of new outbreaks. WHO recommends disposal of all infected or exposed flocks of chicken. Poultry farmers should be compensated. It reduces opportunity for human infection.

WHO guidance on line For Poultry Farmers, Animal handlers, Laboratory workers, Processing plant workers, Human patients, Medical doctors, Food handlers, Air lines Flight crew and guidance for travelers considering Quarantine measuresaffecting relations between nations and countries

Main problem (always danger)A I virus frequently change or mutate itself by exchanging of genes of human influenza virus. This process of gene swapping inside the human can give rise to a completely a new Subtype VirusH5N1 is of particular concern

Portals of EntryAs the virus is present in saliva and droppings and remain viable for a longer period of time, can spread infection among birds, then from birds to mammals through ingestion or inhalation of infecting viruses

Virus Subtypes More than 144 subtypes bearing surface antigensbased on Hemagglutination (H) Neuraminidase (N) activities. Fifteen subtypes are known to infect birds

Highly Pathogenic VirusVirus Type H5N1 Considered to be a highly pathogenic Avian Virus (HPAI) both for birds and human and has species cross barriers potentialH5N1 is in Pakistan

Low to High (LPAI to HPAI) A I viruses are classified as Low Pathogenic Avian Influenza (LPAI) viruses and Highly Pathogenic Avian Influenza (HPAI) viruses. LPAI generally does not produce health threat to human, However, it can mutate into HPAI virus

Fowl Plague to mild infectionHighly Pathogenic Avian Influenza (HPAI) virus is responsible for Fowl plague (100 % mortality) of poultry birds so called: a sweeping disease like Newcastle Disease of Poultry, whilst low pathogenic virus cause enteritis and result in low production without any mortality

Genetic DiversityGenetically quite variable virusShow genetic shift / drift and an instable virus, therefore, its spread and Public Health Significance is unpredictable

Further StudiesWaterfowl Migration AI has higher prevalence and Pakistan is on the cross roads of waterfowl migratory routesThe Birds of PakistanT. J. Roberts Oxford University Press Poultry Houses should not be on these routes

SpreadMostly Birds to Birds(Horizontal transmission)No vertical transmission (Breeder to baby chicks)Birds to Human (zoonotic) Person to person (rare)

Symptoms in BirdsBasically a respiratory disease, pneumonia with face swelling, sneezing with excessive nasal secretion, cyanosis and necrotic combs and wattles. In a highly fatal disease no symptoms before death

Differential DiagnosisAvian Influenza virusshow quite variable symptoms not helpful for diagnosis, may involve digestive and nervous systems confuses with Newcastle Disease (ND) Ranikheith Disease

Postmortem FindingsQuite variable, blood spots on almost all internal organs including proventriculus hemorrhages like ND virus (Paramyxoviridae infection)However, subcutaneous hemorrhages of Leg Shank lesion is a differential point

Confirmed DiagnosisSymptoms and lesions are not characteristic. Demonstration of virus and detection of its specific antibodies using Elisa is required for confirmation of Avian InfluenzaDiagnostic kits are commercially available for Ab & Ag tests

TreatmentA viral disease, no rational therapy is possible, Antiviral drugs such as neuraminidase inhibitors, Supportive treatment, good farm management extends a great help for treatment and control of Avian Influenza. The UK government has stockpile of antiviral drugs for Flu Pandemic

Prevention Vaccination (immunization)No effective vaccination against HPIA virus. For low pathogenic virus, Inactivated oil based vaccine is used to prevent H5N1 to lower production losses in poultry flocksTypes, Subtype and Strain

Five Strategies PlanInvestigation of morbidity and mortality of wild birds (crow and kites)Monitoring apparently healthy birds.Monitoring hunter killed birdsUse of sentinel birds (Guard birds)Environmental sampling of pond / lakes water and feces. Virus can be detected in both feces (droppings) and water samples

Public Health SignificanceProtection against infectionNot yet a single case in Indo Pak has been reported / confirmed amongst farm workers or butchers. However, the disease is consistently knocking at our doors. Virus is genetically quite instable, we have to remain very vigilant with utmost caution. Strict surveillance is required to monitor this zoonotic problem in Pakistan

WHO Monitoring Surveillance programSince it is notifiable disease (a disaster should be declared by the government). Animal Health Association Committee on transmissible diseases of poultry recommended eradication of HPAI virus from the country. WHO supports surveillance program and financial compensation. No legislation policies exist in Pakistan.

WHO Control Policy(World wide)Strict implementation of poultry bylaws.* Construction of poultry houses* Farmer education about biosecurity measures* All in all out farming * Poultry farms away from waterfowl migratory routes Strict quarantine measures Proper disposal of infected material / carcasses (dead birds) etc.

Role of MediaSince Bird Flu is a notifiable disease. Information about current outbreaks of AI has great impact on consumption of poultry and its products (Eggs and Meat), Media News and views about AI is inflicting heavy losses to poultry industry of Pakistan.

CONCLUSIONBird Flu is a basically disease of many exotic and domestic birds, caused by Avian Influenza Virus A, belonging to Orthomyxoviridae family. The disease is characterized by respiratory symptoms but may involve digestive and nervous systems usually confuses with Newcastle Disease.

Conclusion (continue)The severity of the disease depends on the stain of infecting virus, species, age and immune status of poultry. HPAI virus can cause 100% mortality in affected flocks. The virus is genetically quite instable, therefore, the method of spread, virulence and public health significance is unpredictable.

Conclusion (continue) Not yet a single case of human AI in Indo-Pak has been confirmed amongst farm workers or butchers and users of poultry and poultry products. However, the disease is consistently knocking at our doors, we have to remain very vigilant about the fatal disease with utmost caution.

Conclusion (continue)Strict surveillance is required to monitor this zoonotic problem. However, present media as instrumental, indiscriminately spreading news about new outbreaks of AI in many countries of the world including Pakistan. Media has proved more virulent (instrumental) than HPAI virus

Necrotic lesions on wattles and combs

Swollen wattles and combs

Congested Lungs

Pericardial Hemorrhages

Cyanosis (Bluish combs)

Facial swelling

Shank hemorrhages

Proventriculus hemorrhages

Proventriculus hemorrhages

Facial swelling

Conjunctivitis

Swollen spleen

Cut surface of spleen

Intestinal Ulcer like a button

Enlarged Caecal Tonsils

Enteritis

Degenerated Ovules

The End Q & Asession

Monthly Special LectureDiagnosis of Poultry Diseases under field conditions