Bismillah • Beginning with the name of Allah, the most Merciful and Beneficent
Status of Bird Flu in Pakistan
What isBird 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 world Single stranded RNA virus, also share infection in human and other mammals including pigs and horses
Threat of Bird Flu • Recent 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 Factors • There 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 human • In 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 history • Pandemic 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 History Recorded 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 countries • Recent outbreaks (2004-07) with transmissible to human in Canada, Vietnam, Iraq, China, Russia, Ukrane and Pakistan
Economic lossesin Pakistan • AI 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 Facts • Labile / instable virus • AI is constantly mutating virus, change as they grow in human and birds. Small genetic change (mutation) is known as Drift and Shift
Genetic Drift & Shift • The 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 Program • The changing nature and its odd consequences necessitates a constant monitoring of the global Influenza situation and constant adjustment in the composition of Influenzavaccines
Bird Flu Potentials Influenza 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 World • Elimination 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 measures affecting 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 Virus H5N1 is of particular concern
Portals of Entry • As 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 antigens based on Hemagglutination (H) Neuraminidase (N) activities. Fifteen subtypes are known to infect birds
Highly Pathogenic Virus Virus Type H5N1 Considered to be a highly pathogenic Avian Virus (HPAI) both for birds and human and has species cross barriers potential H5N1 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 infection Highly 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 Diversity Genetically quite variable virus • Show genetic shift / drift and an instable virus, therefore, its spread and Public Health Significance is unpredictable
Further Studies Waterfowl Migration • AI has higher prevalence and Pakistan is on the cross roads of waterfowl migratory routes The Birds of Pakistan T. J. Roberts Oxford University Press Poultry Houses should not be on these routes
Spread Mostly Birds to Birds • (Horizontal transmission) • No vertical transmission (Breeder to baby chicks) • Birds to Human (zoonotic) Person to person (rare)
Symptoms in Birds Basically 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 Diagnosis Avian Influenza virus • show quite variable symptoms not helpful for diagnosis, may involve digestive and nervous systems confuses with Newcastle Disease (ND) Ranikheith Disease
Postmortem Findings Quite 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 Diagnosis Symptoms and lesions are not characteristic. Demonstration of virus and detection of its specific antibodies using Elisa is required for confirmation of Avian Influenza • Diagnostic kits are commercially available for Ab & Ag tests
Treatment • A 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 flocks Types, Subtype and Strain
Five Strategies Plan • Investigation of morbidity and mortality of wild birds (crow and kites) • Monitoring apparently healthy birds. • Monitoring hunter killed birds • Use 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 infection • Not 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 program • Since 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 Media Since 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.
CONCLUSION Bird 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