AVIAN INFLUENZA IN BIRDS PRESENTEN BY P.K.KUBAI CLINICIAN/MPH - - PowerPoint PPT Presentation

AVIAN INFLUENZA IN BIRDS

PRESENTEN BY P.K.KUBAI CLINICIAN/MPH EXPERT 30th July 2010

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What is avian influenza?

A highly contagious viral infection, primarily in bird species Clinically, signs range from inapparent to a rapidly fatal

condition characterized by gastrointestinal, respiratory

and/or nervous signs in chickens and turkeys Previously (1955), was known as: Previously (1955), was known as: Virulent avian influenza, or Fowl plague

What is avian influenza?

Avian= bird Influenza=flu

The World Organisation for Animal Health (OIE) lists the disease as Highly Pathogenic Avian Influenza (HPAI) caused by H5N1 and the Low Pathogenic Avian Influenza (LPAI)—caused by H5 and N7 virus subtypes (LPAI)—caused by H5 and N7 virus subtypes Collectively, these diseases are Notifiable The disease is of public health importance because it

• ccasionally causes fatal disease in humans

Currently, the disease infects man through contact with sick birds

What virus causes avian influenza?

AI viruses are of 3 types-A, B and C Type A- affects many animals, birds and humans-causes severe disease

• very many subtypes (H1-16, N1-9)

Type B-primarily human, less severe, less common Type B-primarily human, less severe, less common

• only one type

Type C- also affects humans and a few animals

• can be severe
• least frequent among the three

Influenza A viruses

Only influenza type A viruses have been isolated from bird species Influenza A viruses are further divided into subtypes determined by haemagglutinin (H) and neuraminidase (N) antigens. and neuraminidase (N) antigens. 16 H subtypes and 9 N subtypes have been

• identified. Previously the scare was of an
• utbreak caused by H5N1

Viruses of H5 and H7 subtypes are known to cause the highly pathogenic form

Changing virus

Bird flu virus now infecting many hosts

What birds are affected?

Wild water fowl are natural reservoirs of influenza A viruses. Known to carry H5 and H7 in low pathogenic form Domestic fowl, ducks, geese, turkeys, guinea Domestic fowl, ducks, geese, turkeys, guinea fowl and quail are all susceptible Disease is severest in domestic fowl (chicken) Virus is found in very high concentrations in faeces and nasal discharges

Signs in birds

Low Pathogenic Avian Influenza (LPAI) - common

Signs are very mild and may be missed unless there is routine checking for influenza viruses Ruffled feathers Ruffled feathers Drop in egg production Mild effects on the respiratory system Low mortality

Signs in birds

Highly pathogenic avian influenza (HPAI): Dramatic onset in chicken Chicken are well one moment, and dead in a few hours few hours

HPAI – less common

Sudden onset; Rapid spread; High mortality ~ 100%

within 48 hrs.

High fever; Respiratory

problems—gasping, cough;

Neurological signs—

twisted necks and ataxia;

Watery diarrhoea.

Many organs are affected; have ruffled feathers; very thirsty; swollen faces and necks.

Hemorrhages—in all

• rgans and can be seen on

exposed skin

• Combs and wattles are

swollen and cyanotic

How is the disease spread in birds?

Internationally

Importation of infected poultry and poultry products Migratory birds – infect wild water fowl at water points, these then infect domestic poultry these then infect domestic poultry Movement of contaminated equipment, packaging, feed

How is the disease spread?

Within a Country

Movement of infected poultry and poultry products & contaminated equipment from one place to another Live bird markets

Between Flocks Between Flocks

Movement of farm workers, egg cartons and trucks from infected farm to non infected farms, homes

Within a Flock

Direct and indirect contact Airborne transmission

How is the disease spread?

Poultry to Humans

Direct and indirect contact with infected poultry and contaminated objects Living in close contact with poultry poses high risk risk Sale/slaughter and consumption birds when signs

• f illness appear in a flock (common practice in

the rural areas).

This poses a very high risk especially during slaughter, de-feathering and preparation for cooking

Where is the disease

In S. East Asia- now endemic- these countries produce a lot of chicken Was reported in other countries such as turkey turkey In Africa, the disease in birds was reported in West Africa- Nigeria, Sudan, Djibouti and keeps rearing its head now & again in Egypt

Socioeconomic impact of bird flu

Apart from the risk of infection spreading to people, there is massive losses of chicken as result of the disease and as a control measure- once a disease is reported as a control measure- once a disease is reported in an area, all chicken within the neighbourhood (3km radius are killed and buried or burnt) Fear in the general public – shy from buying or eating chicken- loss of jobs for those in the poultry industry Loss of income, food for the family-poverty, hunger

Preventive measures in place

HPAI made a notifiable disease in Kenya (1996) Importation of poultry and poultry products from affected countries was banned (1998) Animal, health professionals & the public have Animal, health professionals & the public have been sensitized Active surveillance in wild birds and passive surveillance in domestic poultry on-going Emergency response teams in place- both in human and animal health

Preventive measures in place

Laboratory reagents- can now diagnose avian

• influenza. HPAI has not been detected in Kenya

Protective clothing – for staff undertaking surveillance and distributed to regional surveillance and distributed to regional laboratories Collaborating with other institutions locally through the task force and also internationally National action plan has been prepared and is in use

Surveillance

Inspection of live bird markets and/or abattoirs Monitor water points for sick and dead Monitor water points for sick and dead birds Attending to all reported cases of sick or dead birds Being extra vigilant at all ports of entry

Awareness creation

• Put all staff on high alert
• Create awareness in all stakeholders—use all available fora e.g.

barazas, church, services, mosques, public functions, meetings

• Messages to include:

Disease and its symptoms; Reporting all suspicious cases to nearest vet office; Avoid living in close contact with birds; Minimize visitors to poultry houses; Avoid raising different poultry species together; Ensure biosecurity (hygiene); Do not eat sick or dead birds; Observe hygiene at all times; and Cook your chicken well.

Reporting

All animal health workers should make weekly reports

• n avian influenza activities undertaken

Officers should submit zero reports District Veterinary officers (DVOs) submit weekly epidemiological reports to Epidemiology Unit epidemiological reports to Epidemiology Unit A rumour register MUST be maintained by the DVO indicating the type of report that was received, when it was received, action taken, when it was taken and the findings.

Early response

Emergency response teams in place at Kabete and at all RVILs Respond to cases in shortest time possible Send samples to nearest RVIL or to Kabete Send samples to nearest RVIL or to Kabete Samples for further tests to be sent to Kabete

District Disease Control Committees

Reactivate district disease control committees These committees are charged with assessing the:

Risks of an outbreak occurring in the district; Number of farms at risk;

These committees are expected to play an important role in:

Rallying the community to the common cause of fighting an outbreak if it ever occurs. They are also important for disseminating information to the general public.

Conclusion

HPAI has not been diagnosed in Kenya so far We need to do all we can to keep it out of Kenya All of us have a role to play in doing this All of us have a role to play in doing this Let us all work together and keep this disease away