( BIRD FLU )
Dr. INDRAJEET KUMAR
Department of Community Medicine
Emerging & re-emerging disease
Emerging diseases are those infectious disease which have shown
increase in frequency in the last two decades or which threaten to
increase in near future.
e.g: AIDS, SARS, bird flu, swine flu etc.
Re-emerging diseases are those infectious disease which were
previously easily controlled by antibiotics and chemotherapeutic agents
are now appearing in epidemic form.
e.g; malaria, tuberculosis, typhoid.
FACTORS RESPONSIBLE FOR
EMERGENCE AND RE-EMERGENCE OF INFECTIOUS DISEASE
Unplanned and under-planned urbanization.
Overcrowding and rapid urbanization.
Inadequate public health infrastructure.
Resistance to antibiotics.
Increased exposure of humans to vectors and reservoirs of
Rapid and intense international travel.
AVIAN INFLUENZA “BIRD FLU”
Avian influenza or bird flu is a contagious disease
caused by viruses that normally infect only birds
and less commonly pigs.
Mode of transmission.
1. Agent proper:
3. Infectious material:
4. Period of infectivity:
1. AGENT PROPER:
:- Avian influenza virus type-A (orthomyxoviridae family) sub-type: H5N1
:- Killed by heat at 60*c for 30min and by common disinfectants such as 5% formalin,
:- can survive in contaminated manure for 3months in cold climate.
2. RESERVOIR: Wild aquatic birds & migratory birds. e.g siberian crane,
3. INFECTIOUS MATERIAL: Saliva and faeces of birds.
4. PERIOD OF INFECTIVITY: 10days.
All age group is susceptible but it is serious in children & elderly persons
HIGH RISK GROUP
:- workers handling poultry in farms and markets.
:- those involved in culling activity.
:- veterinary and health worker.
:- family members of these workers.
Mode of transmission
BIRDS TO BIRDS by inhalation of faecal matter or droplets.
by feco-oral transmission.
BIRDS TO HUMAN through inhalation when in contact with live infected poultry.
“NO EVIDENCE OF HUMAN TO HUMAN TRANSMISSION”
Clinical signs may include:- ruffled feathers,
soft shelled eggs,
sudden drop in egg production,
edema , cyanosis & swelling of head, eyelids etc.
respiratory distress & increased death losses in a flock.
IN HUMAN BEINGS:- typical influenza like symptoms
(like fever, cough, sore throat, muscle aches)
:- acute respiratory distress .
SPREAD WITHIN A COUNTRY:
:- from one poultry to another by contaminated dust and
soil, airborne, contaminated equipment, vehicles, feed, cages or
clothing, especially shoes can carry them from farm to farm.
:- feet and bodies of animals e.g: rodents and flies which act as
:- droppings from infected wild birds can introduce the virus into both
commercial and backyards poultry.
:- spread from wet market.
SPREAD FROM ONE COUNTRY TO ANOTHER
:- through international trade in live poultry.
:-through migratory birds, including wild waterfowl eg. wild ducks, sea
birds and shore birds.
SAMPLES a. Nasopharyngeal secretion
b. Oro pharyngeal(OP) Swab/ Throat swab
c. Paired serum.
A. DETECTION OF ANTIGEN IN NASAL SECRETION
1. Rapid Test
2 .Immuno-fluorescence test
3. ELISA test
4. Polymerase Chain Reaction (PCR)
B. VIRUS ISOLATION
C. SEROLOGICAL TEST IN PAIRED SERUM SAMPLE
One in acute phase and other in convalescent phase collected at 15days interval.
A 4 fold rise in Influenza A/H5 N1 specific antibody is diagnostic.
1. NICD (National Institute of communicable diseases.
2. Virology section, Dept. of Microbiology, AIIMS, Delhi
3. NICED (National Inst. Of Cholera & Enteric dis.), Kolkata
COLLECTION & TRANSPORTATION OF SAMPLES FROM HUMAN CASES OF AVIAN
Samples should be collected preferably within 72hrs of illness and sent to laboratory
within 24hrs of collection.
Teperature 2 – 8C
Sample is transported using the standard “Triple Packaging System” (WHO)
1. Primary receptacle:- properly labeled, unbreakable, sterile, screw capped
with paraffin seal. Preferably a plastic container. Each primary receptacle wrapped
with enough absorbent material.
2. Secondary receptacle:- a watertight (e.g-sealed plastic bag) container.
An item wise list of contents must be enclosed between the secondary & tertiary
3. Tertiary container:-Best is vaccine carrier with a bio-hazard sign &
address where to send is pasted on it.
1.SUSPECTED CASE OF INFLUENZA - A (H5N1):- Features of Acute Respiratory Infection within seven days of
a. Contact with a confirmed case of influenza A (H5N1) during the infectious period.
b. Recent ( less than 1 week )visit to a poultry farm OR other poultry contact in an area known to have
outbreak of influenza A (H5N1)
c. having worked in a laboratory that are processing samples from persons or animals that are suspected
to have influenza A ( H5N1) infection.
2. PROBABLE CASE OF INFLUENZAA (H5N1)
A Possible Case / Suspected Case
Limited laboratory evidence for influenza A (H5N1)
No evidence for another cause of disease.
3. CONFIRMED CASE OF INFLUENZAA (H5N1)
Suspected or Probable Case as given above with confirmed laboratory evidence.
e.g: Positive Viral Culture or PCR or IFA test or 4fold rise in antibody titre in paired serum for H5N1
CONTACT CASE:- A contact case of pandemic influenza is a person who had close (i.e within
one meter) contact with an infectious case or who has spent more than 60 minutes in a
confined space (such as aeroplane or an enclosed room) with an infectious person.
MANAGEMENT OF AVIAN INFLUENZA CASE
GENERAL AND SUPPORTIVE TREATMENT:-
1. Hospitalize and isolate cases.
2. Monitor vital signs.
3.Maintain airway, breathing and circulation (ABC)
4.Maintain hydration, electrolyte balance & nutrition.
5. Provide oxygen therapy when needed.
6. Manage fever symptomatically with Paracetamol.
1. Antiviral drugs:-
Oseltamivir (Tamiflu):- adults>40kg. 75mg X bid for 5 days
Do not use aspirin, and corticosteroids
Oseltamivir is the drug of choise
Close contacts:- 75mg once daily for at least 7days.
Protection lasts for only during the period of chemoprophylaxis
Only c.i is known hypersensitivity to the drug.
Prevention & control strategy
1. Systemic surveillance of avian influenza in poultry & pigs.
2. Culling or Stamping out (rapid destruction) of all infected or exposed birds.
3. Proper disposal of carcases (dead birds) and faecal matters.
( by incineration or buried deep 2ft using lime & soil in 1:3 ratio)
1. Bio-security practices: > absolute ban on movement of poultry & it’s products.
> closure of poultry or egg market in 10km radius.
2. Quarantining the infected farm upto 3km radius.
Prevention at host level
Stringent sanitary measure (of self & surrounding).
Avoid contact with live animals in poultry & market.
Use of N95 mask or triple layered surgical mask.