Aamir Ali writes on this dangerous infection among chickens and how does it effect human health.
Avian influenza, or “bird flu”, is a contagious disease of animals caused by viruses that normally infect only birds. While all bird species are thought to be susceptible to infection, domestic poultry flocks are especially vulnerable to infections that can rapidly reach epidemic proportions. The disease in birds has two forms. The first causes mild illness, sometimes expressed only as ruffled feathers or reduced egg production. The second form is known as “Highly Pathogenic Avian Influenza” (HPAI) and is characterized by sudden and severe illness resulting in rapid death. When such infections occur, public health authorities need to monitor the situation closely because of concerns about the potential for more widespread infection in the human population. Since mid December 2003 human infections with Influenza-A H5N1 have attracted attention of public health professionals. Infections in humans were been reported in Vietnam and Thailand following outbreaks of highly pathogenic H5N1 infection among poultry. Avian influenza-A viruses do not usually infect humans; however, several instances of human infections have been reported since 1997. India is battling its worst outbreak of avian influenza, which has spread to 13 of West Bengal’s 19 districts. Veterinary staff culled more than 2.6 million birds. India has not reported any human infection of the H5N1 bird flu virus in its four outbreaks of avian influenza since 2006. Widespread epidemics in birds increase opportunities for direct human exposure. As these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. Such an event, therefore, may mark the start of an influenza pandemic. Influenza illness commonly called “the flu”, manifests in mild to severe forms and may have life-threatening complications.
Workers handling poultry in farms, markets & involved in culling activity, veterinary workers and health workers are at higher risk of acquiring the infection. Even the family members of these workers are at higher risk.
Any type of Influenza tends to be more serious in children, elderly persons above 65 years of age and the chronically sick persons.
Certain water birds such as water fowls and migratory birds act as reservoir of influenza viruses by carrying the virus in their intestines and shedding it. Birds that survive infection excrete virus for at least 10 days, orally and in faeces, thus facilitating further spread. The virus can spread from birds to humans through close contact with live infected poultry through inhalation. In fact, in mammals, influenza is primarily a respiratory tract infection while in avian species it can be an infection of both the respiratory tract and the large intestinal tract.
Airborne virus can spread the disease from bird to bird, causing infection when the virus is inhaled. Contaminated equipment, vehicles, feed, cages or clothing, especially shoes can carry the virus from farm to farm. The virus can also be carried on the feet and bodies of animals, such as rodents.
The risk that infection will be transmitted from wild birds to domestic poultry is greater where domestic birds roam freely, share water supply with wild birds, or use water supply that might become contaminated by droppings from infected wild-bird carriers.
In human beings, the reported symptoms of avian influenza range from typical influenza-like symptoms like fever, cough and sore throat, muscle aches, eye infections, pneumonia, viral pneumonia, acute respiratory distress and other severe and life threatening complications.
The facilities of laboratory diagnosis for avian influenza in humans are available in National Institute of Virology, Pune, and National Institute of Communicable Diseases (NICD) Delhi. For diagnosis in animals, the facilities are available at Animal Disease laboratory Bhopal and other Regional Laboratories of Animal husbandry Department.
What steps has the Government taken?
The Divisional Emergency Response Cell has already been geared-up under the supervision of the Divisional Commissioner Kashmir and plans drawn up to monitor and regulate movement of poultry which includes a ban on the poultry movement at the livestock check-posts during the night time to ensure that no strain find its way into the Valley. At present, no case of avian influenza has been reported in the state. However, in view of the out break of bird-flu in West Bengal, the State Government has taken concrete steps to meet any eventuality. Surveillance has been increased all over the State, especially at Lakhanpur, which is the main entry point of the state. The officers have been asked to keep strict vigil and surveillance at all levels, especially in and around the poultry farms and water bodies. Chief Animal Husbandry Officers & Poultry Development Officers have been asked to closely monitor all the wetlands and report any mortality in migratory birds. More than 300 Rapid Response Teams (RRT) have been constituted by the Animal Husbandry department to deal with any eventuality and control rooms have been set-up. In case any area is affected by the disease, the blood sample will be sent to the Animal Disease Lab Bhopal for confirmation. Strict regulation of entry of personnel, material, visitors, vehicles, etc. to such areas will be instituted. Culling of birds and proper disposal of culled birds and the droppings of the poultry would be undertaken systematically, by deep burial or incineration within the affected area. The public would be advised to report any mass deaths of poultry, to the local veterinary hospital and the State Animal Husbandry Department. In the event of detection of infection in the flock, marketing of birds, eggs, etc., will be stopped completely, till advised by the concerned authorities.
Dos & Don’ts:
¨ Do not eat under/semi-cooked or raw poultry, egg or duck dishes.
¨ Wash eggs properly as shells may be contaminated with bird faeces.
¨ Avoid food containing raw or uncooked eggs. Avoid half boiled eggs.
¨ Pregnant women and young children should avoid contact with animals/ birds.
¨ Avoid contact with dead or sick poultry and bird droppings.
¨ Dead birds and their faeces should be buried safely without generating dust, while burying.
¨ Avoid frozen chicken as the bird flu virus can survive for a long time.
¨ All food should be thoroughly cooked to a temperature of 70°C or above.
¨ While cooking whole-chicken, pierce the thickest part of the leg between the drum stick and the thigh with a clean knife and make sure that there are no pink-parts left after cooking.
¨ People working in poultry sector must observe safe practices. They should wash their hands with soap or detergent frequently and also wash their clothes, shoes and sandals at least once a day.
¨ People who have flu-like illness should take additional precautions. Check your temperature for 7 days at least once daily. If you develop a high temperature (>37.5°C), visit a doctor or the nearest health care facility, immediately.
¨ Remember, it is safe to eat well-cooked chicken and eggs.
(Aamir Ali is Project Coordinator (UNDP/Disaster Management) in the Office of the Divisional Commissioner Kashmir and can be emailed at: email@example.com)