Avian influenza is a viral infection in birds. The virus belongs to the orthomyxoviridae family and carries a segmented RNA. Bird flu infection in domestic poultry can cause two forms of disease. One is called low pathogenic avian influenza (LPAI) which may include unnoticed or usually with mild respiratory symptoms including decline in egg production. Another form is called high pathogenic avian influenza (HPAI) which spreads rapidly and it can affect multiple internal organs with mortality 80-90 percent in 48 hours. These flu viruses are carried by the wild migratory birds in their intestine. However they usually don’t get sick from those viruses but they can contaminate the environment by their fecal droppings in the environment. The first report of H5N1 infection in human being was reported in Hong Kong in 1997.
The virus was first isolated in the year 1993 in Pakistan in poultry. Later on various subtypes of avian influenza virus (AIV) like H9N2, H7N2 have been isolated from human being in various parts of the world. It was revealed that H5N1 can cause approximately 60 percent mortality in infected human beings. People working at poultry farms, poultry retailer / butcher, laboratory technician, veterinarian, health professionals are at high risk of getting infected with this disease.
The symptoms of avian flu infection depend on the subtype of AIV like H5N1. Generally, the patient may show signs of cough, difficult breathing, headache, fever, malaise with runny nose. For proper diagnosis of the disease it is important to consult physician and get some laboratory tests. In general antiviral medication with oseltamivir (tamiflu), zanamivir (Relenza) can lessen severity of the signs if medication starts within 48 hours of infection.
We recently carried a study in Pakistan on the prevalence of influenza virus in occupational people. The occupational people are directly involved with poultry industry like poultry attendant, butcher / poultry retailer, vaccinator, laboratory technician, veterinarian and farm consultant.
The survey was done in ten districts of Punjab like Lahore, Chakwal, Faisalabad, Gujranwala, Bahawalnagar, Multan, Rawalpindi, Sheikhupura, Sialkot, Toba Tek Singh. Besides the samples were also taken from Islamabad and Haripur district of Khyber Pakhtun Khan Province. Blood and nasal swabs were taken from 465 people from. Serological evidence showed that the occupational people carry antibodies against avian influenza virus. Nasal swabs show that occupational carried the avian influenza virus.
During sampling from the human being specially in lab technician and farm attendant told that they occasionally suffer from respiratory symptom which persisted for 3-4 days. However it was not clinically confirmed that the illness was due to avian influenza virus. Poultry workers who handle the birds directly specially in the wet market people who are engaged in selling and slaughtering the birds they were found at potential risk of the avian influenza virus infection. In wet market where the birds come from various source and the virus could stay and multiplied easily.
The study was taken only in Punjab province and in future similar work should be done in other provinces of Pakistan. It is suggested that close monitoring should be carried out in the occupational people who are directly exposed to poultry industry as a precautionary measure of any bird flu epidemic. Further mass media can play an important role to create awareness among the human beings on avian influenza. Of course before going to media it must be filtered through respective specialist so that unnecessary panic should not be created in mass people otherwise the poultry industry will be collapsed where many of the people earn their bread and butter from this industry.
DR ABDUL AHAD
UVAS, Lahore
Pakistan's neighboring countries like China, India and Vietnam have stepped up efforts in trying to avoid a bird flu outbreak. India and Pakistan are very vulnerable to such pandemics but no real reason to buy in panic vaccinations.
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