Bird Flu , A global threat!!

1.Bird Flu; A short introduction

Usually, “avian influenza virus” refers to influenza A viruses found chiefly in birds, but infections with these viruses can occur in humans.Highly pathogenic avian influenza A (H5N1) virus is an influenza A virus subtype that occurs mainly in birds. Of the hundreds of strains of avian influenza A viruses, only four are known to have caused human infections: H5N1, H7N3, H7N7, and H9N2. Confirmed cases of human infection from several subtypes of avian influenza infection have been reported since 1997(in Hong Kong).

2. What is H5N1 Virus?

The H5N1 strain is a new and extremely severe influenza virus.

It has a unique capacity to jump the species barrier and cause severe disease in humans. However, the detection so far of only a few human cases, suggest that the virus may not be easily transmitted from birds to human at present. Since mid-2003, the H5N1 virus has caused the largest and most severe outbreaks in poultry on record.

3. Severity of this infection around the globe:

WHO(World Health Organization) has reported human cases of avian influenza A (H5N1) in Asia, Africa, the Pacific, Europe and the Near East. To date, human cases have been reported in six countries, most of which are in Asia: Cambodia, China, Indonesia, Thailand, Turkey, and Viet Nam. Indonesia and Vietnam have reported the highest number of H5N1 cases to date. In Hong Kong in 1997 (18 cases with six deaths), in Hong Kong in 2003 (two cases with one death) and in the current outbreaks that began in December 2003 and were first recognized in January 2004. Since 2003, a growing number of human H5N1 cases have been reported in Asia, Europe, and Africa. More than half of the people infected with the H5N1 virus have died. Most of these cases are all believed to have been caused by exposure to infected poultry. There has been no sustained human-to-human transmission of the disease, but the concern is that H5N1 will evolve into a virus capable of human-to-human transmission.

Three pandemics occurred in the previous century; "Spanish influenza "pandemic in 1918,"Asian influenza "pandemic in 1957, and "Hong Kong influenza " pandemic in 1968.

‘Bird Flu’ is a threat to public health because, if it circulates long enough in humans and farm animals, there is an increased risk that it may evolve into a pandemic influenza strain which could cause disease worldwide. In addition, avian influenza is an economic disaster for the poultry industry as well as small poultry farmers.

4. What are the Symptoms?

Haemophilus influenzae causes illnesses ranging from local respiratory infection to serious invasive disease, including meningitis, epiglottitis, septic arthritis, and septicemia.Symptoms of avian influenza in humans have ranged from typical human influenza-like symptoms (e.g., fever, cough, sore throat, and muscle aches) to eye infections, pneumonia, severe respiratory diseases (such as acute respiratory distress), and other severe and life-threatening complications. The symptoms of avian influenza may depend on which virus caused the infection.

5. How does it transmits?

Most cases of avian influenza infection in humans have resulted from contact with infected poultry (e.g., domesticated chicken, ducks, and turkeys) OR, surfaces contaminated with secretion/excretions from infected birds. The spread of avian influenza viruses from one ill person to another has been reported very rarely, and has been limited, inefficient and unsustained.

6. Treatment available:

There currently is no commercially available vaccine to protect humans against H5N1 virus. Currently available vaccines will not protect against disease in humans, but WHO is urgently working with others to develop a prototype virus for use by vaccine manufacturers.The H5N1 virus that has caused human illness and death in Asia is resistant to amantadine and rimantadine, two antiviral medications commonly used for influenza. Two other antiviral medications, oseltamavir and zanamavir, would probably work to treat influenza caused by H5N1 virus.

In suspected cases, oseltamivir should be prescribed as soon as possible (ideally, within 48 hours following symptom onset) to maximize its therapeutic benefits. The recommended dose of oseltamivir for the treatment of influenza, in adults and adolescents 13 years of age and older, is 150 mg per day, given as 75 mg twice a day for five days. Oseltamivir is not indicated for the treatment of children younger than one year of age.(World Health Organization). But additional studies still need to be done to demonstrate their effectiveness.

Research is already well underway on the development of a human vaccine against this strain(H5N1).

7. Preventive and control measures:

Stockpiling of antiviral medicines,

Training of health professionals on case diagnosis and management,

Reinforcing the surveillance system and monitoring of high risk groups,

Use of personal protective equipments among workers of poultry farms and industries.

Proper cooking habits and food hygiene maintainence.

8. International actions against Bird Flu:

International organizations are appealing to donor nations to help Asian nations attempting to control an epidemic of avian influenza that is proving to be a "disaster for agricultural production" and a threat to human health.

A joint statement issued January 27 by the World Health Organization (WHO), the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE) outlines the dangers and makes the appeal for a coordinated international response. The focus of FAO, OIE and WHO activities is to avert a human and animal pandemic.

Citing the swift and effective international collaborative effort in response to severe acute respiratory syndrome (SARS) In 2003, WHO Director General Dr. Lee Jong-wook said, "Now, we confront another threat to human health and we must reaffirm existing collaboration and form new ones." Lee said, the farmers culling their flocks will suffer serious economic losses, and will require support.

“Farmers in affected areas urgently need to kill infected and exposed animals and require support to compensate for such losses. This will represent a huge cost, especially to struggling economies and small farmers. The international community has a stake in the success of these efforts and poorer nations will need help," Dr. Diouf said. FAO and OIE also called for a tight and effective control of animal movement in affected areas. Farm workers need to be protected during the culling operations by wearing protective clothing. In addition, vaccines need to be supplied. Farmers, especially backyard farmers, need to be supported for losses that will surely be significant.”( Jacques Diouf, FAO Director-General,2004

The U.S. Centers for Disease Control and Prevention (CDC) has responded to the international health threat by sending a team of experts to assist Asian health officials in tracking the diseas

There is currently a ban on the importation of birds and bird products from H5N1-affected countries.

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