Description of Bird Flu - Research Paper Example

Only a few strains of three subtypes of the virus are highly pathogenic in human beings. These are H5N1, H7N3, and H7N7 (Leong et al, 2008). Of these, H5N1 poses a threat to human beings and because of its deadliness, it is referred to as the most highly pathogenic avian influenza. This strain is remarkable for its ability to cause severe sickness and death among birds, especially domesticated birds like chickens, turkeys, or ducks.

History of the Bird Flu
In 1918, the Spanish flu began when a normal type of human influenza virus changed suddenly and became lethal. Scientists believe this virus was a mutated form of the avian influenza/bird flu virus. The first H5N1 outbreak occurred in 1987 but the first human incidence of illness from this deadly strain of avian influenza was reported in 1997 in Hong Kong. Eighteen people were infected and 6 of them died. Since then, over 560 cases have been identified globally with deaths exceeding 300 (WHO, 2011). These infections have been severe and at worst, fatal. The years 2003, 2004, and 2005 are considered major H5N1 resurfacing and infection years (WHO, 2011).

Method of Transmission
Human infection of bird flu occurs primarily as a result of contact with the secretions or feces of sick poultry or, handling dead birds that had been infected by the virus. Because of this, people at high risk of infection include poultry farmers, other people working with poultry, and those who eat undercooked meat, eggs, or/and blood from infected birds. Few cases of human-to-human transmission have also been reported but such transmissions require close and lasting contact with an infected person (Nettleman and Davis, 2011).

Symptoms
According to Pubmedhealth (2011), symptoms of bird flu infection among human beings depend on the strain of the virus contracted. Typical symptoms for the H5N1 virus include diarrhea, coughing, runny nose, difficulty in breathing, fever with temperatures of more than 38oC/100.4F, headache, muscle aches, sore throat, eye infections, and vomiting. These symptoms can progress to pneumonia and even result in respiratory failure. The virus causes acute respiratory distress syndrome (ARDS), a dangerous and often fatal form of pneumonia.

Where it Occurs Mostly in the World
Since the identification of the highly pathogenic avian influenza, birds infected by the strain have been found in Europe, Africa, Asia, and the Middle East. Specific regions where the influenza virus has been found are Alberta, England, Germany Ukraine, South Africa, Malawi, Ethiopia, Australia, Ontario, Hong Kong, Wisconsin, Rostock, Maryland, and Guryev ( Kawaoka, 1998). Countries that have reported human death as a result of the virus are Azerbaijan, Egypt, Indonesia, Cambodia, China, Iraq, Laos, Thailand, Turkey, Nigeria, Pakistan, and Vietnam. Despite control measures, the virus continues to exist in some areas of Asia and Africa (WHO, 2011).

Life History of the Microbe and Chances of Survival

The symptoms of bird flu often show 2-8 days after infection. When the H5N1 virus enters the human body, they multiply in the lower respiratory tract, and as a result, they cause pneumonia. This in turn results in respiratory problems of various severities. This virus is hard to spread but lethal. This is unlike the H1N1 virus which replicates in the upper respiratory tract, making it easy to spread but less lethal. Bird flu infection triggers the body to produce antibodies against it during and after infection. Chances of survival after infection with bird flu depend on the strain of the virus. The H5N1 mortality rate for humans is 60% and this presents a survival rate of 40%. Others are less lethal with almost 100% survival chances. H7N7 has killed only one person in its known history.

Recommended treatment
Under the recommendation of the World Health Organization, Zanamivir (Relenza) or oseltamivir (Tamiflu) treatments are the antiviral medications used currently for the treatment of the disease. They lessen the effects of the disease when taken within 48 hours after the symptoms begin showing. Those with severe infections are put under breathing machines. The small number of human bird flu infections has made it difficult to conduct reliable treatment trials for the disease. There is no cure for bird flu since it is a viral infection. Viruses are non-living and thus nothing can kill them. Therefore, antivirals used only serve to slow down the microbes. Read More