Bird Flu (Avian Influenza)Avian influenza is an acute viral disease of respiratory tract accompanied with high temperature, headache, muscle ache and joint pain, Sore throat and coughing which is very similar to ordinary flu.
Epidemiological StatusSince 1997, scientists have been familiar with different virus types and outbreaks of avian influenza, particularly in the areas of Southeast Asia. H7N7 type of bird flu was reported on poultry farms in the Netherlands and nearby Germany areas in 2003. The current type of bird flu, labeled as H5N1, has been registered in Vietnam, Cambodia, Thailand, China, and Russia.
SymptomsIncubation and symptoms of bird flu are similar to human-type influenza. Adults virulence with ordinary influenza lasts for three to five days, while with bird flu, incubation lasts for sevendays. Incubation of human-type influenza in children lasts for seven days while the bird flu virus is present in the child's body for 21 days.
The avian influenza can't be diagnosed by symptoms alone. It is necessary to do oral or throat swab tests to find evidence of the existence of the avian influenza virus. Human-type influenza symptoms include: high body temperature, sore throat, cough, muscle pain, conjunctivitis and headache. Bird flu, including the above-mentioned symptoms, also causes breathing difficulties, pneumonia and it may be lethal. The death rate of human influenza is below 0.05%. In the case of large and heavy pandemics caused by new type of virus such as H5N1, the death rate is significantly higher. Bird flu is lethal in 30-70% of cases.
Ways of Infection SpreadingThe leading way of this disease transmission is direct and indirect contact with birds and poultry secretions and excretions. Person also may be infected with contaminated water, food of poultry origin, contaminated equipment and clothing and air.
Avian influenza has affected only people who have been in contact with infected birds so far. Scientists are frightened that the virus could mutate into a form that is transmitted from person to person, which would lead to a global epidemic. British scientists are alarmed with the report that a Thailand woman who died of bird flu at the end of 2006, probably got the deadly virus from her daughter. If the report is confirmed, it will be the first recorded case of inter-human transmission of the virus and conclusive evidence that the virus has mutated.
TreatmentAntiviral therapy (amantadine and rimantadine) can be used for treating ordinary flu, while these drugs have no treating effects on avian flu. Tamiflu has been used recently for preventing and treating avian influenza.
PreventionBird flu requires protective equipment for staff working on combating the epidemic. Also isolation of infected people is recommended.
The disinfection for bird flu is a mandatory code. Vaccination is successful way for human-type influenza prevention, but vaccine against bird flu has not been produced yet, although scientists intensively work on it.