Avian Influenza or Bird Flu

Tauseef Akhund Research Officer Paediatric Department. Agha Khan University Karachi Pakistan

 Bird flu is an infection caused by avian (bird) influenza (flu) viruses. These flu viruses occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, bird flu is very contagious among birds and can be lethal for domesticated birds, including chickens, ducks, and turkeys, killing majority of them.

Transmission

Infected birds shed flu virus in their saliva, nasal secretions, and feces. Susceptible birds become infected when they have contact with contaminated excretions or surfaces that are contaminated with excretions. It is believed that most cases of bird flu infection in humans have resulted from contact with infected poultry or contaminated surfaces.

The spread of avian influenza viruses from one ill person to another has been reported very rarely, and transmission has not been observed to continue beyond one person. However, since all influenza viruses have the ability to change, scientists are concerned that the H5N1 virus may acquire the ability to spread easily from one person to another leading to pandemic spread.

At present no one can predict when a pandemic might occur. However, experts from around the world are watching the H5N1 situation very closely and are preparing for the possibility that the virus may begin to spread more easily and widely from person to person.

Population at Risk

The risk from bird flu is generally low to most people because the viruses occur mainly among birds and do not usually infect humans. However, during an outbreak of bird flu among poultry (domesticated chicken, ducks, turkeys), there is a possible risk to people who have contact with infected birds or surfaces that have been contaminated with excretions from infected birds. People should avoid contact with infected birds or contaminated surfaces, and should be careful when handling and cooking poultry.

Due to the changing nature of the influenza virus health care workers are potentially at risk.

 Clinical symptoms

Symptoms of bird flu in humans have ranged from typical flu-like symptoms (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 bird flu may depend on the virulence of which virus caused the infection.

Infection Control Recommendations

• Standard and droplet precautions should be the minimum level of precautions to be used in all health care facilities when providing care for patients with acute respiratory illness. The most critical elements of these precautions include facial protection (eyes, nose, and mouth) and hand hygiene

• Full barrier precautions, which include standard, contact, and airborne precautions (plus eye protection) should be used, when possible, when providing care for suspected or confirmed             H5N1 infected patients with close patient contact and during aerosol-generating procedures.