Bird flu is a viral infection caused by the strains of Avian influenza virus A [ H5N1, H7N9, H9N2] that principally infects birds but has the potential to affect humans also. These strains are naturally found in wild aquatic birds.
Bird flu in humans
Human infections are very rare but if contracted, people affected with H5N1 viruses usually develop severe disease with high mortality.
It can be transmitted by
- Breathing in droplets or dust that contain the virus through close contact with infected birds [bird’s feces, nasal, mouth, or eye secretions]
- Touching surfaces contaminated with the virus [feathers, droppings] and then touching your mouth, nose, or eyes
- Consumption of eggs or meat that is not properly cooked
- Human to human transmission is rare but some cases have been found
Who is at risk?
People with direct exposure to sick birds are at higher risk such as
- Poultry workers
- Slaughtering, de-feathering, handling carcasses of infected poultry for preparing meat for consumption
- Travelers visiting affected areas
- Household contacts of an infected person
The virus is killed at a high temperature of >𝟕𝟒℃, so there is no risk of transmission through properly cooked eggs and poultry meat
Symptoms of Bird flu
Symptoms usually appear 2 to 7 days after exposure. Bird flu may present as a mild to severe flu-like illness with
- Fever
- Cough
- Muscle or body aches
- Fatigue
- Headaches
- Runny nose
- Sore throat
- Eye infection /Conjunctivitis
- Difficulty breathing
- Gastrointestinal symptoms [few cases]- nausea, vomiting, or diarrhea
The illness may progress rapidly from mild infection to severe disease which may include life-threatening complications such as pneumonia, acute respiratory distress syndrome, shock, organ failure, and even death. Pregnant women, elderly [≥65 yr], and people with a weak immune system are at higher risk for serious illness
If you develop a fever, cough, and body aches and have a history of recent travel to the affected area, live bird market, or farms. Call your doctor immediately for proper guidance.
Diagnosis
- Clinical evaluation and & history of exposure
- Testing of respiratory secretions [RT-PCR test]
Precautions to prevent Bird flu
- Avoid visit to the affected areas, bird markets, or close contact with migratory birds
- Avoid eating raw/undercooked poultry products
- Wash hands regularly with soap, sanitize with alcohol, and dry them
- Maintain respiratory hygiene, wear a mask, keep hands and fingers away from eyes, nose, and mouth
- Stay away from infected people and things used by them
- Report the death of a bird in your area to the local authority. Don’t touch the carcass with bare hands
- Stay isolated at home, if you are not feeling well
Treatment
It includes the patient’s isolation, supportive treatment, and use of antiviral drugs [oseltamivir, peramivir, and zanamivir]. The use of antiviral drugs within 2 days of the appearance of symptoms is effective in reducing the severity of diseases and preventing complications.