Bird Flu: Explained

January 28, 2021

Avian influenza, commonly known as bird flu, is a type of viral infection that affects birds as well as other animals and humans too. However, most forms of the bird flu virus are restricted to birds. The most common form is the H5N1 bird flu, which is deadly for birds and can also affect other animals, including humans, who come in contact with the virus.

H5N1 was first discovered in humans in 1997. It is estimated that around 60% of people affected by the infection have died from it. From what is known currently, human contact does not spread the virus. Having said that, there is still a concern among experts of the H5N1 posing a risk of a pandemic.

Symptoms of bird flu

Most of the symptoms of the H5N1 infection is similar to that of the typical flu, including:

  • cough
  • respiratory difficulties
  • diarrhea
  • fever in excess of 38°C or 100.4°F
  • muscle aches
  • headache
  • malaise
  • sore throat
  • runny nose

Before visiting your doctor at the hospital or a clinic, you need to inform them if you have been exposed to bird flu. If you alert them ahead of time, they can take the necessary precautions for protecting staff as well as other patients before providing you the medical care you need.

How is the bird flu caused?

While different types of bird flu exist, the first one that humans were infected by was H5N1. The first instance of the infection occurred in 1997 in Hong Kong. The outbreak of the virus was associated with the handling of infected poultry.

In nature, the H5N1 occurs mainly in wild waterfowl, although it can easily spread to domestic poultry. Transmission of the disease to humans occurs when they come in contact with infected bird nasal secretions, secretion from the eyes or mouth, or feces/faeces.

Bird flu is not transmitted through the consumption of properly cooked eggs or poultry from infected birds. Serving runny eggs is not advisable. Meat is also considered safe if it is cooked to a high enough temperature.

Risk factors for transmission of bird flu

The H5N1 can characteristically survive over an extended period. A bird who is infected by the virus will continue to release it in saliva and feces for as long as ten days. Infection can be spread through touching contaminated surfaces.

The following people have a higher risk of contracting bird flu:

  • Poultry farmers
  • Travelers who visit affected areas
  • Individuals who consume undercooked eggs or poultry
  • People exposed to infected birds
  • Household members of infected people
  • Healthcare professionals providing care to infected patients

Diagnosis of bird flu

There exists a test for identifying bird flu known as influenza A/H5 virus real-time RT PCR primer and probe test. The preliminary results for the test can be done within 4 hours. The availability of the test may vary.

Your healthcare provider may ask for other tests to check for the presence of bird flu causing virus. These tests include:

  • Auscultation, which is a test for detecting abnormal breath sounds
  • Nasopharyngeal culture
  • White blood cell differential
  • Chest X-ray

Further tests may also be needed for assessing the functioning of your kidneys, liver, and heart.

Bird flu treatment

The symptoms caused by a bird flu infection depends on the type of bird flu. So, treatments for infections also vary. Mostly, treatment involves the use of antiviral medication like Tamiflu (zanamivir) or Relenza (oseltamivir) for reducing the severity of the infection. It is important to take the medication within 48 hours of the first appearance of symptoms.

Rimantadine and amantadine are two common types of antiviral medications that should not be used for treating bird flu. This is because the virus responsible for causing the human form of the flu is known to develop resistance to these medications.

Antivirals might be prescribed to your family members as well as other people you have been in close contact with, even if they are not sick. Along with this, as a preventive measure, you need to isolate to prevent spreading the virus to other people. Bird Flu can cause severe inflammation of the lungs, also severe infections can require ventilatory support for maintenance of respiratory functions.