Bird flu or avian influenza is a viral infection that spreads among birds and can affect humans rarely. Read the article for causes, symptoms, mortality rate, and treatment.
Bird flu, otherwise called avian influenza, is a viral infection caused by a type of influenza virus that mainly affects birds but can also infect other animals and humans. When humans get infected, it can result in fatal complications. Almost 12 types of bird flu have been identified so far, including the H5N1 and H7N9, the strains that recently infected humans. H5N1 is the most common type and was discovered in humans in 1997. This type is deadly to the bird, and humans or other animals can get infected by close contact. In 1997, almost 60 % of the infected humans died. Bird flu outbreaks have been recorded in Africa, Asia, North America, and some parts of Europe.
H5N1 does not spread easily from one person to another, and very few human-to-human transmission cases have been reported so far. For example, the virus getting transmitted from an infected baby to the mother. Migratory aquatic birds like wild ducks are the carriers of these viruses, which spread this infection to domestic fowls, such as turkeys, chickens, etc. Bird flu has been recorded in pigs, donkeys, and other animals, making it challenging to eradicate. Doctors are concerned about a possible global outbreak if this virus mutates and gets easily transmissible from one person to another, which is why scientists are working on finding vaccines to protect humans against the bird flu.
Avian influenza is transmitted by close contact with a dead or alive infected bird. You can get infected by:
Touching birds that are infected.
Touching contaminated equipment.
Touching secretions of infected birds, such as feces, and secretions from the nose, eyes, or mouth.
Killing infected poultry for meat.
Cooking with infected poultry.
Going to live bird markets.
You will not get infected by eating thoroughly and adequately cooked eggs and poultry, even if there is an outbreak of the bird flu. The more virulent strains of this virus can spread rapidly among flocks and destroy the entire herd in less than 28 hours. Some strains are less pathogenic and just affect egg production. Indoor poultry, range-raised poultry, live poultry markets, bird farms and trading, etc., have contributed to the recent bird flu outbreaks. Human to human contact is not possible unless there is prolonged contact. But, mutations can make some strains of avian flu to become easily transmissible between humans.
The H5N1 strain was the first avian influenza virus to infect humans, which occurred in Hong Kong in 1997. This outbreak was thought to stem from handling infected poultry. This strain occurs naturally in wild waterfowl, from where it spreads to domestic poultry.
H5N1 can survive for long periods, and infected birds continue to release the virus in feces and saliva for almost ten days. People who are at risk of getting infected are:
Household members of an infected person.
Travelers that visit areas with an outbreak of bird flu.
Those who are exposed to infected birds.
People who eat undercooked poultry or eggs.
The signs and symptoms of bird flu are similar to the flu, such as:
Fever over 100.4°F.
Bleeding from gums and nose.
Eye infection (conjunctivitis)
The symptoms usually take 3 to 5 days to appear after getting infected. The condition can worsen within days, and patients can develop pneumonia and acute respiratory distress syndrome (ARDS).
Life-threatening complications of bird flu include:
Bird flu kills more than 50 % of the infected people, and less than 500 bird flu deaths have been reported since 1997.
The CDC (Centers for Disease Control and Prevention) has approved a test called influenza A/H5 (Asian lineage) virus real-time RT-PCR primer and probe set to diagnose the bird flu virus. This test can provide preliminary results in about four hours, but it is not widely available. If the doctor suspects bird flu, the following tests might also be performed:
The doctor will listen to your lungs and heart using a stethoscope (auscultation) to detect abnormal breath sounds.
White blood cell count.
Nasopharyngeal culture - Samples from the throat and nose are taken to detect the virus. This should be done within the first few days after symptoms appear.
Chest X-ray - To look for pneumonia.
Other tests might be needed to determine how the heart, liver, and kidneys are functioning.
The antiviral drugs Oseltamivir, Zanamivir, or Peramivir are used to reduce the severity of the disease. But, antiviral therapy should be started within 48 hours of the onset of symptoms. Infection with H5N1 in humans can result in severe illness and requires isolation, hospitalization, and treatment in intensive care, and the treatment is determined based on the different symptoms. In severe cases, oxygen support is needed.
Family or household members and other close contacts are also started on antiviral drugs as a preventive measure and are isolated.
The FDA (Food and Drug Administration) has already approved a vaccine to prevent the H5N1 bird flu virus, which is not available to the public yet. The vaccine is being stockpiled to be used in case of a future outbreak. Scientists are also working on developing other types of bird flu vaccines.
The following tips can keep you safe from the bird flu virus:
Clean cutting boards and all utensils and surfaces that come in contact with raw poultry using warm water and soap.
Chicken and other poultry should be cooked thoroughly until the juices run clear and the internal temperature is more than 165 ℉.
Avoid consuming raw and undercooked eggs.
Wash and store eggshells as they are often contaminated with feces.
If you are traveling to a country or any region with bird flu outbreaks, avoid going to live markets and stay away from birds and animals. Please keep your hands clean by washing them with soap and water or an alcohol-based hand sanitizer containing at least 60 % alcohol.
For more information on the bird or avian flu, consult an infectious specialist online now.
Last reviewed at:
08 Jan 2021 - 4 min read
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