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Bird Flu


Bird flu is a viral infection that affects not only birds but human beings and a few other animals. The medical term for this condition is known as avian influenza. Not all species of this virus can be transmitted to human beings. But a few species have been identified that pose a risk for humans and birds. The virus spreads to human beings during the handling of birds, especially domesticated species. Bird flu presents with similar symptoms as influenza, but if it is left untreated, it may develop into a severe form. 


Bird flu is caused by influenza type A viruses. These viruses are carried by wild birds, particularly water birds such as ducks, swans, etc. These birds release this virus in their feces, by which it spreads to other birds. Migratory birds can carry the virus and spread it to other countries worldwide. The most common type of bird flu virus that gets transmitted to human beings is H5N1. Its first case was discovered in 1997. In the early years, this virus was responsible for around 60% of deaths in infected people.

It spreads to humans when they are handling infected bird feces or secretions. Domesticated birds such as hens, chickens, turkeys, etc., are more easily infected by this virus. Eggs and the meat of an infected bird can only be consumed after cooking it properly. Raw eggs or raw meat from an infected bird can also transfer the virus to humans. This virus cannot be spread by human-to-human contact, but the risk may exist in the future.

Risk Factors And Epidemiology

Those at the highest risk of bird flu are poultry farmers. This is because they have to handle birds’ excretions or secretory products. The H5N1 virus can survive for long periods, even on contaminated surfaces. People who work close to birds are at high risk. Vets or doctors that deal with infected birds or humans are also at risk. If you are traveling to an area with active cases of bird flu, you may catch this virus through eggs or poultry. People who eat runny eggs or undercooked meat of birds may also develop this condition if the birds are infected.

Bird flu can infect human beings of all ages, but it is seen more often among young children and older adults (over the age of 60). This virus has spread among regions of Asia, Africa, and a few other countries. The incidence is low in the United States, but the risk may be present. 

Signs And Symptoms

If you get infected by the H5N1 virus, you will begin to develop typical flu-like symptoms in a few days. The exact incubation period of this virus has not been identified yet, but it is estimated to be between 3 to 10 days. The symptoms include fever, cough, diarrhea, headache, sore throat, runny nose, and generalized weakness. If the infection continues to progress to a severe form, it may lead to other complications, including eye infections, pneumonia, acute respiratory distress, or inflammation of the heart and brain. The eventual consequence of these complications is death if the condition is not diagnosed and treated on time. 


Diagnosis of bird flu begins with acquiring a proper history. If you have worked close to birds or traveled to a region with a possible bird flu infection, make sure to mention it to your doctor. Your doctor may also perform a physical examination to check the vitality of your organs such as lungs, heart, brain, kidneys, etc. This virus can be identified by viral serology tests, viral culture tests, rapid antigen testing, polymerase chain reaction (PCR), and a few other techniques. The appropriate test will be chosen by your doctor. Blood tests, nasopharyngeal culture, and chest x rays may also be done to determine the extent of the infection. 

Differential Diagnosis

The symptoms of bird flu are very similar to regular flu and other respiratory tract diseases. These can include common cold, rhinovirus infection, dengue fever, coronavirus, ebola, herpes virus infection, anthrax, streptococcal infection, asthma, chronic obstructive pulmonary disease, emphysema, pericarditis, pulmonary embolism, and other conditions. 


The first line of treatment for bird flu is antiviral drugs. In the majority of the cases, bird flu is treated with oseltamivir or zanamivir. These medications can help in reducing the severity of bird flu symptoms. If you have symptoms of bird flu, these drugs are prescribed to be taken within the first 48 hours. Your doctor may also prescribe these drugs to your close family members or caretakers to prevent the risk of infection. Like all other infections, rest and intake of fluids are necessary until complete recovery has occurred. If you have any severe symptoms, you may get hospitalized for a few days, where your organs will be monitored.

Oseltamivir and zanamivir are the only recommended antiviral drugs for the treatment of bird flu. Amantadine is another antiviral drug that is no longer used to treat this infection because many mutant variations of this virus have developed resistance. 


Patients with flu-like symptoms and no severe complications recover well from this infection within a week. If early complications develop, the risk of fatality is increased. This occurs due to improper functioning or failure of organs in an infected patient. 


Bird flu can be prevented by limiting exposure to infected birds. Poultry workers and others who work closely with birds should be given special instructions about handling these birds. Safe hygiene measures should be practiced to avoid the spread of this infection. There is a vaccination available for bird flu in some countries, but it is suggested for those at high risk. If active cases are going around, avoid going to open poultry markets or eating undercooked poultry products. 

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on April 29, 2023.



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