Viruses are infectious pathogens that are able to invade a large number of living organisms. Birds can become infected with diseases caused by influenza viruses, which spread to birds as well as to humans from a distance. Avian influenza is one such disease. In this article, we present the symptoms of bird flu and talk about its diagnosis and treatment.
Avian influenza is a disease caused by influenza A viruses. It is spread among birds through saliva, mucus secretions and faeces. However, avian influenza has also been reported to occur in humans. The World Health Organization (WHO) has reported two cases of avian influenza in China in 2017.
Experts have verified more than 12 different strains of the virus, only three of which have caused bird flu in humans. However, the constant transformation of the virus can increase the incidence of the disease in humans in the long run.
Symptoms of avian influenza
Symptoms of bird flu usually begin to appear two to seven days after exposure to the virus. Symptoms can range from mild to severe and life-threatening.
In most cases, bird flu has resembled the common flu, which can cause the following symptoms:
- Respiratory problems
- General nausea
- Nasal congestion
- Muscle and joint pain
- Unexplained fatigue
- Red eyes and increased watery eyes
Mild symptoms also include digestive problems such as nausea, vomiting, diarrhea, and abdominal pain. A small proportion of patients have experienced some of the following conditions:
- Acute respiratory distress syndrome
- Altered state of consciousness
What causes bird flu?
Avian influenza is caused by influenza A and its various mutagenic variants. Experts have identified H5N1, H7N9, and H5N6 strains that can occur in humans and of which H5N1 has been the most studied. More than 165 cases of avian influenza were caused by the H5N1 strain between 2003 and 2006, with a mortality rate of more than 50%.
A person can become infected with bird flu when the virus comes in contact with the mucous membranes of the eyes, nose or mouth, or when a person inhales droplets or dust containing the virus. In addition, direct contact with a bird with avian influenza greatly increases the likelihood of becoming infected.
Studies have also shown that human-to-human transmission is very rare and usually occurs within the family. However, the high human capacity of the virus to adapt may raise concerns about the emergence of a new, more contagious virus strain in the future.
Experts have linked to human-caused avian influenza risk factors associated with dealing with domestic or wild birds. Examples of such birds are chickens, turkeys, ducks and geese.
The probability of avian influenza is then higher in the following cases:
- Working with poultry or other activities.
- Unhealthy conditions in shops selling poultry products.
- Travel to Middle Eastern countries where bird flu is more common.
- Contact with faeces, faeces or feathers of infected birds.
- Eating poorly cooked bird meat and eggs.
It is estimated that 90% of avian influenza patients are under 40 years of age and have a higher mortality rate in patients aged 10-19 years.
Diagnosis of avian influenza
Detection of human avian influenza infection requires assessment of symptoms and other signs as well as laboratory diagnostic tests. The Center for Disease Control and Prevention (CDC) recommends taking a swab with a swab from the nose and throat during the first few days.
These samples are examined by specialized laboratories and used to identify pathogens through molecular tests or virus culture. In patients who develop more severe symptoms, the physician should take a sample of the lower respiratory tract to confirm the etiology of the virus.
For some patients, it is necessary to test for influenza A virus type antibodies. To do this, two blood samples are taken from the patient: the first at the beginning of symptoms and the second after three to four weeks. It is important to note that the results take several days to complete.
Experts use imaging techniques, such as a chest X-ray, to determine the condition of the bronchi. The study can also be used to assess what treatments can be used for a patient.
The purpose of treatment for avian influenza is to relieve symptoms and eliminate the pathogen virus. In some cases, the use of neuraminidases has been found to be beneficial. These medicines prevent the affected cells from releasing the virus and spreading it to other cells.
Most influenza A and B viruses are sensitized to oseltamivir or Tamiflu, peramivir, zanamivir, or Relenza. However, the CDC has reported that these drugs have developed some resistance to mutations in H5N1 and H7N9 virus strains in Asian patients.
Treatment measures also include proper fluid replacement therapy and the use of antipyretic and analgesic drugs to relieve symptoms.
Recovery from avian influenza
The severity of the disease depends on the virus strain it causes and how much the virus has been able to affect the airways. In general, the disease has a good prognosis. However, some patients experience complications and require special measures.
When diagnosing bird flu, it is important to follow these guidelines :
- Drink plenty of fluids.
- Avoid drinking cold drinks.
- Ventilate the room.
- Wear a mask.
- Rest well.
The disease usually begins to subside a couple of weeks after starting treatment. However, if a patient develops new symptoms or worsening of symptoms, it is very important to re-seek treatment.
Prevention of avian influenza
The aim of preventing avian influenza is to reduce or eliminate risk factors. The key is to avoid any exposure to the virus.
With this in mind, the following recommendations should be followed:
- Avoid contact with wild or waterfowl.
- Do not touch surfaces or objects that may contain bird droppings or secretions.
- Wash your hands with plenty of soap and water if you have touched contaminated surfaces or objects.
- Wear a mask and protective equipment when working with birds, especially indoors.
- Do not eat eggs unless they have been cooked correctly or handled hygienically.
- Be sure to cook the poultry meat at a temperature of at least 75 degrees.
Similarly, if a trip to a country with a high risk of avian influenza virus is planned, open and unhygienic marketplaces should be avoided. Poorly processed poultry products should also not be eaten.
With regard to vaccines, seasonal influenza vaccines do not prevent the spread of avian influenza, but may reduce the risk of associated viral infections. In the United States, for example, there is a safety stock of vaccines against the Asian virus strain, but these vaccines would not be effective against possible mutations.
Avian influenza should not be underestimated
The symptoms of avian influenza are very fragmented and can easily be confused with the symptoms of other flu diseases or influenza. However, if symptoms occur, it is important to seek medical attention to prevent the disease from progressing badly.
If treatment is not sought in time or the patient has received the wrong kind of treatment, bird flu can have fatal consequences. If a patient develops severe respiratory problems or worsening symptoms, it is important to see a doctor immediately.