There are four different types of influenza virus, and these are types A, B, C, and D. The first two types are behind seasonal flu outbreaks across the world, which usually coincide with the winter months. Types A and B can lead to winter epidemics.
These outbreaks can often lead to an increase in hospital admissions, especially in the elderly, sick, and those with a compromised immune system.
Influenza A virus is the culprit behind flu pandemics that sweep across the globe. These can lead to an increase in deaths, especially in the medically vulnerable.
For a pandemic to occur, a new influenza A virus must emerge and quickly infect people. The fact that new influenza A viruses are behind pandemics is mostly down to there being little to no natural immunity in communities around the world.
The symptoms of an influenza A virus infection can be severe and need hospital intervention. Typical symptoms include fever, fatigue, and body aches, including joint and muscle pain. Coughing and sneezing may be accompanied by a sore throat and difficulty in breathing if the lungs have been affected.
Less common symptoms can include stomach pain, loss of appetite, nausea, vomiting, and even diarrhoea. These last two symptoms can lead to dehydration.
The causes of influenza A infection are mostly due to coming into contact with the virus or being in close contact with an individual who is infected. Close contact between infected individuals in enclosed spaces such as offices and public transport only helps to quicken the spread of the infection.
Since these viruses are constantly changing, seasonal flu epidemics are a major risk factor to public health, even though flu vaccines are out there. A constant risk factor is that a strain of influenza A virus can also one day cause another global pandemic.
Healthwise, those most at risk from an influenza A outbreak are the elderly, sick, and those who may be receiving immunosuppressant drug treatment.
Diagnosis of an influenza A virus infection is usually made by the symptoms that are present. A fever and respiratory distress, including body aches, are classic flu symptoms. Sometimes a nasal or throat swab can be taken to confirm the presence of the virus.
Treatment is usually with rest, but if the illness is severe, then antiviral drugs can be prescribed. If the virus leads to a bacterial infection, then a course of antibiotics can help prevent the secondary infection from becoming worse. There are over-the-counter treatments for headaches, coughs, and fevers.
It is hard to prevent influenza A due to the changing nature of the virus. Yearly flu vaccines can offer protection against severe illness. Otherwise, the best course of action is to avoid potential carriers of the virus during peak flu season.
Some natural remedies, including a healthy, nutrient-rich diet, may help to boost the immune system, which in turn can prevent viruses from taking hold each flu season.