Aetiology
The flu, also known as influenza, is caused by the influenza virus. The influenza virus belongs to the Orthomyxoviridae family, and there are several influenza virus subtypes that can cause illness in humans, including viruses A, B, and C.
The flu spreads from person to person through the air, when someone infected coughs, sneezes or talks, and respiratory droplets spread through the air and are inhaled by other people. It can also spread when a person touches a surface contaminated by the virus and then touches their nose, mouth, or eyes.
The etiology of influenza can also be influenced by factors such as age, a person’s overall health, immune system, previous exposure to the virus, and other environmental factors.
The influenza virus is a highly mutable virus, meaning it can change its genetic structure quickly and evade the human immune system. Because of this, the flu virus is constantly changing, and flu vaccines need to be updated each year to accommodate new circulating strains.
Clinical manifestations
The clinical manifestations of influenza, also known as influenza, can vary in intensity and duration, but usually include some or all of the following symptoms:
High fever (above 38°C)
Dry cough
Sore throat
Nasal congestion
Headache
Muscle and body aches
Extreme fatigue
Chills and cold sweats
Loss of appetite
Flu symptoms can come on suddenly and can last for several days, although most symptoms usually go away after a week. In some cases, fatigue and weakness may persist for several weeks after infection.
In addition to the symptoms mentioned above, the flu can also cause serious complications in some people, especially those with weakened immune systems, such as the elderly, young children, and people with chronic illnesses. Complications of influenza can include pneumonia, ear infections, sinusitis, and exacerbations of chronic diseases such as chronic obstructive pulmonary disease (COPD) and asthma.
In severe cases, the flu can cause hospitalization and, in very rare cases, even death. Therefore, it is important to seek medical attention if flu symptoms occur and if you belong to a risk group.
Diagnosis
Diagnosis of influenza, also known as influenza, is based on a combination of clinical symptoms and laboratory tests.
Your doctor may make a diagnosis of the flu based on the presence of typical clinical symptoms, such as fever, cough, headache, and muscle aches. However, because flu symptoms can be similar to those of other respiratory illnesses, such as the common cold, pneumonia, or bronchitis, lab tests may be needed to confirm the diagnosis of the flu.
The most common laboratory tests to diagnose influenza are polymerase chain reaction (PCR) tests and antigen tests. These tests look for the presence of the flu virus in samples of respiratory secretions, such as nasal mucus or saliva. The sample is taken by swab in the nose or throat and sent to the laboratory for analysis.
PCR tests are the most accurate and can detect the flu virus in the early stages of infection, while antigen tests are less accurate and are usually used in cases of community-confirmed influenza. In some cases, viral culture tests may be performed to confirm the diagnosis of the flu, but these tests are less common and take longer to get results.
It is important to receive a proper diagnosis of influenza to receive proper treatment and to prevent the spread of the disease to others.
Differential diagnosis
The differential diagnosis of influenza, also known as influenza, includes other respiratory illnesses that may have similar symptoms. Some of the illnesses that can be confused with the flu include:
Common cold: The common cold is also a viral respiratory illness, but usually has milder symptoms than the flu. Symptoms of the common cold include nasal congestion, sore throat and cough, but fever is less common and is usually lower than in the flu.
Pneumonia: Pneumonia is a bacterial or viral infection of the lungs that can present flu-like symptoms, including fever, cough, and headache. However, symptoms of pneumonia are usually more severe and may include shortness of breath and chest pain.
Bronchitis: Bronchitis is an inflammation of the bronchi that can be caused by viruses or bacteria and can present flu-like symptoms, such as cough and fever. However, the cough in bronchitis is usually more persistent and can last for several weeks.
Asthma: Asthma is a chronic disease that causes inflammation and constriction of the airways, which can present flu-like symptoms such as coughing and shortness of breath. However, asthma symptoms are generally more persistent and can be triggered by factors such as exercise or exposure to allergens.
Covid-19 and the Flu
COVID-19, caused by the SARS-CoV-2 virus, can also present flu-like symptoms, which can make differential diagnosis difficult. Some of the common symptoms of COVID-19 include fever, cough, sore throat, fatigue, and muscle aches. However, COVID-19 can also cause other symptoms, such as loss of sense of smell or taste, diarrhea, and shortness of breath, which are not common in the flu.
In addition, COVID-19 can cause serious complications in some people, especially those with chronic illnesses or weakened immune systems. These complications can include pneumonia, multiple organ failure, and abnormal blood clotting.
Because the flu and COVID-19 can have similar symptoms, it is important for a healthcare professional to make a proper diagnosis using laboratory tests to distinguish between both diseases and provide appropriate treatment. In addition, prevention measures, such as wearing masks, social distancing, and hand washing, are important to prevent the spread of both flu and COVID-19.
It is important for a healthcare professional to make a proper diagnosis to identify the underlying disease and provide appropriate treatment.
Flu Treatment
Flu treatment focuses on relieving symptoms and reducing the duration of illness. Common treatments include:
Antivirals: Antivirals are medications that can help reduce the duration and severity of flu symptoms, especially if taken within the first 48 hours after the onset of symptoms. Examples of antivirals include oseltamivir (Tamiflu) and zanamivir (Relenza).
Analgesics and antipyretics: Analgesics and antipyretics such as acetaminophen (acetaminophen) and ibuprofen can help relieve pain and reduce fever associated with the flu.
Rest and hydration: Getting plenty of rest and drinking plenty of fluids, such as water, tea, or soup, can help relieve flu symptoms and prevent dehydration.
Cough and nasal congestion medications: Over-the-counter medications such as decongestants and expectorants can help relieve cough and nasal congestion.
Importantly, antibiotics are not effective in treating the flu, as the flu is caused by a virus and antibiotics are only effective in treating bacterial infections.
In severe cases, such as pneumonia or respiratory failure, hospitalization and more intensive treatment, such as administration of oxygen and other medications to support respiratory function, may be required.
It is important to seek medical attention if symptoms worsen or if complications occur, especially in people with weakened immune systems, such as the elderly, young children, or people with chronic illnesses.
