Flu (Influenza): Symptoms, Causes, Treatment & Prevention

 

Flu (Influenza):

The influenza virus is the source of the common respiratory disease known as the flu. Fever, headaches, body pains, coughing, and runny or stuffy noses are common symptoms. If you are pregnant or have an underlying medical condition, you run the chance of experiencing major consequences. The best approach to prevent contracting the flu is to get vaccinated each year.

What is flu (influenza)?

The influenza virus causes the sickness known as the flu. It produces symptoms that can be rather severe, including fever, sore throats, head and body aches, and respiratory issues. Winter is the most dangerous season for flu cases because so many individuals might become ill at once (an epidemic).

A highly contagious viral infection of the respiratory system, influenza (flu) can result in severe illness and sometimes life-threatening complications, such as pneumonia. Individuals of various ages are impacted. Typically, the flu is contracted by breathing in virus-containing cough and sneeze droplets.

Sometimes the illness can kill even healthy people. Certain groups of Victorians—young children, the elderly, pregnant women, Aboriginal and Torres Strait Islander people, persons with compromised immune systems, and people with ongoing medical conditions—are more vulnerable to serious illness and flu-related complications.

 Symptoms:

The flu can at first seem to be a cold with a runny nose, sneezing, and sore throat. Most colds begin slowly. However, the flu usually comes quickly. Furthermore, although a cold can be unpleasant, the flu typically makes you feel considerably worse.

Common flu symptoms include chills, sweats, and aching muscles in addition to a fever, however, these are not always present.

Other symptoms consist of:

• Headache
• Persistent cough, dry
• Difficulty breathing
• Weakness and tiredness
• Stuffy or runny nose
• Sore throat
• Eye pain

vomiting or diarrhea (usually limited to children).

 Also Read: 12 Best Home Remedies for Cold and Flu

Causes:

Flu is caused by the influenza virus. The three most prevalent kinds of influenza that infect humans are A, B, and C. Influenza A and B have more severe symptoms and are seasonal, with the majority of cases occurring in the winter. Influenza C doesn't have severe symptoms, and its annual case count is rather constant. It is also not seasonal.

Both the bird flu and the H1N1 ("swine flu") strains of influenza A.

Viruses are what cause influenza. When a person who has the infection coughs, sneezes, or talks, the viruses spread through the air in droplets. The droplets are directly inhaled. Alternatively, the germs can enter your body by contact with an object—like a computer keyboard—and then enter your mouth, nose, or eyes.

It is possible that a person infected with the virus can spread to others from one day before symptoms appear to five to seven days after they do. Children and others with weakened immune systems might spread the disease a little bit longer.

Factors at risk:

Your chance of getting the flu or how it affects you could be increased by the following factors:

• Years aged. Poorer outcomes from seasonal influenza are more common in young children, particularly in those under the age of 12 months. Additionally, adults above 65 tend to have worse outcomes.

• Conditions to work or residence. People who work or reside in places where a large number of people live, such as nursing homes, are more susceptible to contracting the flu. Additionally, hospital patients are more at risk.

• Weakened immune system. A weakening of the can result from treatments for cancer, anti-rejection medicines, chronic steroid usage, organ transplants, blood malignancy, or HIV/AIDS. This may raise the risk of problems and make it simpler to contract the flu virus.

• Chronic illnesses. Complications from influenza may be more likely in people with chronic illnesses. Asthma and related lung conditions, diabetes, heart illness, diseases of the neurological system, history of stroke, metabolic disorders, airway issues, and kidney, liver, or blood ailments are a few examples.

• Ethnicity or race. People who identify as Black, Latino, American Indian Alaska Native, or both may be more susceptible to influenza-related problems in the US.

• Use of aspirin in those under 20. Reye's syndrome can occur in individuals under the age of twenty who are on long-term aspirin therapy and have an influenza virus infection.

• Pregnancy. Influenza problems are more common in pregnant women, especially in the second and third trimesters of pregnancy. Up to two weeks after the baby is born, there is still a risk.

• Obesity. Flu complications are more common in people with a body mass index (BMI) of 40 or higher.

 How is a case of flu diagnosed?

In addition to taking a sample of mucus from your nose, your physician will listen to your symptoms to diagnose the flu. To check for influenza, they will insert a long stick with a soft tip—a swab—into your nose. Your physician may send the sample to a lab, where results will be available in a day or two, or results could take a days or two to come back.

  How is the flu treated?

Under specific conditions, providers can use antiviral medications to treat the flu. Antivirals may reduce the severity of your illness and lower your chance of developing a serious condition. Many people can recover from the flu without using prescription drugs. Antivirals are prescribed by providers if you:

• Had symptoms for less than 48 hours. If you start antivirals after two days of symptoms, they are less likely to be effective. Your body has already begun to use its antibodies to combat the virus, which has multiplied in number.

• Have an underlying sickness or run at risk of becoming severely ill.

• Antivirals may still be prescribed by doctors if your symptoms have persisted for more than 48 hours.

• PAossess severe symptoms, even if you haven't been well for 48 hours.

• Live with or provide care for those who are at risk for serious flu complications.

Which drugs are used to treat the flu?

Antiviral medications for influenza consist of:

• Tamiflu® (oseltamivir phosphate). Oseltamivir is taken orally as a tablet or liquid. Usually, you take it for several days.

•  Zanamivir®. Using an inhaler, you inhale zanamivir through your mouth. Usually, you must take it for several days. It is not recommended for those with breathing issues like COPD or asthma to use zanamivir.

• peramivir. Via an IV, your doctor administers peramivir to you directly into your veins. Peramivir usually only needs to be taken once.

•   Boloxavir marboxil is taken orally as a tablet or liquid. There is just one dose that you take. If you are expecting, nursing a baby, are in the hospital, or have certain medical conditions, baloxavir marboxil  is not advised.

before beginning an antiviral drug, disclose to your clinician any existing medical issues.

Side effects of the medication:

While the side effects of each antiviral drug vary, nausea and diarrhea are frequently experienced. Medication inhaled can result in bronchospasms, which are spasms that constrict and stiffen your airways.

Prevention:

Getting a flu vaccine yearly is the most effective method of preventing the illness. Vaccines train your immune system how to recognize and fight viruses before they cause illness. It is important to get vaccinated against the influenza virus each year since it has the potential to alter (mutate) slightly.

Vaccination lowers your risk of developing a serious illness, even if you contract a different strain of the flu than what is included in the vaccine. You can receive the flu shot from your provider as a shot or as a mist that they spray into your nose.

Here are some more strategies to lower your chance of contracting the flu:

• Use soap and water to often wash your hands. Use an alcohol-based hand sanitizer in place of soap and water if you are unable to do so.
• When you cough or sneeze, cover your mouth and nose. Instead of using your bare hand to cough or sneeze, use your elbow or a tissue.
• If you or someone else has the flu or any infectious sickness, stay away from other people.
• If you can't avoid being around others because you're unwell, think about donning a mask.
• Avoid touching your lips, nose, eyes, or face.
• Do not share food or cutlery with other people (forks, spoons, cups).

Reference:

• Hibberd PL. Seasonal influenza vaccination in adults. https://www.uptodate.com/contents/search. Accessed Aug. 23, 2023.

• Kellerman RD, et al. Influenza. In: Conn's Current Therapy 2023. Elsevier; 2023. https://www.clinicalkey.com. Accessed Aug. 23, 2023.

• Centers for Disease Control and Prevention. Influenza (Flu) (https://www.cdc.gov/flu/index.htm). Accessed 10/11/2022.

• Merck Manuals. Influenza (https://www.merckmanuals.com/professional/infectious-diseases/respiratory-viruses/influenza). Accessed 10/11/2022.

• National Foundation for Infectious Diseases. Flu (Influenza) (https://www.nfid.org/infectious-diseases/influenza-flu/). Accessed 10/11/2022.

• Neuzil KM, Wright PF. Influenza. In: Loscalzo J, Fauci A, Kasper D, Hauser S, Longo D, Jameson J, eds. Harrison’s Principles of Internal Medicine. 21st ed. McGraw Hill; 2022.