Living with
Influenza

What is Influenza?

Influenza is a highly contagious respiratory disease caused by the influenza virus.
Influenza occurs in seasonal epidemics, increasing in prevalence in the colder, winter months. Influenza is commonly called the flu; however, it is not the same as the “stomach flu,” or gastroenteritis, which causes diarrhoea and vomiting.

Influenza viruses commonly infect the upper respiratory tract, most commonly the nose and throat (pharynx), but also the sinuses, ears, larynx (voice box), and sometimes the upper airways and lungs. Sometimes, influenza is confused with the common cold.

In most healthy people, the flu causes mild illness. However, the flu can be particularly life-threatening for some, causing severe illness in young children, the elderly and in people of any age who are immunosuppressed or who have certain underlying conditions like heart disease and diabetes.

Influenza viruses are incredibly contagious, meaning they spread from person-to-person very easily. Therefore, practicing good hygiene (especially handwashing) is essential to prevent yourself from catching the flu.
Those who are at highest risk of serious complications from influenza illness should do everything they can to avoid getting infected, including getting their yearly flu vaccine and practicing good hand-hygiene. They should also be treated as soon as possible if complications develop.

How do you know you have the flu?

Initially when you have the flu, you may think it is a common cold. Flu symptoms tend to come on suddenly though, while a cold usually develops gradually over a few days. As a rule, flu symptoms generally feel worse or more severe than cold symptoms.

 

You typically start to display symptoms one to four days after being exposed to, and infected with, the influenza virus. The average incubation period of the flu is two days.
Typically, symptoms gradually improve over two to five days, but it is not uncommon to feel run down for up to one to two weeks.

If you have the flu, you may experience some or all of these symptoms:

  • Fever over 37.8 ℃ (100 F) or feeling feverish/having chills and sweats. Some people, commonly children, may experience temperatures as high as 40 ℃ (104 F)
  • Body aches/muscle aches (myalgia)
  • Headache (this is usually towards the front of the head or in the face around the eyes)
  • Dry, persistent cough with or without mild chest discomfort
  • Fatigue and weakness
  • Sore throat
  • Red and/or watery eyes
  • Runny or congested nose
  • Some people may experience a racing or fast heartbeat

When to see your doctor:

Most people with the flu will not need to see their doctor and can manage their symptoms at home. However, if you have flu symptoms and are at risk of complications, see your doctor right away.

For adults: Seek medical attention if you have:

  • A fever greater than 38.5 ℃ (101.3 F) and/or lasting five days or longer and/or recurring fever after a fever-free period
  • Severe or unusual shortness of breath and/or chest pain
  • Severe or unusual wheezing
  • Severe sore throat, severe headache or sinus pain
  • Confusion
  • Green, yellow or blood-stained phlegm
  • A flare-up of your asthma symptoms

For children: Seek medical attention right away if your child has any of the following:

  • Symptoms lasting more than 10 days
  • A fever of 38 ℃ (100 F) in newborns up to 12 weeks
  • Rising fever or fever lasting more than two days in a child of any age
  • Symptoms that worsen or fail to improve
  • Headache or a stiff or sore neck
  • Severe cough
  • Wheezing
  • Earache
  • Confusion
  • Extreme fussiness
  • Unusual drowsiness or lethargy
  • Lack of appetite.

 

What is the difference between the common cold and the flu?

Many people confuse the common cold and the flu.
The flu is caused by the influenza virus, while the common cold is generally caused by the rhinovirus.

Many symptoms of the common cold and flu are similar; however, people with the cold typically have a milder illness compared to those with the flu; whereas people with the flu usually appear more ill and have a more sudden and extreme onset of illness with fever, significant chills and body aches, headache, a more persistent dry cough and substantial weakness.
There is also more risk of illness worsening and secondary bacterial infection occurring when you have the flu.

What causes the flu?

According to a South African Department of Health report, influenza is responsible for between 6 000-11 000 deaths in the country every year, about half of which are reported in the elderly, and another 30 % of which are accounted for by HIV-positive people.

 

The flu is caused by highly contagious influenza viruses, of which there are three types, designated by the letters A, B and C.
While influenza type C usually only causes a very mild illness, or no illness at all, types A and B are responsible for the large seasonal outbreaks seen yearly during colder, winter months. Influenza type B is usually slightly milder than the more common type A that can cause epidemics when protein receptors (called haemagglutinin, H, and neuraminidase, N, receptors) change/mutate on the viral surface.
The last large influenza outbreak was in 2009, what became commonly known as the “swine flu epidemic,” or “H1N1 2009” representing the type of receptors and year the strain was discovered. In fact, influenza viruses are often found in a host of animal species, including many mammals (like pigs) and birds, in which the viruses can mutate (change genetically) and become infectious to humans (a process known as zoonosis).

 

Typically, during seasonal influenza outbreaks, you become infected when an influenza virus enters your body by your mouth, nose or eyes through droplets in the air when another infected person coughs, sneezes or talks (infected people are usually contagious from about one day before they develop symptoms).

Sometimes infected bodily fluids can land on inanimate surfaces and objects, like eating utensils or desks and doorknobs, that have been touched by infected people. If you touch the contaminated objects or surfaces, the virus transfers onto your hands and you then touch their nose, mouth or eyes, becoming infected yourself. In fact, the influenza virus can live on inanimate objects and surfaces for several hours, remaining as a threat for infection during that time.

 

You are at greater risk of developing influenza and getting serious complications from infection because of the following risk factors:

  • Age: Seasonal influenza tends to affect children younger than five years of age, especially those younger than two years old, and adults 65 years or older more severely.
  • A weakened immune system: Individuals with a poorly functioning immune system and chronic illnesses (like HIV or cancer) are more likely to catch the flu. Also, individuals with excessive fatigue, who do not get enough sleep, or who are under excessive stress may be more susceptible to catching the flu.
  • Chronic diseases: Chronic conditions, including lung diseases such as asthma, diabetes, heart disease and kidney, liver or blood disease, may increase your risk of catching the flu and developing influenza-related complications.
    Influenza can also worsen these conditions if you become infected.
  • Pregnancy: Pregnant women, especially those in the second or third trimesters, as well as recently postpartum women (women who have given birth in the last one to two weeks) are more likely to develop severe influenza-related complications.
  • Smoking: You are more likely to catch the flu and to develop severe complications if you smoke or are often exposed to cigarette smoke. Smoking irritates the mucous membranes of the nose, sinuses and lungs, which may make the respiratory tract more susceptible to infections.
  • Exposure: If you are around many people, such as at work, during conferences or on an airplane, you are likely to be exposed to many influenza viruses. Also, when people are in closed, crowded areas, like hospitals, schools, and day-care centres, there is an increased risk because of close contact between people.
    People who work in hospitals are also more likely to become infected, and this is the same if you are hospitalised for a long period of time.
  • Obesity: If you have a BMI (Body Mass Index, or the relation of your weight to your height) of 40 or greater, then you will have an increased risk of developing complications from the flu.

While the flu tends to be more common in winter, you can get it at any time of the year.

How can vaccines prevent the flu? And what other preventative methods are there?

One of the most effective ways to prevent the flu is to have your yearly flu vaccine.
This can be accessed at your doctor, healthcare provider or pharmacy clinics. Importantly, you must receive this “flu shot,” or vaccination by injection, every year, as new strains appear and become more of a threat with each flu season. The annual flu vaccine is updated yearly to cover three of most common strains expected that season.

 

The flu vaccine is based on killed or inactivated viruses that can cause an immune response, but which CANNOT cause the flu. It can be safely administered to people over the age of six months and to people with a weak immune system or pregnant women. However, those with egg allergies, or with a current fever, should consult their healthcare provider about when and how to get the vaccine.
The vaccine is also highly effective at providing protection against the flu, with research finding efficacy is 70-90 % when strains are well-matched to the vaccine, and, at such times, hospitalisations due to influenza-complications can be reduced by a whopping 90 %.

 

You must also practise basic hygiene and other common-sense practices diligently in order to avoid catching and spreading the flu, including:

  • Wash your hands: You must wash your hands frequently and thoroughly, as this destroys the viruses you may have picked up from contaminated surfaces.
    Teach your children the importance of handwashing.
    Wash your hands with soap and water. If soap and water are not available, use an alcohol-based (at least 60% alcohol) hand sanitizer.
  • Cough hygiene: Cover your nose and mouth when you cough or sneeze to prevent spreading the virus to those around you. A sneeze can spray a fine mist of contagious droplets almost 2 metres far.
    You can cough or sneeze into your elbow, hand or a tissue. Discard used tissues right away. Always wash your hands after coughing or sneezing.
  • Regularly disinfect frequently touched surfaces or objects (like doorknobs, light switches, desks, keyboards and cell phones) with an effective product suitable for that surface.
  • Don’t share personal items like drinking glasses, eating utensils, towels or handkerchiefs with other family members or people you live with.
  • Avoid close contact with anyone who is sick.
  • Keep yourself generally healthy: Eat a healthy and balanced diet and get enough exercise and sleep.
    It is worth remembering that no single food or supplement can prevent you catching the flu; however, nutritional deficiencies are known to cause weakened immune systems and are associated with increased risk of infections. A balanced diet is essential for good immune functioning.
    There are many nutrients (vitamins and minerals) that are involved with the normal functioning of the immune system, including copper, folate, iron, selenium, zinc and vitamins A, B6, B12, C and D. Specifically, zinc and vitamins C and D are known to play a central role in maintaining immunity and are used by immune cells directly to fight off respiratory infections, with supplementation often required in severe disease.
    Immune system benefits may also be gained by using certain supplements containing some plant-derived products like Echinacea and black elderberry.
    Therefore, experts do not recommend any one food or nutrient over another, instead they encourage eating a variety of foods, particularly those rich in vitamins and minerals like fruit and vegetables, to maintain a healthy, balanced diet. You can access delicious and healthy recipes from Cooking from the Heart here.
  • Lifestyle modifications: Stopping smoking or reducing the number of cigarettes you smoke per day, as well as getting enough sleep and managing stress, may decrease susceptibility to acquiring influenza.

 

Can antibiotics be used to treat influenza?

No, antibiotics play no role in treating influenza which is caused by a virus. Antibiotics are only effective against diseases caused by bacteria. Antibiotics can also be dangerous to use if not prescribed properly. Furthermore, using antibiotics when they are not necessary leads to antibiotic resistance.

What treatment is available for the flu?

Most people who get the flu will only have mild illness and may not need to see a doctor as they can treat their symptoms at home.

Home treatment for upper respiratory infections mainly includes getting plenty of rest (bedrest) and keeping hydrated (drinking plenty of water).

 

There are many common over-the-counter medications, such as throat lozenges, throat sprays and cough syrups, which can help relieve symptoms; although, these medications cannot help you get better faster. Gargling with warm saltwater may help relieve a sore throat in some people. Decongestant medications, or nasal sprays, and antihistamines may be used for nasal symptoms, as can humidifiers.
Over-the-counter medications must be taken with care and as directed, as they can have other effects than those desired. Pregnant women should discuss the safety of using over-the-counter medications with their pharmacist or healthcare provider before use.

 

Paracetamol-based and non-steroidal anti-inflammatory (NSAID) medications, such as ibuprofen, are common over-the-counter medicines that can help alleviate and manage fever, sore throat, headache and body pain. Consult your healthcare provider or pharmacist about using these medications.

 

The treatment of the flu in infants and small children is also supportive. It is especially important to allow them to get enough rest and to ensure they do not become dehydrated.
Consult with your doctor or pharmacist about using over-the-counter medication and pain killers in children. You can often get special metered sprays or syrups instead of tablets to treat children with. Pain killer medication, like NSAIDs or those that are paracetamol-based, must only be used in consultation with your pharmacist or healthcare provider, and the dosage will have to be adjusted for your child’s age and weight (these details can often be found on the bottle or medication packaging).

Importantly, do not use aspirin or aspirin-containing medications in children or teenagers before consulting your doctor because it may cause serious, unwanted side-effects.
Finally, most over-the-counter cough and cold and flu medications for infants and young children are not recommended for use in children younger than four years of age.

 

Common alternative treatments to prevent or treat the common cold, include supplements that contain vitamin C, zinc and Echinacea, as well as other herbal remedies. Discuss these treatment options with your pharmacist or healthcare professional before use.

 

What should you know about antivirals for the flu?

Prescription (cannot be brought over-the-counter) medications called “antivirals” can be used to treat certain infections that are caused by viruses, like the flu. Antiviral drugs for the flu are available in many different forms (tablets, liquid, an inhaled powder or an intravenous solution) and are usually prescribed to people at high risk of developing influenza-related complications, such as people with asthma, diabetes or heart disease.

 

Antiviral medications are usually most effective when taken within two days of developing flu symptoms. Antivirals can lessen flu symptoms, reduce disease duration by up to one day and can decrease the risk of developing complications when infected by influenza viruses.

 

The most well-known type if antivirals for the flu are the neuraminidase inhibitors: oseltamivir, commonly known as Tamiflu, is the most well-known antiviral for the flu and is taken as an oral medication, while zanamivir is inhaled through a device similar to an asthma pump and should not be used by anyone with certain chronic respiratory problems such as asthma.
However, varying degrees of resistance is shown towards most of these older types of antivirals; meaning treatment with them may not work and they are, therefore, not prescribed as much anymore. Antiviral medications may produce some mild side-effects like nausea and vomiting, which can be lessened by taking the medications with food.

 

Talk to your doctor or healthcare provider about using antivirals if you have influenza-symptoms and are at risk of developing complications.

What are the complications of influenza?

Young children and older adults, as well as people with chronic disease, are at risk of developing severe complications from influenza infections, usually following from secondary bacterial infections.
Such complications include:

Sources

Statistics: The South African Department of Health. (n.d.) A long and healthy life for all South Africans. The South African Government. Available from: http://www.health.gov.za/index.php/component/phocadownload/category/174-influenza?download=1466:influenza#:~:text=Influenza%20(also%20known%20as%20flu,less%20than%20five%20years%20old.

 

US Centers for Disease Control and Prevention. (2019) About Flu. US National Center for Immunization and Respiratory Disease (NCIRD). Available from: https://www.cdc.gov/flu/about/index.html

 

The American Lung Association. Diagnosing and Treating Flu. Available from: https://www.lung.org/lung-health-diseases/lung-disease-lookup/influenza/diagnosing-and-treating-influenza

 

Davis C. (2018) Influenza (Flu). MedicineNet. Available from https://www.medicinenet.com/influenza/article.htm

 

Health24. (2017) Flu (Influenza). Available from: https://www.health24.com/Medical/Flu/About-Flu/Flu-influenza-20120721

 

Nguyen H. (2020) Influenza. Medscape. Available from: https://emedicine.medscape.com/article/219557-overview

 

Mayo Clinic staff. (n.d.) Diseases and Conditions: Influenza (flu). Mayo Clinic. Available from: https://www.mayoclinic.org/diseases-conditions/flu/symptoms-causes/syc-20351719

 

Mayo Clinic staff. (n.d.) Diagnosis and Treatment: Influenza (flu). Mayo Clinic. Available from: https://www.mayoclinic.org/diseases-conditions/flu/diagnosis-treatment/drc-20351725

 

US Centers for Disease Control and Prevention. (2019) What You Should Know About Flu Antiviral Drugs. US National Center for Immunization and Respiratory Disease (NCIRD). Available from: https://www.cdc.gov/flu/treatment/whatyoushould.htm

 

Infection Control Today. (2003) Sleep Loss May Increase the Risk of Catching the Flu. Available from: https://www.infectioncontroltoday.com/general-hais/sleep-loss-may-increase-risk-catching-flu#:~:text=%22Sleep%20loss%20increases%20an%20individual’s,illnesses%20such%20as%20the%20flu.%22

 

Smolderen K, Vingerhoets A, Croon M, Denollet J. (2007) Personality, psychological stress, and self-reported influenza symptomatology. BMC Public Health; 7:339. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2241613/

 

Wong C, Yang L, Chan K, et al. (2013) Cigarette smoking as a risk factor for influenza-associated mortality: evidence from an elderly cohort. Influenza Other Respir Viruses; 7(4):531‐539. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855151/

 

Harvard Medical School Health Publishing. (2014) How to boost your immune system. Available from: https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system

 

Parker-Pope T. (2020) Can I Boost My Immune System? The New York Times. Available from: https://www.nytimes.com/2020/03/10/well/live/can-i-boost-my-immune-system.html

 

Davison G. (2014) Nutritional and Physical Activity Interventions to Improve Immunity. Am J Lifestyle Med. Available from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124954/

 

Reynolds G. (2020) How Exercise May Affect Your Immunity. The New York Times. Available from: https://www.nytimes.com/2020/03/04/well/move/exercise-immunity-infection-coronavirus.html

 

Campell J. & Turner J. (2018) Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan. Frontiers in Immunology. Available from https://doi.org/10.3389/fimmu.2018.00648

 

Maginni S. et al. (2017) Vitamins C, D and Zinc: Synergistic Roles in Immune Function and Infections. Vitamins and Minerals. Available from: https://www.omicsonline.org/open-access/vitamins-c-d-and-zinc-synergistic-roles-in-immune-function-and-infections-2376-1318-1000167.php?aid=92887

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Sources

Statistics: The South African Department of Health. (n.d.) A long and healthy life for all South Africans. The South African Government. Available from: http://www.health.gov.za/index.php/component/phocadownload/category/174-influenza?download=1466:influenza#:~:text=Influenza%20(also%20known%20as%20flu,less%20than%20five%20years%20old.

 

US Centers for Disease Control and Prevention. (2019) About Flu. US National Center for Immunization and Respiratory Disease (NCIRD). Available from: https://www.cdc.gov/flu/about/index.html

 

The American Lung Association. Diagnosing and Treating Flu. Available from: https://www.lung.org/lung-health-diseases/lung-disease-lookup/influenza/diagnosing-and-treating-influenza

 

Davis C. (2018) Influenza (Flu). MedicineNet. Available from https://www.medicinenet.com/influenza/article.htm

 

Health24. (2017) Flu (Influenza). Available from: https://www.health24.com/Medical/Flu/About-Flu/Flu-influenza-20120721

 

Nguyen H. (2020) Influenza. Medscape. Available from: https://emedicine.medscape.com/article/219557-overview

 

Mayo Clinic staff. (n.d.) Diseases and Conditions: Influenza (flu). Mayo Clinic. Available from: https://www.mayoclinic.org/diseases-conditions/flu/symptoms-causes/syc-20351719

 

Mayo Clinic staff. (n.d.) Diagnosis and Treatment: Influenza (flu). Mayo Clinic. Available from: https://www.mayoclinic.org/diseases-conditions/flu/diagnosis-treatment/drc-20351725

 

US Centers for Disease Control and Prevention. (2019) What You Should Know About Flu Antiviral Drugs. US National Center for Immunization and Respiratory Disease (NCIRD). Available from: https://www.cdc.gov/flu/treatment/whatyoushould.htm

 

Infection Control Today. (2003) Sleep Loss May Increase the Risk of Catching the Flu. Available from: https://www.infectioncontroltoday.com/general-hais/sleep-loss-may-increase-risk-catching-flu#:~:text=%22Sleep%20loss%20increases%20an%20individual’s,illnesses%20such%20as%20the%20flu.%22

 

Smolderen K, Vingerhoets A, Croon M, Denollet J. (2007) Personality, psychological stress, and self-reported influenza symptomatology. BMC Public Health; 7:339. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2241613/

 

Wong C, Yang L, Chan K, et al. (2013) Cigarette smoking as a risk factor for influenza-associated mortality: evidence from an elderly cohort. Influenza Other Respir Viruses; 7(4):531‐539. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855151/

 

Harvard Medical School Health Publishing. (2014) How to boost your immune system. Available from: https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system

 

Parker-Pope T. (2020) Can I Boost My Immune System? The New York Times. Available from: https://www.nytimes.com/2020/03/10/well/live/can-i-boost-my-immune-system.html

 

Davison G. (2014) Nutritional and Physical Activity Interventions to Improve Immunity. Am J Lifestyle Med. Available from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124954/

 

Reynolds G. (2020) How Exercise May Affect Your Immunity. The New York Times. Available from: https://www.nytimes.com/2020/03/04/well/move/exercise-immunity-infection-coronavirus.html

 

Campell J. & Turner J. (2018) Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan. Frontiers in Immunology. Available from https://doi.org/10.3389/fimmu.2018.00648

 

Maginni S. et al. (2017) Vitamins C, D and Zinc: Synergistic Roles in Immune Function and Infections. Vitamins and Minerals. Available from: https://www.omicsonline.org/open-access/vitamins-c-d-and-zinc-synergistic-roles-in-immune-function-and-infections-2376-1318-1000167.php?aid=92887