Influenza ('flu)

What is influenza?

Incidence of influenza

Symptoms of influenza

Transmission of influenza

Infection control for influenza

Prevention / remedies / treatment for influenza

References

What is influenza?

Influenza ('flu) is an infectious disease caused by an influenza virus. It is often confused with the common cold, but 'flu is a more serious disease caused by a different virus.

Influenza viruses evolve rapidly, and a vaccine formulated for one year may be ineffective the next year.

Influenza sometimes leads to pneumonia, an inflammatory infection of the lungs. This can occur directly with the 'flu virus, or indirectly as a secondary bacterial infection.

Most people recover in one to two weeks, those in high-risk groups (see below) may take longer.

Incidence of influenza

Influenza typically spreads around the world in seasonal epidemics. Every winter tens of millions of people get the 'flu, with about three to five million severe cases and 250,000 to 500,000 deaths worldwide each year. (3) Some years a new strain of the virus appears and results in a widespread epidemic (pandemic). Three pandemics have occurred in the last 100 years, killing tens of millions of people.

Poultry on large farms are often vaccinated to protect large flocks. (4)

The highest risk of infection is among children, the elderly, those who have chronic illnesses such as asthma, diabetes and heart disease, or are immuno-compromised. Highest rates of exposure are among health care workers, teachers and those in contact with the general public.

Symptoms of influenza

About a third of people infected with an influenza virus show no symptoms. (6)

Symptoms normally start with a rapid onset one or two days after infection with the virus.

• Chills. The first symptom is usually chills. Sometimes there is shivering.
• Fever. Fever normally follows the chills, with a raised temperature, fatigue and aches and pains.
• Nasal congestion.
• Eyes watering and red.
• Sore throat.
• Muscle pains.
• Headache.
• Cough.
• Nausea or vomiting, particularly in children.
• Diarrhoea and abdominal pain, particularly in children.
• Minor red rash that should disappear in a few days. A severe or longer rash should be investigated as it may indicate a different ailment.

Transmission of influenza

A contaminated person is most infectious 2-3 days after they were infected. They are infectious from the day before they start to show any symptoms and for the next 5-7 days.

Patients shed more infectious viruses when their body temperature is higher, and children shed more viruses than adults.

Most influenza is transmitted through the air by coughs or sneezes into the nose, mouth or eyes of another person. It is also transmitted by touching nasal secretions, contaminated surfaces or handshake, and then touching the mouth, nose or eyes.

A virus can survive for a limited time outside the body. If it is in an air droplet from a sneeze or cough, it will not survive long in dry air or on sunlight. Viruses can survive on hard non-porous surfaces (doorknobs, household items) and money (cash) for a day or two, and for up to two weeks in mucus.

In summary, you are more likely to catch influenza indoors, especially in confined, crowded, airtight spaces. You are less likely to get infected outdoors, especially if there is plenty of fresh air and sunlight.

Influenza virus is inactivated by heating to 56C (133F) for an hour, or much quicker at higher temperatures.

Bird 'flu is usually picked up through contact with bird droppings.

Infection control for influenza

• Influenza viruses can be inactivated by sunlight, disinfectants, soap and detergents. (1, 2)
• Frequent hand washing reduces the risk of infection if you are in contact with infected people.
• Don't touch your eyes, nose or mouth.
• Covering coughs and sneezes.
• Avoiding contact with infected people.
• Staying home yourself if you are sick.
• Sanitising infected surfaces with alcohol, bleach, other disinfectants.

Prevention / remedies / treatment for influenza

• Your best defence against influenza is a healthy immune system. Your immune system needs sufficient cholesterol, and regular exercise through exposure to animals (farm, pets, birds), soil and dirt obtained outside in a natural environment.
• Good sleep and plenty of rest. Going back to stressful work or lifestyle before the body has fully recovered raises the risk of getting chronic fatigue or other long-term complications.
• Diet. Stock-based soups (home-made chicken soup is highly recommended), home-made vegetable juice, high-cholesterol foods.
• Apple cider vinegar.
• BHT.
• Hydrogen peroxide.
• Lysine.
• Vitamin D.
• Drink sufficient water.
• Smoking raises the risk of infection, and of getting more severe symptoms.
• Antiviral drugs have been used to treat influenza, but I suspect they have been ineffective. (5) Pharmaceutical companies have chosen not to publish much of the relevant data that they have. Hiding this information usually indicates a lack of effectiveness. Also, pharmaceutical drugs always have horrible side effects.
• See details of remedies recommended by Grow Youthful visitors, and their experience with them.

References

1. Brankston G, Gitterman L, Hirji Z, Lemieux C, Gardam M. Transmission of influenza A in human beings. April 2007, Lancet Infect Dis 7 (4): 257-65. doi:10.1016/S1473-3099(07)70029-4. PMID 17376383.

2. Suarez, D; Spackman E, Senne D, Bulaga L, Welsch A, Froberg K. The effect of various disinfectants on detection of avian influenza virus by real time RT-PCR. 2003, Avian Dis 47 (3 Suppl): 1091-5.

3. World Health Organisation. Influenza (Seasonal) Fact sheet No.211, April 2009.

4. Villegas, P. Viral diseases of the respiratory system. 1998, Poult Sci 77 (8): 1143-5.

5. Jefferson T, Jones MA, Doshi P, et al. Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. 2012; Cochrane Database Syst Rev 1: CD008965.

6. Fabrice Carrat, Elisabeta Vergu, Neil M. Ferguson, Magali Lemaitre, Simon Cauchemez, Steve Leach, Alain-Jacques Valleron. Time Lines of Infection and Disease in Human Influenza: A Review of Volunteer Challenge Studies. 2008, American Journal of Epidemiology, 167 (7): 775-785.