Influenza, commonly known as the flu, is a respiratory illness caused by viruses. There are many different types of flu, from swine flu to the most feared avian flu. This article, however, deals only with the so-called common or seasonal flu. The flu season usually starts in the fall and subsides in late spring. Because of its seasonality, the flu season differs between the Northern and the Southern hemisphere.
On the global scale, flu can affect tens of millions of people and cause 250,000 to 500,000 deaths each year. The United States CDC gives the following statistics. Yearly 5 to 20% of the population get the flu, 200,000 cases are hospitalized due to severe flu complications and 36,000 cases prove to be fatal. Annual healthcare costs approaches US$10 billion
THE FLU is caused by types A, B and C. Each type consists of different subtypes and substrains with A and B being responsible for most epidemics.
(1) Influenza A viruses are of subtypes based on two proteins on the surface of the virus: the hemagglutinin (H) and the neuraminidase (N). The current subtypes of influenza A viruses in humans are A (H1N1) and A (H3N2).
(2) Influenza B viruses do not have subtypes but can be further broken down into different strains.
(3) Influenza C seems to be relatively benign compared to the first two and is not as contagious.
Like many viruses, influenza viruses change with time producing new strains each season. This change occurs by antigenic drift or shift.
(1) Antigenic drift is slow and can lead to new strains after several seasons and is the typical change observed in influenza type B viruses but can also occur in type A.
(2) Antigenic shift happens abruptly and creates a major change that can lead to a new subtype but only occurs in type A.
The influenza viruses attack the epithelial cells lining the respiratory tract starting from the nose, throat, and down to the lungs. They do this by binding using hemagglutinin and neuraminidase proteins on the cells' surface.
Influenza symptoms may be mild to severe to life-threatening. Symptoms can include high fever, headache, chills, sore muscles, fatigue, dry cough, red, watery eyes, sore throat and runny or stuffy nose. The so-called "tummy flu" symptoms may also occur in children, which include abdominal pain, vomiting, and diarrhea.
The flu symptoms shouldn't be confused with the ordinary cold, which is another respiratory illness. A cold usually doesn't cause high fever, muscle pains or stomach symptoms.
The incubation period of the flu can vary from a few days to a week. During this "asymptomatic period", the infected person is already a carrier of the disease and is therefore highly contagious. The flu can last from a few days to less than two weeks. However, in certain cases, complications can develop which are potentially life-threatening. Some of these complications are bronchitis, pneumonia, sinusitis, and ear infections. Anybody can get the flu but those who are highly susceptible to the flu are young children, the elderly and those with existing chronic health conditions and weakened immune systems.
Flu is very contagious. Direct transmission occurs from person to person via droplets that are released when a person coughs or sneezes. Indirect transmission happens when droplets from an infected person are transferred to inanimate objects, which are then touched by another person.
Flu-like symptoms can also occur with many other diseases. It is therefore sometimes difficult for doctors to diagnose the illness. There are many laboratory tests which can confirm whether a person has the flu or not but they cost money and time and are therefore impractical. However, in times of outbreaks and epidemics, it is important to perform tests. Usually, flu cases are diagnosed based on tests performed in a few individuals within a group. If one or two persons test positive for the flu in a closed environment, then the likelihood of subsequent illnesses within the group as being flu is rather high. Samples for flu testing are usually secretions from the nose and the throat, collected either by sterile swab, nasal wash, or aspiration. There are rapid influenza tests which can give results in 30 minutes. The tests are 70% sensitive in detecting the flu and are prone to false negatives. Another alternative is the more reliable but time consuming viral culture which takes about 3 to 10 days.
Several antiviral pharmacological agents have been approved for the treatment of the flu. Because of the seasonal changes in the types and strains of influenza viruses the recommended anti-flu drugs may change. This season, Tamiflu is the choice for treatment and chemoprophylaxis of persons aged 1 year and older and Relenza is approved for treatment of persons aged 7 years and older. Currently, the CDC discourages the use of previously used anti-flu drugs such as Amantadine and Rimantadine because the current circulating strains of flu viruses are resistant to these drugs.
The ultimate preventive measure against the flu is vaccination. However, again due to the constantly changing nature of the influenza viruses, flu vaccines do not afford 100% and lifetime immunity against the flu. Each season, flu vaccines are updated by adding strains collected and identified from the previous season. Flu vaccines contain different strains of the influenza types A and B but not type C.
Based on the 2005 guidelines of the Federal Advisory Committee on Immunization Practices (ACIP), annual flu shots are recommended for children aged 6 months to 5 years old and adolescents up to 18 years old. Vaccination is also highly recommended for people in key professions which may expose them to the infection and spread it to others. These include health care professionals and those working and living in closed units such as dormitories. Flu shots are usually given prior to flu season and afford protection for about a year. However, it takes about two weeks before the protection kicks in.
Over the years, several types of flu vaccines have been developed.
(1) The intranasal vaccine is the live, attenuated influenza vaccine (LAIV) made from living but weakened flu viruses. LAIV is prescribed for people aged 2 to 49 years old. LAIV should not be given to pregnant women, children under 2 years old, adults above 40 years old, and chronic medical conditions including compromised immune system disorders.
(2) The inactivated vaccine, the common flu shot is made from different strains of killed flu viruses. This vaccine is recommended for children from 6 months to 18 years old as well as those older than 50 years old. In addition, people who are not qualified to receive LAIV (as listed above) are recommended to have this vaccine.
Like all pharmacological agents, flu shots can have some side effects. Most of these side effects are mild. Rare severe side effects, mainly in the form of allergic reactions have been reported.
Some inactivated flu vaccines have contained thimerosal in the past, a form of mercury used as preservatives for vaccines. In recent years, there have been concerns about the link between thimerosal and autism in children. This controversy continues although no ample scientific evidence is available to prove this link.
Perhaps the main shortcoming of the flu shot is its efficacy, which is highly dependent on how well the vaccine is matched to the circulating influenza viruses of that season. For this reason, the efficacy of the vaccine in protecting healthy adults from the flu is only 70 to 90% and even less in children and the elderly.
The Global Influenza Surveillance Network (GISN) was set up in 1952 and currently includes more than 110 laboratories in 83 countries. It has recently set up FluNet, a web-based tool for surveillance, reporting, and alert mechanisms. The European Influenza Surveillance Scheme (EISS) issues a weekly report on influenza activity in 30 countries. It collects data from a network of more than 25,000 sentinel doctors covering a total population of 498 million people in Europe. In the US, the CDC is responsible for national influenza surveillance and is dependent on reports from more than 1500 sentinel doctors.
Google Flu Trends, being the new kid on the block, claims that it can estimate flu activity up "to two weeks faster than traditional flu surveillance systems" and bases its predictions on the number of people searching for flu-related topics. Actually its data compared well with the CDC's. Google is now working together with the CDC in flu surveillance and their work has been published in the prestigious scientific journal Nature. Google Flu Trends also presents the data in graphs, maps, and animations which are easy to comprehend by the general public.
Don't forget the CDC's initiative "Take 3" Steps To Fight The Flu; take time to get a flu vaccine, take everyday preventive actions and take flu antiviral drugs if your doctor recommends them.
And if you are still unlucky and get the flu, stay home from work or school including limiting contact with others, wash your hands often with soap and water and avoid touching your eyes, nose or mouth.
To say that Americans are obsessed with dieting is an understatement! Pick up any magazine, tune-in or turn-on any source of advertising and you're bombarded with the latest diet schemes and food fads. More often than not, they are endorsed by some familiar Hollywood celebrity, or promoted using some other cleaver technique.
It's no mystery that the weight-loss industry has built a thriving empire. In America, for example, we spend about 35 billion dollars every year on an assortment of weight loss products and plans. In addition, we spend another 79 billion dollars for medication, hospitalization, and doctors to treat obesity-related problems. Even with this, the obesity epidemic continues to spread. Sadly, we have become the heaviest generation in our Nation's history.
The National Center for Health Statistics reports that we have some very good reasons to be concerned about our weight-gain. Americans, for example are packing-on the pounds faster than ever before and weight-related medical problems are taking center stage. Diseases like heart disease, diabetes and yes...even certain forms of cancer have all been linked to obesity.
Here are a few of the surprising statistics about our weight:
- A whopping 64 percent of U.S. adults are either overweight or obese. That's up approximately 8 percent from overweight estimates obtained in a 1988 report.
- The percent of children who are overweight is also continuing to increase. Among children and teens ages 6-19, 15 percent or almost 9 million are overweight. That's triple what the rate was in 1980!
- Nearly one-third of all adults are now classified as obese. At present, 31 percent of adults 20 years of age and over or nearly 59 million people have a body mass index (BMI) of 30 or greater, compared with 23 percent in 1994.
(The BMI is a number that shows body weight adjusted for height. For adults, a BMI of 18.5 - 24.9 is considered normal. A BMI of 25.0 - 29.9 is overweight and 30.0 or above, is considered obese.)
Modern life both at home and at work has come to revolve around moving from one "seated" position to another: whether it's television, computers, remote controls, or automobiles, we seem to be broadening the scope of our inactive endeavors.
At times, life seems to have gotten almost too easy! For entertainment, we can now just sit-down, dial-up our favorite TV program or DVD movie and enjoy hours of uninterrupted entertainment...
And all those simple calorie burning activities that were once a normal part of our daily routine not so long ago? Long gone! You know the ones I'm talking about...activities like climbing stairs instead of using escalators and elevators. Or, pushing a lawn mower instead of riding around on a garden tractor. And what about that daily walk to school? Now, our kids complain when the school bus happens to be a few minutes late getting to the bus stop!
Along with the convenience of our affluent lifestyle and reduction in energy expenditure, have come changes in our diet. We are now consuming more calorie rich and nutrient deficient foods than ever before.
Here are a few examples of what we were eating in the 1970's compared to our diet today (information is taken from a recent U.S. Department of Agriculture survey):
- We are currently eating more grain products, but almost all of them are refined grains (white bread, etc.). Grain consumption has jumped 45 percent since the 1970s, from 138 pounds of grains per person per year to 200 pounds! Only 2 percent of the wheat flour is consumed as whole wheat.
- Our consumption of fruits and vegetables has increased, but only because the U.S.D.A. includes French fries and potato chips as a vegetable. Potato products account for almost a third of our "produce" choices.
- We're drinking less milk, but we've more than doubled our cheese intake. Cheese now outranks meat as the number one source of saturated fat in our diets.
- We've cut back on red meat, but have more than made up for the loss by increasing our intake of chicken (battered and fried), so that overall, we're eating 13 pounds more meat today than we did back in the 1970s.
- We're drinking three times more carbonated soft drinks than milk, compared to the 1970's, when milk consumption was twice that of pop.
- We use 25 percent less butter, but pour twice as much vegetable oil on our food and salads, so our total added fat intake has increased 32 percent.
- Sugar consumption has been another cause of our expanding waistlines. Sugar intake is simply off the charts. According to the U.S. Department of Agriculture, people are consuming roughly twice the amount of sugar they need each day, about 20 teaspoons on a 2000 calorie/day diet. The added sugar is found mostly in junk foods, such as pop, cake, and cookies.
- In 1978, the government found that sugars constituted only 11 percent of the average person's calories. Now, this number has ballooned to 16 percent for the average American adult and as much as 20 percent for American teenagers.
The days of the wholesome family dinners so near and dear to our hearts, where we all sat around the kitchen table to discuss events of the day, are now a part of our sentimental past. They have been replaced by our cravings for take-out and fast-food. We have gradually come to accept that it's "OK" to sacrifice healthy foods for the sake of convenience and that larger serving portions mean better value.
And, since I have been throwing-out statistics, here's one more: Americans are consuming about 300 more calories each day than we did twenty years ago. We should actually be eating less because of our decreased activity level, but instead are doing the opposite!
Decide TODAY that healthy eating and exercise habits will become a permanent part of your life!
Begin to explore your values and thoughts and other areas of your life where change may be required, and then take action. Begin slowly, but deliberately to make improvements in the areas you identify. And remember, it has taken a very long time to develop your habits, and it will take some time to undo them'so be patient!
Both Katt Mollar & John Neyman, Jr. are contributors for EditorialToday. The above articles have been edited for relevancy and timeliness. All write-ups, reviews, tips and guides published by EditorialToday.com and its partners or affiliates are for informational purposes only. They should not be used for any legal or any other type of advice. We do not endorse any author, contributor, writer or article posted by our team.
Katt Mollar has sinced written about articles on various topics from Food And Drink, Types of Cancer and Candida Infection. The article It's Flu Season Somewhere - What's The Scoop may be found in its entirety with references and links on