Cold and Flu Basics

Overview: Colds and the Flu (or Influenza) are terms that are often used interchangeably. Although they are both viral infections of the upper respiratory system, a cold and the flu are separate diseases with different complications and levels of severity.

Causes: Over 200 different viruses can cause the common cold, but rhinoviruses are the most common culprit. Only the influenza virus causes the flu. There are 3 types of influenza virus:

• Type A: Harbored in many different animals, this is the most severe strain, as well as the most common. Antigenic shifts in this strain of influenza virus are responsible for pandemics, which occur every 30 to 40 years. In 918, one pandemic killed 675,000 Americans and 30 million people worldwide.

• Type B: Primarily found in humans. Not as severe as Type A, but more severe than Type C

• Type C: Found in many species, most mild type. Severity similar to common cold

Symptoms: The symptoms of the common cold and the flu are similar initially, but the flu tends to progress into more serious effects. Symptoms the two share include:

1. Coughing

2. Body aches

3. Nasal congestion

4. Fatigue

5. Fever (for flu 102° F or higher)

6. Headache

The above symptoms are most severe in flu, which can also include:

1. Chills and sweats

2. Loss of appetite

3. Vomiting and diarrhea

4. Indigestion

Diagnosis: The common cold generally does not need to be diagnosed as it will run its course with few serious ill effects. Medical attention should be sought if:

1. fever rises above 102° F

2. symptoms include sweats and chills

3. symptoms get worse instead of better

These symptoms point to a more serious infection than the common cold. For flu there are tests that can be done to identify it as influenza virus within 30 minutes, depending on the test used and the lab processing the results. Tests include:

1. Viral cultures

2. Rapid antigen testing

3. Polymerase chain reaction

4. Immunofluorescence

Complications: Generally, the common cold does not result in any complications, but in some cases a bacterial infection, such as strep throat or pneumonia, will require antibiotics. Small children are sometimes susceptible to ear infections. Flu similarly does not pose many problems to younger healthy individuals, but it can be quite deadly to the elderly if it causes pneumonia.

Treatment: The flu and common cold are generally not treated with anything other than rest, fluids, and over-the-counter medications, which can ease symptoms. However, none of these treatments will speed recovery.

Recently, quick recognition of the flu (24-48 hours after the first symptom) allows treatment with antiviral medications, which can lessen symptoms and shorten length of sickness:

1. Neuraminidase inhibitors deactivate viral enzymes

2. Amantadine or rimantidine are good for prophylaxis or prevent infections from taking hold under high-risk exposure.

Prevention: First and foremost, get one of the yearly flu vaccinations, if available. The vaccine is reformulated each year to protect against flu strains that are likely to arise the coming season. For more common sense prevention of the flu and common cold, consider these tips:

1. Wash your hands. The viruses that cause the flu and colds are transmitted via hand contact with contaminated surfaces like another person’s hand in a handshake or a doorknob.

2. Avoid putting your hands near your eyes, nose or mouth if you haven’t washed your hands. These areas are where the infection can easily take hold.

3. Keep common areas and items clean. Cleaning that doorknob could be better than washing your hands.

4. Avoid prolonged exposure with people who have a cold.

5. Think about your children. If you have children they are more likely to come into contact with many colds and pass them on to you, so take their exposure into account.

6. Keep in good general health. Getting enough sleep, eating a good diet and exercising can be as good at preventing illness as any other preventative measure. If you and your immune system are working well you will be less likely to get sick.