SPONGE

3. Describe your symptoms the last time you were sick.

4. List two ways to prevent the spread of diseases.

Communicable and Chronic Disease - Day 2

Communicable and Chronic Disease

Section 2

Viral Pathogens

Types of Disease

• As we mentioned last time, viruses are the smallest common pathogen. They are not even cells – they have no nucleus or organelles.

• Viruses are essentially a small capsule with a strand of DNA inside.

Types of Disease

• A virus will attach to a cell and break open the cell membrane.

• From there it will inject its DNA into the cell’s nucleus.

• The viral DNA tricks the nucleus into making more viruses, which will fill up the cell. Eventually the cell will explode and the viruses will pour out to infect other cells.

Fighting Viral Infections

• There are vaccines for some viruses, but many viruses mutate so quickly that the old vaccines no longer work. Scientists are always hurrying to make new vaccines to prevent the spread of these new mutations.

Fighting Viral Infections• There is no cure for

most viral infections except for healthy living and rest.

• Most medicines that relieve viral illnesses help the symptoms of the illness – they don’t actually kill off the virus.

Common Viral Diseases

• The common cold is caused by 200 different viruses, though 1/3 of colds are caused by the rhinovirus. High stress levels make you much more likely to get a cold than being in cold weather.

• The cold can be passed through the air or by contact.

Common Viral Diseases• Influenza is a quickly

changing virus that is highly contagious. In the past, the flu was a deadly disease, though now it is dangerous mostly in the very old and in newborns.

• The flu is also transmitted through the air or by touch.

Common Viral Diseases

• Chicken Pox is an infection that results in a red, blistering rash.

• The virus is spread through saliva (sneezing, etc.) or by touching the liquid that seeps out of the pox.

• The pox is extremely infectious, but a vaccine has been available since 1995.

Common Viral Diseases• Rabies is spread by

infected saliva, usually from a dog, bat or raccoon bite.

• The virus travels to the brain where it causes swelling.

• If left untreated, a fever and spasms will develop. The infected person will lose their ability to swallow and eventually die.

Common Viral Diseases

• Pneumonia is an infection of the lungs caused by bacteria or viruses.

• Symptoms include fever, coughing and difficulty breathing.

Common Viral Diseases

• Mononucleosis is a disease common to young people. It is caused by a virus and results in a sore throat. Mono also makes the infected person very tired, sometimes for months.

• Mono is spread through contact, and is often called, “the kissing disease.”

Preventing Communicable Diseases

• Preventing the spread of disease can be accomplished by taking small steps in everyday life.

• Avoid contact with infected people.

• Wash your hands thoroughly and often.

• Disinfect objects that are often touched by hands. (desktops, doorknobs, computer areas.)

Preventing Communicable Diseases

• Cough into your shoulder, not into your hands or the air.

• Itch your face with the wrist or sleeve instead of your fingers.

• If you are infectious, stay away from large groups of people.