Day 29 of 30
Common diseases and prevention
Lessons are AI-drafted and being reviewed and improved over time.
Learning Objective
Compare communicable and noncommunicable diseases and describe how each kind can be prevented or reduced.
A disease is a condition that disrupts the normal working of the body. Scientists group diseases into two broad kinds. Communicable diseases are caused by pathogens and can spread from one person to another. Noncommunicable diseases do not spread; they develop from genes, environment, and lifestyle, or from a mix of these.
Communicable diseases are caused by bacteria, viruses, fungi, or parasites. Strep throat is caused by bacteria, and antibiotics treat it. The common cold and the flu are caused by viruses, so antibiotics do not help. Athlete's foot is a fungus. Malaria is caused by a parasite carried by mosquitoes. Pathogens spread in several ways: by direct contact, in droplets from coughs and sneezes, through contaminated food or water, from contaminated surfaces, and by animals such as mosquitoes and ticks, which are called vectors.
Prevention follows from the route. Washing your hands with soap, covering coughs, and keeping surfaces clean limit contact and droplets. Cooking and storing food safely and drinking clean water prevent foodborne illness. Staying home when you are sick protects others. Vaccines train the immune system to recognize a pathogen before it can make you sick. When most people in a community are vaccinated, the pathogen has trouble finding anyone to infect, so it spreads less, and people who cannot be vaccinated, such as newborns, are better protected. This is called community immunity.
Noncommunicable diseases include heart disease, type 2 diabetes, asthma, many cancers, and allergies. Cancer begins when cells divide out of control and form a tumor. Some risk factors cannot be changed, such as age and family history. Others can: being physically active, eating a balanced diet, not using tobacco, and limiting sun exposure all lower the risk of many noncommunicable diseases. Checkups and screenings find some conditions early, when treatment works best.
Remember that many illnesses are caused by more than one factor, and that having a risk factor does not guarantee a person will get sick. Doctors diagnose and treat disease, and it is always wise to talk with a trusted adult if you feel unwell.
Common mistakes: thinking you catch a cold from being cold, when viruses are the cause, and thinking antibiotics treat every infection. Next: the unit assessment.
A disease caused by a pathogen that can spread from person to person.
A disease that does not spread between people, such as heart disease.
An animal, such as a mosquito, that carries a pathogen from one host to another.
Something that raises the chance of getting a disease.
Protection of a whole community when most people are immune, which helps those who cannot be vaccinated.
Actions taken to lower the chance of getting a disease.
Instructions
Materials Needed
- 20 paper slips
- Marker
What is the difference between a communicable and a noncommunicable disease? Give an example of each.
List three ways pathogens can spread.
Why does washing hands and covering coughs help prevent illness?
Explain community immunity.
Name two risk factors for heart disease or diabetes that a person can change.
Teaching Tip
Be careful to separate "can be caused by germs" from "is caused by germs." Many students assume every illness is infectious. The simulation is most convincing when students run the 0 percent and 70 percent versions back to back.
Go Deeper
Research how the discovery that germs cause disease changed hospitals and public health, or how scientists track an outbreak.
The AI tutor is not currently available.