Grade 3 (age 8-9)

grade 3 Infectious Disease & Prevention

Infectious Disease & Prevention

An infectious disease is an illness caused by germs like bacteria or viruses that are far too small to see. They pass from a sick person to a healthy one in the droplets of a cough or sneeze, or on things we touch. That is why a cold spreads around a class, but washing your hands, covering coughs with your elbow, and resting when sick stops a lot of it. Press the buttons to compare how germs spread with how prevention blocks them, and learn the 5 steps of washing hands.

What is an infectious disease?

🦠 What is an Infectious Disease?

①Caused by tiny invisible germs or viruses

②Spreads from sick to healthy people

③Travels by cough, sneeze, or contact

④Examples: cold, flu, COVID

How do germs spread?

💡 Routes of Spread

①Droplet: through sneeze/cough droplets

②Contact: through touch

③Airborne: floating germs in the air

④Following prevention rules can stop them!

Proper Hand Washing

Washing Steps

Proper Hand Washing in 5 Steps

🧼 Power of Hand Washing

①Wash with soap for 30+ seconds

②Scrub between fingers and under nails

③Rinse thoroughly with running water

④Hand washing helps reduce many infections

Prevention Rules

Infection Prevention Rules

Summary

Core Prevention

Hand wash + Mask + Cough etiquette = Prevention

Small habits protect big health

Spread Routes

Droplet + Contact + Air = Routes

Block the routes to stop infection

🎯 Key Points

①Caused by germs/viruses spreading

②Travels by cough, sneeze, or touch

③Hand washing is the most important defense

④Always follow mask and cough etiquette

⑤Vaccines build immunity in advance

Examples and Unit Test

Example 1

What do we call it when germs spread through the droplets that come out when you cough or sneeze?

Infectious diseases spread as germs or viruses move from a sick person to a healthy person.

Spreading through the droplets of a cough or sneeze is called droplet transmission.

▸ Droplet transmission

Infectious diseases spread by droplets, contact, and air.

Example 2

How long should you wash your hands with soap to prevent infectious disease, and how effective is hand washing?

To remove germs on your hands, you should scrub thoroughly with soap.

Washing with soap for 30 seconds or more can greatly reduce infectious disease.

▸ 30 seconds or more / it greatly reduces infectious disease

Proper hand washing alone can prevent a lot of infectious disease.

Unit-test style

Which statement about infectious disease and prevention is correct?

①Infectious diseases are caused by germs or viruses

②Washing hands briefly with only water is enough

③It is best to cover a cough with your hand

④Infectious diseases cannot be prevented

⑤A mask only needs to cover the mouth

▸ ① Infectious diseases are caused by germs or viruses

Infectious diseases are illnesses caused by invisible germs or viruses spreading.

Hands should be washed with soap for 30 seconds or more (②), a cough is covered with the elbow (③), disease can be prevented by hand washing and masks (④), and a mask should cover both nose and mouth (⑤).

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