Diseases and Pathogens
Concept: Communicable and Non-communicable Diseases
- The diseases that spread from infected persons to healthy persons are called communicable or infectious diseases.
- Pathogens such as viruses, bacteria, and fungi cause communicable diseases.
- A person develops a communicable disease after becoming infected by the pathogen or an infected person.
Examples:Hepatitis A, Ebola, COVID-19
- The diseases that do not get transferred from person to person are called non-communicable or non-infectious diseases.
- The main types of non-communicable diseases include cardiovascular diseases, cancer, chronic respiratory diseases, and diabetes.
Examples:Parkinson's disease, autoimmune diseases, osteoarthritis, osteoporosis, Alzheimer's disease, cataracts, etc.
Modes of transmission of communicable diseases:
- Person-to-person contact: Infectious diseases are commonly transmitted through direct person-to-person contact.
Direct contact can be through touch or the exchange of body fluids.
- Droplet spread: Infections spread through the droplets released during coughing and sneezing.
- Contaminated objects: Some pathogens are effective on the things touched by an infected person for some time.
Transmission occurs when one touches those infected objects, and then touches their mouth, nose and eyes.
- Food and drinking water: Infectious diseases can be transmitted via contaminated food and water.
- Animal-to-person contact: Some infectious diseases can be transmitted from an infected animal to a healthy person.
It happens when an infected animal bites or scratches any exposed body part of the animal.
Examples:Common cold, meningitis.
Examples:Typhoid, cholera, jaundice.
Prevention of spread of communicable diseases:
- Handling and preparing food safely: The following things should be taken care of while preparing food—
- All utensils should be washed and cleaned properly.
- Fruits and vegetables should be washed properly before cooking or eating.
- Raw meat or fish should be washed and cooked properly. Uncooked or partially cooked meat and fish may have deadly microbes.
- Food should be refrigerated when not consumed.
and after returning home from outside.
Bathrooms and the kitchen should be washed and scrubbed regularly.
one should never share the needles; rather, they should only be used once and disposed of properly.
resistance against many communicable diseases like chicken pox, small pox, polio, etc.
Some common communicable diseases and their causal organisms
|S. No.||Name of the disease||Mode of transmission||Causal organism|
|1.||Cholera||Food and water||Bacteria|
|2.||Typhoid||Food and water||Bacteria|
|3.||Jaundice||Food and water||Bacteria|
|8.||Tetanus||Bite/wound exposed to dust or iron object||Bacteria|
Cardiovascular diseases: The diseases that affect the heart and blood vessels.
Vaccine: A vaccine contains a dead or weakened virus that, when introduced in the body triggers the synthesis of antibodies (specialised proteins) that kill the weakened virus. These antibodies stay in our blood and keep a check on the same virus if it enters our body again in the future. The process of introducing a vaccine in a living organism is called vaccination.
Did You Know?
The process of vaccination is centuries old. Edward Jenner was the first scientist who introduced the concept of vaccination in 1796, almost 100 years before viruses were even discovered.