Definition
Disease: Is a condition that causes the body to function less effectively. Diseases produce specific signs or symptoms
- sign of disease → can be observed/measured.
- rashes, fever, coughing, vomiting.
- Symptom of disease → can be described/felt by patient.
Infectious and Non-Infectious Diseases
Infectious / transmissible disease → can be spread from one person to another.
- caused by disease-causing organisms → Pathogens
- E.g. of pathogens → bacteria and viruses.
- E.g. → Influenza, HIV, pneumococcal disease (all are infectious diseases)
- E.g. of pathogens → bacteria and viruses.
Non infectious diseases → not caused by pathogens.
- cannot be spread from one person to another.
- May be inherited, caused by malnutrition, environmental factors (e.g. pollution) and lifestyle choices.
- e.g. → excess alcohol consumption may cause liver cirrhosis, excessive consumption of polyunsaturated fats and trans fat may cause coronary heart disease. Cigarette smoking may cause atherosclerosis and coronary heart disease. Other non infectious diseases → type 2 diabetes and sickle cell anaemia
Spread of Infectious Diseases
Through Droplets in Air
- RESPIRATORY DROPLETS IN AIR
- Person coughs / sneezes → numerous tiny respiratory droplets → expelled.
- These droplets may contain pathogens.
- Anyone in close range (about 1m) → may breathe in these droplets → become infected.
- During disease outbreak → people are advised → wear mask + exercise SD.
Direct Contact
Some diseases → spread through direct contact
- infected person may infected another person → exchanging body fluids → during sexual intercourse.
- STIs (sexually transmitted infections) → such as HIV (Human Immunodeficiency Virus) → can be transmitted this way.
- Some diseases → Hepatitis B and syphilis → can be transmitted from mother to baby through breastfeeding.
Infectious diseases → can also be spread → when blood from infected person → comes into contact with:
- mucous membrane → e.g. membranes lining the eye, nose, mouth of an uninfected person
- bloodstream of uninfected person, such as through a break in the skin
Contaminated Food and Water
- Food and water → can be contaminated → pathogens such as bacteria → that cause disease known as cholera
- Can occur when food and water → not properly stored/handled
- Methods to prevent + control spread of water-borne and food-borne diseases:
- Practice hygienic food preparation and storage.
- Having good personal hygiene
- Maintaining clean water supply
- Ensuring proper sewage treatment.
Structures of Bacterial Cell and Virus
Structures of Bacterial Cell and Virus
How Can Infectious Diseases Be Prevented and Managed
How Can Infectious Diseases Be Prevented and Managed