Types of diseases

1. DISEASES

2. DEFINITIONS
• Health: This is a state in which the mind and body is functioning properly
• Disease: This is any condition that prevents the body from being healthy
• There are 4 categories of diseases:
• Infectious
• Deficiency
• Genetic
• Physiological

3. CONCEPT ATTAINMENT
• Use the Jamboard link to categorize some diseases
• https://jamboard.google.com/d/138xeLwo0u1fNSPD-
cQEhU30xsdn_I2E8OlV075a0mcs/edit?usp=sharing
• Can you state how people get these diseases?
• What are some common symptoms these diseases share?

4. INFECTIOUS DISEASES
• These are caused when a pathogen (microorganism) enters the body and causes
harm
• Types of pathogens include:
• Viruses (HIV, Coronavirus)
• Bacteria (Tetanus, Cholera)
• Fungi (Ringworm, Athlete’s foot)
• Protists (Malaria, Dysentery)

5. HOW THE BODY
PROTECTS ITSELF

6. WHY DO WE GET A FEVER?

7. HOW TO TREAT INFECTIOUS DISEASES?
Pathogen Examples Treatment Examples
Bacteria Cholera, Tuberculosis,
Meningitis, Syphillis,
Pneumonia
Antibiotics Penicillin, Cephalosporin,
Tetracyclines
Virus HIV, Hepatitis, Dengue,
Polio, Influenza
Antiviral drugs Oseltamivir, marboxil,
ART(Anti-retroviral
Therapy)
Fungi Athlete’s foot, ringworm,
Yeast infection, Dandruff
Antifungal medication Clotrimazole, terbinafine,
amphotericin

9. DEFICIENCY DISEASES
• Caused by a lack of certain food groups in the diet
• Typically cured by consuming the deficient nutrient, however they can cause
permanent damage if not treated
• These diseases are more common in developing countries where access to a
balanced diet is not easy to acquire

10. DEFICIENCY DISEASES
Disease Symptoms Deficient Nutrient Food that contain
nutrient
Marasmus Weight loss, tiredness Carbohydrates Flour, Provisions, rice
Kwashiorkor Swollen stomach, stunted
growth
Proteins Legumes, meat, eggs,
dairy
Scurvy Bleeding gums, joint pains Vitamin C Fruits (especially citrus)
Rickets Brittle bones, stunted
growth
Vitamin D, Calcium Dairy, Green leafy
vegetables
Anaemia Tiredness, pale skin Iron Red meat, green leafy
vegetables

11. QUESTION
• 1. Developing countries have issues with deficiency diseases. Suggest why and
recommend how they can tackle this.
• 2.Doctors sometimes recommend antibiotics to patients who had the flu for a
long period of time. Explain why. What are some concerns about this practice?

12. HEREDITARY (GENETIC) DISEASES
• These are diseases that are passed on from parent to child through their genes
• These diseases can be caused by recessive genes or mutations
• These diseases will cause some part(s) of the body to malfunction

13. HEREDITARY (GENETIC) DISEASES
Disease Symptoms Level
Cystic Fibrosis Constant mucus build up in
lungs, Tiredness
Single gene
Sickle cell Anaemia Tiredness, pale skin Single gene
Haemophilia Problems with blood clotting Single gene
Diabetes (type 1) Cannot control blood glucose
levels
Multifactorial
Obesity Excess body fat Multifactorial
Down Syndrome Learning disability,
dysmorphia
Chromosomal
Turner syndrome Issues with sexual
development
Chromosomal

14. PHYSIOLOGICAL DISEASES
• These are caused when a part of the body malfunctions
• There are several possible causes of physiological diseases
• Cancerous – Cells division occurs too fast and tumors develop, eg, cancer
• Degenerative – Tissues and organs do not work as well as we get older, eg, Arthritis,
Arrythmia, cataracts
• Metabolic – Organs stop working due to defect, eg, diabetes,
• Psychological – Imbalances of chemicals in the brain, eg, bipolar disorder,
schizophrenia

15. TREATMENT AND CONTROL OF INFECTIOUS DISEASES
• The causes and spread of infectious diseases can be controlled by focusing on the
interactions between the host (humans), the pathogen and the environment
• Many of the diseases themselves can be treated with medicines and it is possible
to be vaccinated or immunized against some diseases
• Disease causing pathogens can be destroyed by using substances that kill them.
These substances include antibiotics, disinfectants and antiseptics and sterilization
techniques, such as heating or boiling

16. TREATMENT AND CONTROL OF INFECTIOUS DISEASES
• Measures that affect the environment:
• improved standards of living, hygiene and the treatment of sewage
• eradication of insects, such as mosquitoes and houseflies
• provision of safe, clean drinking water
• food inspections, such as the inspection of meat at abattoirs
• better preparation and storage of food (pasteurisation and cold storage)
• laws which require notification of certain diseases, such as rabies and leprosy; this allows for
quick treatment and quarantine (isolation of infected individuals)
• improved public health programmes, including vaccination programmes and education
programmes.

17. TREATMENT AND CONTROL OF NON-INFECTIOUS DISEASES
• Diet:
• The amount of sugar and fat you eat affects your risk of developing physiological
diseases, such as heart disease, hypertension and diabetes. If people eat too
much sugar and fat, they tend to gain weight. Overweight people have a higher
risk of these diseases
• Too much of the wrong sort of fatty food increases the levels of cholesterol in the
blood. Eating food containing a lot of saturated fat seems to raise the levels of
cholesterol in the blood
• Too much salt in the diet can raise blood pressure.

18. TREATMENT AND CONTROL OF NON-INFECTIOUS DISEASES
• Exercise:

19. MOSQUITO LIFE CYCLE

20. MOSQUITO LIFE CYCLE
• Eggs: Adult, female mosquitoes lay their eggs on the inner, wet walls of containers
with water, above the waterline. Mosquitoes generally lay 100 eggs at a time.
• Larva: Larvae emerge from mosquito eggs, but only after the water level rises to
cover the eggs. Larvae feed on microorganisms in the water.
• Pupa: Pupae will develop until the body of the newly formed adult flying mosquito
emerges from the pupal skin and leaves the water.
• Adult: After adult mosquitoes emerge, male mosquitoes feed on nectar from
flowers and female mosquitoes feed on humans and animals for blood to produce
eggs

21. MOSQUITOS AS A VECTOR
• A vector refers to something that can transmit a disease from one person to
another without being affected by the disease
• Mosquitoes cause more human suffering than any other organism -- over one
million people worldwide die from mosquito-borne diseases every year.
• Mosquitos are usually found in hot regions around the world (South America,
Caribbean, Africa)

22. MOSQUITO BORNE DISEASES
Disease Vector Symptoms Statistics (annual)
Malaria Anopheles Muscle aches, anaemia 300-500 million
Chikungunya (Chik. V) Aedes aegypti Fever, joint pain 30 – 40 000
Dengue Aedes aegypti Vomiting, Bleeding from
orifices
350-400 million
Yellow Fever Aedes aegypti Headaches, muscle pain 200 000
West Nile Virus Culex Muscle stiffness,
convulsions
1.5 Million

23. MOSQUITO CONTROL