MODULE 7: Infectious diseases

Question 1

VIRUS: Structure, Size, Reproduction, Transmission and Examples

Answer 1

Structure: Non-cellular, Contains DNA, RNA and protective coat

Size: Not visible with light microscope, 30 to 300 nm, larger than Prions but smaller than Bacteria

Reproduction: Requires a living host to replicate, unable to reproduce on their own.

Transmission: Air water droplets ingestion

Examples: AIDS/HIV COVID

Question 2

VIRUS: Composition

Answer 2

Head containing DNA, Collar, Sheath, Tail Fibres

Question 3

BACTERIAL: Structure, Size, Reproduction, Transmission and Examples

Answer 3

Structure: Unicellular, prokaryotic cell. Cell wall surrounding cell.

Size: Up to 100 um. Visible with a light microscope.

Reproduction: Asexual, binary fission (dividing in two)

Transmission: Air transmission via water

Examples: Tuberculosis (Mycobacterium)

Question 4

PROTOZOAN: Structure, Size, Reproduction, Transmission and Examples

Answer 4

Structure: Eukaryotic unicellular organisms. Can’t make their own food

Size: 50 to 100 um. Visible with light microscope

Reproduction: Asexually, binary fission

Transmission: Vector (uses something to transport e.g. mosquito)

Example: Malaria (Plasmodium sp.)

Question 5

FUNGI: Structure, Size, Reproduction, Transmission and Examples

Answer 5

Structure: Eukaryotic cells with cell walls. Some are unicellular although most are multicellular.

Size: um to mm

Reproduction: Asexual and Sexual depending on Fungi

Transmission: Direct contact with fungus

Examples: Tinea (Tinea corporis), Thrush (Candida Albicans)

Question 6

PRION: Structure, Size, Reproduction, Transmission and Examples

Answer 6

Structure: Non-Living, do not contain DNA, they are a defective form of a protein molecule. Attacks brain, nerve cells.

Size: Low nm, Not visible with light Microscope.

Reproduction: Come in contact with normal prion proteins, they alter their structure and change them into infectious prion proteins

Transmission: Direct contact with contaminated surgical instruments.

Examples: Bovine Spongiform encephalopathy (aka Mad Cow Disease)

Question 7

MACRO-PARASITE: Structure, Size, Reproduction, Transmission and Examples

Answer 7

Structure: Eukaryotic cells-multicellular organism. Mostly Arthropods or worms, External Parasites “exoparasite”, Internal Parasites “endoparasite”.

Size: mm to metres, Visible with naked eye.

Reproduction: Eggs laid (larvae)

Transmission: Faeces, Oral Transmission
Examples: Tapeworm, Paralysis Tick

Question 8

Vector Transmition? and example

Answer 8

Vector Transmission: Involves animals assisting in the transfer of pathogens between individuals. Biological Vectors such as mosquitos, transfer the pathogen from one individual to another, but the pathogen also undergoes part of its life cycle in the vector. Mechanical Vectors, such as flies, physically transfer the pathogen from one person to another, without being infected themselves. Book Definition: A special case of indirect transmission of pathogens occurs through arthropods and usually involves bite.

Example: Malaria

Question 9

Quarantine? Examples?

Answer 9

Period of isolation used to prevent the spread of infectious disease
Compulsory hospitalisation or closing schools and workplaces.
Surveillance and isolation of things moving across borders.
Border Security and quarantine are essential for preventing the spread of disease at airports, seaports, border stations etc.

Question 10

Artificial Passive Immunity?

Answer 10

Antibodies created by another person or animal are injected into another person.
Protection is only temporary
Example - Anti-venom: Small quantities of venom are injected into a horse, which was able to produce.

Question 11

Public Health Campaign 1

Answer 11

National Immunisation Program (Ongoing since 1997)

To increase vaccination coverage and prevent the spread of vaccine-preventable diseases such as measles, mumps, rubella, and whooping cough.

The program provides free vaccines to eligible Australians and promotes the importance of immunisation through various media channels.

Australia has achieved high immunisation rates, helping to control the spread of several infectious diseases.

Question 12

2 types of antibiotics

Answer 12

Bactericidal: Antibiotics kill the bacteria by interfering with information of the cell membrane, or cell contents

Bacteriostatic: Antibiotics stop bacteria from multiplying it interferes with DNA replication protein production or other cellular metabolic processes for example amoxicillin

• destroys cell wall and kills insides
• Narrow or Broad Spectrum drugs