SPH 200 Exam Prep Questions and Answers
Verified 100% Correct
Communicable disease
Illness caused by an infectious agent or its toxins = direct or indirect transmission of the
infectious agent or its products from an infected individual or via vector or fomite to a
susceptible host
Bacteria
Ubiquitous single cell organisms - exist as commensal, opportunistic or parasitic
Huge range of infectious types
Amenable to antibiotic treatment
Viruses
Replicate within a living cell - exist as DNA or RNA surrounded by a protein coat, amenable to
vaccination as a prevention strategy
Protozoans
Single celled organisms - wide variety of morphologies, many infectious routes, often have both
a proliferative and dormant stage
Treatment varies based on infection
Helminths
Parasitic worms - common in developing countries, linked to poor sanitation and hygiene,
flatworms, roundworms, tapeworms
Treatment varies based on worm type
,Prions
improperly folded forms of normal proteins - cause spongiform encephalopathy
Poorly understood, no treatment
Routes of transmission
1) Respiratory
2) Tissue penetration
3) Gastrointestinal
4) Vector
5) Sexual contact
6) Transplantation
Respiratory transmission
= High risk to public health
- Fast and easy
- Difficult to prevent
Tissue penetration transmission
- Risk only in areas where parasites are present
- High risk in endemic areas bc difficult to control
Gastrointestinal transmission
- High risk to public health
- Food and waterborne transmissions
- Everybody eats and drinks
, Vector transmission
- Risk varies based on presence of suitable vectors
- If vectors present - transmission can be rapid and difficult to control`
Sexual contact transmission
- High risk but easy to prevent
- Prevention relies on behaviour
- Many asymptomatic which makes detection difficult
Transplantation transmission
Low risk of occurrence but development of disease is guaranteed
Very preventable with proper procedures
Entry and exit from the host
- Respiratory tract - nose or mouth
- GIT - mouth
- urogenital tract - urethra
- skin
- mucosa - eyes, nose, esophagus
Entry and exit linked to transmission methods
Pathogen characteristics determine entry/exit
Some biological hazards can have multiple transmission routes/entry and exit possibilities
Disease reservoir
Verified 100% Correct
Communicable disease
Illness caused by an infectious agent or its toxins = direct or indirect transmission of the
infectious agent or its products from an infected individual or via vector or fomite to a
susceptible host
Bacteria
Ubiquitous single cell organisms - exist as commensal, opportunistic or parasitic
Huge range of infectious types
Amenable to antibiotic treatment
Viruses
Replicate within a living cell - exist as DNA or RNA surrounded by a protein coat, amenable to
vaccination as a prevention strategy
Protozoans
Single celled organisms - wide variety of morphologies, many infectious routes, often have both
a proliferative and dormant stage
Treatment varies based on infection
Helminths
Parasitic worms - common in developing countries, linked to poor sanitation and hygiene,
flatworms, roundworms, tapeworms
Treatment varies based on worm type
,Prions
improperly folded forms of normal proteins - cause spongiform encephalopathy
Poorly understood, no treatment
Routes of transmission
1) Respiratory
2) Tissue penetration
3) Gastrointestinal
4) Vector
5) Sexual contact
6) Transplantation
Respiratory transmission
= High risk to public health
- Fast and easy
- Difficult to prevent
Tissue penetration transmission
- Risk only in areas where parasites are present
- High risk in endemic areas bc difficult to control
Gastrointestinal transmission
- High risk to public health
- Food and waterborne transmissions
- Everybody eats and drinks
, Vector transmission
- Risk varies based on presence of suitable vectors
- If vectors present - transmission can be rapid and difficult to control`
Sexual contact transmission
- High risk but easy to prevent
- Prevention relies on behaviour
- Many asymptomatic which makes detection difficult
Transplantation transmission
Low risk of occurrence but development of disease is guaranteed
Very preventable with proper procedures
Entry and exit from the host
- Respiratory tract - nose or mouth
- GIT - mouth
- urogenital tract - urethra
- skin
- mucosa - eyes, nose, esophagus
Entry and exit linked to transmission methods
Pathogen characteristics determine entry/exit
Some biological hazards can have multiple transmission routes/entry and exit possibilities
Disease reservoir
