Objectives 8-10

Question 1

define a carrier

Answer 1

someone who is asymptomatic who habours and passes on pathogens to other people

Question 2

what is a transient carrier

Answer 2

infection during incubation or recovery period of an infection

Question 3

what is a chronic carrier

Answer 3

sub-clinical infection where the carrier state persists for long periods of time

Question 4

what are examples of chronic carrier diseases?

Answer 4

• hepatitis-B
• tuberculosis
• gonorrhoea
• MRSA
• Typhoid

Question 5

define zoonoses

Answer 5

disease that occur mainly in wild or domestic animals but can be transmitted to humans

Question 6

how are zoonoses infections acquired?

Answer 6

• handling animals
• handling animal products
• receiving bites from blood sucking insects

Question 7

examples of zoonoses

Answer 7

• Rabies
• Anthrax
• Brucellosis
• Leptospirosis
• Toxoplasmosis
• bubonic plague
• yellow fever

Question 8

what are examples of insect (vectors) infections?

Answer 8

Fleas = bubonic plague

Mosquitoes = malaria, yellow fever, filariasis, dengue fever, ross river fever

Bed bugs = Chagas’ disease

Tsetse flies = sleeping sickness

Body lice = epidemic typhus

Ticks = rocky mountain spotted fever, Q fever, Lyme disease

Question 9

what diseases can be contracted from the non-living reservoir soil?

Answer 9

• Soil does harbour some notable pathogens
• Clostridium botulinum (spores)
• Clostridium tetani (spores)
• Certain fungi that can cause mycoses
• coccidioidomycosis
• infective stages of some larger parasitic organisms such as nematodes.

Question 10

what diseases can be contracted from the non-living reservoir air?

Answer 10

 dust from the soil
 dust from humans (skin scales, dried nasal mucus and sputum)
 droplets from coughs and sneezes
 droplets or dried particles from other body products (such as the gastro-intestinal tract, infected wounds, etc).

Question 11

what diseases can be contracted from the non-living reservoir water?

Answer 11

Dysentary
Cholera
Typhoid
Poliomyelitis
Hepatitis-A
Giardiasis
Cryptosporidiosis
Legionnaire’s disease
Amoebic meningitis

Question 12

what are examples of a primary reservoir infection with food?

Answer 12

• when the disease is being transmitted directly from the animal being eaten to the human consumer.
• Ex: Salmonella in eggs or chicken
• Ex: parasitic “worms” (tapeworms, flukes and nematodes) in poorly-cooked beef or pork.

Question 13

what are examples of a secondary reservoir infection with food?

Answer 13

• when the food itself becomes contaminated by new organisms and those new organisms are allowed to reproduce
• ex: classical staphylococcal food poisoning.