Question 1

While a reservoir can be a source of infection, not all sources of infection are reservoirs.

Accepted Answer

A reservoir is any person, animal, plant, soil, or substance in which an infectious agent normally lives and multiplies, typically serving as a source of infection. However, sources of infection can also include direct contact with an infected individual or exposure to a contaminated environment, which do not necessarily serve as places where the infectious agent lives and multiplies.

Question 2

Members of the genus Vibrio, which includes the species which cause cholera are found in marine environments. However, most cases of cholera occur when people drink water that has been contaminated with feces from other humans with cholera. If an effective vaccine against cholera were developed so that humans would become immune to the disease, both the reservoir and the source of the cholera bacteria would be eliminated.

Accepted Answer

While an effective vaccine against cholera could significantly reduce the incidence of the disease in humans, the reservoir of Vibrio cholerae in marine environments would not be eliminated. The bacteria naturally inhabit water sources and can be found independent of human fecal contamination.

Question 3

A newly emerged infectious disease whose pathogen cause has not yet been identified is lethal in more than 90% of cases. Epidemiological evidence suggests that this pathogen is transmitted only through direct contact with the blood of ill or recently deceased patients. Patient blood and tissue samples would best be handled at BSL- 2 until more information can be learned about the pathogen.

Accepted Answer

Given the high lethality rate and the unknown nature of the pathogen, along with transmission through direct contact with blood or tissues of ill or deceased patients, samples should be handled at a minimum of Biosafety Level 3 (BSL-3), if not BSL-4, to ensure maximum containment and protection for laboratory personnel.

Question 4

If you had the ability to genetically engineer a pathogenic bacterium, what features would you include? Choose a portal of entry and a portal of exit for your pathogen. Then choose three virulence factors from at least two the following areas: toxins, adhesins, invasins, acquisition of nutrients, and avoidance of the immune system, and describe how each factor will help your bacterium survive in the host. Your virulence factors should make sense for the portals of entry and exit that you chose.

Accepted Answer

The answer of If you had the ability to genetically...

Question 5

You are a consultant with an architectural firm designing a BSL- 3 hospital facility for patient care and diagnostic laboratory services. The facility will specialize in airborne pathogens such as Mycobacterium tuberculosis. Describe the characteristics of pathogens handled in a BSL- 3 facility and describe at least five features that must go into the facility design.

Accepted Answer

The answer of You are a consultant with an architectural...

Question 6

Contrast pathogenicity and virulence, and describe why virulence can be considered an evolving property.

Accepted Answer

The answer of Contrast pathogenicity and virulence, and describe why...

Quiz 10: Host-Microbe Interactions and Pathogenesis

While a reservoir can be a source of infection, not all sources of infection are reservoirs.

Contrast pathogenicity and virulence, and describe why virulence can be considered an evolving property.