MCB 2004 Mastering Biology Chapter 14 Questions

Which of the following is considered a major category of transmission of disease?

Contact, vehicle, and vector transmission

In the sixth segment of the animation, why is the disease epidemic in North America?

The disease occurs at a higher rate than what would normally be expected in this region.

The health of the patient

should be the primary concern of the healthcare worker.

Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a

nosocomial infection

Expected prevalence of a disease is

the expected occurrence of a disease based on past observations.

How can surgeons help to limit nosocomial infections?

They should perform surgeries and invasive procedures only when absolutely necessary.

What is the role of epidemiology?

To learn how to treat and prevent various diseases.

Which of the following statements is true regarding hand washing?

Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.

Which of the following statements about biological transmission is FALSE? - The pathogen may be injected by the bite of the vector. - Houseflies are an important vector. - The pathogen reproduces in the vector. - The pathogen may require the vector as a host. - The pathogen may enter the host in the vector's feces.

Houseflies are an important vector.

T/F: Both normal and transient flora can become opportunistic pathogens.

True

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?

West Nile virus outbreaks have increased in number and affected areas since 1937.

Which of the following is a fomite?

a hypodermic needle

During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.the situation is an example of

a zoonosis

A nosocomial infection is

acquired during the course of hospitalization.

Which of the following would be considered a fomite? - Contaminated water - An infected toy - A tick - A fly

an infected toy

The yeast Candida albicans does not normally cause disease because of

antagonistic bacteria.

T/F: Reservoirs of infections are always animate objects.

False

Epidemiology is defined as the study of

where and when a disease occurs, and how it is transmitted.

Etiology

the study of the cause of disease

Which of the following characteristics do commensalism, mutualism, and pathogenicity have in common?

- life cycle coordination between the host and symbiont - common physical requirements between the organisms

A rabbit was found to have floppy ear disease, which causes long-ear infections. Its etiology (cause) is unknown. Unknown Microorganism X from the infected rabbit's right ear is successfully isolated and cultured on laboratory growth media. The ear of a healthy laboratory mouse is then inoculated with isolated microorganism, and after a period of time, no disease is observed. Which of the following statements accurately describe(s) the conclusion(s) that can be drawn from this experiment? Select all that apply.

-A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed. -Microorganism X might not be linked to floppy ear disease, because the inoculated mouse remained healthy.

During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?

-An arbovirus is maintained in nature through biological transmission. -An arbovirus is an arthropod-borne virus.

This activity asks you to identify Koch's postulates for determining the etiology of infectious diseases. Which statements accurately describe Koch's postulates?

-The same pathogen must be present in every case of the disease. -The pathogen must be isolated from the diseased host and grown in pure culture. -The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal. -The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.

What features of West Nile virus make it an emerging disease of special concern?

-West Nile virus is an arthropod-borne virus transmitted by mosquitoes. -West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. -West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

Which of the following would be considered a vector? - Water containing bacteria from fecal matter - A fly carrying disease from fecal matter to food - Saliva that is transmitted between individuals during kissing - Water droplets that come from a sneeze from an infected individual

A fly carrying disease from fecal matter to food

Which of the following would be an example of disease transmission via indirect contact? - A tick that is infected with Lyme disease bites a hiker, and the hiker gets Lyme disease. - A restaurant worker has diarrhea caused by Norovirus. He fails to wash his hands adequately before preparing the salad, and his customers get sick. - A student sneezes on her test booklet. The instructor grades it and catches her cold. - Mr. Smith sneezes on an airplane, and the person sitting beside him catches his cold.

A student sneezes on her test booklet. The instructor grades it and catches her cold.

Which of the following can contribute to postoperative infections? errors in aseptic technique normal microbiota on the operating room staff antibiotic resistance using syringes more than once All of the answers are correct.

ALL

Emergence of infectious diseases can be attributed to all of the following EXCEPT ease of travel. climatic changes. new strains of previously known agents. antibiotic resistance. The emergence of infectious diseases can be attributed to all of these.

All

Which one of the following is NOT a zoonosis? - tapeworm - cat-scratch disease rabies - Hantavirus pulmonary syndrome - All of these are zoonoses.

All of these are zoonoses

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic?

Antibiotics can be used in aerosols, thereby entering the environment.

The CDC is located in

Atlanta, GA.

What type of nosocomial infection is likely to arise from intravenous catheterizations?

Bacteremia

This activity asks you to sort statements that describe the benefits and limitations of using Koch's postulates to determine the etiology of infectious diseases. For each of the following statements, determine whether it describes a benefit or a limitation of Koch's postulates.

Benefit: -laboratory findings provide experimental evident that support the germ theory of disease -healthy, susceptible animals can be used as model organisms for testing many types of infections, thus avoiding the unethical inoculation of healthy human hosts -The steps are designed to systematically link a pathogen to specific infectious disease Limitation: -Different pathogens can produce the same signs and symptoms, making it difficult to determine which microorganism is causing a disease -Some pathogens cause several different diseases, which make it difficult to link on pathogen to one disease using Koch's postulates -Some infectious agents have specific growth requirements that prevent them from being artificially cultured in the laboratory

This activity asks you to view Foundation Figure 14.3 and determine the purpose of key components of this experiment. The key components include the diseased or dead animal, the healthy laboratory animal, the microscope, and the growth media.Robert Koch performed experiments to determine the specific microorganisms associated with specific diseases.

Diseased or dead animal- original source of the infectious microbial agent Healthy laboratory animal- organism injected with a potential infectious agent Microscope- tool used to view and identify individual microorganisms Growth media- nutrient-rich environment for isolating and culturing microorganisms

Which of the following is an example of the symbiotic relationship known as mutualism? - saprophytic Mycobacterium of the ear - a tapeworm in the gastrointestinal tract of a human - Corynebacterium on the surface of the eye - E. coli within the large intestine

E. coli within the large intestine

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?

Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

Which of the following is the best mode of controlling the spread of West Nile infections?

Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

Which of the following is NOT a reservoir of infection? a healthy person a sick animal a hospital a sick person None of the answers is correct; all of these can be reservoirs of infection.

None of the answers is correct; all of these can be reservoirs of infection.

Which of the following pairs is mismatched? - salmonellosis vehicle transmission - influenza droplet infection - syphilis direct contact - malaria vector - None of the pairs is mismatched.

None of the pairs is mismatched

Which of the following statements concerning pathology, infection, and disease is true? - Microorganisms that make up the normal microbiota of an individual never cause disease. - The majority of microorganisms are pathogenic. - Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease. - The term infection is synonymous with the term disease.

Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

How can health care workers reduce the occurrence of nosocomial infections?

Practice more stringent aseptic techniques

Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates?

The pathogen must be isolated from inoculated animals and must be different from the original organism.

Which of the following statements about nosocomial infections is FALSE?

The patient was infected before hospitalization.

Which is an example of vehicle disease transmission? - The presence of Listeria on undercooked chicken served for dinner - The bite of a mosquito containing malaria - Touching a telephone with cold viruses on its surface

The presence of Listeria on undercooked chicken served for dinner

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?

The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

Why are invasive procedures likely to increase the risk of nosocomial infections?

These procedures allow microbes from the skin to enter the bloodstream of the patient.

Which of the following is NOT an example of microbial antagonism? - bacteria causing disease - acid production by bacteria - bacteria competing for nutrients - bacteria occupying host receptors - bacteriocin production

bacteria causing disease

Which of the following diseases is NOT spread by droplet infection? - tuberculosis - measlesthe - common cold - botulism - diphtheria

botulism

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered

contact transmission

Infectious disease

disease directly caused by microorganisms and not by other means, for example, genetic or degenerative diseases

The following choices list several types of diseases, along with factors that may contribute to their emergence. Which disease and associated factor do NOT match? - increased incidence of Lyme disease; increases in deer populations - increased incidence of malaria; global warming spread of cholera to new regions; modern travel - emergence of avian influenza A (H5N1); use of antibiotics

emergence of avian influenza A (H5N1); use of antibiotics

If a disease occurs at a fairly stable rate, it is said to be

endemic

The science that deals with when diseases occur and how they are transmitted is called

epidemiology.

Koch's Postulates

experimental requirements for identifying the agent of an infectious disease

A cold transmitted by a facial tissue is an example of

fomite

Which one of the following does NOT contribute to the incidence of nosocomial infections?

gram-negative cell walls

A needlestick is an example of

indirect contact transmission by fomite.

Biological transmission differs from mechanical transmission in that biological transmission - works only with noncommunicable diseases. - involves reproduction of a pathogen in an arthropod vector prior to transmission. - requires direct contact. - involves fomites. - occurs when a pathogen is carried on the feet of an insect.

involves reproduction of a pathogen in an arthropod vector prior to transmission.

A commensal bacterium

may also be an opportunistic pathogen.

The major significance of Robert Koch's work is that - microorganisms can be cultured. - microorganisms are present in a diseased animal. - diseases can be transmitted from one animal to another. - microorganisms are the result of disease. - microorganisms cause disease.

microorganisms cause disease

Which of the following is a fungal zoonosis that can be transmitted by direct contact?

ringworm

Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?

single-use

If a patient notices a healthcare worker not following suggested precautions,

they should immediately bring it to the attention of the healthcare worker.

Germ Theory of Disease

this theory states that microorganisms cause infected diseases

During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.The method of transmission of the disease in the situation was

vehicle

As a health care worker, you are keenly aware of how important it is to avoid harming patients. You worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the most important thing you can do to avoid this?

wash my hands before interacting with any patient