A commensal bacterium

A) does not receive any benefit from its host.

B) is beneficial to its host.

C) may also be an opportunistic pathogen.

D) does not infect its host.

E) B and D only

C

Which of the following statements is TRUE?

A) Symbiosis refers to different organisms living together.

B) Members of a symbiotic relationship cannot live without each other.

C) A parasite is not in symbiosis with its host.

D) Symbiosis refers to different organisms living together and benefiting from each other.

E) At least one member must benefit in a symbiotic relationship.

E

A nosocomial infection is

A) always present, but is inapparent at the time of hospitalization.

B) acquired during the course of hospitalization.

C) always caused by medical personnel.

D) only a result of surgery.

E) always caused by pathogenic bacteria.

B

The major significance of Robert Koch's work is that

A) microorganisms are present in a diseased animal.

B) diseases can be transmitted from one animal to another.

C) microorganisms can be cultured.

D) microorganisms cause disease.

E) microorganisms are the result of disease.

D

Koch's postulates don't apply to all diseases because

A) Some microorganisms can't be cultured in laboratory media

B) Some microorganisms don't cause the same disease in laboratory animals

C) Some microorganisms cause different symptoms under different conditions

D) Some microorganisms can't be observed

E) All diseases aren't caused by microorganisms

E

Which of the following diseases is NOT spread by droplet infection?

A) botulism

B) tuberculosis

C) measles

D) the common cold

E) diphtheria

A

Mechanical transmission differs from biological transmission in that mechanical transmission

A) Doesn't require an arthropod

B) Involves fomites

C) Doesn't involve specific diseases

D) Requires direct contact

E) Doesn't work with noncommunicable diseases

C

Which of the following definitions is INCORRECT?

A) endemic - a disease that is constantly present in a population

B) epidemic - fraction of the population having a disease at a specified time

C) pandemic - a disease that affects a large number of people in the world in a short time

D) sporadic - a disease that affects a population occasionally

E) none of the above

B

Which of these infections can cause septicemia?

A) bacteremia

B) focal infection

C) local infections

D) septicemia

E) systemic infection

B

Which type of infection can be caused septicemia?

A) bacteremia

B) focal infection

C) local infections

D) septicemia

E) systemic infection

E

Koch observed Bacillus anthracismultiplying in the blood of cattle. What is this condition called?

A) bacteremia

B) focal infection

C) local infection

D) septicemia

E) systemic infection

D

Nosocomial infections are most often caused by

A) Escherichia coli

B) Staphylococcus aureus

C) Enterococcus

D) Pceudomonas

E) Klebsiella

A

Transient microbiota differ from normal microbiota in that transient microbiota

A) cause diseases.

B) are found in a certain location on the host.

C) are always acquired by direct contact.

D) are present for a relatively short time.

E) never cause disease.

D

Which of the following statements about nosocomial infections is FALSE?

A) They occur in compromised patients.

B) They may be caused by opportunists.

C) They may be caused by drug-resistant bacteria.

D) They may be caused by normal microbiota.

E) The patient was infected before hospitalization.

E

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in

A) body odor.

B) fewer diseases.

C) increased susceptibility to disease.

D) normal microbiota returning immediately.

E) no bacterial growth because washing removes their food source.

C

Which of the following is NOT a reservoir of infection?

A) a sick person

B) a healthy person

C) a sick animal

D) a hospital

E) None of the above

E

All of the following is a communicable disease except

A) malaria

B) AIDS

C) tuberculosis

D) tetanus

E) typhoid fever

D

Which of the following is a fomite?

A) water

B) droplets from a sneeze

C) pus

D) insects

E) a hypodermic needle

E

All of the following statements about biological transmission are true except

A) The pathogen reproduces in the vector.

B) The pathogen may enter the host in the vector's feces.

C) Houseflies are an important vector.

D) The pathogen may be injected by the bite of the vector.

E) The pathogen may require the vector as a host.

C

Which of the following definitions is INCORRECT?

A) acute: a short-lasting primary infection

B) inapparent: infection characteristic of a carrier state

C) chronic: a disease that develops slowly and lasts for months

D) primary infection: an initial illness

E) secondary infection: a long-lasting illness

E

Symptoms of disease differ from signs of disease in that symptoms

A) are changes felt by the patient.

B) are changes observed by the physician.

C) are specific for a particular disease.

D) always occur as part of a syndrome.

E) None of the answers is correct.

A

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

A) ecology.

B) epidemiology.

C) communicable disease.

D) morbidity and mortality.

E) public health.

B

Figure 14.1 shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level?

A) a

B) b

C) c

D) d

E) none of the above

D

Emergence of infectious diseases can be attributed to all of the following EXCEPT

A) antibiotic resistance.

B) climatic changes.

C) digging up soil.

D) microbes trying to cause disease.

E) travel.

D

Which of the following pairs is mismatched?

A) malaria — vector

B) salmonellosis — vehicle transmission

C) syphilis — direct contact

D) influenza — droplet infection

E) None of the pairs is mismatched.

E

All of the following can contribute to postoperative infections except

A) using syringes more than once

B) normal microbiota on the operating room staff

C) errors in aseptic technique

D) antibiotic resistance

E) All of the answers are correct.

E

In Figure 14.2, what is the endemic level of rotavirus infections?

A) 0%

B) Approximately 10%

C) Approximately 20%

D) 35%

E) The month of January

B

A cold transmitted by a facial tissue is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

E

A cold transmitted by an unprotected sneeze is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

B

A sexually transmitted disease is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

A

Gastroenteritis is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

E

A needle stick is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

C

Legionellosis transmitted by a grocery store mist machine is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

E

Plague transmitted by a flea is an example of

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

D

The most likely mode of transmission plague between humans is

A) direct contact.

B) droplet transmission.

C) fomite.

D) vector.

E) vehicle transmission.

B

Situation 14.1 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. burnetiiantibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.

Situation 14.1 is an example of

A) human reservoir

B) a zoonosis

C) a nonliving reservoir

D) a vector

E) a focal infection

B

Situation 14.1 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. burnetiiantibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.

In Situation 14.1, the etiologic agent of the disease is

A) sheep.

B) soil.

C) Coxiella burnetii.

D) pneumonia.

E) wind.

C

Situation 14.1 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. burnetiiantibodies. 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 was

A) direct contact.

B) droplet.

C) indirect contact.

D) vector-borne.

E) vehicle.

E

Which of the following is NOT an example of microbial antagonism?

A) acid production by bacteria

B) bacteriocin production

C) bacteria occupying host receptors

D) bacteria causing disease

E) none of the above

E

The yeast Candida albicans does not normally cause disease because of

A) symbiotic bacteria.

B) antagonistic bacteria.

C) parasitic bacteria.

D) commensal bacteria.

E) none of the above.

B

Haemophilus bacteria require heme protein produced by Staphylococcus bacteria. This is an example of

A) Antagonism

B) Commensalism

C) Parasitism

D) Synergism

E) None of the above

D

Which one of the following is NOT a zoonosis?

A) cat-scratch disease

B) Hantavirus pulmonary syndrome

C) rabies

D) tapeworm

E) none of the above

E

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

A) communicable disease.

B) latent infection.

C) nosocomial infection.

D) sporadic disease.

E) None of the answers is correct.

C

The graph in Figure 14.3 shows the incidence of polio in the United States. The period between 1945 and 1955 indicates a(n)

A) endemic level.

B) epidemic level.

C) sporadic infection.

D) communicable disease.

E) pandemic.

B

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

A) Formation of biofilms

B) Lapse in aseptic techniques

C) Gram-negative cell walls

D) Lack of hand-washing

E) Lack of insect control

C

For a particular disease at a specific time period, morbidity rates should always be equal or greater than mortality rates.

True/False

True

Testing the effectiveness of a new drug for anthrax would be best performed as an experimental study.

True/False

True

MMWR is a publication by the CDC that reports on only emerging diseases.

True/False

False

A researcher only needs to select a cohort group when implementing an analytical epidemiological study.

True/False

False

Diseases that are referred to as emerging infectious diseases have only been discovered in the past fifty years.

True/False

False

Compromised hosts are always suffering from suppressed immune systems.

True/False

False

A host is not considered diseased until an infection changes one's state of health.

True/False

True

Reservoirs of infections are always animate objects.

True/False

False

Urinary tract infections are the most common forms of nosocomial infections.

True/False

False

Both normal and transient flora can become opportunistic pathogens.

True/False

True