Chapter 3: Identification of Infectious Disease Processes

A patient was just admitted to a long-term care facility from the local hospital. The patient is being treated for psoriasis. The psoriasis does not appear to be responding to treatment, and 48 hours later, the infection preventionist (IP) receives a report that a Certified Nursing Assistant has developed an itchy rash. The patient’s physician visits and determines that the patient has crusted scabies and not psoriasis. Another name for crusted scabies is:

a. American scabies

b. Norwegian scabies

c. Canadian scabies

d. English scabies

b. Norwegian scabies

Guidelines for transporting specimens include:

1) Transport within 2 hours of collecting a specimen

2) Transport in leakproof specimen containers and sealable leakproof bags

3) Transport specimen in the syringe used to collect it

4) Refrigerate all specimens prior to transport

a. 1, 4

b. 2, 3

c. 1, 2

d. 3, 4

c. 1, 2

Which is true about a tuberculin skin test (TST):

a. Positive TST indicates active tuberculosis (TB) infection

b. Negative TST rules out active TB infection

c. Positive TST indicates past exposure to TB

d. Negative TST indicates past exposure to TB

c. Positive TST indicates past exposure to TB

The optimal time to collect a sputum specimen for acid-fast bacilli (AFB) testing to rule out TB would be:

a. First thing in the morning

b. After a respiratory treatment

c. Prior to the patient going to bed

d. Prior to a respiratory treatment

a. First thing in the morning

A hospital has hired a new manager of the Microbiology section in the laboratory. During the initial discussion with the manager about the infection

prevention and control program, the manager stressed the importance of collaboration between the departments. Including healthcare-associated

infections (HAIs). Of the choices below, which activity will best meet this goal?

a. The Microbiology staff’s compliance with the annual flu vaccination program and tuberculosis skin testing.
b. The Microbiology staff’s educational sessions for hospital staff to help prevent infection.
c. Microbiology’s prompt notification to the Infection Prevention and Control department of any organisms suggesting resistance patterns.
d. The Microbiology manager’s attendance at local, state, and/or national infection prevention and control educational conferences.

c. Microbiology’s prompt notification to the Infection Prevention and Control department of any organisms suggesting resistance patterns.

The primary immune response after exposure to a communicable disease results after production of:

a. Immunoglobulin D (IgD)
b. Immunoglobulin M (IgM)
c. Immunoglobulin A (IgA)
d. Immunoglobulin G (IgG)

b. Immunoglobulin M (IgM)

When are IgM antibodies to Hepatitis A virus (HAV) detectable in the blood?

a. Within 24 hours of exposure
b. Within 3 weeks of exposure
c. 3 days after exposure
d. 8 to 12 weeks after exposure

b. Within 3 weeks of exposure

The incubation period for pertussis in immunocompetent persons is usually:

a. 7 to 10 days
b. 3 to 5 days
c. 10 to 12 days
d. 2 to 4 days

a. 7 to 10 days

A patient who was hospitalized for 2 days calls 3 days after discharge and reports that scabies has been diagnosed. The IP knows that scabies is not healthcare-associated because:

a. Scabies is confirmed that all linens the patient came into contact with had been properly laundered.
b. The incubation period for scabies is shorter than 5 days.
c. Scabies is only transmitted through direct contact and none of the healthcare personnel who cared for the patient are infested.
d. Scabies is due to recent healthcare stay. The IP knows that scabies infestation is not healthcare-associated because:

b. The incubation period for scabies is shorter than 5 days.

A nurse is concerned that a patient in the neurology ward has Creutzfeldt-Jakob disease after receiving a lab report stating that the patient had a positive nucleic acid test for John Cunningham virus (JCV). The nurse’s response is:

a. Unsure.
b. The test is positive for Creutzfeldt-Jakob disease, which is a prion disease.
c. The test is positive for JCV (a polyomavirus), which is not a prion disease.
d. The test is positive for JCV (a polyomavirus), which is a prion disease.

c. The test is positive for JCV (a polyomavirus), which is not a prion disease.

An IP is conducting an educational session to help the nursing staff understand infectious disease transmission. She explains that the initial element in virulence is the ability of pathogens to survive in the external environment during transit between hosts. What is this process?

a. The development of virulence.
b. Secretion of enzymes that enhance spread through tissues.
c. A mechanism for transmission to a new host.
d. Avoidance of host resistance.

c. A mechanism for transmission to a new host.

The management of an infected surgical site includes the following foundational principles:

1. Open and drain the incision

2. Debride fibrous debris and necrotic soft tissue

3. Replace hardware

4. Implement antimicrobial management as needed

5. Manage the open wound

a. 1, 2, 3, 4

b. 2, 3, 4, 5

c. 1, 3, 4, 5

d. 1, 2, 4, 5

d. 1, 2, 4, 5

During annual TST, an employee’s test result was read as 10 mm induration. The employee’s last TST was negative. This initial result indicates a:

a. Positive test

b. False positive

c. Negative test

d. False negative

a. Positive test

A microbe that can grow in the absence of oxygen but is also able to utilize oxygen for growth is a/an:

a. Aerobe

b. Obligate anaerobe

c. Facultative anaerobe

d. Microaerophilic aerobe

c. Facultative anaerobe

Western blot testing for human immunodeficiency virus (HIV) is used to detect:

a. HIV DNA in a serum sample

b. HIV RNA in a serum sample

c. HIV antibodies in a serum sample

d. HIV proteins in a serum sample

c. HIV antibodies in a serum sample

An infection preventionist (IP) is reviewing the cerebrospinal fluid (CSF) results of a patient and notes elevated white blood cell count (WBCs), markedly increased neutrophils, low glucose level, and elevated protein concentration. What type of meningitis should she suspect?

a. Bacterial

b. Viral

c. Fungal

d. Aseptic

a. Bacterial

Which of the following statements about influenza is false?

a. Influenza is primarily spread between individuals via respiratory secretions.

b. Influenza symptoms start 48 to 72 hours after infection and typically 48 hours before the onset of symptoms.

c. Viral shedding normally persists for less than 5 days but can be prolonged in elderly or immunocompromised persons.

d. The typical influenza symptomology is not always predictive of influenza in elderly or immunocompromised persons.

b. Influenza symptoms start 48 to 72 hours after infection and typically 48 hours before the onset of symptoms.

Which of the following statements is false regarding influenza viruses?

a. They are divided into three categories: A, B, and C.

b. Influenza A strains have been the predominant cause of worldwide epidemics (pandemics).

c. Influenza A and B strains have been named according to their state and year of their initial isolation.

d. Influenza B strains have not been associated with large epidemics.

d. Influenza B strains have not been associated with large epidemics.

Which factor is commonly associated with Clostridium difficile infections (CDIs)?

a. Chemotherapeutic agents

b. ACE inhibitors

c. Prophylactic antibiotics or antibiotic to treat a primary bacterial infection

d. Antiviral medication to treat a primary viral infection

c. Prophylactic antibiotics or antibiotic to treat a primary bacterial infection

The IP is reviewing the history of a patient who has been in the facility on a ventilator for 1 week. All of the following are risk factors for colonization and infection with multidrug-resistant pathogens except:

a. Antimicrobial therapy in preceding 90 days

b. Current hospitalization for 5 days or more

c. Immunosuppressive state of therapy

d. Low frequency of antibiotic resistance in the facility

d. Low frequency of antibiotic resistance in the facility

The current community-acquired pneumonia (CAP) national guidelines used in the United States include all of the following except:

a. Antibiotic timing (within 6 hours of arrival)

b. Antibiotic selection

c. Blood cultures performed in the Emergency Department before antibiotics were administered

d. Ensure that all patients are screened for pneumococcal vaccination

d. Ensure that all patients are screened for pneumococcal vaccination

Measures that can be practiced for prevention of aspiration include all of the following except:

a. Antibiotic prophylaxis

b. Oropharyngeal cleaning and decontamination with chlorhexidine solution

c. Orotracheal intubation, unless contraindicated, rather than nasotracheal intubation

d. The head of the bed elevated at an angle of 30 to 45 degrees

a. Antibiotic prophylaxis

All of the following are descriptions of patients with immunocompromised status except:

a. HIV with CD4 count <200

b. Leukemia or lymphoma

c. Neutropenia (absolute neutrophils count <500/mm3)

d. 1 year post-bone marrow transplant

d. 1 year post-bone marrow transplant

The paroxysmal stage of pertussis usually lasts:

a. 1 to 6 weeks

b. 11 to 15 weeks

c. 15 to 20 weeks

d. 6 to 21 weeks

a. 1 to 6 weeks

Which of the following is not an effect of malnutrition on the body’s immune system?

a. Intestinal bacteria may be altered

b. Tissue integrity is impaired

c. Mucosal secretions are decreased

d. Urine may be colonized with bacteria

Lyme disease is commonly found in all of the following regions of the United States except:

a. New England

b. Mid-Atlantic

c. Upper Midwest

d. Southeast

d. Southeast

All of the following organisms can penetrate the intact epithelium of the conjunctiva or cornea except:

a. Staphylococcus aureus

b. Streptococcus pneumoniae

c. Neisseria meningitidis

d. Neisseria gonorrhoeae

a. Staphylococcus aureus

A patient is admitted with pruritic lesions on the hands, webs of fingers, wrists, the extensor surfaces of the elbows and knees, and the outer surfaces of the feet, armpits, buttocks, and waist. The most likely diagnosis is:

a. Scarlet fever

b. Herpes zoster

c. Scabies

d. Measles

c. Scabies

Which of the following is not likely to contaminate total parenteral nutrition?

a. Mycobacterium fortuitum

b. Candida albicans

c. Pseudomonas aeruginosa

d. Staphylococcus epidermis

a. Mycobacterium fortuitum

A urine specimen collected from an indwelling urinary catheter was sent to the laboratory for culture and sensitivity testing. Culture results reported a count of 50,000 CFU/mL of Escherichia coli. Sensitivity testing reported resistance to cephalosporin and sensitivity to ciprofloxacin. This organism is an example of:

a. Methicillin resistance

b. Aminoglycoside resistance

c. Extended-spectrum beta-lactam (ESBL) resistance

d. Fluoroquinolone resistance

c. Extended-spectrum beta-lactam (ESBL) resistance

A patient has nasal swab positive for methicillin-resistant Staphylococcus aureus (MRSA) in the absence of symptoms. This is an example of

a. Colonization

b. Infection

c. Asymptomatic infection

d. Symptomatic infection

a. Colonization

Which of the following is not a mechanical barrier to infection?

a. Intact skin

b. Mucous membranes

c. Secretions

d. Cilia

c. Secretions

Patients with cell-mediated immunity dysfunction are susceptible to infections attributed to pathogenic intracellular bacteria. Examples of these organisms include:

1. Salmonella typhi

2. Bacteroides fragilis

3. Listeria monocytogenes

4. Staphylococcus aureus  

a. 2, 3

b. 1, 3

c. 1, 2

d. 3, 4

b. 1, 3

What is the name for a substance that prevents water-soluble elements such as antibiotics and disinfectants from reaching pathogens?

a. Cell wall

b. Biofilm

c. Sludge

d. Biocarbon

b. Biofilm

Gram-negative bacterium that is responsible for chronic antral gastritis and is a major factor in peptic ulcer disease is:

a. Streptococcus pyogenes

b. Salmonella typhi

c. Clostridium difficile

d. Helicobacter pylori

d. Helicobacter pylori

The spirochete Borrelia burgdorferi is the agent responsible for:

a. Legionnaires’ disease

b. Syphilis

c. Lyme disease

d. Aseptic meningitis

c. Lyme disease

Higher morbidity rates in chronic Hepatitis B virus (HBV) carriers are associated with a co-infection of which of the following:

a. Hepatitis D

b. Hepatitis C

c. Hepatitis E

d. Hepatitis A

a. Hepatitis D

Gram stains classify an organism as Gram-positive or Gram-negative. The determinant factors for Gram stains are cell wall components of:

a. Peptidoglycans

b. Lipids

c. Polysaccharides

d. Mycolic acids

a. Peptidoglycans

39. An example of an obligate intracellular parasitic bacterium would be an organism responsible for:

1. Hepatitis

2. Q fever

3. Malaria

4. Epidemic typhus

a. 1, 3

b. 2, 4

c. 3, 4

d. 1, 2

b. 2, 4

Which one of the following statements is true regarding bacterial spores?

a. They are resistant to antibiotics

b. They allow bacteria to multiply in adverse condition

c. They are usually formed by Gram-negative bacteria

d. They can be identified with Gram-negative stain

a. They are resistant to antibiotics

Which organism found in food poisoning causes the most rapid onset of symptoms?

a. Salmonella enteritidis  

b. Shigella sonnei  

c. Staphylococcus aureus  

d. Escherichia coli

c. Staphylococcus aureus  

The nurse is teaching nurses how to assess infection risks in patients. Depletion of what cell type provides the best indication of susceptibility to most bacterial infections?

a. Monocyte

b. Eosinophil

c. Neutrophil

d. Lymphocyte

c. Neutrophil

A 14-year-old boy from rural Maryland was seen in the emergency room with fever, fatigue, chills, headache, and a large annular lesion on his left thigh, which the patient described as burning and itching. What is the most probable vector of this child’s illness?

a. Tick

b. Mosquito

c. Flea

d. Louse

a. Tick

Which immune marker represents past exposure to disease?

a. IgG

b. IgE

c. IgM

d. IgA

a. IgG

The Emergency Department reports three cases of cramping, nausea, pain, and diarrhea within a 24-hour period. All persons attended a family reunion picnic they all attended. The IP suspects which of the following foodborne illnesses.

a. Salmonella

b. Hepatitis A

c. Staphylococcus aureus

d. Clostridium perfringens

a. Salmonella

When reviewing the Gram stain of a person with a wound infection, IP sees Gram-positive organisms in clusters. Which organism would this most likely represent?

a. Streptococcus

b. Enterococcus

c. Corynebacterium

d. Staphylococcus

d. Staphylococcus

He receives a call from a young man who thinks he was exposed to HIV. He has just taken his first test (an enzyme-linked immunosorbent assay [ELISA]), which was negative. Which of the following is the most likely time frame after exposure in which HIV antibodies would be measurable in a blood test?

a. 1 to 3 months

b. 6 to 12 months

c. 12 months

d. 7 days

a. 1 to 3 months

The causative organism of Creutzfeldt-Jakob disease is a:

a. Helminth

b. Diphtheroid

c. Spirochete

d. Prion

d. Prion

Anaerobic cultures should be used for any of the following except:

a. Transtracheal aspirate

b. Blood

c. Spinal fluid

d. Sputum

d. Sputum

Routine microbiologic sampling is indicated for which of the following?

a. Respiratory therapy equipment

b. Dialysis fluid

c. Sterile disposable equipment

d. Operating room surfaces

b. Dialysis fluid