Microbiology : PreTest Self-Assessment & Review

James D. Kettering

Chapter 1 Virology - all with Video Answers

Educators

Chapter Questions

Problem 1

An HIV-positive patient asks you if you can tell him the chances of him progressing to symptomatic AIDS. Which one of the following tests would be most useful?
a. CD4 lymphocyte count
b. HIV antibody test
c. HIV RT PCR
d. Neopterin
e. HIV p24 antigen

Check back soon!

00:45

Problem 2

Which of the following viruses causes an acute febrile rash and produces disease in immunocompetent children but has been associated with transient aplastic crises in persons with sickle cell disease?
a. Rubeola
b. Varicella-zoster
c. Parvovirus
d. Rubella
e. Herpes simplex

Tate Hilken

Numerade Educator

03:33

Problem 3

Infection with herpes simplex virus, a common human pathogen, is best described by which of the following statements?
a. The CNS and visceral organs are usually involved
b. It rarely recurs in a host who has a high antibody titer
c. It can be reactivated by emotional disturbances or prolonged exposure to sunlight
d. Initial infection usually occurs by intestinal absorption of the virus
e. Infection with type 1 virus is most common

Dennis Howard

Numerade Educator

01:06

Problem 4

The latest and most effective therapy for AIDS patients includes azidothymidine (AZI), dideoxyinosine (DDI), and saquinavir or similar agents. Use of these three drugs would inhibit which of the following viral processes?
a. RNase, DNase
b. gp120 formation
c. p24 antibody expression
d. All membrane synthesis
e. Reverse transcriptase, protease

Dennis Howard

Numerade Educator

02:14

Problem 5

An HIV-positive patient prior to being treated with AZT, DDI, and saquinavir has a CD4 lymphocyte count and an HIV RNA viral load test done. Results are as follows:

CD4: 50 CD4 lymphocytes per microliter
HIV RNA: 750,000 copies per ml

Which of the following statements best describes the above patient?
a. This patient is no longer in danger of opportunistic infection
b. The 5-year prognosis is excellent
c. The patient's HIV screening test is most likely negative
d. The patient is not infectious
e. The viral load of 750,000 copies per $\mathrm{ml}$ suggests that the patient will respond to triple therapy

Ali Crampton

Numerade Educator

00:32

Problem 6

This HIV-positive patient with a viral load of 750,000 copies of HIV $\mathrm{RNA} / \mathrm{ml}$ and a total CD4 count of 50 is at an increased risk for a number of infectious diseases. For which of the following diseases is the patient at no more added risk than an immunocompetent host?
a. Pneumocystic pneumonia
b. Mycobacterial disease
c. Kaposi's sarcoma
d. Pneumococcal pneumonia
e. Herpes simplex virus

Joanna Quigley

Numerade Educator

02:19

Problem 7

Infectious mononucleosis, a viral disorder that can be debilitating, is characterized by which of the following statements?
a. It is most prevalent in children less than 14 years old
b. It is caused by a rhabdovirus
c. The causative pathogen is an Epstein-Barr virus
d. Affected persons respond to treatment with the production of heterophil antibodies
e. Ribavirin is the treatment of choice

Ummatul Choudary

Numerade Educator

00:20

Problem 8

A tube of monkey kidney cells is inoculated with nasopharyngeal secretions. During the next 7 days, no cytopathic effects (CPEs) are observed. On the eighth day, the tissue culture is infected accidentally with a picornavirus; nevertheless, the culture does not develop CPEs. The most likely explanation of this phenomenon is that
a. The nasopharyngeal secretions contained hemagglutinins
b. The nasopharyngeal secretions contained rubella virus
c. Picornavirus does not produce CPEs
d. Picornavirus does not replicate in monkey kidney cells
e. Monkey kidney cells are resistant to CPEs

Sam Limsuwannarot

Numerade Educator

01:26

Problem 9

The clinical picture of arbovirus infection fits one of three categories: encephalitis, hemorrhagic fever, or fever with myalgia. One of the characteristics of arboviruses is that they
a. Are transmitted by arthropod vectors
b. Are usually resistant to ether
c. Usually cause symptomatic infection in humans
d. Are closely related to parvoviruses

Joanna Quigley

Numerade Educator

00:55

Problem 10

Which one of the following statements best describes interferon's suspected mode of action in producing resistance to viral infection?
a. It stimulates a cell-mediated immunity
b. It stimulates humoral immunity
c. Its direct antiviral action is related to the suppression of messenger RNA formation
d. Its action is related to the synthesis of a protein that inhibits translation or transcription
e. It alters the permeability of the cell membrane so that viruses cannot enter the cell

Joanna Quigley

Numerade Educator

Problem 11

Coronaviruses are recognized by club-shaped surface projections that are $20 \mathrm{~nm}$ long and resemble solar coronas. These viruses are characterized by their ability to
a. Infect infants more frequently than adults
b. Cause the common cold
c. Grow well in the usual cultured cell lines
d. Grow profusely at $50^{\circ} \mathrm{C}$
e. Agglutinate human red blood cells

Check back soon!

00:46

Problem 12

Delta hepatitis only occurs in patients who also have either acute or chronic infection with hepatitis B virus. The delta agent is
a. An incomplete hepatitis B virus
b. Related to hepatitis A virus
c. A hepatitis B mutant
d. An incomplete RNA virus
e. Hepatitis C

Joanna Quigley

Numerade Educator

01:06

Problem 13

Which of the following antiviral agents is a purine nucleoside analogue that has shown promise with Lassa fever, influenza A and B, and respiratory syncytial virus (RSV)?
a. Amantadine
b. Rimantadine
c. Vidarabine
d. Ribavirin
e. Acyclovir

Dennis Howard

Numerade Educator

01:45

Problem 14

Echoviruses are cytopathogenic human viruses that mainly infect the
a. Respiratory system
b. Central nervous system
c. Blood and lymphatic systems
d. Intestinal tract
e. Bladder and urinary tract

Tanner Fonjweng

Numerade Educator

00:47

Problem 15

The most sensitive test for the diagnosis of herpes simplex (HSV) meningitis in a newborn infant is
a. HSV IgG antibody
b. HSV polymerase chain reaction (PCR)
c. HSV culture
d. Tzanck smear
e. Cerebrospinal fluid (CSF) protein analysis

Grant Castaneda

Numerade Educator

01:58

Problem 16

Acute hemorrhagic conjunctivitis (AHC) is a contagious ocular infection characterized by pain, swelling of the eyelids, and subconjunctival hemorrhages. AHC has been reported to be caused by which of the following viruses?
a. Coronavirus
b. Reovirus
c. Rhinovirus
d. Enterovirus
e. Respiratory syncytial virus

Asma Venkitta

Numerade Educator

02:19

Problem 17

Mumps virus accounts for 10 to $15 \%$ of all cases of aseptic meningitis in the United States. Infection with mumps virus
a. Is apt to recur periodically in many affected persons
b. Will usually cause mumps orchitis in postpubertal males
c. Is maintained in a large canine reservoir
d. Usually produces severe systemic manifestations
e. Is preventable by immunization

Ummatul Choudary

Numerade Educator

Problem 18

The serum of a newborn infant reveals a 1:32 cytomegalovirus (CMV) titer. The child is clinically asymptomatic. Which of the following courses of action would be advisable?
a. Repeat the CMV titer immediately
b. Wait 6 months and obtain another titer on the baby
c. Obtain a CMV titer from all siblings
d. Obtain an anti-CMV IgM titer from the mother
e. Obtain an anti-CMV IgM titer from the baby

Check back soon!

Problem 19

A 3-year-old child presents at the physician's office with symptoms of coryza, conjunctivitis, low-grade fever, and Koplik's spots. The causative agent of this disease belongs to which group of viruses?
a. Adenovirus
b. Herpesvirus
c. Picornavirus
d. Orthomyxovirus
e. Paramyxovirus

Check back soon!

01:13

Problem 20

One of the most common sexually transmitted diseases that may lead to cervical carcinoma is caused by which of the following viruses?
a. Cytomegalovirus
b. Papillomavirus
c. Epstein-Barr virus
d. Herpes simplex virus
e. Adenovirus

Joanna Quigley

Numerade Educator

Problem 21

Which virus is the leading cause of the croup syndrome in young children and, when infecting mammalian cells in culture, will hemabsorb red blood cells?
a. Group B coxsackievirus
b. Rotavirus
c. Parainfluenza virus
d. Adenovirus
e. Rhinovirus

Check back soon!

04:14

Problem 22

Hepatitis $\mathrm{E}$, a recently characterized hepatitis virus, is best described by which of the following statements?
a. It is not a threat to the blood supply
b. It is a major cause of blood-borne hepatitis
c. It is prevalent in North America
d. It is a single-stranded DNA virus
e. The disease resembles hepatitis $C$

Noah Boudrie

Numerade Educator

01:34

Problem 23

Meningitis is characterized by the acute onset of fever and stiff neck. Aseptic meningitis may be caused by a variety of microbial agents. During the initial $24 \mathrm{~h}$ of the course of aseptic meningitis, an affected person's cerebrospinal fluid is characterized by
a. Decreased protein content
b. Elevated glucose concentration
c. Lymphocytosis
d. Polymorphonuclear leukocytosis
e. Eosinophilia

Leah Lampen

Numerade Educator

Problem 24

Infection with hepatitis $D$ virus (HDV; delta agent) can occur simultaneously with infection with hepatitis B virus (HBV) or in a carrier of hepatitis B virus because HDV is a defective virus that requires HBV for its replicative function. What serologic test can be used to determine whether a patient with $\mathrm{HDV}$ is an HBV carrier?
a. HBsAg
b. $\mathrm{HBc} \operatorname{IgM}$
c. $\mathrm{HBeAg}$
d. HBs IgM
e. HBs $\lg G$

Check back soon!

Problem 25

A nurse develops clinical symptoms consistent with hepatitis. She recalls sticking herself with a needle approximately 4 months before after drawing blood from a patient. Serologic tests for HBsAg, antibodies to HBsAg, and hepatitis A virus (HAV) are all negative; however, she is positive for $\operatorname{IgM}$ core antibody. The nurse
a. Does not have hepatitis B
b. Has hepatitis A
c. Is in the late stages of hepatitis B infection
d. Is in the "window" (after the disappearance of $\mathrm{HBsAg}$ and before the appearance of anti-HBsAg)
e. Has hepatitis $C$

Check back soon!