CIC exam With Questions And Answers
Chain of Infection - Answer - 1)Infectious agent= organism with ability to cause disease; greater
virulence, invasiveness, and pathogenicity => increased odds of infection
2) Reservoir: place where microbes can persist and reproduce
3) Portal of Exit: way for microbe to leave the reservoir
4) Mode of transmission: method of microbe transfer from one place to another
5) Portal of entry: opening that allows microbe to enter host
6) Susceptible host: Lacks immunity or physical resistance to prevent invasion by microbe
Is a circle; each link must be present in sequential order for infection to occur
Virulence - Answer - Measure of microbe's ability to invade and create disease
Depends on ability to:
Survive in environment between hosts
Transmit between hosts (moving; adherence)
Proliferate
IgM - Answer - Pentamer; primary response, short-lived (<6 months); best at fixing complement
IgG - Answer - Monomer; main blood antibody, secondary response; longer lived. opsonization and
toxin neutralization. 4 subclasses
Physical barriers - Answer - Skin; fever; secreted antimicrobials; innate immunity
Complement system - Answer - 11=protein cascade; classically activate by ab:ag complexes; alternate
by pathogen surfaces
Skin defects; examples and associated pathogens - Answer - Wounds, burns, trauma, serious derm
problems, indwelling devices, injections. Skin flora- S. aureus, CNS, strep pyo, corynebacteria, malassezia
furfur
, Mucous membrane barrier defects; examples and associated pathogens - Answer - chemo-induced
mucositosis, head/neck trauma, smoking, inhalational injury, antacids/PPIs. Resident flora- anaerobes,
aerobic GNR, candida, enteroccus, bovis
Body passage obstruction; examples and associated pathogens - Answer - Tumors, foreign bodies,
stones, cystic fibrosis. Resident flora overgrow or invade; site-specific.
Abnormal number or function of granulocytes - Answer - Leukemia, chemo, congenital disorders,
diabetes. If short term (< 2 wks) then aerobic GNR, Sa, CoNS. IF long term, add fungi (candida, t. glabrata,
aspergillus)
Abnormalities of cell-mediated immunity - Answer - BMT, HIV, steroids, malnutrition, 3rd tri pregnancy.
Bacteria: Intracellular pathogens (listeria, salmonella, mycobacteria, nocardia, legionella).
Fungi: candida, Cryptococcus, coccidioides, histoplasma. Virus: Herpes group
Also toxoplasma and strongyloides.
abnormalities of humoral immunity - Answer - BMT, HIV, some cancers, aging. Strep pneumo,
encapsulated H. flu, Neisseria meningitidis
Preventing infection for immunocompromised patients - Answer - Take thorough patient history.
Prepare before starting with all vaccines, procedures, line placement, screening. Support gastric acidity.
Prevent exposures with awesome hygiene, approp food and water precautions, visitor education, no
flowers or plants, and possible abx prophy (for infections that might reactivate or high-risk for
pneumocystis)
Mycoplasma spp. - Answer - No cell wall --> limited abx choices. Cause atypical pneumonia. Usually
diagnosed by serology
Chlamydiae - Answer - obligate intracellular parasites. Elementary body=infectious, reticulated=
intracellular. DFA or ELISA for detection of antigen is most common. Can also detect antibodies.
Rickettsiae - Answer - obligate intracellular parasites. arthropod vectors. Rarely culturing; detected by
serology using ELISA for antibodies.
, Textbook viral replication cycle - Answer - 1. Attachment 2. penetration/entry 3. replication 4.
maturation/assembly 5. release
Sensitivity - Answer - % of true + who test +; inherent to test
Specificity - Answer - % of true neg who test neg; inherent to test
PPV - Answer - Likelihood that a + test represents a true case (% T+/all+); depends on the test and on
prevalence of disease in population
NPV - Answer - Likelihood that a negative test result is a true non-case (%TN/allN); depends on test and
population prevalence
CSF analysis- bacterial mening - Answer - 1000-5000 WBCs, mostly PMNs. Increased pressure. Increased
protein . Decreased glucose. Bacteria seen on smears.
CSF analysis- viral mening - Answer - Pressure, glucose normal. Lymphocytes seen, but few WBC in
general. Protein normal-elevated. Nothing on smears.
CSF analysis- fungus mening - Answer - Pressure variable. Glucose low, protein high. WBCs vary, but
lymphocytes predominate. India ink smear +.
CSF analysis- TB mening - Answer - Pressure variable. Glucose low to megalow. WBCs vary, mostly
lymphocytes. Protein elevated. AFB stain +
Cold Agglutinins test - Answer - Used to detect antibodies for Mycoplasma pneumoniae or
mononucleosis. Positive test is high titer, with resp Sx indicates M. pneumo infection, viral pneumo, or
primary atypical pneumo
CRP test - Answer - Serum sample looking for the CR protein; normal value is none or low CRP. Indicates
current acute inflammation
, Liver Function Tests - Answer - chemistry assays on blood; looking for various things including enzymes,
bilirubin, ammonia, and albumin. Generally higher is worse. Helps detect liver problems, differentiate
among liver problems, measure liver damage, and follow response to Tx.
Arterial Blood Gas (ABG) - Answer - blood from artery, measures oxygen and CO2 tension, pH. Assesses
gas exchange, which is helpful in recognizing pneumonia
Sedimentation rate - Answer - Measures rate of RBCs sinking; faster indicates acute
infection/inflammation (among other things, is not very specific)
Toxin production tests - Answer - Many ways of doing, including EIA and HPLC. limulus amebocyte
lysate tests for endotoxin.
Weil-Felix agglutination - Answer - Serum, test for rickettsial antibodies. High titer or 4x rise in titer
indicates rickettsial infection.
Urinalysis - Answer - Multiple tests. Normal has various chemistry values and should have no or few
cells. High WBCs, leukocyte esterase, and nitrite indicate infection.
Complete blood count: WBC count - Answer - 4000-10000 is normal. High indicates
infection/inflammation. Low indicates AIDS or some other infections
CBC:WBC differential - Answer - Gives percents of cell types. Should be:
PMN>lymphocytes>monocytes>eosinophils>basophils. If inc PMNs and "left shift", acute bacterial
infection. If inc lymphocytes and reactive lymphs, some viral infections. Monocytes increase with EBV,
TB, endocarditis, and rickesttsia. Eosinophils increase with allergies, parasites, and mycobacteria.
Basophils shouldn't be high but it happens with allergies, variola, and varicella.
CBC: absolute neutrophil count - Answer - Normal is >2x109/L; less indicates neutropenia. <.5x109/L is
severe neutropenia
Lymphocyte subset - Answer - Additional test beyond CBC to differentiate T and B cells, and the types of
T cells. Important in monitoring HIV patients, also info about response type.
Chain of Infection - Answer - 1)Infectious agent= organism with ability to cause disease; greater
virulence, invasiveness, and pathogenicity => increased odds of infection
2) Reservoir: place where microbes can persist and reproduce
3) Portal of Exit: way for microbe to leave the reservoir
4) Mode of transmission: method of microbe transfer from one place to another
5) Portal of entry: opening that allows microbe to enter host
6) Susceptible host: Lacks immunity or physical resistance to prevent invasion by microbe
Is a circle; each link must be present in sequential order for infection to occur
Virulence - Answer - Measure of microbe's ability to invade and create disease
Depends on ability to:
Survive in environment between hosts
Transmit between hosts (moving; adherence)
Proliferate
IgM - Answer - Pentamer; primary response, short-lived (<6 months); best at fixing complement
IgG - Answer - Monomer; main blood antibody, secondary response; longer lived. opsonization and
toxin neutralization. 4 subclasses
Physical barriers - Answer - Skin; fever; secreted antimicrobials; innate immunity
Complement system - Answer - 11=protein cascade; classically activate by ab:ag complexes; alternate
by pathogen surfaces
Skin defects; examples and associated pathogens - Answer - Wounds, burns, trauma, serious derm
problems, indwelling devices, injections. Skin flora- S. aureus, CNS, strep pyo, corynebacteria, malassezia
furfur
, Mucous membrane barrier defects; examples and associated pathogens - Answer - chemo-induced
mucositosis, head/neck trauma, smoking, inhalational injury, antacids/PPIs. Resident flora- anaerobes,
aerobic GNR, candida, enteroccus, bovis
Body passage obstruction; examples and associated pathogens - Answer - Tumors, foreign bodies,
stones, cystic fibrosis. Resident flora overgrow or invade; site-specific.
Abnormal number or function of granulocytes - Answer - Leukemia, chemo, congenital disorders,
diabetes. If short term (< 2 wks) then aerobic GNR, Sa, CoNS. IF long term, add fungi (candida, t. glabrata,
aspergillus)
Abnormalities of cell-mediated immunity - Answer - BMT, HIV, steroids, malnutrition, 3rd tri pregnancy.
Bacteria: Intracellular pathogens (listeria, salmonella, mycobacteria, nocardia, legionella).
Fungi: candida, Cryptococcus, coccidioides, histoplasma. Virus: Herpes group
Also toxoplasma and strongyloides.
abnormalities of humoral immunity - Answer - BMT, HIV, some cancers, aging. Strep pneumo,
encapsulated H. flu, Neisseria meningitidis
Preventing infection for immunocompromised patients - Answer - Take thorough patient history.
Prepare before starting with all vaccines, procedures, line placement, screening. Support gastric acidity.
Prevent exposures with awesome hygiene, approp food and water precautions, visitor education, no
flowers or plants, and possible abx prophy (for infections that might reactivate or high-risk for
pneumocystis)
Mycoplasma spp. - Answer - No cell wall --> limited abx choices. Cause atypical pneumonia. Usually
diagnosed by serology
Chlamydiae - Answer - obligate intracellular parasites. Elementary body=infectious, reticulated=
intracellular. DFA or ELISA for detection of antigen is most common. Can also detect antibodies.
Rickettsiae - Answer - obligate intracellular parasites. arthropod vectors. Rarely culturing; detected by
serology using ELISA for antibodies.
, Textbook viral replication cycle - Answer - 1. Attachment 2. penetration/entry 3. replication 4.
maturation/assembly 5. release
Sensitivity - Answer - % of true + who test +; inherent to test
Specificity - Answer - % of true neg who test neg; inherent to test
PPV - Answer - Likelihood that a + test represents a true case (% T+/all+); depends on the test and on
prevalence of disease in population
NPV - Answer - Likelihood that a negative test result is a true non-case (%TN/allN); depends on test and
population prevalence
CSF analysis- bacterial mening - Answer - 1000-5000 WBCs, mostly PMNs. Increased pressure. Increased
protein . Decreased glucose. Bacteria seen on smears.
CSF analysis- viral mening - Answer - Pressure, glucose normal. Lymphocytes seen, but few WBC in
general. Protein normal-elevated. Nothing on smears.
CSF analysis- fungus mening - Answer - Pressure variable. Glucose low, protein high. WBCs vary, but
lymphocytes predominate. India ink smear +.
CSF analysis- TB mening - Answer - Pressure variable. Glucose low to megalow. WBCs vary, mostly
lymphocytes. Protein elevated. AFB stain +
Cold Agglutinins test - Answer - Used to detect antibodies for Mycoplasma pneumoniae or
mononucleosis. Positive test is high titer, with resp Sx indicates M. pneumo infection, viral pneumo, or
primary atypical pneumo
CRP test - Answer - Serum sample looking for the CR protein; normal value is none or low CRP. Indicates
current acute inflammation
, Liver Function Tests - Answer - chemistry assays on blood; looking for various things including enzymes,
bilirubin, ammonia, and albumin. Generally higher is worse. Helps detect liver problems, differentiate
among liver problems, measure liver damage, and follow response to Tx.
Arterial Blood Gas (ABG) - Answer - blood from artery, measures oxygen and CO2 tension, pH. Assesses
gas exchange, which is helpful in recognizing pneumonia
Sedimentation rate - Answer - Measures rate of RBCs sinking; faster indicates acute
infection/inflammation (among other things, is not very specific)
Toxin production tests - Answer - Many ways of doing, including EIA and HPLC. limulus amebocyte
lysate tests for endotoxin.
Weil-Felix agglutination - Answer - Serum, test for rickettsial antibodies. High titer or 4x rise in titer
indicates rickettsial infection.
Urinalysis - Answer - Multiple tests. Normal has various chemistry values and should have no or few
cells. High WBCs, leukocyte esterase, and nitrite indicate infection.
Complete blood count: WBC count - Answer - 4000-10000 is normal. High indicates
infection/inflammation. Low indicates AIDS or some other infections
CBC:WBC differential - Answer - Gives percents of cell types. Should be:
PMN>lymphocytes>monocytes>eosinophils>basophils. If inc PMNs and "left shift", acute bacterial
infection. If inc lymphocytes and reactive lymphs, some viral infections. Monocytes increase with EBV,
TB, endocarditis, and rickesttsia. Eosinophils increase with allergies, parasites, and mycobacteria.
Basophils shouldn't be high but it happens with allergies, variola, and varicella.
CBC: absolute neutrophil count - Answer - Normal is >2x109/L; less indicates neutropenia. <.5x109/L is
severe neutropenia
Lymphocyte subset - Answer - Additional test beyond CBC to differentiate T and B cells, and the types of
T cells. Important in monitoring HIV patients, also info about response type.
