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Micro Viruses Flashcards

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USMLE® Step 1 flashcards
1
Q 
Reassortment 
What is it?
What does it lead to?
Danger?
Example
A

Viruses with segmented genomes exchange segments
High frequency re-combination
Worldwide pandemics
Influenza virus

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2
Q

Complementation

A

1 of 2 viruses that infects a cell has a mutation that results in a nonfunctional protein. The non-mutated virus complements the mutated one by making a functional protein that serves both viruses

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3
Q

Phenotypic mixing

A

Simultaneous infection –> Genome of virus A partially or completely coated in surface protein from virus B

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4
Q

Live attenuated vaccines
What does it induce?
Risk
Names

A

Humoral and cell-mediated immunty
Reversion to virulence (rare)
“Live! one night only! see Small Yellow Chickens get vaccinated with Sabin’s and MMR! It’s INcredible”
Smallpox, Yellow fever, Chickenpox (VZV), Sabin’s Polio, MMR, Influenza (intranasal)

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5
Q

Can MMR be given to HIV pts?

A

Even though its a live attenuated vaccine, it can be given to HIV pts if they don’t show signs of immunodeficiency

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6
Q

Killed Vaccines
What does it induce?
Names

A

Only humoral response
“SalK = Killed. RIP Always”
Rabies, Influenza (injected), Salk Polio, HAV

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7
Q

Recombinant vaccines

A

HBV (Ag = recombinant HBsAg)

HPV (6, 11, 16, 18)

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8
Q

dsDNA viruses

A

All DNA viruses except Parvoviridae

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9
Q

ssDNA viruses

A

Parvoviridae (Parvovirus)

“Part-of-a-virus” has less DNA”

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10
Q

Circular DNA viruses

A

Papilloma and Polyoma (circular supercoiled), and Hepadnaviruses (circular, incomplete)

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11
Q

Linear DNA viruses

A

All DNA viruses except for Papilloma, Polyoma, and Hepadnaviruses

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12
Q

ssRNA viruses

A

All RNA viruses except for Reoviridae

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13
Q

dsRNA viruses

A

Reoviridae

“REpeatO virus is redundant with 2 strands”

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14
Q

+ssRNA viruses

A

“I went to a Retro Toga party where i drank Flavored Coronas and ate Hippy California Pickles”

Retrovirus, Togavirus, Flavivirus Corona virus, Hepevirus, Calicivirus, Picornavirus

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15
Q

Naked viral genome infectivity

A

Infectious: dsDNA viruses (except Poxvirus and HBV), and +ssRNA (like mRNA) viruses
Non-infectious: -ssRNA and dsRNA. Require polymerase contained in complete virion

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16
Q

Virus ploidy

A

All viruses are haploid except retrovirus which has 2 identical ssRNA molecules

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17
Q

Where do viruses replicate?

A

All DNA viruses replicate in the nucleus except poxvirus

All RNA viruses replicate in the cytoplasm except influenza and retroviruses

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18
Q

Non-enveloped viruses
Names
Where is envelope from?

A

“give PAP smears and CPR to Naked HEPpy”
DNA = PAPP, RNA = CRP and HEP
Papillomavirus, Adenovirus, Parvovirus, Polyomavirus, Calcivirus, Picornavirus, Reovirus, Hepevirus
Usually from cell membrane except for Herpes, which gets it from nuclear membrane

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19
Q

DNA viruses names

A

“HHAPPPPy”

Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma

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20
Q

Icosahedral DNA viruses?

A

All except Pox (complex)

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21
Q

DNA viruses that replicate in the nucleus?

A

All except Pox (carries its own DNA dependent RNA pol)

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22
Q

Herpesviruses
Nucleic acid? Envelope?
Names

A

dsDNA, Linear. Enveloped

HSV1, HSV2, VZV (HHV3), EBV (4), CMV (5), HHV6, HHV7, HHV8

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23
Q 
Hepadnavirus 
Nucleic acid? Envelope?
Names w/ disease 
Vaccine 
Transcription
A

dsDNA, partially circular. Enveloped
HBV: acute or chronic hepatitis
Vaccine available. Contains HBV surface Ag
Not a retrovirus but has a reverse transcriptase

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24
Q

Adenovirus
Nucleic acid? Envelope?
Diseases

A 
dsDNA, Linear. Not enveloped 
Febrile pharyngitis (sore throat, acute hemorrhagic cystitis), Pneumonia, Conjunctivitis (pink eye)
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25
Q

Parvovirus
Nucleic acid? Envelope?
Names with diseases

A

-ssDNA, Linear. Not enveloped
B19: aplastic crisis in sickle cell disease, Erythema infectionsum (5th disease, slapped cheek), RBC destruction in fetus –> hydrops fetalis and death, Pure RBC aplasia and RA-like symptoms in adults

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26
Q

Papillomavirus
Nucleic acid? Envelope?
Names with diseases
Vaccine

A 
dsDNA, Circular. Not enveloped 
HPV 1,2,6,11: warts
Cervical intraepithelial neoplasia (CIN)
Cervical cancer (16, 18)
Vaccine for 16 and 18
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27
Q

Polyomavirus
Nucleic acid? Envelope?
Names with diseases and Findings

A

dsDNA, Circular. Not enveloped
JC: progressive multifocal leukoencephalopathy (PML) in HIV pt
MBP present in CSF
BK: Transplant pt, commonly targets kidneys
“JC = Junky Cerebrum. BK = Bad Kidney”

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28
Q

Poxvirus
Nucleic acid? Envelope?
Diseases

A

dsDNA, Linear. Enveloped
Smallpox, Vaccina (cowpox - milkmaid’s blisters)
Molluscum contagiosum: flesh colored dome lesions with central dimple

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29
Q 
HSV1
Nucleic acid? Envelope?
Diseases caused by it?
Latency?
Transmission?
A

dsDNA, Linear. Enveloped
Oral (and some genital lesions), Gingivostomatitis, Keratoconjunctivitis, Temporal lobe encephalitis (most common cause of sporadic encephalitis in the US), Herpes Labialis
Latent in V ganglia
Respiratory secretions, Saliva

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30
Q 
HSV2
Nucleic acid? Envelope?
Diseases caused by it?
Latency?
Transmission?
A

dsDNA, Linear. Enveloped
Genital (and some oral lesions), Herpes genitalis, Neonatal herpes
Latent in Sacral ganglia
Sexual contact, Perinatal

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31
Q 
VZV
Name
Nucleic acid? Envelope?
Diseases caused by it?
Latency?
Vaccine?
Transmission?
A 
HHV3
dsDNA, Linear. Enveloped 
Varicella-Zoster (chickenpox and shingles), Encephalitis, Pneumonia
Latent in DRG or Trigeminal Ganglia
Vaccine available
Respiratory secretions
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32
Q 
EBV
Name
Nucleic acid? Envelope?
What does it infect?
Diseases caused by it?
Latency?
Transmission?
A 
HHV4
dsDNA, Linear. Enveloped 
Infectious mononucleosis, Burkitt's Lymphoma, Hodgkin's Lymphoma, Nasopharyngeal carcinoma
Infects B cells
Latent in B cells 
Respiratory secretions, Saliva
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33
Q 
CMV
Name
Nucleic acid? Envelope?
Diseases caused by it?
Who gets infected?
Histo
Latency?
Transmission?
A

HHV5
dsDNA, Linear. Enveloped
Congenital infection, Mononucleosis (negative Monospot), Pneumonia, Retinitis
Immunosuppressed and Transplant pts
Owl’s eye inclusions
Latent in mononuclear cells
Congenital, Transfusion, Sexual contact, Saliva, Urine, Transplant

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34
Q 
HHV6
Nucleic acid? Envelope?
Diseases caused by it with presentation?
Transmission 
Related virus?
A

dsDNA, Linear. Enveloped
Roseola (exanthem subitum): high fevers for several days that can cause seizures, followed by diffuse macular rash
Undetermined transmission
HHV7 a less common cause of Roseola

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35
Q 
HHV8
Nucleic acid? Envelope?
Diseases caused by it?
Who gets it?
Transmission
A

dsDNA, Linear. Enveloped
Kaposi sarcoma in HIV pt
Sexual contact

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36
Q

HSV identification

A

PCR is test of choice
Tzaneck test: smear of an open skin vesicle to detect multinucleated giant cells commonly seen in HSV1, HSV2, VZV
Infected cells also have intra-nuclear Cowdry A inclusions

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37
Q 
Mononucleosis 
Caused by...
Presentation 
Peak incidence?
Histo 
Diagnosis
A

EBV infecting B cells
Fever, HSM, Pharyngitis, and Lymphadenopathy (esp posterior cervical nodes)
15-20 years of age
Atypical lymphocytes seen on peripheral blood smear are not infected B cells, they are reactive Tc cells
+Monospot test

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38
Q

Monospot Test
What is it?
Positive test equals…

A

Heterophile Abs detected by agglutination of sheep or horse RBCs
Mononucleosis, Hodgkin’s lymphoma, Endemic Burkitt’s lymphoma, Nasopharyngeal carcinoma

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39
Q

Reovirus
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

dsRNA, Linear, Not enveloped, 10-12 segments
Icosahedral (double)
Coltivirus: Colorado tick fever. Arbovirus transmitted by arthropods (mosquitoes and ticks)
Rotavirus: #1 cause of fatal diarrhea in children

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40
Q 
Picornaviruses 
Nucleic acid? Envelope? Segments 
Caspid 
Diseases 
Replication process
Transmission
A

+ssRNA, Linear, Not enveloped, Non-segmented
Icosahedral
“PERCH”
Polio, Echovirus (aseptic meningitis), Rhinovirus (common cold), Coxsackievirus [aseptic meningitis, herpangina (mouth blisters, fever), hand-foot-and-mouth disease, myocarditis], HAV
All cause aseptic (viral) meningitis except rhinovirus and HAV
RNA is translated into 1 large polypeptide that is cleaved by proteases into functional viral proteins
All are enteroviruses (fecal-oral spread) except Rhinoviruses

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41
Q

Hepevirus
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

+ssRNA, Linear, Not enveloped, Non-segmented
Icosahedral
HEV

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42
Q

Caliciviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

+ssRNA, Linear, Not enveloped, Non-segmented
Icosahedral
Norovirus: viral gastroenteritis

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43
Q

Flaviviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

+ssRNA, Linear, Enveloped, Non-segmented
Icosahedral
“CYD went from STL to the Nile”
HCV, Yellow fever, Dengue, St Louis encephalitis, West Nile Virus.
All except HCV are Arbovirus: transmitted by arthropods (mosquitoes and ticks)

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44
Q

Togaviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

+ssRNA, Linear, Enveloped, Non-segmented
Icosahedral
Rubella
Eastern/Western Equine Encephalitis (Arbovirus: transmitted by arthropods (mosquitoes and ticks))

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45
Q 
Retrovirus 
Nucleic acid? Envelope? 
Caspid
Special capability
Diseases
A

+ssRNA, Linear, Enveloped
Icosahedral (HTLV), Complex and Conical (HIV)
Reverse transcriptase
HTLV: T cell leukemia, HIV: AIDS

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46
Q

Coronaviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

+ssRNA, Linear, Enveloped, Non-segmented
Helical
Common cold and SARS

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47
Q

Orthomyxoviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

-ssRNA, Linear, Enveloped, 8 segments
Helical
Influenza virus

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48
Q 
Paramyxoviruses 
Nucleic acid? Envelope? Segments 
Caspid
Diseases
Markers 
Treatment
A

-ssRNA, Linear, Enveloped, Non-segments
Helical
Causes disease in children “PaRaMysovirus”
Parainfluenza (croup: seal-like barking cough), RSV (bronchiolitis in babies, treat with Ribavirin), Measles, Mumps
Surface F (fusion) protein causes respiratory epithelial cells to fuse and form multi-nucleated cells
Palivizumab (monoclonal Ab against F protein) prevents pneumonia caused by RSV infection in premature infants

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49
Q

Rhabdoviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

-ssRNA, Linear, Enveloped, Non-segments
Helical
Rabies

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50
Q

Filoviruses
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

-ssRNA, Linear, Enveloped, Non-segments
Helical
Ebola/Marburg hemorrhagic fever
Often fatal

51
Q 
Arenaviruses 
Nucleic acid? Envelope? Segments 
Caspid
Diseases
Transmission
A 
-ssRNA, Circular, Enveloped, 2 segments
Helical 
LCMV: Lymphocytic Choriomeningitis Virus 
Lassa fever encephalitis 
Spread by mice
52
Q 
Bunyaviruses 
Nucleic acid? Envelope? Segments 
Caspid
Diseases
Transmission
A

-ssRNA, Circular, Enveloped, 3 segments
Helical
California encephalitis, Sandfly/Rift Valley fevers, Crimean-Congo hemorrhagic fever
Hantavirus (hemorrhagic fever, pneumonia)
All but Hantavirus are Arbovirus: transmitted by arthropods (mosquitoes and ticks)

53
Q

Delta Virus
Nucleic acid? Envelope? Segments
Caspid
Diseases

A

-ssRNA, Circular, Enveloped, Non-segmented
Uncertain symmetry
HDV is a defective virus that requires HBV co-infection

54
Q

Negative-Stranded Viruses
Replication process
What special proteins does it have?
Names

A

Transcribe neg strand to +
Brings its own RNA-dependent RNApol
“Always Bring Polymerase Or Die Failing Replication”
Arenavirus, Bunyavirus, Paramyxovirus, Orthomyxovirus, Delta virus, Filoviruses, Rhabdoviruses

55
Q

Segmented Viruses

A

All are RNA viruses
“BOAR”
Bunyaviruses, Orthomyxoviruses (influenza), Arenaviruses, Reoviruses

56
Q 
Rhinovirus 
Kind of virus 
Diseases it causes?
Types 
Route of infection
A

Picornavirus
Causes common cold
Over 100 serologic types
Acid labile - destroyed by stomach acid

57
Q 
Yellow Fever Virus 
Kind of Virus 
Transmission 
Reservoir 
Presentation
A

Flavivirus (also an arbovirus)
Aedes Mosquitoes
Monkey and human reservoir
High fever, black vomit, jaundice

58
Q 
Rotavirus 
Kind of virus?
Diseases it causes
Context 
PathoPhys
Prophylaxis
A

Reovirus
“ROTAvirus = Right Out The Anus”
Infantile gastroenteritis: acute diarrhea
Winter, day-care centers, kindergartens
Villous destruction with atrophy leads to ↓ absorption of Na and loss of K
CDC recommends vaccination of all infants

59
Q 
Influenza Viruses 
Kind of virus 
Ags
What are pts at risk for?
Evolves?
Vaccines
A

Orthomyxoviruses
Hemagglutinin (promotes viral entry) and Neuraminidase (promotes progeny virion release)
Pts at risk for fatal bacterial superinfection
Rapid genetic changes
Killed vaccine is a major mode of protection. Vaccine containing live, temp sensitive mutant that replicates in the nose but not in lung also available for children

60
Q

Influenza virus
Genetic Shifts/Antigenic Shifts
Genetic Drifts

A

“Sudden Shifts more deadly than graDual Drift”
Shifts cause pandemics. Reassortment of viral genome; segments undergo high frequency recombination such as when human flu A virus recombines with swine flue A virus
Drift causes epidemics. Minor (antigenic drift) changes based on random mutation

61
Q

Rubella Virus
What kind of virus
Presentation
Children vs Congenital disease?

A

Togovirus
Rubella (German 3 day measles): Fever, Postauricular adenopathy, Lymphadenopathy, Arthralgias, Fine Truncal rash that starts at head and moves down
Mild disease in children, Serious congenital disease (ToRCHS infection)

62
Q 
Measles 
What causes it?
Presentation 
Possible sequelae 
Do not confuse with?
A

Paramyxovirus
“3Cs: Cough, Coryza, Conjunctivitis”
Koplik spots (red spots with blue-white center on buccal mucosa) and descending maculopapular rash. Presents last and spreads from head to toe including hands and feet (vs truncal rash in rubella)
SSPE (Subacute Sclerosing Panencephalitis) occuring years later, Encephalitis, Giant cell pneumonia (rarely in immunosuppressed)
Do not confuse with Roseola (HHV6)

63
Q

Mumps
What causes it?
Presentation
Danger

A

Paramyxovirus
“Mumps makes your parotid glands and testes as big as POM-poms”
Parotitis, Orchitis (inflammation of testes), and aseptic Meningitis
Sterility (esp after puberty)

64
Q 
Rabies Virus 
What kind of virus? Shape? 
Histo? What does it infect?
Incubation 
Post-exposure treatment 
How does it travel?
Presentation 
Transmission
A

Rhabdoviruses. Bullet-shaped virus
Negri bodies in cytoplasm of neurons
Purkinje cells of cerebellum
Weeks to months incubation
Wound cleansing and vaccination +/- rabies immune globulin
Travels to CNS by migrating in a retrograde fashion up nerve axons
Fever, Malaise –> Agitation, Photophobia, Hydrophobia –> Paralysis, Coma –> Death
Bat, Raccoon, Skunk, Dog bites

65
Q 
HAV
Kind of virus?
Mode of transmission?
Carrier
Incubation time
HCC risk
Symptoms 
Time course of infection
A 
Picornavirus (Non-enveloped +strand RNA)
Fecal-Oral
No carrier
Short incubation (weeks)
No risk of HCC
Asymptomatic 
Acute
66
Q 
HBV
Kind of virus?
Mode of transmission?
Carrier
Incubation time
HCC risk
A 
Hepadnavirus (Enveloped dsDNA)
Parenteral, Sexual, Vertical
Has Carriers
Long incubation (months)
Integrates into host genome and acts as oncogene
67
Q 
HCV
Kind of virus?
Mode of transmission?
Carrier
Incubation time
HCC risk
Course of infection
What can it cause?
A 
Flavivirus (Enveloped +sRNA)
Primarily blood, IVDU, Post-transfusion
Has Carriers
Long incubation
HCC risk from chronic inflammation
Chronic course
Cirrhosis, Carcinoma
68
Q 
HDV
Kind of virus?
Mode of transmission?
Carrier
Incubation time
HCC risk
Can it infect alone?
Prognosis
A 
RNA delta virus (enveloped, -ssRNA)
Parenteral, Sexual, Vertical
Has carriers
Superinfection - short. D infects after B
Co-infection - long. B and D infect together
HCC risk
Defective virus and dependent on HBV
Superinfection has worsened prognosis
69
Q 
HEV
Kind of virus?
Mode of transmission?
Carrier
Incubation time
HCC risk
High mortality rate in
Mnemonic
A 
Hepevirus (Non-enveloped +ssRNA)
Fecal-Oral especially with water-born epidemics 
No carriers
Short intubation 
No risk for HCC
High mortality rates in pregnant women
Enteric, Expectant, Epidemics
70
Q

Signs and Symptoms of all Hepatitis viruses

A

Fever, jaundice, elevated ALT/AST

71
Q

Viral reproduction of HBV

A

B uses its own DNA dependent DNA pol to make full dsDNA

Uses host RNA pol to make mRNA

72
Q 
Anti HAV (IgM)
Best to detect?
A

IgM Ab to HAV

Best test to detect HAV

73
Q 
Anti HAV (IgG)
What does it indicate?
What does it do?
A

IgG Ab indicates prior HAV infection and/or vaccination

Protects against re-infection

74
Q

HBsAg

A

Surface antigen indicates Hep B infection

75
Q

Anti HBs

What does it indicate

A

Ab to HBsAg

Indicates immunity to HepB

76
Q

HBcAg

A

Antigen associated with core HBV

77
Q

Anti HBc
IgM
IgG
Positive during…

A

Ab to ABcAg
IgM = acute or recent infection
IgG = prior exposure or chronic infection
Positive during window period

78
Q

HBeAg
What is it?
What does it indicate?

A

A second, different antigenic determinant in the HBV core

Indicates viral replication and therefore high transmissibility

79
Q

Anti HBe
What is it?
What does it indicate

A

Antibody to HBeAg

Indicates low transmissibility

80
Q 
Labs in Acute HBV
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg +
Anti HBs -
HBeAg +
Anti HBe - 
Anti HBc IgM
81
Q 
Labs in Window HBV
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg -
Anti HBs -
HBeAg -
Anti HBe + 
Anti HBc IgM
82
Q 
Labs in Chronic HBV (high infectivity)
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg +
Anti HBs -
HBeAg +
Anti HBe - 
Anti HBc IgG
83
Q 
Labs in Chronic HBV (low infectivity)
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg +
Anti HBs -
HBeAg -
Anti HBe + 
Anti HBc IgG
84
Q 
Labs in Recovery HBV 
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg -
Anti HBs +
HBeAg -
Anti HBe + 
Anti HBc IgG
85
Q 
Labs in Immunized HBV 
HBsAg
Anti HBs
HBeAg
Anti HBe
Anti HBc
A 
HBsAg -
Anti HBs +
HBeAg -
Anti HBe - 
Anti HBc -
86
Q

Sequence of events in HBV infection

A

SECES

HBsAg, HBeAg, AntiHBc, AntiHBe, AntiHBs

87
Q

Which Hepatitis viruses can cause acute infection?

A

A,B,C,D,E

88
Q

Which hepatitis viruses can cause chronic infection?

A

B, C, D

89
Q

HBV Treatment

A

Interferons (alpha and pagylated)

Lamivudine, Adefovir, Entecavir, telbivudine (Nucleoside Analogs –/ HBV DNApol)

90
Q

HIV
Nucleic acid? Enveloped? Segments?
Structural genes

A

+ssRNA, Linear, Enveloped. Diploid (2 molecules of RNA)
env: gp120 and gp41 formed from cleavage of gp160 to form envelope proteins
gp120 stuck on top of gp41 and attaches to host CD4 T cell. gp41 is transmembrane and mediates fusion and entry
gag (p24): caspid protein
pol: Reverse transcriptase, aspartate protease, integrase

91
Q

HIV Pathogenesis

Immunity

A

ssRNA –> dsDNA –> integrates into host genome
Virus binds CCR5 (early) or CXCR4 (late) co-receptor and CD4 on T cell
Binds CCR5 and CD4 on macrophages
CCR5 homozygous mutation = immunity

92
Q

How are envelope proteins acquired by the HIV virus?

A

Acquired through budding from host cell plasma membrane

93
Q

HIV virus inside to outside

A

RNA + reverse transcriptase –> caspid protein p24 –> Matrix protein p17 –> Lipid membrane –> gp41 goes through membrane and gp120 on top of it

94
Q

HIV diagnosis
When are they falsely negative
When are they falsely +

A

Presumptive Dx made with ELISA for antiHIV Abs (sensitive with high false positive rule out with low threshold)
+ results are confirmed with Western blot assay for AntiHIV Abs (specific, high false negative rate, rule in with high threshold)
Falsely negative in first 1-2 months after infection
Falsely + in babies born to infected mothers (anti gp120 crosses placenta)

95
Q

HIV monitoring

A

PCR/viral load determines amount of viral RNA in the plasma
High viral load associated with poor prognosis
Used to monitor effects of drug therapy

96
Q

AIDS Dx

A

CD4+ less than 200 (normally 500-1500)

HIV+ with AIDS-defining condition (PCP) or CD4/CD8 ratio less than 1.5

97
Q

Couse of HIV infection

A

CD4 count drops then rebounds briefly (after HIV RNA copies peak) then steady decreases
HIV RNA copies peaks then drops (when CD4 count rebounds) then gradually rises

98
Q

Stages of HIV infection

A

“4Fs”

  1. Flu-like acute
  2. Feeling fine (latent)
  3. Falling count
  4. Final crisis
99
Q

What happens during latency

A

Virus replicates in lymph nodes

100
Q

Common diseases of HIV+ adults

A

Reactivation of past infections (TB, HSV, Shingles)
Disseminated bacterial and fungal infections
Non-Hodgkin’s Lymphoma

101
Q

HIV pt w/ low-grade fever, cough, HSM, Tongue ulcer
Pathogen
Findings
CD4

A

Histoplasma capsulatum (causes only pulmonary symptoms in immunocompetent hosts)
Oval yeast cells w/in Macrophages
CD4 less than 100

102
Q

HIV pt w/ Fluffy white cottage-cheese lesions
Pathogen
Findings
CD4

A 
C albicans (thrush)
Pseudohyphae
Oral if CD4 less than 400, Esophageal if CD4 less than 100
103
Q

HIV pt w/ Superficial vascular proliferation
Pathogen
Findings

A 
Bartonella henselae (bacillary angiomatosis 
Biopsy reveals neutrophilic inflammation
104
Q

HIV pt w/ Chronic watery diarrhea
Pathogen
Findings
CD4

A

Cryptosporidium

Acid-fast cyst in stool when CD4 less than 200

105
Q

HIV pt w/ Encephalopathy
Pathogen
Findings
CD4

A

JC virus reactivation (cause of PML)
Reactivation of latent virus
Results in demyelination
CD4 less than 200

106
Q

HIV pt w/ Abscesses
Pathogen
Findings
CD4?

A

Toxoplasma gondii
Many ring-enhancing lesions on imaging
CD4 below 100

107
Q

HIV pt w/ Meningitis
Pathogen
Findings
CD4?

A

Cryptococcus neoformans
India ink stain reveals yeast with narrow-based budding and large capsule
CD4 less than 50

108
Q 
HIV pt w/ Retinitis 
Pathogen
Findings 
May also occur w/...
CD4?
A

CMV
Cotton wool spots on funduscopic exam
May also occur with esophagitis
CD4 less than 50

109
Q

HIV pt. w/ Dementia

A

Directly associated with HIV. Must differentiate from other causes

110
Q

HIV pt w/ Superficial neoplastic proliferative vasculature
Pathogen
Do not confuse w/
Findings

A

HHV8 (causes Kaposi Sarcoma)
Do not confuse with bacillary angiomatosis caused by B henselae
Biopsy reveals lymphocytic inflammation

111
Q

HIV pt w/ Hairy Leukoplakia
Pathogen
Location

A

EBV

Often found on lateral tongue

112
Q

HIV pt w/ Non-Hodgkin’s Lymphoma
Pathogen
Location

A

EBV

Often on oropharynx (Waldeyer’s ring)

113
Q

HIV pt w/ Squamous Cell Carcinoma
Pathogen
Location

A

HPV

Anus (men who have sex with men) or Cervix (women)

114
Q

HIV pt w/ Primary CNS lymphoma
Pathogen
Distribution
Differentiate from

A

EBV
Focal or multiple
Differentiate from toxoplasmosis

115
Q

HIV pt w/ Interstitial pneumonia
Pathogen
Findings

A

CMV

Biopsy reveals cells with intra-nuclear (Owl’s Eye) inclusion bodies

116
Q

HIV pt w/ Invasive aspergillosis
Pathogen
Findings

A

Aspergillus fumigatus

Pleuritic chest pain, Hemoptysis, Infiltrates on imaging

117
Q

HIV pt w/ Pneumonia
Pathogen
CD4

A

Pneumocystis jirovecii

CD4 less than 200

118
Q

HIV pt w/ TB-like disease
Pathogen
CD

A

Mycobacterium avium-intracellulare

CD4 less than 50

119
Q

Prions
Pathology
Qualities of the protein
Presentation

A

Conversion of a normal cellular protein (termed prion protein PrPc) to a β-pleated form (PrPsc) which is transmissible
PrPsc resists degradation and facilitates the conversion of still more PrPc to PrPsc
Spongiform encephalopathy and dementia, ataxia, and death

120
Q

Forms of Prion disease

A

Sporadic: Creutzfeldt-Jakob disease –> rapidly progressive dementia
Inherited: Gerstmann-Straussler-Scheinker Syndrome
Acquired: Kuru

121
Q

Icosahedral RNA viruses

A

Reovirus and All +ssRNA viruses except Coronavirus

122
Q

Helical RNA viruses

A

All -ssRNA viruses + Coronavirus

123
Q

RNA viruses with circular genomes

A

“BAD”
All are -ssRNA viruses
Arenavirus, Bunyavirus, Delta virus

USMLE (25 decks)

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