Quizlet - Viruses Flashcards
1
Q
Naked Icosahedral virus
A
2
Q
Enveloped Icosahedral virus
A
3
Q
Enveloped helical virus
A
4
Q
Recombination
A
Exchange of genese btw 2 Chromosomes by crossing over w/in regions of significant base sequence homolgy.
5
Q
Reassortment
A
When viruses w/ segmented genomes (e.g., influenza virus) exchange segments. High-frequency recombination. Cause of worldwide influenza pandemics.
6
Q
Complementation
A
When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus complements the mutated one by making functional protein that serves both viruses.
7
Q
Phenotypic mixing
A
Occurs w/ simultaneous infxn of a cell w/ 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) w/ surface protein of virus B. Type B protein coat determines the infectivity of the phenotypically mixed virus. However, the progeny from this infxn have a type A coat that is encoded by its type A genetic material.
8
Q
Viral vaccines
A
Live attenuated vaccines induce humoral and cell-mediated immunity, but have reverted to virulence on rare occasions. Killed vaccines induce only humoral immunity, but are stable. No boosters are needed for live-attenuated vaccines. It’s dangerous to give live vaccines to immunocompromised pts or their close contacts.
9
Q
Important live attenuated vaccines
A
Measles, mumps, rubella, Sabin polio, VZV, yellow fever, smallpox MMR = Measles, mumps, rubella
10
Q
Important killed vaccines
A
R abies, I nfluenza, Salk P olio, and HA V vaccines killed = RIP A lways
11
Q
Important recombinant viral vaccines
A
HBV (Ag = recombinant HBsAg) HPV (types 6, 11, 16, and 18)
12
Q
DNA viral genomes
A
All DNA viruses except the parvoviridae are dsDNA. All are linear except papilloma, polyoma, and hepadnaviruses (circular). All are dsDNA (like our cells), except part-of-a-virus (parvovirus)
13
Q
RNA viral genomes
A
All RNA viruses except Reoviridae are ssRNA All are ssRNA (like our mRNA) except re peato virus (reo virus) is dsRNA
14
Q
Naked viral genome infectivity
A
Purified nucleic acids of most sdDNA (except poxviruses and HBV) and (+)strand RNA (~mRNA) viruses are infectious. Naked nucleic acids of (-)strand ssRNA and dsRNA viruses are not infectious. They require enzymes contained in the complete viriion.
15
Q
Virus ploidy
A
All viruses are haploid (w/ 1 copy of DNA or RNA) except retroviruses, which have 2 identical ssRNA molecules (~diploid)
16
Q
Viral replication
A
DNA viruses all replicate in the nucleus (except poxvirus) All RNA viruses replicate in the cytoplasm (except influenza virus and retroviruses)
17
Q
Non-enveloped viruses (list)
A
Naked (nonenveloped) viruses include: Calcivirus Picornavirus Reovirus Parvovirus Adenovirus Papilloma Polyoma Naked CPR and PAPP smear
18
Q
Enveloped viruses
A
Generally, enveloped viruses acquire their envelopes from plasma membrane when they exit from the cell. Exceptions are herpesviruses, which acquire envelopes from the nuclear membrane.
19
Q
DNA enveloped viruses (list)
A
Herpesviruses (HSV types 1 and 2, VZV, CMV, EBV), HBV, smallpox virus
20
Q
DNA nucleocapsid viruses (list)
A
Adenovirus, papillomaviruses, parvovirus
21
Q
RNA enveloped viruses (list)
A
Influenza virus, parainfluenza virus, RSV, measles virus, mumps virus, rubella virus, rabies virus, HTLV, HIV
22
Q
RNA nucleocapsid viruses (list)
A
Enteroviruses (poliovirus, coxsackievirus, echovirus, HAV), rhinovirus, reovirus (rotavirus)
23
Q
DNA viruses (list)
A
HHAPPPPy viruses! Hepadna Herpes Adeno Pox Parvo Papilloma Polyoma
24
Q
All DNA viruses:
A
1.) Are double stranded (EXCEPT parvo: ssDNA) 2.) All are linear (EXCEPT papilloma and polyoma - circular, supercoiled and hepadna - circular, incomplete) 3.) Are icosahedral (EXCEPT pox: complex) 4.) Replicate in the nucleus (EXCEPT pox - carries own DNA-dep RNA pol)
25
Viral families: Herpesvirus Envelope? DNA strxr? Medical importance?
Enveloped. dsDNA, linear. HSV-1: oral (and some genital) lesions, keratoconjunctivitis HSV-2: genital (and some oral) lesions VZV: chickenpox, zoster, shingles EBV: mononucleosis, Burkitt's lymphoma CMV: infxn in immunosuppressed pts, especially transplant recipients; congenital defects HHV-6: roseola (exanthem subitum) HHV-8: Kaposi's sarcoma-associated virus (KSHV)
26
Viral families: Hepadnavirus Envelope? DNA strxr? Medical importance?
Enveloped. Partial circular dsDNA. HBV: Acute or chronic hepatitis. Vaccine available: use has increased tremendously. Not a retrovirus, but has reverse transcriptase.
27
Viral families: Adenovirus Envelope? DNA strxr? Medical importance?
Nonenveloped. Linear dsDNA Febrile pharyngitis - sore throat Pneumonia Conjunctivitis (pink eye)
28
Viral families: Parvovirus Envelope? DNA strxr? Medical importance?
Nonenveloped. Linear (-)ssDNA (smallest DNA virus). B19 virus: aplastic crises in sickle cell dz, slapped cheeks rash - erythema infectiosum (fifth dz), hydrops fetalis.
29
Viral families: Papillomavirus Envelope? DNA strxr? Medical importance?
Nonenveloped. Circular dsDNA HPV: warts, CIN, cervical cancer.
30
Viral families: Polyomavirus Envelope? DNA strxr? Medical importance?
Nonenveloped. Circular, dsDNA. JC: progressive multifocal leukoencephalopathy (PML) in HIV
31
Viral families: Poxvirus Envelope? DNA strxr? Medical importance?
Enveloped. Linear dsDNA (largest DNA virus). Smallpox, although eradicated, could be used in germ warfare. Vaccinia: cowpox (milkmaid's blisters) Molluscum contagiosum.
32
Herpesviruses: HSV-1 Dz? Route of Transmission?
Dz: Gingivostomatitis keratoconjunctivitis temporal lobe encephalitis (most common cause of sporadic encephalitis in the USA) Herpes labialis Transmission: Respiratory secretions Saliva
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Dz: Gingivostomatitis keratoconjunctivitis temporal lobe encephalitis (most common cause of sporadic encephalitis in the USA) Herpes labialis Transmission: Respiratory secretions Saliva
HSV-1
34
Herpesviruses: HSV-2 Dz? Route of Transmission?
Dz: Herpes genitalis [below] Neonatal herpes Transmission: Sexual contact Perinatal
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Dz: Herpes genitalis [below] Neonatal herpes Transmission: Sexual contact Perinatal
HSV-2
36
Herpesviruses: VZV (Varicella-Zoster Virus) Dz? Route of Transmission?
Dz: Shingles (below) Encephalitis Pneumonia Transmission: Respiratory secretions *VZV remains dormant in the trigeminal and dorsal root ganglia.
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Dz: Shingles (below) Encephalitis Pneumonia Transmission: Respiratory secretions *VZV remains dormant in the trigeminal and dorsal root ganglia.
VZV (Varicella-Zoster Virus)
38
Herpesviruses: EBV Dz? Route of Transmission?
Dz: Infectious mononucleosis Burkitt's lymphoma Nasopharyngeal carcinoma Transmission: Respiratory secretions, saliva
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Dz: Infectious mononucleosis Burkitt's lymphoma Nasopharyngeal carcinoma Transmission: Respiratory secretions, saliva
EBV
40
Herpesviruses: CMV Dz? Route of Transmission?
Dz: Congenital infxn Mononucleosis (negative Monospot) Pneumonia. Infected cells have characteristic owl's eye appearance (below) Transmission: Congenital Transfusion Sexual contact Saliva Urine Transplant
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Dz: Congenital infxn Mononucleosis (negative Monospot) Pneumonia. Infected cells have characteristic owl's eye appearance (below) Transmission: Congenital Transfusion Sexual contact Saliva Urine Transplant
CMV
42
Herpesviruses: HHV-8 Dz? Route of Transmission?
Dz: Kaposi's sarcoma (in HIV pts) Transmission: Sexual contact
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Dz: Kaposi's sarcoma (in HIV pts) Transmission: Sexual contact
HHV-8
44
EBV
A herpesvirus. Can cause mononucleosis. Infects B cells. Also associated w/ development of Hodgkin's and endemic Burkitt's lymphomas, as well as nasopharyngeal carcinoma.
45
Mononucleosis due to EBV Sx/findings?
Fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (especially posterior cervical LNs). Abnormal circulating cytotoxic T-cells (atypical lymphocytes). Positive Monospot test.
46
When does EBV peak?
Peak incidence 15-20 yrs. Most common during peak kissing years (kissing dz)
47
Positive Monospot test
Heterophil Abs detected by agglutination of sheep RBCs (positive in EBV infxn)
48
Herpesviruses (list)
Get herpes in a CHEV rolet C MV H SV E BV V ZV
49
Tzanck test
A smear of an opened skin vesicle to detect multinucleated giant cells. Used to assay for HSV-1, HSV-2, and VZV. Tzanck heavens I don't have herpes!
50
Cowdry A inclusions
Intranuclear inclusions shown in cells infected w/ HSV (would show up on Tzanck smear)
51
Viral family: Reoviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
No Envelope. dsRNA , linear, 10-12 segments Icosahedral (double) capsid Reovirus: Colorado tick fever Rotavirus: #1 cause of fatal diarrhea in children
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No Envelope. dsRNA , linear, 10-12 segments Icosahedral (double) capsid Reovirus: Colorado tick fever Rotavirus: #1 cause of fatal diarrhea in children
Reoviruses
53
Viral family: Picornaviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
No envelope ss(+)RNA, linear Icosahedral capsid. Poliovirus: polio-Salk/Sabin vaccines -- IPV/OPV Echovirus: aseptic meningitis Rhinovirus: common cold Coxsackievirus: aseptic meningitis, herpangina --febrile pharyngitis, hand, foot, and mouth dz, myocarditis HAV: acute viral hepatitis
54
No envelope ss(+)RNA, linear Icosahedral capsid. Poliovirus: polio-Salk/Sabin vaccines -- IPV/OPV Echovirus: aseptic meningitis Rhinovirus: common cold Coxsackievirus: aseptic meningitis, herpangina --febrile pharyngitis, hand, foot, and mouth dz, myocarditis HAV: acute viral hepatitis
Picornaviruses
55
Viral family: Hepevirus Envelope? RNA structure? Capsid symmetry? Medical importance?
No envelope. ss(+)RNA, linear Icosahedral capsid. HEV
56
No envelope. ss(+)RNA, linear Icosahedral capsid. HEV
Hepevirus
57
Viral family: Calciviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
No envelope. ss(+)RNA, linear. Icosahedral capsid. Norwalk virus -- viral gastroenteritis.
58
No envelope. ss(+)RNA, linear. Icosahedral capsid. Norwalk virus -- viral gastroenteritis.
Calciviruses
59
Viral family: Flaviviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(+)RNA, linear. Icosahedral capsid. HCV Yellow fever* Dengue* St. Louis encephalitis* West Nile Virus* (*=arbovirus)
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Enveloped. ss(+)RNA, linear. Icosahedral capsid. HCV Yellow fever* Dengue* St. Louis encephalitis* West Nile Virus* (*=arbovirus)
Flaviviruses
61
Viral family: Togaviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(+)RNA, linear. Icosahedral capsid. Rubella (German measles) Eastern equine encephalitis* Western equine encephalitis* (*=arbovirus)
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Enveloped. ss(+)RNA, linear. Icosahedral capsid. Rubella (German measles) Eastern equine encephalitis* Western equine encephalitis* (*=arbovirus)
Togaviruses
63
Viral family: Retroviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(+)RNA, linear. Icosahedral capsid. Have reverse transcriptase HIV/AIDS HTLV - T-cell leukemia
64
Enveloped. ss(+)RNA, linear. Icosahedral capsid. Have reverse transcriptase HIV/AIDS HTLV - T-cell leukemia
Retroviruses
65
Viral family: Coronaviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(+)RNA, linear. Helical capsid. Coronavirus -- common cold and SARS
66
Enveloped. ss(+)RNA, linear. Helical capsid. Coronavirus -- common cold and SARS
Coronaviruses
67
Viral family: Orthomyxoviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)RNA, linear. 8 segments. Helical capsid. Inflenza virus.
68
Enveloped. ss(-)RNA, linear. 8 segments. Helical capsid. Inflenza virus.
Orthomyxoviruses
69
Viral family: Paramyxoviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)RNA, linear, nonsegmented. Helical capsid. P aR aM yxovirus: P arainfluenza -- croup R SV -- bronchiolitis in babies; Rx -- ribavirin Rubeola (M easles) M umps
70
Enveloped. ss(-)RNA, linear, nonsegmented. Helical capsid. P aR aM yxovirus: P arainfluenza -- croup R SV -- bronchiolitis in babies; Rx -- ribavirin Rubeola (M easles) M umps
Paramyxoviruses
71
Viral family: Rhabdoviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)RNA, linear. Helical capsid. Rabies.
72
Enveloped. ss(-)RNA, linear.
Helical capsid. Rabies. Rhabdoviruses
73
Viral family: Filoviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)RNA, linear. Helical capsid. Ebola/Marburg hemorrhagic fever -- often fatal!
74
Enveloped. ss(-)RNA, linear. Helical capsid. Ebola/Marburg hemorrhagic fever -- often fatal!
Filoviruses
75
Viral family: Arenaviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)circular RNA, 2 segments. Helical capsid. LCMV -- lymphocyticc choriomeningitis virus. Lassa fever encephalitis -- spread by mice.
76
Enveloped. ss(-)circular RNA, 2 segments. Helical capsid. LCMV -- lymphocyticc choriomeningitis virus. Lassa fever encephalitis -- spread by mice.
Arenaviruses
77
Viral family: Bunyaviruses Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)circular RNA, 3 segments. Helical capsid. California encephalitis* Sandflly/Rift Valley fevers Crimean-Congo hemorrhagic fever* Hantavirus -- hemorrhagic fever, pneumonia (*=arbovirus)
78
Enveloped. ss(-)circular RNA, 3 segments. Helical capsid. California encephalitis* Sandflly/Rift Valley fevers Crimean-Congo hemorrhagic fever* Hantavirus -- hemorrhagic fever, pneumonia (*=arbovirus)
Bunyaviruses
79
Viral family: Deltavirus Envelope? RNA structure? Capsid symmetry? Medical importance?
Enveloped. ss(-)circular RNA. Helical capsid. HDV.
80
Enveloped. ss(-)circular RNA. Helical capsid. HDV.
Deltavirus
81
Negative-stranded Viruses
Must transcribe (-) strand to (+) Virion brings its own RNA-dependent RNA polymerase. Include: A renaviruses B unyaviruses P aramyxoviruses O rthomyxoviruses F iloviruses R habdoviruses Always Bring Polymerase Or Fail Replication
82
Segmented Viruses
All are RNA viruses. Include: B unyaviruses O rthomyxoviruses (influenza viruses) A renaviruses R eoviruses (BOAR ) Influenza virus has 8 segments of (-)RNA These segments undergo reassortment, causing antigenic shifts that lead to worldwide pandemics of the flu.
83
Picornaviruses
Include: P oliovirus E chovirus R hinovirus C oxsackievirus H AV (PERCH on a 'peak ' [pico]) RNA is translated into 1 large polypeptide that is cleaved by proteases into functional viral proteins. Can cause aseptic (viral) meningitis (except rhinovirus and HAV). (PicoRNA virus = small RNA virus)
84
Rhinovirus
A picornavirus. Nonenveloped RNA virus. Cause of common cold. (Rhino has a runny nose) >100 serologic types.
85
Yellow fever virus
A flavivirus (also an arbovirus) transmitted by Aedes mosquitos. Virus has monkey or human reservoir. Sx: high fever, black vomitus, and jaundice. Councilman bodies (acidophilic inclusions) may be seen in liver. ( Flavi = yellow)
86
Rubella virus
A togavirus. Causes German (3-day) measles: Fever, lymphadenopathy, arthralgias, fine truncal rash. Causes mild dz in children but serious congenital dz (a TORCH infxn)
87
Rotavirus
The most important global cause of infantile gastroenteritis. Segmented dsRNA virus (a reovirus). Major cause of acute diarrhea in the USA during winter, especially in daycare centers, kindergartens. Villous destruction w/ atrophy leads to decreased absorption of Na+ and water. ROTA = R ight O ut T he A nus
88
Influenza virus
Orthomyxoviruses. Enveloped, ssRNA, w/ segmented genome. Contain hemagglutinin (promotes viral entry) and neuraminidase (promotes progeny virion release) Ags. Responsible for worldwide influenza epidemics; pt at risk for fatal bacterial superinfeciton. Rapid genetic changes.
89
A major mode of protection from influenza virus?
Killed viral vaccine. A reformulated vaccine is offered each fall to elderly, healthcare workers, etc.
90
Influenza virus and genetic shift
(pandemic) Reassortment of viral genome (such as when human flu A virus recombines w/ swine flu A virus) S udden S hift is more deadly that graD ual D rift
91
Influenza virus and gentic drift
(Epidemic) Minor (antigenic drift) changes based on random mutation. S udden S hift is more deadly that graD ual D rift
92
Paramyxoviruses
Paramyxoviruses cause dz in children. They include those that cause: parainfluenza (croup: seal-like barking cough), mumps , measles , and RSV (which causes repiratory tract infection [bronchiolitis, pneumonia] in infants)
93
Rubeola (measles) virus
A paramyxovirus that causes measles. Koplik spots (red spots w/ blude-white center on buccal mucosa [below]) are diagnostic. SSPE (yrs later), encephalitis (1:2000), and giant cell pneumonia (rarely, in immunosuppressed) are possible sequelae. Rash spreads from head to toe [below]
94
3C's of Measles
C ough C oryza (head cold) C onjunctivitis *Also look for K oplik spots (not actually a C, but close enough)
95
Mumps virus
A paramyxovirus. Sx: P arotitis O rchitis (inflammation of the testes)* [aseptic] M eningitis Mumps makes your parotid glands and testes as big as POM -poms *Can cause sterility (especially after puberty)
96
Rabies virus
Negri bodies are characteristic cytoplasmic inclusions in neurons affected by rabies viru: Bullet shaped capsid: Rabies has a long incubation period (wks-months), which allows for immunization after exposure. Causes fatal encephalitis w/ seizures, hydrophobia, hypersalivation, and pharyngeal spasm. Travels to CNS by migrating in a retrograde fashion up nerve axons.
97
How is rabies virus more commonly contracted in the USA?
Bat, raccoon, and skunk bites > dog bites (in USA)
98
Arbovirus
Transmitted by arthropods (mosquitoes, ticks). Classic examples: dengue fever (aka break-bone fever) and yellow fever . A variant of dengue fever in SE Asia is hemorrhagic shock syndrome . ARBO virus = AR thropod-BO rne virus Includes some members of F lavivirus, T ogavirus, and B unyavirus: F ever T ransmitted by B ites
99
Lots of spots: Rubella
Togavirus; German 3-day measles.
100
Lots of spots: Rubeola
Paramyxovirus; measles.
101
Lots of spots: Varicella
Herpesvirus; chickenpox and zoster.
102
Lots of spots: Variola
Poxvirus; smallpox (no longer present outside of labs).
103
How many families of Hepatitis viruses are there?
5: HAV HBV HCV HDV HEV
104
HAV
RNA picornavirus. Transmitted primarily by fecal-oral route. Short incubation (3 weeks). No carriers. HepA is A symptomatic (usually) A cute, A lone (no carriers)
105
HBV
DNA hepadnavirus. Transmitted primarily by parenteral, sexual, and maternal-fetal routes. HepB = B lood-B orne Long incubation (3 months). Carriers. Cellular RNA polymerase transcribes RNA from DNA template. Reverse transcriptase transcribes DNA genome from RNA intermediate. However, the virion enzyme is a DNA-dependent DNA polymerase .
106
HCV
RNA flavivirus. Transmitted primarily via blood and resembles HBV in its course and severity. Carriers. Common cuase of post-transfusion hepatitis and of hepatitis among IV drug users in the USA. HepC = C hronic, C irrhosis, C arcinoma, C arriers.
107
HDV
Delta agent. A defective virus that requires HBsAg as its envelope. HDV can coinfect w/ HBV or superinfect; the latter has a worse prognosis. Carriers. HepD = D efective, D ependent on HBV.
108
HEV
RNA hepevirus. Transmitted enterically and causes water-borne epidemics. Resembles HAV in course, severity, incubation. High mortality rate in pregnant women. HepE = E nteric, E xpectant mothers, E pidemics
109
Both HBV and HCV...
... predispose pt to chronic active hepatitis, cirrhosis, and hepatocellular carcinoma.
110
HepA and HepE are transmitted...
... via the fecal-oral route. The vowels hit your bowels .
111
IgG HAVAb
Indicates prior infection; protective against reinfection.
112
IgM HAVAb
IgM Ab to HAV; best test to detect active hepatitis A.
113
HBsAg
Ag found on surface of HBV; continued presence indicates carrier state.
114
HBsAb
Ab to HBsAg; provides immunity to hepatitis B.
115
HBcAg
Ag associated w/ core of HBV
116
HBcAb
Ab to HBcAg; positive during window period [see below]. IgM HBcAb is an indicator of recent dz. IgG HBcAb signifies chronic dz.
117
HBe Ag
A second, different antigenic determinant in the HBV core. Important indicator of active viral replication and therefore transmissibility. Be ware!
118
HBeAb
Ab to e antigen ; indicaters low transmissibility.
119
Viral vs. alcoholic hepatitis (liver enzymes)
Viral hepatitis: ALT > AST Alcoholic hepatitis: AST > ALT
120
When do you see HBsAg?
acute disease [not in window phase] [not in complete recovery] chronic carrier state [not in immunized]
121
When do you see HBsAb?
[Not in acute dz] [In window phase, basically no. (Pt has surface Ab, but available Ab is bound to HBsAg, so not detected by assay)] Complete Recovery [not in chronic carrier state] Immunized
122
When do you see HBcAb?
Acute Disease (IgM in acute stage; IgG in chronic or recovered stage) Window Phase Complete Recovery Chronic Carrier State [not in immunized]
123
What HBV Ag/Ab's would show up in acute disease?
HBsAg and HBcAb [not: HBsAb]
124
What HBV Ag/Ab's would show up in the window phase?
HBcAb only.
125
What HBV Ag/Ab's would show up in complete recovery?
HBsAb and HBcAb. [not: HBsAg]
126
What HBV Ag/Ab's would show up in chronic carrier state?
HBsAg and HBcAb. [not: HBsAb]
127
What HBV Ag/Ab's would show up in immunized individuals?
HBsAb only.
128
HIV structure and proteins
129
HIV's genome
Diploid (2 molecules of RNA, but not dsRNA).
130
HIV: p24
Capsid protein
131
HIV: gp41 and gp120
Envelope proteins.
132
Function of reverse transcriptase in HIV
Synthesizes dsDNA from RNA. dsDNA integrates into host genome.
133
HIV virus binding
Virus binds CXCR4 and CD4 on T-cells; binds CCR5 and CD4 on macrophages. Homozygous CCR5 mutation = immunity. Heterozygous CCR5 mutation = slower course.
134
ELISA and HIV dx
Used for presumptive diagnosis (sensitive, high false-positive rate and low threshold, RULE OUT test); postitive results are then confirmed w/ Western blot assay (specific, high false-negative rate and high threshold, RULE IN test). ELISA/Western blot tests look for Abs to viral proteins; these tests are often falsely negative in the first 1-2 months of HIV infxn and falsely positive initially in babies born to infected mothers (angti-gp120 crosses placenta).
135
PCR/viral load and HIV
Tests are increasing in poluarity: allow the physician to monitor the effect of drug therapy on viral load.
136
AIDS diagnosis
< or = 200 CD4+, HIV positive w/ AIDS indicator condition (e.g., PCP) or CD4/CD8 ratio <1.5
137
4 stages of HIV infxn
1.) F lu-like (acute) 2.) F eeling fine (latent) 3.) F alling count 4.) F inal crisis During latent phase, virus replicates in LN's
138
Levels as HIV infxn progresses: CD4+ lymphocytes? Anti-p24 Abs? Anti-gp120 Abs? Virus, p24 Ag?
CD4+ T-cells have an early dip, stabilize, and fall during stages 3-4 (years after infxn) Anti-p24 and Anti-gp120 Abs rise starting ~1 mo. post-infxn, stabilize @ 3 mos (at end of acute infxn). Virus, p24 Ag: spike early (w/ start of acute Sx's), drop to low level until stages 3-4 (years later), when they take off
139
Organ system affected in AIDS: Brain (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Crytococcal meningitis Toxoplasmosis CMV encephalopathy AIDS dementia PML (JC virus)
140
Organ system affected in AIDS: Eyes (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: CMV retinitis
141
Organ system affected in AIDS: Mouth and throat (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Thrush (Candida albicans) HSV CMV Oral hairy leukoplakia (EBV)
142
Organ system affected in AIDS: Lungs (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Pneumocystis jiroveci pneumonia (PJP) TB histoplasmosis
143
Organ system affected in AIDS: GI (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Cryptosporidiosis Mycobacterium avium-intracellulare complex CMV colitis Non-Hodgkin's lymphoma (EBV) Isopora belli
144
Organ system affected in AIDS: Skin (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Shingles (VZV) Kaposi's sarcoma (HHV-8)
145
Organ system affected in AIDS: Genitals (what is the infxn/dz associated?)
Infxn/dz associated w/ AIDS: Genital herpes warts cervical cancer (HPV)
146
HIV-assicated infxns that increase in risk at CD4+ count: < 400
Infxn: Oral thrush Tinea pedis (athlete's foot) Reactivation VZV Reactivation tuberculosis Other bacterial infxns (e.g., H. influenzae, S. pneumoniae, Salmonella)
147
HIV-assicated infxns that increase in risk at CD4+ count: < 200
Infxn: Reactivation HSV cryptosporidosis Isopora Disseminated coccidioidomycosis Pneumocystis pneumonia
148
HIV-assicated infxns that increase in risk at CD4+ count: < 100
Infxn: Candidal esophagitis Toxoplamosis histoplasmosis
149
HIV-assicated infxns that increase in risk at CD4+ count: < 50
Infxn: CMV retinitis and esophagitis Disseminated M. avium-intracellulare Cryptococcal meningitis
150
Neoplasms associated w/ HIV
Kaposi's sarcoma (HHV-8) Invasive cervical carcinoma (HPV) Primary CNS lymphoma non-Hodgkin's lymphoma
151
HIV encephalitis
Occurs late in the course of HIV infxn. Virus gains CNS access via infected Macrophages. Microglial nodules w/ multinucleated giant cells.
