Infecto 1 Flashcards
Meningococcus/Enterovirus (121 cards)
1
Q
Neisseria meningitidis is a commensal of the human _____
A
Nasopharynx; 10% of the population are colonized
2
Q
N. meningitidis is a gram _____; encapsulated; oxidase-_____; aerobic/anaerobic; diplococcus
A
negative; positive; aerobic
3
Q
What allows for the definition of the 12 serological capsular groups?
A
Differences in the chemistry of the polysaccharide capsule
4
Q
MeningoD; Name the 6 serological types responsible for almost all cases of disease:
A
A; B; C; W; X; Y
5
Q
Outbreaks are usually caused by multiple strains (T/F)
A
False; most outbreaks are clonal; caused by single strains
6
Q
How is N. meningitidis transmitted?
A
Aerosol droplets and respiratory secretions; cant survive for long in the enviroment
7
Q
MeningoD; Carriage peaks during _____ (age period)
A
adolescence and young adulthood
8
Q
Highest rate of meningococcal disease occurs in: (age)
A
Infants <1yr; immunologic inexperience
9
Q
Most cases of meningococcal d. in <1yr are caused by wich strain?
A
B strain
10
Q
After 1yr which strain causes meningo d.?
A
85% are caused by B and C strains; remainder by Y
11
Q
MeningoC; Disease occurs ____ after acquisition of the pathogen.
A
1-14d
12
Q
How does N. meningitidis circumvents secretory IgA?
A
Invasive bacteria secretes IgA A1 “protease”
13
Q
Resistance to complement-mediated lyses and phagocytosis is mediated by
A
Polysaccharide capsule and “lipopolysaccharide”
14
Q
Most of the tissue damage in meningo d. is caused by
A
host immune mechanisms activated by meningo d. components (LPS)
15
Q
Capillary leak syndrome is explained by:
A
microvascular injury that leads to increased vasc permeability
16
Q
Main complication of Capillary leak Sd:
A
Pulmonary edema
17
Q
Which cytokine has a negative effect on myocardial contractility?
A
IL-6
18
Q
N. meningitidis can penetrate the blood-brain barrier (T/F)
A
True; this is facilitated by pili and possibly Opc (Opsonization protein C)
19
Q
Cite the two main mechanisms CNS damage occurs by:
A
Direct meningeal inflammation and indirectly by circulatory collapse
20
Q
Main neurological cause of death in meningo d.
A
increased intracranial pressure > herniation
21
Q
Levels of Serum Bactericidal Antibody are highest and lowest:
A
Highest at birth and amog adults; lowest between 6m and 2yr
22
Q
Nonpathogenic Neisseria can elicit natural antibodies (T/F)
A
True; N. lactamica and others can estimulate antibodies production
23
Q
MeningoD; Serum bactericidal antibody is ____ dependent
A
Complement
24
Q
Complement deficiencies increase menigo d. risk up to:
A
1000-fold
25
Monoclonal antibody against complement prot C5
Eculizumab; increases risk of meningo d.
| For paroxysmal nocturnal hemoglobinuria & atypical hemolytic uremic Sd
26
Most common form of meningococcal infection:
Asymptomatic carriage in the nasopharynx
27
Main presentation of "invasive" meningo d.
Meningitis; 30-50% of cases
28
Clinical presentations of invasive meningo d. other than meningitis (5)
Bacteremia; meningo septicemia; pneumonia; chronic meningo; occult bacteremia
29
Describe initial rash in meningo d.
Maculopapular; indistinguishable from viral rashes; 10% of cases
30
MeningoD; Rash that develops in 80% of cases:
Nonblanching or petechial rash
31
Fulminant meningo d. skin lesion:
prominent petechiae and "purpura"; also known as purpura fulminans
32
Most children <5yrs report headache during meningo meningitis (T/F)
False; most infants do not report headache
33
Seizures occurs less frequently in meningitis by meningococcus (T/F)
True; seizures more common in pneumococcus and haemophilus b
34
Serotype that can cause a meningo"encephalitis" like case:
Group A
35
Simptoms of "chronic" meningococcemia: (6)
fever; nontoxic appearance; arthralgia; headache; splenomegaly; maculopapular petechial rash
36
Mean duration of chronic meningo:
6-8 wks; cultures may be sterile; sulfonamide therapy is a risk factor
37
First line of ATB for suspected menigo d.
Third gen Cephalosporin (Ceftriax)
| Offers protection against pneumococcus and H. influenzae
38
Meningo D; When should vancomycin shold be considered as aditional ATB?
Local high rate of B-lactam-resistant pneumococcus
39
Necrotic skin lesions are less frequent when **this** ATB is used
Ceftriaxone
40
Meningococcal disease; Recommended treatment duration
5-7 days
41
Decreased susceptibility to penicillin in meningo d. is caused by:
Altered penicillin-binding protein 2; doesn’t seem to affect response to therapy
42
Because of pulmonary edema; ETI is recommended after
40ml/kg with compensated shock; reduces work of breathing
43
CTC are recommended in meningo meningitis (T/F)
False; alhough used in meningitis by h influenzae; no data supports use in meningo .d
44
Which viral infection usually reactivates during meningo infection?
Latent herpes simplex
45
Immune complex vaculitis may occur at wich point of meningo .d
First 10 days
46
Most commmon complication of severe meningo septicemia
Focal skin infarction; typically lower limbs
47
Most frequent neurologic sequela of meningo meningitis
Deafness; 5-10%
48
MeningoD; Profilaxis is indicated for:
Close contacts; contact with oral secretions
49
MeningoD; Up to ___ occur in the first week after the index case but the risk persists for up to ___
30%; 1yr
50
Drugs used in profilaxis:
Ceftriaxone; ciprofloxacin; rifampin (doesn’t erradicate colonization in 15%)
51
Profilaxis is recommended for medical personel (T/F)
False; only if exposure to aerosols (mouth to mouth; intubation; suctioning) before 24h of atb
52
MeningoD; Type of contact precaution:
Droplet infection control for 24h
53
Why are Meningo D booster doses recommended during adolescence?
Antibody levels wane after infant immunization
54
Meningo vaccine for adolescents
Men "ACWY"; single dose
55
Enteroviruses are ___; ___ stranded; in the picornaviridae family
nonenveloped; single; Picorna = Small RNA
56
Enteroviruses are part of the picornaviridae along with: (3)
Rhinoviruses; hep A; Paraechoviruses
57
Enteroviruses have 4 species:
A-B-C-D
58
Enteroviruses; Although more than 100 types…
Only 10-15 causes most cases
59
Enterovirus; ___ can cause similar clinical presentations
Paraechoviruses
60
Enterovirus; responsible for ___ of acute febrile illnesses and ___ of hospitalizations for suspected sepsis
33-65%; 55-65%
61
Enterovirus; More than ___ occur in children tounguer than __ of age
25%; 1year
62
Enterovirus; Breastfeeding increases/reduces risk for infection
Reduces; likely via enterovirus-specific antibodies
63
Enterovirus; Spreading occurs by
fecal-oral and respiratory; hemorrhagic conjunctivitis may spread airborne
64
Enterovirus; Vertical transmission along with ___ and ___ are possible
peripartum; breastfeeding
65
Enterovirus; can survive on enviromental surfaces T/F
True; transmission via "fomites"
66
Enterovirus; Incubation period is tipically ___
3-6 days; except for 1-3 day in acute hemorrhagic conjunctivitis
67
Enterovirus; respiratory shedding occurs for ___ and fecal continues for ___
<1-3wks; 7-11wks
68
Enteroviruses; Survival in the GI tract is favored by:
Acid stability
69
Enterovirus; Primary; transient viremia (minor) results in…
Spread to distant parts of the reticuloendothelial system
70
Enterovirus; Damage can occur in different organs such as: (8)
CNS; Heart; Liver; Pancreas; Lungs; Muscles; Kidneys; Skin
71
Enterovirus; CNS infections have ___ in the CSF
Pleocytosis; macrophages and T lymphocytes
72
Enterovirus; Encephalitis is associated to ___ species
A71; can complicate with pulmonary edema/hemorrhage/pneumonitis
73
Enterovirus; Mechanism postulated as responsible for neurologic damage in A71 infection
Immunologic cross-reactivity
74
Enterovirus; Myocarditis is characterizes by…
Perivascular and intesrstitial inflammatory infiltrates and myocyte dmg
75
Enterovirus; In utero infections are characterized by (2)
Placentitis and infections of multiple fetal organs
76
Enterovirus; Most important immune defense:
Developmento of type-specific neutralizing antibodies
77
Enterovirus; Heterotypic antibodies may…
Enhance disease by a different serotype
78
Enterovirus; Hypo/Agammaglobulinemia predispose to…
severe; chronic infections
79
Enterovirus; A71 diseas increases after ___ mo of age
6; maternal antibodies level decline
80
Enterovirus; Symptomatic diseas is more common in…
Young children
81
Enterovirus; Mot common symptomatic manifestation:
Nonespecific febrile illness
82
Enterovirus: Illness usually begins ___ with fever of ___; malaise; irritability
abruptly; 38.5-40
83
Enterovirus; Meningitis may be present but…
Specific clinical features such as meningeal findings or bulging fontanelle are absent
84
Enterovirus; Fever lasts a mean of __ days
3; can be biphasic
85
Enterovirus; Ilness lasts a mean of ___ days but can range from ___
4-7; 1 day to >1wk
86
Enterovirus; WBC count is generally normal but transient ___ can be seen
Neutropenia; concomitant bacterial infection is rare but possible
87
Enterovirus; Skin manifestations can include: (5)
Macular; maculopapular; urticarial; vesicular; petechiae
88
Enterovirus; Frequency of cutaneous manifestations is ___ related to age
Inversely
89
Enterovirus; Serotypes associated with rashes are: 4
Echoviruses; coxsackie A; coxsackie B; A71
90
Enterovirus; Coxsacke A16 causes
Hand-foot-and-mouth disease; A71; Cox B and some echoviruses are also implicated
91
Enterovirus; H-F-M disease courses with high fever T/F
False; usually low-grade or without fever and mild illness
92
Enterovirus; H-F-M disease can also have lesions in __ and ___
Buttocks and groin
93
Enterovirus; Coxsackie A6 is responsible for relatively severe ___ disease and ___
H-F-M; herpangina; can present desquamation of palms and soles and nails (onychomadesis)
94
Enterovirus; H-F-M disease can complicate with (5)
Encephalitis; acute flaccid paralysis; myocarditis; pericarditis; shock
95
Enteroviru; Herpangina is characterized by… (4)
Sudden fever; sore throat; dysphagia; "painful lesions in the posterior pharynx
96
Enterovirus; Herpangina is associated with __ and ___ viruses
A71; Coxsackie A; others can be implicated
97
Enterovirus; Related to outbreaks of pneumonia and wheezing
Enterovirus D68
98
Enterovirus; Bornholn disease consists of:
Pleurodynia; caused mainly by cox B and echoviruses; paroxismal thoracic pain
99
Enterovirus; Acute hemorrhagic conjunctivitis are caused by…
Enterovirus D70 and cox A24; explosive and highly contagious
100
Enterovirus; Acute hemorrhagic conjunctivitis clinical features include sudden and severe eye pain and…
Photophobia; blurred vision; lacrimation; conjunctival erythema; lid edema; preauricular adenophaty and subconjuntival hemorrhage
101
Enterovirus; Acute hemorrhagic conjunctivitis due to D70 hallmark symptom
Subconjunctival hemorrhage; more rare with cox virus
102
Enterovirus; Acute hemorrhagic conjunctivitis eye discharge is initially serous but…
Can become mucopurulent with secondary bacterial infection
103
Enterovirus; ___ cases of myocarditis and pericarditis of proven etiology
25-35%; Coxsackie B mostly; Cox A and echo also
104
Enterovirus; Mio/pericarditis shows ___ on echography (3)
Ventricular dilation; reduced contractility; pericardial effusion
105
Enterovirus; Myo/pericarditis; Enzimes are often…
elevated
106
Enterovirus; Associated to orchitis:
Coxsackie B; often biphasic; fever and preurodynia or meningitis may precede orchitis by 2 weeks
107
Enterovirus; Most common cause of viral meningitis in ___-immunized populations
Mumps; 90% of cases; Cox B; Echo; D70; A71
108
Enterovirus; CSF in meningitis predominates ___ in the first 48h before becoming mostly ___
Polymorphonuclear; mononuclear
109
Enterovirus; Normal CSF rules out meningitis T/F
False; can be normal in up to half of cases despite detection of enterovirus in CSF
110
Enterovirus; __ of cases of encephalitis with an identified cause
10-20%; Echo; Cox A; A71
111
Enterovirus; Acute flaccid myelitis syndome:
Flaccid limb weakness; MRI abnormal spinal cord gray matter;
112
Enterovirus; Neonatal infections are tipically caused by…
Cox B; Echoviruses
113
Enterovirus; Neonatal symptoms can occur as early as __ and severe disease generraly develops within ___
1st day of life; 2wks
114
Enterovisus; Traditionally; ___ has been used to confirm infection
Cell lines viral culture; Sensitivity ranges from 50-75%
115
Enterovirus; PCR testing for suspected meningitis decreases diagnostic tests; ___ ; ___ and ___
hospital stay time; ATB use; overall cost
116
Enterovirus; Paraechovirus __ and __ are the most comon causes of symptomatic infection
1; 3
117
Enterovirus; Paraechovirus CNS infection has CSF __
Normal celullarity
118
Enterovirus; Paraechovirus rash is descrived as:
Rash involving extremities with palm and sole erythema
119
Enterovirus; Antidepressant that interacts with enterovirus 2C protein
Fluoxetine; in vitro activity against enteroviruses B and D
120
Enterovirus; Hypogammaglonulinemic patiens have reduced incidence of chronic infection with…
Use of high-dose IV immunoglobulin
121
Enterovirus; Currently there is a vaccine in phase 3 clinical trials for ___
A71
