Unit 14 - STI's Flashcards
1
Q
List the STI’s that will be covered in this lecture
A
- syphilis
- gonorrhea
- chlamydial infection
- genital herpes
- HPV
- HIV
2
Q
What is syphilis caused by?
A
Treponema pallidum
subspecies = pallidum
*invasive organism
3
Q
How many new cases/yr worldwide of syphilis?
A
11 million
4
Q
Syphilis is more common in which gender?
A
male
5
Q
Syphilis:
Incubation time?
A
1-90 days
6
Q
Syphilis:
3 phases
A
1) Primary
2) Secondary
3) Tertiary (late)
7
Q
Syphilis:
Describe the primary phase
A
- Chancres (skin lesions) at site of inoculation
- Usually painless & heal spontaneously
- Highly infectious
8
Q
Syphilis:
Describe the secondary phase
A
- signs of disseminated (widely spread disease)
- 2-12 weeks after infection
- skin lesions on truck, palms, & soles of feet
- LESION FLUID HIGHLY INFECTIOUS
- signs of other organ involvement
- 3-12 weeks, disappearance of symptoms
- latent phase follows
9
Q
Syphilis:
Describe the latent phase
A
-asymptomatic
-antibodies present
-three outcomes (untreated patients)
1-relapse
2-no relapse
3-tertiary phase
10
Q
Syphilis:
Describe the tertiary phase
A
- can occur long after initial infection
- neurologic cardiovascular symptoms
- may have gummas (nonspecific granulomatous lesions)
11
Q
What is congenital syphilis?
A
- Mothers with untreated/improperly treated syphilis
- Signs of secondary syphilis at birth
- Prevented if women are screened in early pregnancy and treated with penicillin
12
Q
Syphilis:
What is used for lab diagnosis?
A
Dark field of fluorescent microscopy
13
Q
Syphilis:
List 3 types of serodiagnosis
A
1 - Nontreponemal antibodies
2 - Treponemal antibodies
14
Q
Syphilis:
Describe serodiagnosis performed with nontreponemal antibodies
A
VDRL: general disease release laboratory test
RPR: rapid plasma reagin test
15
Q
Syphilis:
Describe serodiagnosis performed with treponema antibodies
A
FTA-ABS: fluorescent treponema antibody absorption
Agglutination tests
- MHA-TP (microhemagglutination test)
- TP-PA test (treponema pallidum particle agglutination test)
16
Q
Syphilis:
Treatment
A
penicillin, doxycycline
17
Q
Syphilis:
Prevention of secondary and tertiary syphilis
A
early diagnosis and treatment
18
Q
Gonorrhoea:
What is the cause?
A
Neisseria gonorrhoeae
19
Q
Gonorrhoea:
Describe Neisseria gonorrhoeae
A
gram negative diplococci
20
Q
Gonorrhoea:
Where does Neisseria gonorrhoea affect the human body?
A
- cervix, uterus, and fallopian tubes (female reproductive tract)
- urethra (males &females)
- mouth, throat, eyes, anus
21
Q
Gonorrhoea:
Women have a ____% chance of infection post single encounter
A
50%
22
Q
Gonorrhoea:
Men have a ____% chance of infection post single encounter
A
20%
23
Q
Gonorrhoea:
Vertical transmission results in _____ ________
A
opthalmia neonatorum
24
Q
Neisseria gonorrhoeae are ______
A
capnophiles
25
What are capnophiles?
capnophiles are microorganisms that thrive in the presence of high concentrations of carbon dioxide
26
Neisseria gonorrhoeae likes ____ atmospheres
humid
27
______ new cases of gonorrhoea/yr worldwide
97 million
28
Gonorrhoea:
| List the virulence factors
```
pilus
por proteins
opa proteins
LOS
Rmp proteins
IgA protease
capsule
```
29
pilus
aid attachment to human mucosal epithelium; contains constant and hyper variable regions - analogous to immunoglobulins (Igs) - that contribute to antigenic diversity in gonococci
30
por proteins
form pores through outer membrane; antigenic; specific serotypes associated with virulence
31
opa proteins
assit binding to epithelial cells
32
LOS
lipooligosaccharide (endotoxin activity)
33
Rmp proteins
inhibit 'cidal' activity of serum
34
IgA protease
core contains enzyme; released by cell to destroy IgA 1
35
capsule
resists phagocytosis, unless antibody present
36
Gonorrhoea in females is often ________
asymptomatic
37
If gonorrhoea is present in females, it will develop in ____ days
2-7
38
Symptom of gonorrhoea in females?
vaginal discharge
39
Untreated complications of gonorrhoea in females?
- PID
- chronic pelvic pain
- infertility
40
Symptoms of gonorrhoea in males?
- urethral discharge
| - painful urination
41
Other conditions of gonorrhoea?
- Anorectal (purulent discharge), pharyngeal (sore throat) & ophthalmic infections
- Ophthalmia neonatorum in newborns
42
Diagnosis of gonorrhoea uses a _____ ______
gram stain
43
Urethral discharge from symptomatic males with urethritis is caused by??
gram negative diplococci inside PMN's
44
Gonorrhoea:
| gram stain is not as useful for women - why?
normal vaginal and rectal flora have G-coccobacilli
45
Gonorrhoea:
| gram stain is not as useful for women - how do you diagnose instead?
must confirm diagnosis by culture
46
Gonorrhoea:
| Treatment?
antibiotics
| *key concern is resistance
47
Is there immunity for gonorrhoea?
no
48
What makes up the largest proportion of STIs reported in Canada and the US ?
genital chlamydiosis
49
Genital chlamydiosis:
| ______ new cases in 1999, worldwide
92 million
50
Genital chlamydiosis:
| What causes it?
obligate intracellular bacterium
51
Genital chlamydiosis:
| Serotypes L1, L2, and L3 cause?
1) STIs
- lymphogranuloma venerum (LGV)
- genital chlamydiosis
- nongonococcal urethritis
2) ocular and respiratory infections
52
Genital chlamydiosis:
| Serotypes A-C cause?
trachoma (bacterial infection of the eye)
53
Genital chlamydiosis:
| Describe the life cycle of chlamydia
- Elementary body binds host columnar epithelial cells
- Enters epithelial cell -> forms reticulate/initial body -> replicates by binary fission -> inclusions -> elementary bodies -> release form cell -> infectious cycle
*see slide 21 for life cycle
54
Genital chlamydiosis:
| Describe the diagram from slide 21 (the life cycle of chlamydia)
- attachment (EB attaches to specific receptor on host cell)
- entry (parasite-specified endocytosis)
- differentiation to RB
- multiplication of RBs
- differential to EBs
- release (EB progeny spread to adjacent cells)
* EB = elementary body
* RB = reticulate body
* from entry to differentiation to RB = takes 9-10 hours
* from differentiation to Rb to release = 20 hours
55
Genital chlamydiosis:
| Describe the presumptive diagnosis of chlamydia
- clinical suspicion based on symptoms
| - positive non culture result (EIA, DFA, or nucleic acid detection)
56
Genital chlamydiosis:
| Describe the definitive diagnosis of chlamydia
-culture and ID of inclusion bodies
OR
-combination of 2 non culture methods
57
List 2 other possible causes of vaginitis and urethritis
1) Candidiasis
| 2) Trichomoniasis
58
What is candidiasis caused by?
C. albicans
| *causes 80-90% of vaginal candidiasis
59
Carriage
Is when a bacteria jumps onto an object or individual, but is then quickly removed – so it is there only for a brief period of time.
60
Infection
Is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce.
61
Symptoms of vaginitis and urethritis caused by Candidiasis
itching, erythema, discharge: nil to thick
62
Treatment of vaginitis and urethritis caused by Candidiasis
OTC drugs - possible resistance?
63
What causes Trichomoniasis?
Trichomonas vaginalis
64
Trichomonas vaginalis is a ______ parasite
protozoan
65
Trichomoniasis produces what kind of discharge?
profuse, offensive, yellow-green
**can be asymptomatic
66
Treatment for trichomoniasis?
Metronidazole
67
Genital herpes is caused by what virus?
HSV-2
68
HSV-1 transmitted by ____
saliva
69
What does HSV-1 cause?
Oropharyngeal infections in children, cold-sores after reactivation
70
How is HSV-2 spread?
venereal route
71
What is genital herpes characterized by ____ _____
ulcerating vesicles
72
Primary lesions appear on penis/vulva ____ days post infection
3-7
73
Genital herpes:
| Break down to form painful ulcers which lead to ??
swollen lymph nodes, fever, headache, malaise
74
Genital herpes:
| Healings takes how long?
2 weeks
75
Genital herpes:
| Describe the pathophysiology
virus, lesion -> sensory nerve ending -> latent infection in dorsal root ganglion neurons
76
Genital herpes:
| Describe reactivation
reactivation, travel down same route -> recurrent lesions (genital cold sores)
77
Genital herpes:
| Mother to infant during birth -> ??
neonatal disseminate herpes or encephalitis
78
Genital herpes:
| Diagnosis ?
- Virus DNA in vesicle fluid or ulcer swabs
| - Immunofluorescence
79
Genital herpes:
| Treatment?
Antivirals
80
Genital herpes:
| Recurrent infections can be troublesome - how do we combat this?
6-12 months of low dose antiviral to stop/reduce frequency of recurrences
81
HPV
human papilloma virus
82
HPV causes
- papillomas/warts
| - cervical cancer
83
There are ___ distinct types of HPV
120
84
____ genital types of HPV
>40
85
Can HPV be grown in culture?
No
86
How can you diagnose HPV?
Cytology sections
- Pap smears
- Koilocytes
Nucleic acid detection
-PCR
87
HPV:
| Vaccine available?
Yes
| Quadrivalent vaccine
88
HPV:
| What types are in the quadrivalent vaccine?
HPV types 6, 11, 16, and 18
89
HIV
human immunodeficiency virus
90
HIV is a ______
retrovirus (lentivirus) - slow virus
91
What is a retrovirus?
A retrovirus is a single-stranded positive-sense RNA virus with a DNA intermediate and, as an obligate parasite, targets a host cell.
92
What is a lentivirus?
is genus of retroviruses that cause chronic and deadly diseases characterized by long incubation periods, in man and other mammalian species.
*basically a slow retrovirus
93
HIV is isolated from??
blood lymphocytes
94
HIV likely started in ____
africa
95
HIV-1 and HIV-2 arose from closely-related _____ viruses
primate
96
List the 3 groups of HIV-1
M (Main)
N (New)
O (Outlier)
97
Describe M (Main) type of HIV-1
A-J
- B most common in NA and Europe
- A & C
98
Describe N (New) and O (Outlier) type of HIV-1
West Central Africa
99
Increased _____ is causing a change in subtype distribution
travel
100
HIV infects cells with ____ surface marker
CD4
| ex. Th cells
101
HIV:
| Describe the Pathogenesis
1) Entry: binding of viral gp120 envelope glycoprotein to CD4 receptor
2) chemokine co-receptor (CCR5) - establishing infection
* individuals with CCR5 gene deletions are resistant
* disease progression seen with HIV variants using CSCR4 receptor
3) Viral replication halts after integration of provirus (latent in cell)
* see slide 32 for diagram
102
Routes of transmission:
| ___% infants infected in utero and intrapartum
20
103
Routes of transmission:
| ____% post-natally
11-16%
*associated with breastfeeding for up to 24 months
104
Clinical definition of HIV
CD4+ count, 200 mm^3 (> 1000 mm^3)
105
HIV:
| Describe Treatment
HAART (highly active antiretroviral therapy)
106
HIV:
| Describe Drawbacks
- Mitochondrial toxicity and altered fat distribution
- HIV inhabits CSF and GU tract
- Drugs cannot reach, high load in semen
- Resistance
107
HIV:
| Diagnosis
- Serological (HIV-1 & HIV-2 Abs)
- Molecular analysis - detect HIV-1 RNA or proviral DNA
- Measuring load of HIV-1 RNA also performed (RT-PCR)
108
Which STI's have vaccines?
hepatitis and HPV
109
____ intervals between the onset of infectiousness and disease increase the chances of transmission
Long
