Unit 1 Flashcards
(132 cards)
1
Q
Reportable Disease
A
Laws and regulations of a state or jurisdiction require it to be reported
2
Q
Notifiable Disease
A
Regular, frequent and timely information regarding individual cases is necessary for prevention and control the disease.
3
Q
Incidence
A
Number of new diagnoses per 100,000 people
4
Q
Order of infection incidence in rate/100,000 (largest to smallest)
A
Common cold (25,000) Gonorrhea (104) Influenza (25) AIDS (13) Strep pneumonia (10) Measles (
5
Q
SARS
A
Severe Acute Respiratory Syndrome Coronavirus Nov 2002 - July 2003 Contagious pneumonia 8000 cases worldwide Came from Civets Spread from Hotel Metropole
6
Q
Swine Flu (H1N1)
A
Started in Mexico - 2009 Quarantine efforts Triple recombination between human and animal influenza 0.01% of world population died (250,000 deaths)
7
Q
Percent of world population that died from influenza pandemic of 1919
A
3%
8
Q
Percent of world population that died from influenza pandemic of 1968
A
0.03%
9
Q
MERS
A
2012 - 2014 Middle East Respiratory Syndrome Coronavirus Found in camels and bats 100 deaths worldwide
10
Q
Type-2 Diabetes
A
Resembles infectious condition Modification of the microbiome of experimental animas can induce T2D Differences in GI microorganisms - no specific pathogen
11
Q
Other diseases that may be due to an infectious agent
A
Alzheimer’s MS
12
Q
Pediculus humanus capitus (head lice) - Site of infection
A
Scalp - especially behind ears
13
Q
Pediculus humanus capitus (head lice) - Classic presentation
A
School girls sharing hair accessories
14
Q
Pediculus humanus capitus (head lice) - Treatment for patient
A
Insecticidal shampoo TWICE with 10 DAYS IN BETWEEN. Combing.
15
Q
Pediculus humanus capitus (head lice) - treatment for environment
A
Hot wash all clothes and linen. Check family and classmates.
16
Q
Pediculus humanus capitus (head lice) - Special consideration
A
Allergic reactions to louse saliva Secondary staph infection
17
Q
Pediculus humanus corporis (body lice) - Site
A
Clothing - especially seams
18
Q
Pediculus humanus corporis (body lice) - Classic presentation
A
Homeless person
19
Q
Pediculus humanus corporis (body lice) - Treatment for patient
A
Refer for services Improve hygiene
20
Q
Pediculus humanus corporis (body lice) - Treatment for environment
A
Discard clothing or wash plus insecticide treatment
21
Q
Pediculus humanus corporis (body lice) - Special considerations
A
Can transmit typhus Trench fever Relapsing fever
22
Q
Pthirus pubis (pubic lice) - Site
A
Pubic hair
23
Q
Pthirus pubis (pubic lice) - Classic presentation
A
Sexually promiscuous
24
Q
Pthirus pubis (pubic lice) - Treatment for patient
A
Shave pubic hair or coat with vaseline
25
Pthirus pubis (pubic lice) - Treatment for environment
Hot wash all clothes and linens Check partners and children
26
Pthirus pubis (pubic lice) - Sepecial considerations
Marker for other STDs Condoms not protective
27
Spirochetes - Treponema
Syphilis Yaws Pinta
28
T. pallidum - general features
Syphilis Not visible to light microscope --\> dark field Delicate, motile (corkscrew), human restricted, not culturable Transmission: sexual, blood, congenital (readily cross placenta, leads to severe secondary syphilis) Virulence based on immune evasion
29
T. pallidum Pathogenesis
Penetrates abrasions and mucous membranes to enter lymphatics and blood stream. Invades CNS Surface of spirochete is non-immunogenic Down regulates Th1 cells
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Stages of syphilis
Primary: 3-6 wks, painless chancres on genitals which usually "heals" Secondary: 4-10 wks, Systemic symptoms flu-like, rash on palms and soles, condoylomata lata, high Ab titers Latent syphilis: secondary symptoms resolve but may return intermittently over time Tertiary: Gummatous syphilis - granulomatous lesions Cardiovascular syphilis - aneurysm Neurosyphilis - meningitis, meningovascular syphilis, parenchymal neurosyphilis
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Parenchymal neurosyphilis
Tabes dorsalis - damage to spinal cord - impaired sensation and wide-based gait Disruption of dorsal roots - loss of pain, temp sensation and areflexia General paresis - from damage to cortical brain tissue - dementia
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Argyll-Robertson pupil
Hallmark of neurosyphilis One or both pupils fail to constrict in response to light, but can constrict to focus on near object
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T pallidum Dx
Observation of symptoms like chancre (great imitator), rash, condylomata lata Imaging Lumbar puncture Lab - VDRL/RPR flocculation assay Histology - Endarteritis
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Treatment and prevention of Syphilis:
Penicillin STD panels Neurological symptoms may not heal Condoms!
35
Jarisch-Herxheimer reaction
8-24 hrs after treatment for syphilis. Flu-like symptoms
36
T. pertenue - Yaws
Tropical areas of Africa, Asia, South America and Oceania Overcrowding and poor sanitation Transmitted through direct contact with skin lesions Multiple stages - but no neuro or cardiac involvement Treat with penicillin G
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T. carateum - Pinta
Skin lesions Young adults Transmitted through direct contact Hyperpigmentation Restriction to skin - No constitutional symptoms (unlike Yaws) Central and South America Human restricted Treat with Penicillin G
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Features of human cancer cells
Make tumors if transplanted to animals Undifferentiated Immortal Not contact inhibited Resistant to apoptosis Abnormal chromosomes These changes can be induced by viruses
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Human growth genes (proto-oncogene): myc
Transcription factor
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Human growth genes (proto-oncogene): src
Membrane signaling of growth factor binding
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Human growth genes (proto-oncogene): ras
signal transduction from surface receptors
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Human growth genes (proto-oncogene): sis
Platelet-derived growth factor
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Human growth genes (proto-oncogene): erb B
Growth factor receptor
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Human growth genes (proto-oncogene): fms
Growth factor receptor
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Human growth genes (proto-oncogene): LMO2
Hematopoiesis
46
Oncogenes are overexpressed by what processes?
Amplification Mutation Translocation
47
True or False: Oncogenic viruses are species-specific.
True
48
Mechanisms through which retroviruses cause cancer
Express oncogenes Insert promoter and cause expression of regional oncogenes
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Mechanisms through which DNA viruses cause cancer
Disturb cell cycle to prevent apoptosis: - Inactivate p53 - inactivate Rb
50
SV40 virus
Primate virus Causes cell transformation and cancer in rodents and JUST malignancy in humans (no cancer) Expression of T antigen - inactivates p53 and Rb Contaminant in early polio vaccines
51
Adenovirus
Human virus Cause cell transformation and cancer in rodents (NOT humans) E1A and E1B always expressed in transformed cells - analogous to T-antigen
52
Many animal cancers are caused by viruses
Mouse mammary tumor virus - breast cancer in mice Feline leukemia virus - leukemia in domestic cats Marek's disease virus - lymphomas in chickens
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Human viruses that cause cancer
HPV EBV HepB and HepC Human T-cell lymphotropic virus Kaposi sarcoma herpes virus
54
HPV
Low risk types cause warts High risk types (like HPV-16 and HPV-18) cause squamous cell carcinoma in cervix, penis and oropharynx E6 and E7 inactivates p53 and Rb Vaccines reduce risk of CIN
55
EBV
Herpes virus causes mono in the west and childhood lymphoma (Burkitt's) in Africa and AIDS patients Can cause naso-pharyngeal cancer (Asia) Overexpresses myc
56
Hep B
Causes chronic hepatits which predisposes to cirrhosis and liver cancer (Asia) There is a vaccine
57
Human T cell Leukemia Virus (HTLV-1)
RNA virus - no oncogene tax gene - overexpresses interleukin-2 and its receptor Dysregulates RNA metabolism Blood borne Caribbean Causes leukemia and lymphoma
58
Kaposi sarcoma herpes virus (KSHV, HHV8)
Carrier rate of 50%in Africa Associated with Kaposi's sarcoma in patients with HIV
59
N. Gonorrhoeae - Features like N. meningitidis
Diplococci
Human-restricted
oxidase-positive
Cleared by complement
Grows in vitro - chocolate agar
Gram negative LOS
60
N. Gonorrhoeae - Features NOT like N. meningitidis
Not encapsulated
Hundreds of serotypes
Sensitive to dehydration and cold
Plasmid-borne antibiotic resistance
Cephalosporin resistant
Does NOT ferment maltose
61
N. Gonorrhoeae - pathogenesis
Transmission - sexual or at birth
Neonate - purulent conjunctivitis --\> untreated lead to permanent blindness
Male - Anterior urethritis
Female - asymptomatic cervicitis
62
N. Gonorrhoeae - virulence factors
IgA protease - Clears IgA from mucosal surfaces to colonize
Pili - Attach to epithilium
Opa - Opacity-associated proteins enhance cell adherence and entrance
Porin A and B channels - Serum resistance and enhance entry
LOS - Induces local inflammatory response
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N. Gonorrhoeae - PID
Causes PID when bacteria mixes with refluxed menstrual blood or attached to sperm
Lower abdominal pain
vaginal discharge
Dysuria
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N. Gonorrhoeae - bacteremia
Dissemination
Certain strains more likely
Serum resistance thanks to Porin A
More common in women
Arthritis/dermatitis
65
N. Gonorrhoeae - Dx
Exam - Single-exposure contraction.
Observation of symptoms.
Lab - Urine and exudate testing - (gram negative intracellular diplococci) Urethral swab (most sensitive) Endocervical smear (culture on Thayer-Martin) Immunofluoresence
66
N. Gonorrhoeae - Rare sequellae
Gonococcal meningitis
Endocarditis (aortic valve)
67
N. Gonorrhoeae - Treatment
If allergic to penicillin use cephalosporin
Ceftriaxone or cefixime
Add azithromycin or doxycycline b/c chlamydia coninfection
Aspirate septic joints
68
N. Gonorrhoeae - Prevention
Neonate - Prophylactic erythromycin ointment or silver nitrate to eyes immediately
Condoms
Report
EPT - expedited partner treatment
69
Chlamydia replication
Obligate intracellular bacteria
Involves elementary and reticulate bodies
Enters cell as elementary body then reorganizes into reticulate body
Multiply by fission
Reorganize into EB
Escape cell through lysis or reverse endocytosis
70
Other obligate intracellular bacteria
Rickettsia
71
Chlamydia - EB
Small
Infectious agent
Rugged
Bind to receptors in lungs or mucus membranes
72
Chlamydia - RB
Non-infectious form
Metabolically active
Replicating
Requires ATP from host
Gram negative
Inclusions
73
Chlamydia - Inflammatory response
Causes swelling and discharge
No immune memory - reinfection is common
74
C. trachomatis - Blinding trachoma
Leading cause of preventable blindness
Spread by secretions - direct and fomites
Untreated eyelids turn inward
75
C. trachomatis
Urogential Chlamydia
One bug - 18 serovars
76
C. trachomatis - Lymphogranumloma Venereum
South and Central America
Painless ulcer --\> swollen lymph nodes (buboes)
Aspiration of buboes and fistulas may speed healing
77
C. trachomatis - genital chlamydia
Often asymptomatic
Males are reservoirs
Increases risk of acquiring HIV
78
C. trachomatis - genital chlamydia - risk factors
Nonbarrier contraceptive use
Multiple sex partners
Single
79
C. trachomatis - genital chlamydia - PID
Leading cause of PID and infertility in women
Increased risk for chronic pain and ectopic pregnancy
80
C. trachomatis - genital chlamydia Dx
Observation of symptoms
Lab (test for co-incident chlamydia with all STIs - Cytologic Dx, isolation in cell culture, detect rRNA by DNA probe hybridization, ELISA and PCR
81
C. trachomatis - Reactive arthritis
Reactive arthritis secondary to an immune-mediated response
Conjunctivitis, Urethritis, Arthritis (can't see, can't pee, can't climb a tree)
Patients are HLA-B27 positive
Treated with NSAIDs
82
C. trachomatis - genital chlamydia treatment
Antibiotic must be intracellular
1st choice: Doxycycline or azithromycin
2nd choice: erythromycin and amoxicillin - test the cure
Treat partner - reinfection is common
83
C. trachomatis - genital chlamydia prevention
Education
Condoms
84
Treatment of occupational exposure to HIV
Post exposure prophylaxis
85
HIV - general features
Retrovirus, +ssRNA, 2 copies, enveloped
Symptoms: Fever, weight loss, mouth and esophageal sores, thrush, enlarged liver and spleen, lymphadenopathy
86
HIV - Routes of transmission
Unprotected sex w/ infected partner
Sharing needles w/ infected person
(Rare) mother to fetus
(Rare) blood products
87
HIV - exposure and infection
Cross barrier
Local propagation
Local expansion
Dissemination
Lymphatic tissue reservoir established
88
HIV cell tropism
Only infects humans
Needs 2 coreceptors to bind - CD4 and chemokine receptor
CCR5 in Macrophages
CXCR4 in T cells
Early - Non-syncytium inducing
Late - Syncytium inducing
89
HIV - Syncytia
When infected cells fuse with uninfected cells
90
HIV life cycle
Binds to receptors - Env
Fusion of envelope and cell membrane
Uncoats and releases the 2 copies of it's genome
Reverse transcriptase makes DNA
DNA moves to nucleus and integrase incorporates it into host DNA
Transcribed along with cell
All cell components assemble close to cell membrane
Budding
91
Stages of HIV
Exposure
Primary HIV - acute
Seroconversion
Latent period
Early symptomatic HIV infection
AIDS (CD4 count below 200/mm3)
Advanced HIV infection (CD4 below 50 mm3)
92
Symptoms of AIDS
Encephalitis
Meningitis
Retinitis
Esophagitis
Pneumocystitis pneumonia
TB
Tumors in lungs, skin, GI tract
Chronic diarrhea
93
HIV - Mechanism of disease
Viremia
Accelerated viral replication
Destruction of immune system
94
Epidemiology of young people and STIs - incidence and prevalence
19 million new cases each year
Half occur in people ages 15-24
1 in 4 teens has an STI
95
Young people and STIs - confidentiality
It is not required for physicians to inform parents or partners of a teenaged patient's diagnosis or treatment
96
Five P's of sexual history
Partners
Prevention of pregnancy
Protection from STIs
Practices
Past history of STIs
97
Common causes of vaginosis
Candida
Trichomonas
Bacterial Vaginosis
98
Trichomonas symptoms - female
Foul frothy discharge
Vaginal itching/redness
Dyspareunia
Dysuria
Post coital bleeding
Excessive/prolonged menses
99
Trichomonas symptoms - male
Often asymptomatic
NGU
Consider it with recurrent urethritis
100
Bacterial vaginosis - symptoms
Odorous discharge
Itching
101
Bacterial vaginosis - prevalence
Found in 24-47% of STI patients
102
Trichomonas - vaginal discharge
Frothy, gray or yellow-green
Malodorous
103
Trichomonas - clinical findings
Cervical petechiae (strawberry cervix)
104
Trichomonas - pH
\>4.5
105
Trichomonas - KOH whiff test
Often positive
106
Trichomonas - NaCl wet mount
Motile flagellated protozoa, many WBCs
107
Bacterial Vaginosis - vaginal discharge
Homogenous
Adherent
Thin milky white
Malodorous (foul, fishy)
108
Bacterial Vaginosis - pH
\>4.5
109
Bacterial Vaginosis - KOH whiff test
Positive
110
Bacterial Vaginosis - NaCl wet mount
Clue cells
No/few WBCs
111
Candidiasis - symptoms
Itch
Discomfort
Dysuria
Thick discharge
112
Candidiasis - vaginal discharge
Thick
Clumpy
White cottage cheese appearance
113
Candidiasis - clinical findings
Inflammation and erythema
114
Candidiasis - pH
Less than 4.5
115
Candidiasis - KOH whiff test
Negative
116
Candidiasis - NaCl wet mount
Few WBCs
117
Candidiasis - KOH wet mount
Only one with KOH wet mount result
Pseudohyphae (or spores if non albicans species)
118
Bacterial vaginosis
Requires three of the following: positive whiff test, clue cells, pH \>4.5, homogenous non-inflammatory discharge
119
Treatment for BV and Trichomonas
Metronidazole (but different doses)
120
Most common causes of cervicitis
Chlamydia
Gonorrhoea
121
Tests to order for cervicitis
Nucleic acid amplification test (NAAT) - gold standard
Culture - for medical legal purposes
122
NAAT
Amplifies target nucleic acids
Can collect sample when performing an exam
Can also use first 10-15 cc of urine specimen from men and women
123
Time course of HIV infection
Anti-HIV Ab appears - 3-12 wks
124
CD4 count milestones
500 - skin disease - seborrheic dermatitis, papulopuritic eruptions
350 - pulmonary - TB
300 - oral thrush, oral hairy leukoplakia
100-200 - kaposi's, PCP, esophageal candida
Less than 100 - Opportunistic infections
125
Seborrheic dermatitis risk factors
Everyday: stress, weather, oily skin, infrequent shampoo, lotions that contain alcohol, obesity
Neurological conditions including Parkinson's, head injury, stroke
HIV
126
Goals of antiretroviral therapy
Suppress HIV replication - impede spread
Prevent/delay destruction of immune system
Achieve normal survival
All while maintaining a tolerable life
127
Indications for treatment of HIV
Symptomatic - any CD4 count
Asymptomatic - CD4 count less than 350
128
Indications for deferring therapy for HIV
Asymptomatic - CD4 count \>350, plasma HIV RNA copies can be either greater or less than 100,000. If greater then physician decides.
Personal situations
Significant barriers to adherence
Comorbidities
Long-term nonprogressors
129
Benefits of early treatment of HIV
Not clear
Some studies show increased survival benefit
130
Concerns for early treatment of HIV
ARV-related toxicities
Non-adherence to ART
Drug resistance
Cost
131
Reasons to consider rapid initiation of ART
Pregnancy
AIDS-defining condition
Acute opportunistic infection
Low/rapidly declining CD4 count (less than 200)
132
Targets of HIV therapy
NRTI
NNRTI
Protease inhibitors
Integrase inhibitors
Fusion inhibitors
CCR5/CXCR4 blockers
