Contact Infectious Disease Flashcards
Describe this Contact Infectious Disease: Trachoma (Non-sexual disease)
(Causative Agent/Characteristic, Virulence Factors, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristc
- AKA: x
- CA: Chlamydia trachomatis strain (different serotype than Genital Chlamydia)
- Characteristic: Gram-negative, coccobacillus, obligate intracellular parasite
Virulence Factors
- Invades and Replicates in epithelial cells
- 2 morphological forms
-> Elementary bodies:
–» Infectious, invade epithelial cells
-> Reticulate bodies:
–» Non-infectious, replicate intracellularly
Tissue/Organ Affected
- x
Reservoir
- Human
Mode of Transmission
- Direct: Hand-to-eye contact
-> Eye discharge - Indirect: Sharing objects
-> Towels/handkerchiefs - Arthropod: Sand Flies
-> Carrying eye discharge
Predisposing Factors
- Unsanitary conditions
- Over-crowding
- Children
Incubation Period
- x
SXS
- Inflammation (conjunctivitis) of upper eyelid
-> scarring/contraction of conjunctiva -> eyelashes turn inward -> eyelashes scratch cornea -> corneal cloudiness -> permanent blindness
Diagnosis
- Clinical/SXS
Treatment
- Surgery
- ABX
Preventative Measures
- No vaccine available
- Vector control of sand flies
- Washing hands
MISC
- POE - mucous membrane (conjunctiva)
- Leading preventable causes of blindness worldwide
- Most cases of blinding trachoma occur in Africa
-> HIGH infection rates < 5yr
Describe this Contact Infectious Disease: Gonorrhea
(Causative Agent/Characteristic, Virulence Factors, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: Neisseria gonorrhoeae
- Characteristic: Gram-negative, encapsulated diplococcus (coffee-bean)
Virulence Factors
- Capsule & Fimbriae
-> attaches to epithelial mucosa - Op proteins in CW
-> Bind to T cell receptors -> inhibit immune response
Tissue/Organ Affected
- x
Reservoir
- Human
Mode of Transmission
- Direct: sexual contact
Predisposing Factors
- x
Incubation Period
- x
SXS
- Gonococcal Urethritis (caused by N. gonorrhea)
- Men: (More SXS)
-> Painful urination
-> Creamy, yellow discharge
-> Epididymitis (testicular pain) - Women (Few/No SXS)
-> Pelvic inflammatory disease (PID; inflammation of ovaries/fallopian tubes = major cause of sterility)
MAY BECOME SYSTEMIC IF UNTREATED:
-> Endocarditis (heart inflammation)
-> Meningitis (brain/spinal cord membrane inflammation)
-> Arthritis (joint inflammation)
Infants:
-> Ophthalmia neonatorum (neonatal conjunctivitis)
–> Infant blindness bc gonorrhea/genital chlamydia inf of eyes during vaginal birth
Diagnosis
- Urine test or oral/urethral-rectal swab
- PCR
- Culture (look for gonococci)
Treatment
- ABX
-> Injection
-> Oral meds
Preventative Measures
- Education & safe sex practices
MISC
- Highest infection rates in teens/young adults (bc sexually active)
- Coinfection with Genital Chlamydia
Describe this Contact Infectious Disease: Genital Chlamydia
(AKA/Causative Agent/Characteristic, Virulence Factors, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: Chlamydia
- CA: Chlamydia trachomatis strain (different serotype than Trachoma)
- Characteristic: Gram-negative, coccobacillus; obligate intracellular parasite
Virulence Factors
- Invades and Replicates in epithelial cells
- 2 morphological forms
-> Elementary bodies:
-» Infectious, invade epithelial cells
-> Reticulate bodies:
-> Non-infectious, replicate intracellularly
Tissue/Organ Affected
- x
Reservoir
- Human
Mode of Transmission
- Direct: sexual contact (through epithelial mucosa)
Predisposing Factors
- x
Incubation Period
- x
SXS
- Non-gonococcal urethritis (caused by N. gonorrhea)
- Men: (More SXS)
-> Painful urination
-> Watery, clear discharge - Women (Few/No SXS)
-> Pelvic inflammatory disease (PID; inflammation of ovaries/fallopian tubes = major cause of sterility)
May also cause (in infant):
-> Ophthalmia neonatorum (neonatal conjunctivitis)
–> Infant blindness bc gonorrhea/ genital chlamydia inf of eyes during vaginal birth
Diagnosis
- Nucleic Acid Amplification Tests (NAAT)
-> most sensitive test available
-> PCR is a type of NAAT
-> Performed on vaginal/urethral swabs or urine
Treatment
- ABX
Preventative Measures
- Education & safe sex practices
MISC
- Most common bacterial STD in U.S = millions cases (in US)
- Coinfection with Gonorrhea
Describe this Contact Infectious Disease: Syphilis
(Causative Agent/Characteristic, Virulence Factors, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: Treponema pallidum
- Characteristic: Gram-negative, spirochete (endo flagella/axial filaments); motile
Virulence Factors
- Lipid outer layer
-> weak immune system
Tissue/Organ Affected
- x
Reservoir
- Human
Mode of Transmission
- Direct: sexual contact
Predisposing Factors
- x
Incubation Period
- x
SXS
Primary Stage/Phase:
-> Chancre (painless core at site of infection)
–» Highly infectious
Secondary Stage/Phase:
-> Flat, skin & Mucosal rashes
–» Palms & soles
-> Latent period: decades
Tertiary Stage/Phase:
-> Appears decades later after latency
-> Formation of gummas (soft tumor-like lesions) on bone, brain, heart & skin
-> Arthritis
-> Cardiovascular dmg -> cardiovascular syphilis
-> Neurological dmg, dementia -> neurosyphilis
Diagnosis
- Serology
-> Direct DXS: look for T. Pallidum
-> Indirect DXS: look for Ab
Treatment
- ABX
-> effective only in early stages
Preventative Measures
- Education & safe sex practices
MISC
- Congenital syphilis
-> Development damage to fetus & stillbirths
Describe this Contact Infectious Disease: Trichomoniasis
(AKA/Causative Agent/Characteristic, Virulence Factors, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: Trich
- CA: Trichomonas vaginalis
- Characteristic: Kingdom Protista, protozoan parasite; Motile: Flagella, undulating membrane; Pear-shaped
Virulence Factors
- Axostyle: sharp point for anchoring to epithelial cells
Tissue/Organ Affected
- x
Reservoir
- Men
Mode of Transmission
- Direct: sexual contact
Predisposing Factors
- x
Incubation Period
- x
SXS
- Men:
-> Asymptomatic carriers: found in urine & semen
-> Some urethral discharge
-> Painful urination - Women:
-> Symptomatic
-> Frothy, greenish-yellow, foul odor discharge
-> Painful urination
Diagnosis
- Microscopic observations of live, motile protozoa from swab of the infection site
Treatment
- Antiparasitic/antiprotozoal drugs
Preventative Measures
- Education & safe sex practices
MISC
- Most common non-viral STD in U.S = millions+ new cases/year
- Risk of low birth weight or premature births
Describe this Contact Infectious Disease: Genital Herpes
(Causative Agent, Virulence Factors, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: Herpes Simplex Virus Type 2 (HSV-2), HHV; Herpesviridae family; DNA
- Characteristic: x
Virulence Factors
- Hide in NS = latent viral infection
Tissue/Organ Affected
- x
Reservoir
- Human
Mode of Transmission
- Direct: sexual contact
Predisposing Factors
- x
Incubation Period
- x
SXS
- Painful, fluid-filled/raised vesicles on the genitals
-> Heals within 2 weeks (not cured)
-> Outbreaks of vesicles; primary episode -> recurrent outbreaks - Painful urination
Diagnosis
- Culture
- PCR
Treatment
- Antivirals (management/suppress SXS)
Preventative Measures
- Education & safe sex practices
MISC
- 25% adults >30yr infected in U.S
- Neonatal Herpes:
-> Herpes crosses the placental barrier -> infects the fetus
-» Damage CNS = developmental delays, blindness, hearing loss
-> Low Survival rate (40%)
-> Newborns infected during delivery
Describe this Contact Infectious Disease: Hepatitis B
(Causative Agent, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: Hepatitis B Virus: DNA
- Characteristic: x
Virulence Factors
- x
Tissue/Organ Affected
- x
Reservoir
- x
Mode of Transmission
- Direct: sexual contact (body fluids)
- Accidental needle sticks (healthcare workers)
Predisposing Factors
- x
Incubation Period
- x
SXS
Mild to Severe SXS:
Acute Infection:
-> Most adults fully recover
-> Jaundice
-> Loss of appetite
-> Fever
-> Nausea
-> Vomiting
Chronic Infection:
-> Liver failure
-> Cirrhosis
-> Liver cancer
Diagnosis
- Serology (Abs)
- Liver Ultrasound
- Liver Biopsy
Treatment
- NO CURE (management)
To manage chronic disease:
- Antivirals
- Interferon Injection
- Liver transplant
Preventative Measures
- Vaccine
- Education & safe sex practices
MISC
- Small % of infected patients -> chronic Hepatitis B
Describe this Contact Infectious Disease: Hepatitis C (NOT STD)
(Causative Agent, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: Hepatitis C Virus: RNA
- Characteristic: x
Virulence Factors
- x
Tissue/Organ Affected
- x
Reservoir
- x
Mode of Transmission
- Contaminated blood
-> blood transfusions
-> tattoos
-> IV drug use
Predisposing Factors
- x
Incubation Period
- x
SXS
Acute Infection:
-> Most PT will develop chronic hepatitis
-> Usually asymptomatic
-> Jaundice
-> Loss of appetite
-> Fever
-> Nausea
-> Vomiting
Developed Chronic Infection:
-> Liver failure (~25%)
-> Cirrhosis (~25%)
-> Liver cancer
Diagnosis
- Serology (Abs)
- Liver Ultrasound
- Liver Biopsy
Treatment
- NO CURE (management)
- Daily Antiviral: 2-6mnth
-> Can help 95% of people
-> Notoriously expensive ($1000/pill)
-> Virus is undetectable in blood - Liver transplant
Preventative Measures
- NO VACCINE
- Universally safe precautions/blood handling
MISC
- Large % of infected patients -> chronic Hepatitis C
- Large % of PT with Hepatitis C were born ~mid 1900’s
Describe this Contact Infectious Disease: HIV/AIDS
(Causative Agent/Characteristic, Virulence Factor, Mode of Transmission, Predisposing Factors, SXS, Diagnosis, Treatment, Preventative Measures)
AKA/Causative Agent/Characteristic
- AKA: x
- CA: HIV (human immunodeficiency virus), Retroviridae Family, Retrovirus, RNA
Two strains: HIV-1 (more deadly) & HIV-2 - Characteristic: Enveloped, spikes (gp120; attach to host cell), enzymes (reverse transcriptase, integrase)
Virulence Factors
- High gene mutation
-> Rapid antigenic variation - Targets human host cells: CD4+ T cells (surface marker on T helper cells) = destroy Cell-Mediated Immunity
Tissue/Organ Affected
- x
Reservoir
- x
Mode of Transmission
- Primary method: sexual contact
-> Exchange body fluids - Secondary method: non-sexual contact
-> Blood (contaminated) transfusions/organ transplant
-> Breast milk
-> Transplacental
-> Sharing contaminated IV needles (HIV-contaminated blood)
Predisposing Factors
In chronological order from most to least:
- Men having sex with men (MSM)
- Heterosexuals
- IV drug users
- MSM and IV drug users
Incubation Period
- x
SXS
Viremia (Sys inf):
Phase 1:
- Asymptomatic
-Hardened, swollen lymph nodes = lymphadenopathy
Phase 2:
- Serious disease SXS
-> Persistent Candida albicans (fungal) infections
-> Persistent diarrhea
-> Fever
Phase 3:
- Clinical AIDS indicator Conditions unusual opportunistic infection (bc weak immune system)
-> Atypical (fungal) Pneumonia
-> Kaposi’s Sarcoma (cancer of the skin and BV; HHV-8)
-> Miliary TB (Sys TB infection)
Diagnosis
- ELISA
-> Detects pathogen or Ab - Plasma Viral Load
-> Detects & quantifies the amount of HIV circulating in the blood - Rapid tests & self-testing Kits
-> Detects HIV ab in saliva
-> Results available in 20 minutes
Treatment
- NO CURE
- Anti-Retroviral drugs/therapy (ART) - management
-> HAART
-> Fusion/Cell Entry Inhibitors
-> Reverse Transcriptase Inhibitor (2 types)
-> Integrase Inhibitors
-> Protease Inhibitor
Preventative Measures
- NO VACCINE
- Education & safe sex practices
- PrEP (Pre-exposure prophylaxis)
-> Sold under the name Truvada
MISC
- x
What does HIV stand for? What does AIDS stand for?
HIV = human immunodeficiency virus
AIDS = acquired immunodeficiency syndrome
Generally describe how HIV/AIDS became known as. Include specific dates
1981: cluster of Pneomocytis (atypical) pneumonia, Kaposi sarcoma (cancer), and loss of immune function were discovered in young, homosexual men. AIDS EPIDEMIC BEGINS
1982: term Acquired Immunodeficiency Syndrome is used for first time
1983: discovery of virus causing the loss of immune function -> eventually named Human Immunodeficicy Virus (HIV)
HIV/AIDS spread from “__________” ________ (africa) to human populations
old world
monkeys
What does SIV stand for? Where does it come from?
SIV = Simian Immunodeficiency Virus
-> comes from monkeys
Name the different strains of human HIV
Which is the most deadly? Name some important info about them
HIV-1 = MOST PATHOGENIC/DEADLY
- Related to SIV in gorillas and chimpanzes
- 99% of cases WW
HIV-2
- endemic to West Africa
- Lower mortality rate than HIV-1
Where is HIV/AIDs most prevalent in the world?
Africa
____________ is the most common mode of HIV transmission worldwide
Heterosexual transmission
Name, in chronological order from highest to smallest, the common predisposing grous for new HIV infections in the US
- Men having sex with men (MSM)
- Heterosexuals
- IV drug users
- MSM and IV drug users
Describe the pathogenesis of HIV to CD4+ T cells
- Viremia -> HIV (in blood) travels to lymphoid tissue, where CD4+ T helper cells are present
- HIV uses its gp120 (glycoporotein spike) to attach to the human host CD4+ T helper cell receptors and coreceptors (Attachment)
- Virus enters via fusion and is inside host CD4+ T helper cell (Entry)
- HIV gets uncoated to expose the viral RNA inside the host CD4+ T cell (Uncoating)
- Viral RNA is reversely transcribed into DNA (via reverse transcriptase)
- Viral DNA integrates (via integrase) into host CD4+ T helper cells chromosomal DNA = PROVIRUS = enters lytic OR lysogenic cycle
-> Active infection: new virions (progeny HIV) bud from host cell (lytic; underwent biosynthesis, maturation, release)
-> Latent infection: DNA is hidden in the chromosome as provirus (lysogenic cycle)
Describe the phases/stages of HIV infection
Phase 1: 0-3 years
- # of CD4+ T helper cells declines because # HIV goes up
- # of CD4+ T helper cells begin to go back up and # HIV declines quickly (but never reaches 0; stabalizes)
- # of CD4+ T helper cells slowly decreases
- Asymptomatic; hardened/swollen lymph nodes (lyphadenopathy)
- Seroconverions occurs: makes Abs; detectable at end of 3 months
Phase 2: 3-8 years
- # of CD4+ T helper cells decline steadily
- Only a few infected cells release HIV
- Few serious disease SXS occur:
-> Persistant Candida albicans (fungal) infections
-> Persistant diarrhea
-> Fever
Phase 3: 8-10 years
- # of CD4+ T helper cell count falls below 200 CD4+ T helper cells/μl of blood
- Clinical AIDS Indiacator Conditions: unusual oppotunistic infections
-> Atypical (fungal) pneumonia
-> Kapsoi Sarcoma (cancer of skin and BV due to HHV8)
-> Miliary TB (mycobacterial that has spread; sys inf).
*TRUE or FALSE: Although AIDS indicator conditions are not present until Phase 3, you are still considered to have AIDS when you are in Phase 1 or 2
False, only at Phase 3 do you truly have HIV/AIDs
How do our 3rd line of host defenses (adaptive immunity) respond to HIV exposure?
Humoral Immune Response
- HIV-specific antibodies are produced in the seroconversion stages
-> Takes 3 months (part of Phase 1)
-> PT can still transmit HIV before seroconversion
Cell-Mediated Immune Response
- CD8 + T helper cell suppresses viral replication
TRUE or FALSE: HIV virus target CD4+ T helper cells and CD8+ T helper cells
False, the target is ONLY the CD4+ T helper cells
Name and describe each diagnositic method for HIV/AIDS (what does it detect?)
ELISA (enzyme-linked immunosorbent assay) test
- detects pathogen (HIV) or Ab (IgM; anti-HIV Abs)
Plasma Viral Load (PVL)
- detects and quantifies concentration of HIV circulating in the blood
-> useful before seroconversion ends
Rapid Tests and Self-Testing Kits
- detects HIV antibodies in saliva (results avaliable in 20 minutes)
Doctor Miguel wants to detect and quantify the amount of HIV circulating in the blood of a current patient, Abdullah. He notes that it has been 5 months since his patient was infected with HIV.
Nurse Josh wants to run a PVL (Plasma Viral Load) on the PT.
Nurse Abby says he cannot do this because the diagnostic tool would not be very useful.
Explain why running a PVL would not be very useful.
PVL are only useful before seroconversion ends, which is before 3 months. It has been 5 months since the patient was infected.
PVL are useful between months 1-3 of HIV infection.
Define: Seroconversion
period of time between infection and detectable presence of HIV antibodies
(body is still making Abs, but they are not detectable until end of 3 months)
Other than preventing HIV/AIDS through education and safe sex practices, PrEP (Pre-Exposure prophylaxis) is another way to prevent HIV/AIDS. Briefly describe this is
- HIV medicine taken daily to decrease changes of HIV infection
-> Lowers risk dramatically (protect >90% from sex; >70% from IV drug use) - Sold as: Truvada
- HAS TO BE TAKEN BY HIV-NEGATIVE PERSON ONLY!
One way to manage HIV/AIDs is through Anti-Retroviral drugs/therapy (ART). What is the goal of ART?
goal = decrease plasma viral load (concentration of HIV virus) to undetectable amounts (however, you are still HIV-positive)
Name 5 categories of Anti-Retroviral drugs used for management of HIV/AIDS
Highly Active Antiretroviral Therapy (HAART)
- uses combination (cocktail) of multiple drugs to combat resistant HIV strains
Fusion/Cell Entry Inhibitors
- prevent fusion of HIV virus with host CD4+ T helper cells
Reserse Transcriptase Inhibitors
- Two types
- prevent conversion of viral RNA into viral DNA (= cannot integrate -= no hybrid DNA/provirus)
Integrase Inhibitors
- prevent integration of viral DNA into host cell (CD4+ T helper cell) DNA (= no hybrid DNA/provirus)
Protease Inhibitors
- inhibit protease that cleave viral precuror proteins into structural and functional proteins (ex: protein spikes)
What type of infections are commonly associated with AIDS?
Fungal infections
Bacterial infections
Viral infections
Cancers
