Viruses - DNA - NOT from Herpes Family Flashcards
Polyomavirus; JC and BK
lab tests
Et Tu, BK?
Circular DS DNA
Naked virus (No envelope!)
Polyomavirus; JC and BK
2 main polyomavirus strains
Et Tu, BK?
- JC virus (John Cunningham virus)
- BK virus
JC Virus (a Polyomavirus)
MOA
aka John Cunningham Virus
Et Tu, BK?
- JCV causes persistent asymptomatic infection in approximately one-third of the adult population.
- The virus causes disease only when the immune system has been severely weakened. (causes PML!)
- Immunocompromised people, or in AIDS pts with CD4 < 200.
- PML has a mortality rate of 30–50 percent in the first few months.
JC Virus (a Polyomavirus)
signs and symptoms
aka John Cunningham Virus
Et Tu, BK?
- JCV causes progressive multifocal leukoencephalopathy (PML), a demyelination disease (by killing oligodendrocytes that produce myelin for the CNS)
- Multifocal non-enhancing brain lesions in white matter (dds vs Toxoplasmosis w/ ring enhancing lesions)
- buzzwords: AIDS pt. with motor neuropathy
BK Virus (a Polyomavirus)
signs and symptoms
Et Tu, BK?
- Nephropathy & other urinary tract problems
- Hemorrhagic cystitis* (Sudden onset of hematuria w/ bladder pain and irritable bladder syndrome)
- Common in transplant pts* (Kidney nephropathy and bone marrow transplants)
* DDX Adenovirus which also has hemorrhagic cystitis, but is more common in boys and swimming in public pools.
HPV
lab tests
Pilloma Bugs
DS DNA
Naked virus (No envelope!)
- Pap smear and cervical cancer screening.
- Koilocytes in squamous* cells (large, dense, wrinkled nucleus that may be binucleated).
* Detecting morphological changes; sampled from the transformation zone (where squamous eipthelium from outer ectocervix comes into contact with columnar epithelium in the inner endocervix).
HPV
know the main HPVs strains
Pilloma Bugs
100’s of HPV strains!
- HPV 1 - 4
- HPV 6 & 11**
- HPV 16 & 18**
- HPV 31 & 33
HPV
HPV 1 - 4
signs and symptoms
Pilloma Bugs
- Verruca** (wart) **vulgaris (common)
- aka “cutaneous common wart”
- transmission requires direct physical contact
- Children typically get on hands and feet
HPV
HPV 6** and **11
signs and symptoms
Pilloma Bugs
- Laryngeal Papillomatosis (Recurrent respiratory papillomatosis): Tumors (papilloma’s) develop in airways. Typically seen in children, and often obtained during vaginal birth (but not considered an STD)
- Anal genital warts (Condyloma acuminata*): seen in sexually active pts.
* ddx from secondary syphilis w/ Condylomata lata
HPV
HPV 16**, **18, 31, and 33
signs and symptoms
Sketchy Tip: Remember 16/18. add 15 to each to get 31/33
Pilloma Bugs
- most common STD
- Ano_genital_ carcinoma (Squamous Cell Carcinoma): Cervical, vulvar, vaginal, penile, anal
- Buzzwords = “bleeding after sex” or “cancer”
- In anal or penile cancer a major RF is immunosupression, especially in HIV* pts.
* HPV is an AIDS-defining illness)
HPV
HPV 16**, **18, 31, and 33
MOA
Sketchy Tip: Remember 16/18. add 15 to each to get 31/33
Pilloma Bugs
- HPV upsets the cells normal cycle.
- Tumor supressor proteins p53 and RB (Retinoblastoma protein) normally stop the cell cycle advancement from G1→S.
- HPV encodes E6** and E7** to promote the proteolysis of p53 (E6) and **RB (E7**) → removal of tumor supressors ↑ risk of cancer!
- AIDS-defining illness. Its thought HIV helps to enhance the E6/7 expression.
HPV
HPV Vaccine
Pilloma Bugs
- HPV vaccine is Gardasil
- Its an inactivated quadravalent vaccine
- Used for strains 6, 11, 16, and 18*
* These 4 strains cause ~70% of cervical cancers
Parvovirus b19
lab tests
AKA: 5th disease, Slapped cheek disease, Erythema infectiosum
Bombs Away
SS* DNA
* (The only SS DNA on sketchy!!!)
Naked virus (No envelope!)
“parvo” = small (It’s the smallest virus in sketchy)
Parvovirus b19
Source
AKA: 5th disease, Slapped cheek disease, Erythema infectiosum
Bombs Away
- Transmitted by respiratory droplets
- Transferred from mother to fetus (a TORCHeS Infection)
Parvovirus b19
signs and symptoms
AKA: 5th disease, Slapped cheek disease, Erythema infectiosum
Bombs Away
- Low grade fever that lasts a week → as fever breaks slapped cheek rash → Erythema (lacy) rash that begins on the face and goes down the body
- Adults (Teachers!!!) can present with joint pain, arthritis, soreness, and edema
- Transient aplastic anemia in sickle cell pts (due to depletion of bone marrow) looks like cobwebs in bone scans, and can fade out when virus clears.
- Babies in utero exposed to Parvovirus in trimesters 1 or 2 (a TORCHeS Infection)→ hydrops fetalis (massive edema) → fatal
Parvovirus b19
ddx vs. Roseola
AKA: 5th disease, Slapped cheek disease, Erythema infectiosum
Bombs Away
- Parvovirus b19 presents with a low grade fever that lasts a week → as fever breaks slapped cheek rash → Erythema (lacy) rash that begins on the face and goes down the body
- Roseola which presents with a high grade fever for 3-4 days, can include febrile seizures, and is followed by a diffuse lacy rash that spares the face.
TORCHeS Infections
TORCHeS Infections:
Toxoplasmosis
Other (HIV, VZV, Parvovirus B19, enteroviruses, others)
Rubella
Cytomegalovirus
Herpes
Syphilis
Adenovirus
lab tests
A Den-O lions
DS DNA
Naked virus (No envelope!)
Adenovirus
Source
A Den-O lions
- Transmitted by respiratory droplets and fecal-orally.
- Most at risk are little children**, **military recruits, and public pools.
Adenovirus
signs and symptoms
A Den-O lions
3 major disease processes:
- Tonsillitis (most common cause of infection in adenoids and tonsils).
- Hemorrhagic cystitis*
- Viral conjuctivitis aka “Pink Eye“ (common cause)
* DDX BK Virus (a Polyomavirus) which also has hemorrhagic cystitis, but is more common in immunocompromised (transplant pts, or pts with AIDS)
Adenovirus
Vaccine
A Den-O lions
Military** recuits get a **live vaccine
Pox Virus
lab tests
Pox in a Box
- DS DNA
- Enveloped virus
- Dumbbell-shaped core
- Largest known DNA virus
- Guarneri inclusion bodies*
* (B-type intracytoplasmic bodies in infected cells, appear as blobs on stains) found on skin lesion / blister biopsy
Pox Virus
MOA
Pox in a Box
- Pox Virus comes with everything it needs inside of it, including making their own envelopes.
- Replicates in the cytoplasm (only DNA virus in sketchy that does).
- Replication sites are seen on stains as Guarneri inclusion bodies
- Brings its own DNA dependent RNA polymerase (reads DNA, produces primary transcript RNA!) to produce all of the proteins that it needs (including DNA polymerase)
Pox Virus
3 main Pox virus strains
Pox in a Box
- Small pox virus
- Cow pox virus
- Molluscum contageosum virus
Small pox virus ( a Pox Virus)
signs and symptoms
Pox in a Box
- Small pox virus: Raised skin on surfaces. Scattered ulcers and blisters that are the same age*
* (ddx Variola aka Chickenpox which also has scattered ulcers and blisters but of mixed ages and stages of healing.)
- Cow pox virus: causes symptoms similar to small pox. transmitted by contact with infected cow udders.
Molluscum contageosum virus ( a Pox Virus)
signs and symptoms
Pox in a Box
- Flesh colored, dome shaped, umbilicated (dimpled) lesions. Usually painless.
- Most common in children. Found anywhere on body except palms** and **soles. Most often seen on trunk, axilla, anticubital fossa, and poplitial fossa.
- In adults** usually presents as a **single lesion from sexual transmission. If it spreads diffusely it is due to immunosuppression (likely HIV).
Hepatitis B (a Hepa_dna_virus)
lab tests
Hep B Love
- Circular Partially* DS DNA
(becomes fully DS during replication)
- Enveloped virus
- Ground glass appearance (from HBsAg)
- ALT↑ in acute infections then ↓ once symptoms end.
- In neonates** initial phase of HBV, serum **ALT levels are normal!
- SPECIES (mnemonic to determine phase of Hep B)
Hepatitis B (a Hepa_dna_virus)
MOA
Hep B Love
- Circular partially DS DNAbecomesfully DS during replication
- Replicates both inside the nucleus and in the cytoplasm! (unique!!!)
- Hep B contains its own reverse transcriptase (like HIV) and goes from SS DNA → SS RNA → DS DNA (but unlike HIV, Hep B does not integrate into hosts chromosomes)
Hepatitis B (a Hepa_dna_virus)
Source
Hep B Love
- Spread via Sex and Drugs
(similar to Hep C vs. Hep A spread fecal orally)
- Vertical transmission (a TORCHeS infection!) through blood* during child birth
* (Hep B is to large to cross placental wall, transmitted via blood during delivery)
Hepatitis B (a Hepa_dna_virus)
Acute Hep B
signs and symptoms
Hep B Love
- Purpuric rash → non-blanching dark macules
- Arthritis, Arthralgia
- Polyarteritis Nodosa (PAN)
- Membranous glomerulonephritis (MGN)
- Membranoproliferative glomerulonephritis (MPGN)
Hepatitis B (a Hepa_dna_virus)
Chronic Hep B
signs and symptoms
Hep B Love
- Only about 5-10% develop into chonic infection in adults. (vs. Hep C which is ↑)
- Newborns have a 90-95% chance of chronic infection.
- Long term Hep B → liver cancer (hepatocellular carcinoma)
Hepatitis B (a Hepa_dna_virus)
Polyarteritis Nodosa (PAN)
Hep B Love
- Systemic vasculitis that affects medium to small arteries.
- Small aneurysms are strung along the artieries like the beads of a rosary.
- Beads on a string appearance.
- Damages kidneys → ↓ GFR and Hypertension
Hepatitis B (a Hepa_dna_virus)
Membranous glomerulonephritis (MGN)
Hep B Love
- A type of glomerulonephritis caused by deposits in the kidney glomerular basement membrane* (GBM) thickening, and activating complement → damaging the glomeruli.
* (vs. MPGN** which is in **both the glomerular mesangium* AND basement membrane.)
- By light microscopy, the basement membrane is observed to be diffusely thickened.
- Using Jones’ stain, the GBM appears to have a “spiked” or “holey” appearance.
Hepatitis B (a Hepa_dna_virus)
Membranoproliferative glomerulonephritis (MPGN)
aka mesangiocapillary glomerulonephritis
Hep B Love
- A type of glomerulonephritis caused by deposits in the kidney glomerular mesangium* AND basement membrane (GBM) thickening, and activating complement → damaging the glomeruli.
* (vs. MGN which is only in the GBM.)
- GBM is rebuilt on top of the deposits, causing a “tram tracking“ appearance under the microscope.
Hepatitis B (a Hepa_dna_virus)
SPECIES
(mnemonic to help determine phase of Hep B)
Hep B Love
SPECIES
- S: Hep B Surface antigen (HBsAg)
- E: Hep B E antigen (HBeAg)
- C: Anti-Hep B Core antibody (anti-HBc or HBcAb)
- E: Anti-Hep B E antibody (anti-HBe or HBeAb)
- S: Anti-Hep B Surface antibody (anti-HBs or HBsAb)
Hepatitis B (a Hepa_dna_virus)
Hep B Surface antigen (HBsAg)
SPECIES mnemonic (to help determine phase of Hep B)
Hep B Love
- 1st clinically measurable
- (+) for active infection (acute or chronic)
- Leads to “ground glass appearance”
Hepatitis B (a Hepa_dna_virus)
Hep B E antigen (HBeAg)
SPECIES mnemonic (to help determine phase of Hep B)
Hep B Love
- Not enough time to create antibodies yet
- Highly corelates with infectivity.
Hepatitis B (a Hepa_dna_virus)
Anti-Hep B Core antibody (anti-HBc or HBcAb)
SPECIES mnemonic (to help determine phase of Hep B)
Hep B Love
- (+) in the window period*
* (where the body starts producing Anti-Hep B Surface antibodies to bind the Hep B surface antigen.)
- Either HNsAg or HBsAb may be also detected.
Hepatitis B (a Hepa_dna_virus)
Anti-Hep B E antibody (anti-HBe or HBeAb)
SPECIES mnemonic (to help determine phase of Hep B)
Hep B Love
- Low infectivity
Hepatitis B (a Hepa_dna_virus)
Anti-Hep B Surface antibody (anti-HBs or HBsAb)
SPECIES mnemonic (to help determine phase of Hep B)
Hep B Love
- Indicates recovery
- Also used to check for immunization*
* (HBsAb will be the only antibody that is (+) in immunization pts, both HBcAb and HBeAb will be negative!)
Hepatitis B (a Hepa_dna_virus)
Treatment
Hep B Love
- Lamivudine and NRTI’s
- Interferon Alpha
- Anti Hep B Ig w/ Hep B vaccine to neonates at risk
Hepatitis D
Key info
Hep B Love
- Circular NEG sense RNA
- Enveloped virus
- NEEDS Hep B Surface antigen (HBsAg) to cause infection!
- Can cause co-infection at same time as Hep B, or a super-infection* if transmitted on top of existing Hep B infection
* (Post infection has worse outcomes)
