Viral Pathogens Flashcards
1
Q
transient infection
A
-short term
2
Q
chronic latent infections
A
- virus remains in cell without actively replicating (long term)
- usually DNA viruses
3
Q
chronic productive infections
A
-long term, actively replicating viruses
4
Q
transforming infections
A
- viruses can be carcinogenic
- usually DNA viruses
5
Q
common cold viruses
A
- rhinoviruses
- cornaviruses
- respiratory droplet
- acute, self-limited infection
- symptoms: fever, cough, nasal congestion, minor aches and pains, headache, sneezing
- no vaccine
6
Q
rhinovirus
A
- naked, (+) ssRNA
- over 100 distinct serotypes
- most common virus in humans
7
Q
coronaviruses
A
- enveloped, (+) ssRNA
- SARS (sever acute respiratory syndrome)
8
Q
rubella virus (German measles)
A
- enveloped, (+) ssRNA
- respiratory droplet
- mild, self-limited disease (may have a rash)
- destructive fetal pathogen*
- live, attenuated vaccine
9
Q
rubella virus: congenital infection
A
- fetal deafness
- cataracts
- glaucoma
- heart defects
- mental retardation
- salt and pepper retinopathy
10
Q
west nile virus
A
- flavivirus
- enveloped, (+) ssRNA
- mosquito vector
- symptoms: asymptomatic, headache, myalgia, maculopapular rash
- no vaccine
- rare complications (1% of cases): hepatitis, myocarditis, pancreatitis, acute flaccid paralysis
11
Q
measles
A
- enveloped, (-) ssRNA
- paramyxovirus
- respiratory droplet
- symptoms: fever, URI, maculopapular rash, Koplik spots*, subacute sclerosing panencephalitis (rare)
- live vaccine
12
Q
mumps
A
- enveloped (-) ssRNA
- paramyxovirus
- respiratory droplets
- symptoms: parotitis, pancreatitis, orchitis in adult males, meningoencephalitis
- live, attenuated vaccine
13
Q
respiratory syncytial virus (RSV)
A
- enveloped, (-) ssRNA
- paramyxovirus
- transmission: respiratory droplet (100% exposure), direct contact, fomite (5 hrs on counter)
- clinical manifestations: cold-like symptoms, bronchiolitis (2-3% of cases)
- treatment: palliative
14
Q
influenza virus
A
- enveloped, (-) ssRNA
- two main groups: A and B
- 200-500k deaths annually
- respiratory droplet
- clinical manifestations: chills, fever, headache, muscle aches, general malaise, pneumonia*
- seasonal, inactivated vaccine (trivalent or quadrivalent)
15
Q
surface proteins involved in antigenic drift and shift
A
hemagglutinin, neuraminidase
16
Q
antigenic drift
A
- random mutations
- slow, gradual, not a big change from year to year
17
Q
antigenic shift
A
- co-infection
- hybrid virus
- new surface Ag (H1N1)
- quick, significant, virus acquires new surface antigen different from previous strains
18
Q
Zika virus
A
- enveloped, (+) ssRNA
- flaviviridae
- transmission: mosquito bites, sex, mother to fetus
- clinical manifestations: usually mild (fever, rash, HA, joint and muscle pain, conjunctivitis), Guillain-Barre syndrome?
- fetal microcephaly
- treatment: palliative
19
Q
viral hemorrhagic fevers
A
- enveloped, RNA viruses
- Lassa fever, Rift Valley fever, Ebola virus, Marburg virus, yellow fever, Dengue
- transmission: insect bite/inhalation/direct contact
- fever and hemorrhage: endothelial cell infection, platelet and endothelial dysfunction, hemorrhage and necrosis in multiple organs
20
Q
herpes virus
A
- enveloped, dsDNA
- transmission: kissing, sex
- manifestation: fluid-filled vesicles
- HSV type I: cold sores, encephalitis (rare)
- HSV type II: genital herpes, meningitis (rare)
- no vaccine
21
Q
latent herpesvirus infections
A
- virus lays dormant in respective ganglion, integrating into host genome
- HSV I: trigeminal ganglion
- HSV II: sacral root ganglion
- recurrence: head trauma, stress, fever, UV light, menstrual cycles, immunosuppression
22
Q
herpes keratitis
A
- latent infection on cornea
- dendritic epithelial ulcer
- recurrent HSV keratitis: corneal scarring, thinning, neovascularization, decreased corneal sensation, vision loss
- treatment: topical and oral antivirals
23
Q
varicella-zoster virus (VZV)
A
- enveloped, dsDNA
- droplet or direct contact
- chickenpox/varicella
- self limiting infection
- vesicular rash
- meningitis (rare)
- pneumonia (rare)
- latent in dorsal root ganglia
- live, attenuated vaccine
24
Q
shingles
A
- recurrence of herpes zoster virus
- lies dormant in dorsal root ganglion
- usually infect only one dermatome
- severe nerve pain, which can persist even after infection ends
25
Q
herpes zoster ophthalmicus
A
- shingles on the face and can involve eyes
- Hutchinson’s sign (lesion on tip of nose- precursor to ocular involvement bc nasociliary nerve supplies nose and cornea)
- clinical manifestations: conjunctivitis, scleritis (rare), iritis, pseudodendrites, neurotrophic keratitis, elevated IOP
- treatment: topical and oral antivirals
- special consideration: post-herpetic neuralgia
26
Q
epstein-barr virus
A
- enveloped, dsDNA
- transmission: saliva, selectively infects B cells
- infectious mononucleosis: kissing disease, benign, self-limited
- clinical presentation: lymphadenopathy, fatigue, fever, sore throat, splenomegaly
- Burkitt’s Lymphoma
- no vaccine
27
Q
cytomegalovirus (CMV)
A
- enveloped, dsDNA
- transmission: direct contact with bodily fluids, kissing
- congenital infections: CNS dysfunction
- CMV retinitis in AIDS patients
28
Q
human papillomavirus (HPV)
A
- papillomavirus
- naked, dsDNA
- transmission: skin or genital contact
- clinical manifestations: skin warts, genital warts, anal warts
- carcinogenesis: subtypes 16 and 18, inactivates p53
- common cancer sites: cervical cancer*, vulva, vagina, penis, anus, oropharynx
- subunit vaccine
29
Q
hepatitis
A
- clinical manifestations: jaundice, fever, anorexia, malaise, fibrosis (chronic), cirrhosis (chronic), hepatocellular carcinoma (chronic)
- causes: toxins, autoimmune diseases, hepatitis viruses A, B, C, D, E
30
Q
hepatitis A virus
A
- picornaviridae virus
- nonenveloped, (+) ssRNA
- transmission: fecal-oral route
- clinical manifestations: acute, viral hepatitis, asymptomatic in 90% of infected children
- treatment: palliative
- prevention: sanitation, hygiene, inactivated virus vaccine, gamma-globulin shot
31
Q
hepatitis B virus
A
- hepadnavirus family
- enveloped, dsDNA (+) reverse transcriptase
- pararetrovirus, partially double-stranded
- transmission: blood borne, sexual, vertical
- pathogenesis: cytotoxic T lymphocytes eliminate infected cells
- clinical manifestations: acute, viral hepatitis, fulminant hepatic failure, chronic hepatitis (cirrhosis, carcinogenic)
- treatment: interferon therapy, antiviral medications
- prevention: subunit vaccine
32
Q
hepatitis C virus
A
- flaviviridae family
- enveloped, (+) ssRNA
- many different genotypes
- transmission: blood borne, sexual, congenital
- acute infection (20% of cases): asymptomatic, mild hepatitis (15%), spontaneous resolution (10-50% of cases)
- chronic infection (80% of case): cirrhosis* (10-30%), liver failure, hepatocellular carcinoma*, portal hypertension
- treatment: interferon therapy, anitviral medications
- no effective vaccine
33
Q
adenovirus
A
- adenoviridae family
- nonenveloped, dsDNA
- transmission: respiratory droplet, fecal-oral route, fomites
- common clinical manifestations: URI, gastroenteritis, conjunctivitis
- severe clinical manifestations: meningitis, encephalitis, pneumonia
- prevention: vaccine, hygiene
34
Q
adenoviral conjunctivitis
A
- frequently associated with URI
- most common cause of viral conjunctivitis
- auto-inoculation
- clinical manifestations: hyperemia, chemosis, epiphoria, decreased acuity, eyelid edema, corneal infiltrates, subconjunctival petechiae, follicles, pseudomembranes, palpable preauricular node
- treatment: palliative, betadine treatment
- diagnosis: RPS adeno detector
- often spreads to other eye
