Viruses and Prions Flashcards
What is the morphology of rubivirus (rubella)?
enveloped RNA virus
All RNA viruses are ssRNA except ________.
reoviridae-dsRNA
What are the clinical manifestations of parainfluenza virus? (2)
croup (parainfluenza type 1) barking cough and sridor, slight fever, most often in the fall. Pneumonia (parainfluenza type 3) in children year round
How is hepatitis B transmitted? (3)
blood, sexual intercourse and perinatal transmission
What do you see in the peripheral blood in mononucleosis?
atypical lymphocytes (cytotoxic T cells)
What do you see in the peripheral blood in mononucleosis?
atypical lymphocytes (cytotoxic T cells)
Identify the major virulence factor associated with influenza virus.
secretes neuraminidase which degrades mucous layer of respiratory tract.
Which virus is often responsible for pink eye (conjunctivitis)?
adenovirus
What is the morphology of cytomegalovirus?
dNA enveloped herpes virus
What is the arbovirus mode of transmission?
transmitted by arthropods (mosquitoes, ticks)
Name two diseases caused by EBV
infectious mononuelosis, Burkitt’s lymphoma
How is hepatitis A transmitted?
human to human, fecal to oral
What is the morphology of Influenza virus types A, B, C?
segmented RNA orthomyxoviruses, enveloped
How is adenovirus transmitted? (3)
respiratory droplets, fecal-oral and fomites
What are the clinical manifestations of hepatitis D?
coinfection with HBV increases risk of fulminant hepatitis, cirrhosis
Which DNA virus can cause aplastic crises in sickle cell disease?
parvovirus (B19 virus)
What Ab is present in those with current HBV infection or are chronic hep B carriers?
HBsAg
Identify the major virulence/toxicity factors associated with Epstein-Barr. (2)
has a viral capsid antigen. Infects lymphoid cells (mostly B cells)
Prions: Name examples of prion diseases
CJD, kuru, scrapie, mad cow
How is prions transmitted?
eating infected tissue (esp nervous tissue). Organ transplants, hGH. Contaminated instruments.
Name the route of transmission for VZV.
respiratory secretions
Describe the clinical course of respiratory syncytial virus infection. (5)
respiratory disease-1-4 days of incubation, then rhinitis, cough, wheezing and respiratory distress. Pharyngitis.
Are MMR (measles, mumps, rubella) vaccines live or ‘killed’?
live attenuated
Identify the major virulence/toxicity factors associated with measles virus (rubeola). (3)
hemagglutinin helps to penetrate cells. Has cell fusing and hemolytic properties.
What are the clinical manifestations of Varicella zoster? (3)
chicken pox 14-21 day incubation followed by pruritic papulovesicular rash over entire body. Mild in children but can cause encephalitis in adults. Herpes zoster (shingles) painful vessicles appear along dermatome of infected sensory nerve. Postherpetic neuralgia possible.
What is the major reservoir for cytomegalovirus?
humans
What is the morphology of mumps virus?
rNA enveloped paramyxovirus
What are the clinical manifestations of influenza virus types A, B, C?
influenza-24-48 hours incubation followed by sudden fever, headache, myalgias and cough
Koilocytes are characteristic of what disease?
condylomata acuminata
Identify relevant epidemiology and risk factors associated with influenza virus. (2)
type A can change antigens and cause pandemics. Type B may cause local epidemics.
What is the morphology of human papilloma virus?
non-enveloped DNA papovirus surrounded by an icosahedral nucleocapsid
Name two classic illnesses associated with arbovirus.
dengue fever (in SE Asia= hemorrhagic shock syndrome) and yellow fever
What is the most appropriate way of diagnosing molluscipoxvirus?
skin biopsy
Do hepadnavirus, herpesviruses, and poxvirus have an envelope?
yes
What are the clinical manifestations of Epstein-Barr virus? (2)
infectious mononucleosis-fever, sore throat, lymphadenopathy and splenomegaly. Chronic fatigue syndrome (putative). Burkitt’s lymphoma-association not clear, but EBV may be capable of inducing malignant transformations.
What are the clinical manifestations of smallpox virus? (3)
smallpox (eradicated) 12-14 days incubation followed by sudden fever, chills, myalgia, then a rash that turns pustular and slow to heal. 35% mortality.
Name the diseases caused by HSV-1. (4)
gingivostomatitis, keratoconjunctivitis, temporal lobe encephalitis, herpes labialitis
Which hepatitis virus has a short incubation period?
hep A (3 weeks)
Name the routes of transmission for HSV-2. (2)
sexual contact, perinatal
Describe the clinical course of mumps. (4)
14-24 day incubation period followed by prodrome of fever, malaise and anorexia, then swelling of parotid glands (usually bilateral).
What is the most common association with coxsackie viruses?
most common non-bacterial CNS infection in North America
Name the diseases caused by HSV-2. (2)
herpes genitalis, neonatal herpes
Name two complications of mumps.
orchitis (danger of sterility) and meningitis (self limiting)
List four symptoms of mononucleosis.
fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (esp posterior auricular nodes)
When lab findings are useful to help diagnose cytomegalovirus? (4)
cell culture; tissue staining shows owl’s eye inclusion bodies; PCR and immunfluorescent staining available
Name two virus families with circular DNA
papilomavirus and hepadnavirus
What is the morphology of hepatitis C?
rNA flavivirus, eveloped
Identify the major virulence factor associated with respiratory syncytial virus.
f glycoprotein in envelope causes cells to fuse (syncytium).
Identify relevant epidemiology and risk factors associated with rhinovirus.
epidemics in spring and fall
The common cold is caused by which virus?
rhinovirus
What is the morphology of rotavirus?
a reovirus-double stranded RNA virus, no envelope
Name three symptoms of yellow fever.
high fever, black vomitus and jaundice
Identify relevant epidemiology and risk factors associated with hepatitis A. (2)
children; occasional epidemics from restaurants (fecally contaminated food or water)
Identify the major virulence factors associated with humanimmunodeficiency virus. (2)
gp 120 and gp 41 on its envelope
What are the clinical manifestations of hepatitis B? (3)
chronic hepatitis-10-12 week incubation followed by fever, nausea and jaundice with hepatomegaly, dark urine, malaise, lasting two weeks. 1-2 weeks after recovery, intermittent arthralgia, fatigue, jaundice, cholestasis and pruritis.
What is the morphology of hepatitis A?
rNA enterovirus, non enveloped
What lab findings are useful to help diagnose Herpes simplex (I and II)?
cell culture; ELISA or PCR testing of the lesion
What are the clinical manifestations of adenovirus? (6)
acute respiratory disease (miliary). Pneumonia (infants). Pharyngitis and or conjunctivitis (with fever). gastroenteritis. Hemorrhagic cystitis (dysuria, mild pain on urination, gross hematuria).
How is human immunodeficiency virus transmitted?
exchange of body fluids (requires high infective dose)
Identify relevant epidemiology and risk factors associated withmeasles virus (rubeola). (2)
epidemics common in unimmunized children and college students
Triad of mumps symptoms are?
aseptic meningitis, orchitis, and parotitis
If a patient received a hepatitis B vaccine (has no infection), which Ab displays positive serology?
HBsAb
How are alpha and flavi viruses transmitted?
arthropod bites (mosquitos)
Which organisms cause condylomata acuminata?
HPV-6 and HPV-11
What bluish-gray spots on the buccal mucosa re diagnostic of measles?
koplik spots
Which reovirus is considered the most important global cause of infantile gastroenteritis?
rotavirus
What is the major reservoir for Herpes simplex (I and II)?
humans
Which populations is associated with Epstein-Barr virus?
college students
What are the clinical manifestations of coxsackie viruses?
60? of infections are subclinical. Myocarditis or pericarditis (Cocksackie Type B) -usually self limiting but can lead to fatal arrythmia or heart failure.
What is the ‘most common’ associated with respiratory syncytial virus?
major cause of pneumonia and bronchiolotis in infants
Identify relevant epidemiology and risk factors associated with hepatitis D.
coinfection with HBV
What is the morphology of Varicella zoster?
dNA enveloped herpes virus
What is the morphology of parainfluenza virus?
enveloped RNA virus
Prions: Prions are associated with ________ encephalopathy
spongiform
What is the morphology of hepatitis D?
incomplete viral particle
All DNA viruses are dsDNA except ______________.
parvoviridae
What are the clinical manifestations parvovirus B19? (3)
erythema infectiosum (fifth disease)-4-12 days incubation followed by a mild flu-like illness, a slapped-cheek rash which spreads to legs and arms with a lacy macular pattern 1-2 days later.
Which hep virus has a long incubation period?
B (3 months)
Identify the major virulence/toxicity factors associated wit prions.
do not cause inflammation; not recognized by immune system; resistant to heat, chemicals, UV light or enzymes
Identify the major virulence/toxicity factors associated with adenovirus. (1)
has hemagglutinin fiber to help it attach to mucosal epithelium.
What is the morphology of rhinovirus?
small single stranded RNA virus
What is the #1 cause of fatal diarrhea in children?
rotavirus (a reovirus)
From where do herpesviruses acquire their envelopes?
nuclear membrane of the host cell
Which lab findings are useful to help diagnose respiratory syncytial virus? (2)
chest x-ray shows interstitial infiltrates and areas of collapse; Antigens detected in respiratory secretions
What is the morphology of coxsackle viruses?
rNA virus
What is the ‘most common’ associated with parainfluenza virus?
xxx
How is poliovirus transmitted?
fecal oral
What is the morphology of parvovirus B19?
small DNA virus, single stranded, linear
What are the clinical manifestations of Herpes simplex (I and II)? (2)
type I-lesions above waitst, esp around the face (cold sores). type II-primary painful lesions below the waist with fever and inguinal lymph node enlargement.
Identify relevant epidemiology and risk factors associated with cytomegalovirus.
worldwide, 80% carry antibodies.
What is a Tzanck test?
a smear of an opened skin vesicle to detect multinucleated giant cells (seen in HSV-1, HSV-2, VSV)
What is the major reservoir for small pox virus?
no reservoir known since eradication in 1979, except lab samples
What lab findings are useful to help diagnose hepatitis A? (3)
serum IgM rises in early stage; serum IgG levels rise and remain elevated for life; serum liver enzymes dramatically elevated.
HIV infected patients become symptomatic _____ years after exposure.
3-10 years
Prions: multiple choice: Prions are
a) infectious proteins only
b) infectious RNA
c) infectious DNA
d) infectious proteins occasionally mixed with nucleic acids
a) infectious proteins
How do you test for mononucleosis?
heterophil antibody test (aka ‘monospot’)
Name the diseases caused by VZV. (3)
varicella-zoster (shingles), encephalitis, pneumonia
What is the mode of transmission for hepatitis C?
blood (IV drug users)
What structural similarity is shared by herpesviruses, HBV, and smallpox virus?
they are DNA enveloped viruses
Rabies is caused by which viral family?
rhabdoviruses
Name three naked DNA viruses (no envelope).
parvo, adeno, and papilloma
HIV is diagnosed by _____ and confirmed with _______.
ELISA; western blot
What are the clinical manifestations of hepatitis C? (5)
chronic hepatitis-nausea, malaise, fever, arthralgia, fatigue, tendency for only 25% to develop jaundice
How is measles virus (rubeola) transmitted?
respiratory droplets
How is rotavirus transmitted?
fecal-oral route
Which single stranded linear DNA virus is responsible for slapped cheeks rash in children?
parvovirus
Recent hepatitis B infection. Which Ab would display positive serology?
HBsAb and HBcAb (positive during window period)
Name the routes of transmission for EBV. (2)
respiratory secretions. saliva
What are the clinical manifestations of cytomegalovirus? (3)
cytomegalic inclusion disease-congenital abnormalities, liver and brain damage, abortion, still births. Infection may be assymptomatic. CMV mononucleosis, CMV hepatitis-acute fever with signs of hepatitis
Describe the clinical presentation of human herpes virus-6 infection. (4)
roseola infantum-(ages 6 months to 4 years) sudden high fever (seizures rare) followed by faint macular rash 3-5 days later with slapped cheek appearance. Self limiting.
What lab findings are useful to help diagnose human papilloma virus?
diagnosis is clinical, but pap smears used to monitor changes to cervix.
What is the morphology of advenovirus?
dNA non-enveloped virus with Icosahedral nucleocapsid
RNA viruses: Which single stranded linear, nonsegmented RNA virus family is responsible for measles, mumps, and croup?
paramyxovirus
Describe the clinical course of hepatitis infection. (3)
acute hepatitis-3-4 weeks incubation followed by fever, nausea, jaundice dark urine and clay coloured not become a chronic carrier
What is the morphology of molluscipoxvirus?
large DNA virus, enveloped
How is rabies virus transmitted?
bite from any infected animal (bats more common than dogs)
Name the routes of transmission for HSV-1. (2)
respiratory secretions and saliva
What is the morphology of prions?
non viral glycoprotein 5nm in diameter
Describe the clinical course of measles. (6)
measles-7-14 day incubation followed by cough, coryza, conjunctivitis for 2-4 days followed by Koplik’s spots (bright red lesions with white centre), followed by maculopapular rash with photophobia, pruritis
Identify the major virulence factor associated with Varicella zoster.
virus may become latent in dorsal root ganglia.
Picorna-, Calci-, Flavl-, Toga-, Retro-, and Coronaviruses all share which RNA form?
single stranded linear RNA
What are the clinical manifestations of rhinovirus? (2)
common cold-major cause of URI in all ages, year round. 2-3 days incubation followed by acute URI symptoms for 3-7 days.
What is the morphology of smallpox virus?
large, DNA virus, enveloped
What is pathognomic or the most common association with rotavirus? (2)
40-60% of all acute gastroenteritis in children under age two
What is the morphology of rabies virus?
RNA, enveloped
Which laboratory marker is monitored to determine the course of HIV drug therapy?
hIV PCR/ viral load
What virus causes measles?
paramyxovirus
How does rabies travel to the CNS?
retrograde migration up nerve axons
Name two RNA viruses which do not replicate in the cytoplasm.
influenza virus and retroviruses
Who is immune to HIV?
individuals homozygous for CCR5 mutation
What are the clinical manifestations of human papilloma virus? (2)
plantar warts-generally asymptomatic but may be painful. Condyloma acuminata (genital warts)-can be benign or preneoplastic (16, 18 and 31)
Name the most common opportunistic infections acquired in those human immunodeficiency virus. (5)
pneumocystis pneumonia, tuberculosis, mycobacterium avium-intercellulare, cryptococcal mneingitis and candidiasis
Which hepatitis virus types lead to chronic carrier status?
B, C, and D
Name the routes of transmission for CMV. (5)
congenital, transfusion, sexual contact, saliva, urine, transplant
Yellow fever is transmitted by ____.
the Aedes mosquito (flavivirus)
How is human papiloma virus transmitted? (2)
skin to skin contact. STD
What lab findings are useful to help diagnose Varicella zoster? (3)
diagnosis based on clinical signs and symptoms; cell culture possible; serological titres can help in diagnosis
How is mumps virus transmitted?
respiratory droplets
What are the clinical manifestations of polio virus? (2)
gastroenteritis (abortive pollomyelitis)-mild fever with headache, sore throat, damage, reversible or permanent paralysis
How is Herpes simplex (I and II) transmitted?
type I-saliva. type II- oral to genital or genital to oral
What are the clinical manifestations of rabies virus?
30-50 day incubation varies on proximity of bite to head. Restlessness, malaise and fever then excitement, hypersalivation and excruciating laryngeal and pharyngeal muscle spasms
What are the clinical manifestations of rotavirus? (3)
infant diarrhea-1-3 days incubation followed by sudden nausea and vomiting for 1-3 days, then a low fever and frequent watery stools for 5-8 days. Death by dehydration.
How is coxsackie viruses transmitted?
fecal oral
What are the clinical manifestations of rubivirus (rubella)? (3)
rubella (German Measles)-14-21 day incubation followed by 1-5 days of malaise and lymphadenopathy, followed by 1-3 days of maculopapular rash spreading from face to trunk.
What is the morphology of Epstein-Barr virus?
dNA enveloped herpes virus
How is rubivirus (rubella) transmitted? (2)
respiratory droplets or transplacentally
How is Epstein-Barr transmitted?
human to human (saliva-the kissing disease)
What is the pathognomic symptom of measles virus (rubeola)?
koplik’s spots on buccal mucosa
What are the clinical manifestations of molluscipoxvirus?
molluscum contaglosum-2-8 week incubation followed by painless pearly nodules. Sometimes ‘cheesy’ matter may be expressed. Self limited, but slow to fade.
Mononucleosis is caused by _____.
EBV
How is Influenza virus types A, B, C transmitted?
respiratory droplets
What lab findings are useful to help diagnose Epstein-Barr virus? (3)
blood smear shows absolute lymphocytosis and atypical lymphocytes; monospot test shows heterophile Abs for first 2 weeks of infection; rising IgG (previous infection) and IgM (acute infection) titres useful to follow course of disease
What is the morphology of human immunodefiency virus?
rNA retrovirus
What is the morphology of measles virus (rubeola)?
rNA enveloped paramyxoviridae
What are the three ‘Cs’ of measles?
cough, coryza, conjunctivitis
What is the morphology of polio virus?
non enveloped RNA picoRNAvirus, an enterovirus
Describe the ulcers associated with HSV-2.
genital herpes with painful penile, vulvar or cervical ulcers
What are the clinical manifestations of prions?
15-20 months incubation, then slow, progressive dementia and other neurological symptoms (compare Alzhemers). Creutzfeld-Jacob disease?
Prions: Jeopardy style: pathologic prions take on this conformation
what is beta-pleated sheet
What is the morphology of respiratory syncytial virus?
enveloped RNA virus
What regions are associated with alpha and flavi viruses? (2+3)
yellow fever in tropical Africa and South America. Dengue fever in Middle East, Africa and Caribbean
