+ RNA viruses Flashcards
+ Strand RNA Virus Families (5)
- Picornoviridae (NE)
- Calciviridae (NE)
- Togaviridae (E)
- Flaviviridae (E)
- Coronaviridae (E)
Picornoviridae (features, subfamilies (3))
- non-enveloped +RNA viruses
- Contains groups Enterovirus, hepatovirus, rhinovirus
Calciviridae (features, viruses (2))
non-enveloped + RNA viruses
-contains Norwalk virus, Hepatitis E
Picornoviridae Hepatoviruses (1)
Hepatitis A
Rhinoviruses
Subfamily of picornaviridae
- live at 33º since infect nose
- common cold
Enteroviruses (family, viruses (4))
Subfamily of picornaviridae
- includes coxsackievirus, echovirus, enterovirus, poliovirus
- acid-stable, 37º
Enveloped + RNA virus families (3)
Togaviridae, Flaviviridae, Coronaviridae
Togaviridae (characteristics, subfamilies (2))
- enveloped + RNA virus family, arthropod borne
- Contains alphaviruses and rubiviruses
Flaviviridae (characteristics, subfamilies)
- enveloped + RNA virus family, arthropod borne
- contains flavivirus and Hep C subfamilies
Coronaviridae (characteristics, symptoms, viruses)
- enveloped + RNA virus family
- Named for glycoprotein “crown”
- helical capsid (unlike everything else + RNA, icosahedral)
- most cause cold, GI, asymptomatic
- contains MERS, SARS
Alphaviruses (classification, viruses (4))
+ RNA enveloped viruses within togaviridae
- Chikungunya
- Eastern Equine Encephalitis Virus
- Western Equine Encephalitis Virus
- Venezuelan Equine Encephalitis Virus
Rubiviruses (classification, viruses (1))
- RNA enveloped viruses within togaviridae
- Rubella
Flaviviruses (classification, viruses (7))
- RNA enveloped viruses within Flaviviridae
- Dengue fever virus
- Japanese encephalitis virus
- St Louis Encephalitis virus
- Tickborne encephalitis virus
- West Nile Virus
- Yellow Fever Virus
- Zika Virus
Picornaviridae replication cycle (polio as ex)
picornavirus, non-enveloped icosahedral + RNA virus
- VP1,2,3,4
- VPg instead of 5’ cap on viral RNA
- IRES (internal ribosomal entry site) in 5’ UTR allows translation without 5’ cap
- one RNA, so one ORF, one polyprotein transcript, viral proteases cleave (and disable normal host cellular transcription)
Poliovirus (class, infection)
picornaviridae
-fecal-oral spread, mostly GI asymptomatic. Rarely viremia, more rarely CNS spread to cause poliomyelitis
Coxsackievirus (classification, disease, symptoms)
-+ strand RNA enterovirus (picornaviridae)
Common in kids- hand/foot/mouth disease
-in immunocompromised adults, meningitis rash and conjunctivitis
Echovirus (classification, disease symptoms)
- strand RNA enterovirus (picornaviridae)
- meningitis, conjunctivitis, rash (like coxsackie virus) + diarrhea
Enterovirus (classification, symptoms)
- strand RNA enterovirus (picornaviridae)
- GI symptoms
Flavivirus vs togavirus
F: one ORF, polypeptide, structural genes at 5’ end
T: two ORFs, structural is subgenomic, at 3’ end
Alphavirus (EEEV, WEEV, VEEV, Chikungunya)
- RNA enveloped togavirus subfamily
- accidentally transferred to humans by mosquito, cause flu-like symptoms
- Chikungunya cause arthritis-like
Rubivirus
- RNA enveloped togavirus subfamily
- Causes Rubella: respiratory transmission, fever malaise rash. Causes congenital malformations in first trimester
West Nile Virus (classification, symptoms, rare symptoms)
Flavivirus, +RNA enveloped flaviviridae transmitted by mosquitos
- Asymptomatic (80%), causes fever, headaches, fatigue, rash, myalgia, nausea,
- rarely Guillan-Barre, encephalitis, paralysis
Dengue Fever (classification, symptoms, rare symptoms)
Flavivirus, +RNA enveloped flaviviridae transmitted by mosquitos
- “Breakbone Fever”- fever, rash, BONE AND JOINT PAIN, lymphadenopathy. Lasts months but not fatal. 10% lead to
- “Dengue Hemorrhagic Fever”: shock + hemorrhage (due to 4 serotypes, Ab from one bind another but dont neutralize, coat, form immune complex, type III hypersensitivity
Yellow Fever
Flavivirus, +RNA enveloped flaviviridae transmitted by mosquitos
- JAUNDICE, fever, headache, myalgia. Shock and UGI bleeds if spread to organs
- 2 types: jungle (accident from monkeys) and urban (human) yellow fever
Zika Virus (classification, symptoms)
Flavivirus, +RNA enveloped flaviviridae transmitted by mosquitos
- asymptomatic or mild (fever, rash, arthralgia, conjunctivitis)
- microcephaly, brain defects in fetuses
Hepatitis C
Flavivirus, +RNA enveloped flaviviridae
- Transmitted by contaminated blood, sexually, IV drugs
- 25% acute hepatitis, many lead to chronic infection, cirrhosis. Can lead to hepatocarcinoma
SARS, MERS (classification, symptoms)
+RNA enveloped virus, coronaviridae
- severe acute respiratory syndrome, pneumonia
- MERS same but middle east instead of china
Norwalk Virus (classification, symptoms)
Caliciviridae + RNA virus
- causes epidemic gastroenteritis 24-48 hours, common in enclosed areas like cruise ships.
- distinguish from rotavirus since mainly adults, not infants
