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30 Cards in this Set
- Front
- Back
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Picornaviridae
___VIRUS -Poliovirus -Coxsackie A virus -Coxsackie B virus -Echovirus types ___VIRUS ___VIRUS -Hepatitis A virus |
ENTERO,
RHINO, HEPARNA |
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Picornavirus
Virion is ___, small (25 to 30 nm) icosahedral capsid ss + RNA genome (7-8 kb). Single mRNA, 1 polyprotein cleaved to produce structural and enzymatic proteins. VP1,2,3,4 structural proteins. VPg linked to 5’end RNA. Poliovirus blocks cellular mRNA translation (viral protease degrades 200 kD ___ protein). Replicates in the cytoplasm, citolytic |
naked,
Cap-binding |
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Picornaviruses
Enteroviruses are resistant to pH 3 to 9, detergents, mild sewage treatment, and heat (fecal-oral transmission), do not cause enteric disease. Rhinoviruses are ___ at acidic pH; optimum growth temperature is ___°C (upper respiratory tract). |
labile,
33 |
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Picornaviruses-Enteroviruses are spread via ____
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fecal-oral-route
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Asymptomatic __% cases
Early childhood Paralytic Polio in __% of cases No specific anti-viral therapy available for enteroviral infections Prevention of Paralytic Polio One of the triumphs of modern medicine 2 types of Polio vaccines IPV Inactivated virus (Salk, 1955), safer now used OPV Live attenuated virus, oral (Sabin, 1962), revertants |
90,
<2 |
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Clinical syndromes associated with Coxsackie A viruses
___ - characterized by fever, sore throat, pain on swallowing, anorexia, vomiting. Classic finding is vesicular lesions in the mouth soft palate. ___ - consists of vesicular lesions on the hands, feet, mouth and tongue. It subsides in a few days. Foot and Mouth disease extremely dangerous for the livestock |
Herpangina,
Hand-foot-mouth disease |
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Clinical syndromes associated with Coxsackie B viruses
___ - also called devil’s grip, characterized by sudden onset of fever and unilateral low thoracic chest pain that may be excruciating. Lasts approximately 4 days. Myocarditis, Pericarditis |
Pleurodynia (Bornholm’s disease)
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Flaviviruses
Enveloped ___ viruses Similar to Togaviruses (Alphaviruses genus) ___ primary target after entry Other organs affected after primary viremia (liver, cns) - Hepatitis __ and ___ |
ss RNA
Macrophages, C and G |
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Flaviviruses
___ St. Louis encephalitis virus (SLE) - North America West Nile Virus (WNV) - Africa, Asia, Europe North America Japanese encephalitis virus (JE) - Asia Russian Spring Summer encephalitis - Russia Powassan encephalitis - North America JE - #1 cause of encephalitis in Asia SLE and WNV are mosquito-borne, associated with serious neurologic diseases in USA WNV is new to USA since 1999, probably brought via infected bird that was transported by jet air cargo ___ Dengue - Tropics Yellow Fever - Africa, South America |
Encephalitis,
Hemorrhagic Fevers |
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The primary host for flaviviruses is ___,
man and domestic animals are ___ |
wild birds,
incidental hosts |
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Saint Louis Encephalitis and West Nile Virus
Only __% of infected patients develop clinical illness ___: -Most common clinical manifestation of WNV infection -Influenza-like illness endemic to Africa, the Middle East, and Western Asia Neurologic illness more common in older patients (2002 “epidemic” of WNV in the USA in younger patients affected) -Meningitis or encephalitis most frequent -Polio-like illness with flaccid muscle weakness in severe cases No available anti-viral treatment. There are experimental trials using interferon-alpha or specific immune globulin for WNV encephalitis. |
1,
West Nile Fever |
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Unique features of Reoviridae
___ naked capsid virion (60-80 nm) (not an envelope) Double-stranded RNA genome (22-27 kb) Segmented genome (like influenza), 10-12 segments, genome rearrangement Virion is resistant to environmental and ___ conditions. External capsid lost and the infective particle (ISVP) is liberated, epithelial cells penetrated by viropexis. Virus is released by cell lysis. |
Double-layered,
gastrointestinal |
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Reoviridae responsible for human disease
Orthreovirus - Mild upper respiratory tract illness, gastrointestinal tract illness Orbivirus/coltivirus - Febrile illness with headache and myalgia (zoonosis) ___ - Gastrointestinal tract illness, respiratory tract illness (?) |
Rotavirus
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Mechanism of Rotavirus Diarrhea
Cytolytic and toxin-like action on the intestinal epithelium causes loss of electrolytes and prevents ___ Large amounts of virus are released during the diarrheal phase Disease can be significant in ___ but asymptomatic in adults |
readsorption of water,
infants younger than 24 months |
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Epidemiology of Rotavirus
Most common cause of serious diarrea Disease/Viral Factors -Capsid virus is resistant to environmental and gastrointestinal conditions -Large amounts of virus are released in fecal matter -Asymptomatic infection can result in release of virus Transmission -Virus is transmitted in fecal matter, especially in ___ -Respiratory transmission may be possible Modes of control -___ and isolation of known cases are modes of control -Experimental live vaccines use bovine or monkey rotavirus |
daycare settings,
Hand washing |
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___ most common cause of severe diarrhea (50%)
600,000 fatalities (mostly children) in underdeveloped countries |
Rotavirus
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Colorado Tick Fever
Acute disease caused by ___ which is a ___ Causes fever, headache, severe myalgia and may result in serious hemorrhagic disease One of the most common tick-borne viral diseases in the USA |
coltivirus,
Reoviridae |
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Caliciviruses (Noroviruses) Norwalk and Astroviruses Small, round, gastroenteritis viruses
Viruses are ___ naked capsid similar to Picorna Viruses Viruses are resistant to environmental pressure: detergents, drying, and acid Viruses are transmitted by fecal-oral route in contaminated water and food Viruses cause outbreaks of gastroenteritis, usually associated with ___ 23 million cases in the US Disease causes diarrhea,vomiting, fever, nausea Resolves after 48-72 hours without serious consequences |
ss RNA,
cruise ships |
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Viral Hemorrhagic Fevers
Febrile viral illness with widespread hemorrhage from body’s epithelial surfaces Diverse viral causes and geographic distribution (tropical-subtropical) Often disease cycle includes important role for ___ or vectors (arboviruses) Some of these viral agents can be dangerous, require high level of laboratory containment |
animal reservoirs
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Pathogenesis of Hemorrhagic fevers
Capillary fragility Intravascular volume depletion ___ shock (heart unable to supply enough blood because of blood loss), organ hemorrhage and necrosis Multi-organ failure Causes ___ - Direct infection of vascular endothelium leads to viral cytopathic destruction of blood vessel integrity, and increased vascular permeability. ____ -Infected macrophages and activated lymphocytes release factors which activate complement, leading to increased vascular permeability. -Cytotoxic T-cells attack infected endothelial cells lining blood vessels. |
Hypovolemic,
Virological, Immunological |
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Hemorrhagic Rash
Skin “rash” often caused by ___ (“pinpoint” hemorrhages in skin) and ___ (bruise larger than 1 cm) |
petechiae,
ecchymoses |
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Flaviviruses and Alphaviruses (Togaviruses family)
Enveloped single stranded positive RNA genome (similar structure, replication, host, disease) Alphaviruses replicate in the cytoplasm (early and late genes) and bud at the plasma membrane Flaviviruses replicate in the cytoplasm (1 polyprotein) and bud at internal membrane They are ___, spread by arthropod vectors (injected in the bloodstream) Alphaviruses mostly animal hosts (Venezuelan, Eastern, Western Equine encephalitis), human infected as well (encephalitis) Flaviviruses animal and human hosts (___, ___, West Nile Encephalitis) |
arboviruses,
Dengue, Yellow Fever |
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Flaviviruses-Dengue
Dengue virus - Worldwide distribution (Asia, Pacific, Caribbean, Africa), but especially tropics. Dengue fever: -Relatively mild systemic illness (“break bone fever”) with high fever, headache, maculopapular rash, back and bone pain. -Fever can fall and rise again (___ temperature course). Typically lasts 4-6 days. -Up to 100 million cases worldwide. Major epidemics occurred in Caribbean (Cuba) and Pacific and China in the late 1970's. Dengue hemorrhagic fever and Dengue shock syndrome (DHF/DSS): -More severe disease developing from Dengue virus infection, with predominance of dengue type 2 -Up to 250,000 cases per year. Reflects increasing severity of dengue infections. -Clinical features: Prominent plasma leakage (hemoconcentration) and thrombocytopenia, hepatomegaly, pneumonia, CNS symptoms. ___ shock. |
“saddleback”,
Hypovolemic |
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Flaviviruses-Yellow Fever
Yellow Fever virus -Endemic in Africa, South America -Animal host is ___. -Mosquito vector. -Aedes aegypti responsible for most urban epidemics (man-mosquito-man). Yellow Fever clinical illness -Similar to Dengue fever and to DHF -Severe systemic illness with involvement of liver, kidney, heart. -___ from liver failure causes the “yellow” fever. Mortality approximately __%. -Live virus vaccine available, using attenuated 17D virus strain. |
monkey,
Jaundice, 50 |
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Bunyaviruses
Enveloped RNA viruses with nucleocapsids containing 3 circular negative RNA species (L,M,S) Capable of ___ Target tissues are CNS, liver, kidney and ___ Arboviruses spread by mosquitoes, flies, ticks (except ___, rodents) |
genetic rearrangement,
vascular endothelium, Hantaviruses |
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Bunyaviruses, 4 major pathological genera:
Crimean-Congo fever virus (genus Nairovirus) California encephalitis virus (genus Bunyavirus) Rift Valley fever virus (genus Phlebovirus) Genus Hantavirus -Not transmitted by arthropod vectors but ___ species Hantaan virus -Korean hemorrhagic fever (KHF) -rodent host Apodemus agrarius, found in Korea, China, Asian regions of Russia -Hemorrhagic Fever with Renal Syndrome (HFRS): -High fever, renal dysfunction (renal tubular necrosis and oliguria), hemorrhagic manifestations, fatality approximately 5% ___ virus -Southwestern US, Brazil, Argentina -Hantavirus pulmonary syndrome, (1993 New Mexico autbreak): -Fever, myalgia, cough, headache -Rapid onset of pulmonary edema and respiratory failure -Hemoconcentration, coagulopathy, but not renal failure -Death in approximately 50% of cases. |
rodent,
Sin Nombre |
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Filoviruses
Enveloped, filamentous RNA viruses with single stranded RNA genome Genome enclosed in a single ___ nucleocapsid Animal hosts, vectors method of transmission unknown (bats? Wild monkeys?) Endemic to Africa Disease occurs in monkeys and humans Virus spread in body secretions and fluids (airborne pathogen) Highly contagious Outbreaks in medical personnel Self limiting outbreaks Two major hemorrhagic fever agents ___ and ___ |
helical,
Marburg virus and Ebola virus |
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___viruses
Marburg virus (Marburg agent) -Endemic in East and South Africa. -Virus is named for Marburg, Germany, where it was first detected in laboratory worker in 1967, 32 infected 7 died. Marburg illness: -High fever, headache, nausea, vomiting, myalgia, widespread hemorrhage -Intravascular volume depletion and interstitial edema -Hypovolemic shock. -CNS disease (coma, hemiplegia) are common. -Mortality 25-30% -Pathogenesis: Virus has broad and efficient cellular tropisms Treatment: no effective anti-viral treatments, ___ to limit spread of infection. |
Filo
isolate patients |
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Filoviruses
Ebola virus (Majinga, Sudan) -Endemic in Africa; recurrent outbreaks of fatal human illness in -Zaire and Sudan. Sporadic outbreaks in small villages near the jungle. -Clinical features: similar to ___ illness. -Mortality __-__% -Serological studies found low titer anti-Ebola antibody in healthy human populations. in central Zaire and Sudan, suggesting that sub-clinical infections may occur. -Threat to great apes populations (Congo, Zaire). -Animal Reservoir is unknown, Bats? Insects? |
Marburg,
70-90 (higher than marburg) |
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Arenaviruses
Enveloped RNA viruses with 2 circular RNA segments ___ in the virion, function ? Usually cause persistent infection of ___ Virus spreads to humans from rodents (zoonoses) Two hemorrhagic viruses: ___, ___ |
Ribosomes,
rodents, Lassa fever virus, Junin virus (Argentinian Hemorrhagic Fever) |
