(+) RNA Viruses Flashcards
Naked picornavirus, transmitted through fecal-oral route, presents with acute disease that rarely may be severe but has no chronic phase, notorious for outbreaks in restaurants
Hepatitis A
Enveloped flavivirus, transmitted parenterally or sexually, subclinical acute phase with the majority infected moving to chronic phase, increased risk of hepatocellular carcinoma and cirrhosis
Hepatitis C
Naked hepevirus, transmitted through fecal-oral route, causes severe acute disease in pregnant patients with 25% mortality, no chronic phase
Hepatitis E
Naked icosahedral picornavirus, fecal-oral transmission but do not cause gastroenteritis, acid stable
Enteroviruses (polio, coxsackie, echovirus)
Naked icosahedral picornavirus, acid labile, grows at 33C, over 100 serotypes, most common cause of the common cold in summer and fall
Rhinovirus
This virus targets the anterior horn motor neurons and can cause flaccid asymmetric paralysis. A live (Sabin) and killed (Salk) vaccine is available, and in the U.S. we use the Salk
Polio
All enteroviruses (polio, coxsackie, echovirus) can cause this disease
Aseptic meningitis
This virus causes hand, foot and mouth disease or herpangina
Coxsackie A
This virus causes a presentation of heart attack in a young child (Bornholm disease/devil’s grip). Also a significant cause of myocarditis.
Coxsackie B
Naked icosahedral virus transmitted by fecal oral route that is famous for causing nausea, vomiting, and diarrhea on cruise ships
Norwalk virus
Name the viruses in the flaviviridae family and their characteristics
St. Louis Encephalitis, West Nile, Dengue, Yellow Fever
all enveloped arboviruses
Which flavivirus has an available vaccine?
Yellow fever virus. All others are prevented with vector control.
Flavivirus with a human or monkey host that causes break bone fever or hemorrhagic shock
Dengue
Flavivirus with mosquito vector and bird host that causes encephalitis
St. Louis Encephalitis - Southern States
West Nile - All over U.S.
Name the togaviridae and their characteristics
Arboviruses: Eastern equine encaphalitis, Western equine encephalitis, Venezuelan equine encephalitis
rubella
all enveloped icosahedral
Which togaviridae have available vaccines?
EEE and WEE (killed)
Rubella (live attenuated)
Baby with cataracts, heart issues, microcephaly and deafness. More serious if acquired during the first 16 weeks of gestation. Which congenital infection is this?
Rubella (cataracts are key)
This virus causes a disease known as German measles, which consists of a macular rash that begins on the foreheads and progresses to torso and sickness lasts for about 3 days
Rubella
Enveloped helical virus with hemagglutinin molecules on surface, second most common cause of common cold with peak incidence in winter and spring
Coronavirus
Atypical pneumonia with fever, flu-like illness, dry cough, dyspnea, progressive hypoxia, recent travel to Far East or Toronto
Severe acute respiratory distress syndrome coronavirus (SARS-CoV)
These are enveloped viruses that use virion-associated reverse transcriptase and dsDNA as a template for replication
Retroviridae - Human T-cell leukemia virus and human immunodeficiency virus
Which protein on HIV acts as attachment by binding to CCR5 (macrophages) and CXCR4 (T cells)? Which causes viral fusion?
gp120 - attachment
gp41 - fusion
What is the name of the gene that is necessary for the progression of HIV infection to AIDS?
Nef
What mutation will make an individual immune to HIV infection?
Homozygous CCR5 mutation (virus can’t attach)
What is the first antigen/antibody that can be detected in the serum upon HIV infection?
p24
What tests are used for screening, confirmation, and determination of viral load in HIV?
Screening - ELISA
Confirmation - Western blot
Viral load - PCR
What cytokine is responsible for the wasting syndrome due to HIV?
TNF-alpha
