Flashcards in Semester 2 - Non-enveloped Viruses Deck (63)
What are some features of non-enveloped viruses?
Many are resistant to common disinfectants, desiccation, acidification = highly stable
Commonly associated with GI and respiratory tract infections
What are some examples of DNA viruses?
What are some examples of RNA viruses?
Picornaviruses (poliovirus, rhinovirus, enterovirus)
What are some characteristics of Adenoviruses?
Large, dsDNA virus, 57 human serotypes
Highly stable virions - non-enveloped viruses more resistant to desiccation, acid treatment, etc.
Ubiquitous human virus, used as a vector of gene therapy/vaccination approaches
Infection often asymptomatic (depends on serotype)
How are genes expressed in Adenoviruses?
Occurs in the nucleus using host cell machinery
Genes are spliced and modified similarly to host genes
Early genes (E genes) enzymatic/regulatory
Late genes (L genes) structural
What are the symptoms of a respiratory adenovirus infection (1, 2, 5, 6, 14)?
Associated with acute respiratory disease
Croup (upper airway inflammation), hoarseness of the throat
Fever, rhinorrhea, cough, sore throat
Tonsilitis, bronchiolitis, pneumonia in more severe cases
What are the symptoms of an enteric Adenovirus (40, 41) infection?
Associated with gastroenteritis
Food-borne illness, fecal-oral transmission
Diarrhea, fluid and electrolyte loss
What are the signs and symptoms of conjunctivitis/keratoconjunctivitis Adenovirus (3, 4, 7, 8, 19, 37) infection?
Direct inoculation of the eye
Infection of the conjunctiva and/or cornea
Unilateral 'red-eye' may spread to both eyes
Highly contagious, also associated with fever and pharyngitis (pharyngoconjunctival fever)
What are the signs and symptoms of a hemorrhagic cystitis Adenovirus (11, 21) infection?
Inflammation of the bladder
Dysuria, painful urination, hematuria
Also associated with nephritis
More common in children/adolescents, and immunocompromised patients
How are the adenoviruses transmitted?
Mucosal (respiratory, fecal-oral)
How are the adenoviruses treated?
Supportive treatment (treat symptoms)
Antivirals for more severe infections
What are some characteristics of Human Papillomaviruses (HPV)?
Large, dsDNA virus, >100 human serotypes
Infection of undifferentiated basal keratinocytes (skin, mucous membrane), replication in terminally differentiated epithelial cells
Utilize host DNA polymerase
Different serotypes are associated with distinct pathologies
What are some main characteristics of Genital warts?
Includes vulvar, penile, and anal warts, as well as oral papillomas
90% caused by serotypes 6, 11
How is HPV transmitted?
What are some characteristics of cancer caused by HPV?
Cervical, anal, oropharyngeal
Subtypes 16, 18, others
HPV drives cell cycle progression to activated cellular DNA polymerase for use by the virus
E6 early protein inhibits p53 tumor suppressor gene
E7 early protein inhibits pRb tumor suppressor gene
What is Gardasil and what serotypes does it work for?
Indicated for girls 9-26 years
Types 16, 18 cause 75% of cervical cancer genes
Types 6, 11 associated with most cases of genital warts
Recombinant subunit vaccine (L1 capsid protein)
What is the treatment for HPV?
Prevention - vaccine
Imiquimod (immune modulator)
Podofilox (inhibits topoisomerase II DNA replication)
Trichloroacetic acid (kills replicating cells)
Non-pharmacological interventions are suitable for many superficial warts
What does a PAP smear look for?
Not infection alone and not serotype
What are some characteristics of parvovirus?
(+) ssDNA, non-enveloped
Most members infect animals (canine, bovine etc) but NOT zoonotic
Replication occurs in the nucleus and utilizes host cellular functions
Virus particle is highly stable - resistant to dessication, acidification, and heat
How is parvovirus transmitted?
What are the symptoms of a parvovirus infection?
Hemorrhagic diarrhea and vomiting
What are the human parvoviruses?
Adeno-associated virus (AAV)
What are the signs and symptoms of a Parvovirus B19 infection?
Children: erythema infectiosum, low grade fever, followed by rash on face spreading to extremeties (may last several weeks). Typically mild
Adults: rash more severe, typically itches. Arthritic symptoms and joint inflammation common (hands, wrists, knees, ankles)
How is Parvovirus B19 transmitted?
What is the treatment for Parvovirus B19?
Supportive, typically unnecessary
What are some characteristics of Picornaviruses?
Small, (=) ssRNA, non-enveloped viruses (pico = small)
Icosahedral capsid comprised of 4 proteins VP1-4
What are the human pathogens of Picornaviruses?
Where does replication occur for the Picornaviruses?
Replication occurs in the cytoplasm
Direct translation of (+) genome into a single polyprotein, following by proteolytic cleavage by viral protease
What are the signs and symptoms of a Rhinovirus infection?
Sore throat, nasal congestion, runny nose, sneezing, cough
Muscle ache, muscle weakness, fatigue
Seasonal epidemiological pattern of infection