Virology Flashcards
Linear, ds DNA genome, icosahedral capsid, enveloped. Replication in nucleus
Herpes Viruses
Alpha Herpes Viruses
HSV1, HSV2, VZV
Latency in Herpes Viruses
Soon after initial infection, no virus particles produced, few viral genes expressed. Stages: establishment, maintenance, reactivation
Neurotropisms of Herpes Viruses
HSV1- trigem HSV2-sacral, lumbar VZV- dorsal root
LAT - Latency Associated Transcript
only gene consistently expressed during latency in HSV. Produces microRNAs that repress viral gene exp, prevent apop, impair CD8 T cell fxn (possibly). (VZV does not have LAT)
Herpetic Whitlow, Blepharitis, Encephalitis
HSV1
urogenital infections and meningitis
HSV2
HSV pathogenesis
spread through secretions –> breaks in skin or mucosa, rep in epi cells and spread to lymph nodes, taken up by sensory nerves and latency established. Recurrences less painful and remain local due to antibody levels
Adult cases of VZV
more severe than childhood chicken pox, may result in pneumonia
Dx of VZV
clinical appearance +/- Tzanck smear (look for multinuc giant cells)
circular ds DNA genome, non enveloped, icosahedral capsid, small
Papovaviridae
HPV 6,11
anogenital warts
HPV vaccine
tetravalent - 6, 11, 16, 18 Consists of the L1 capsid protein from each that self assembles into pseudocapsids
large, complex, enveloped ds linear DNA genome
Poxviridae
Virus replicates in cytoplasm
Pox viruses
Death in Smallpox due to
toxic effects on vascular endothelium
Cytoplasmic inclusions in keratinocytes
molluscum contagiosum
Eradication of smallpox effective because
humans are only reservoir, no healthy carriers, no sub clinical infections, effective vaccine available
Should not receive the smallpox vaccine
pregnant or breast feeding, immunodef, atopic dermatitis pts, under 18 y/o, prior heart disease
Cocksackie A
Abruptions/rashes/vesicles
Cocksackie B
Think myalgias and joint pain
CD46,SLAM & nectin-4
measles receptors - also has H protein
photophobia
maybe think of measles, conjunctivitis
cause of death in measles
bacterial pneumonia
Basis for vaccine’s effectiveness in MMR
antigenically stable monotypic viruses
concern for causing harm to the fetus if infection occurs during pregnancy
Parvo-B19 & Rubella
mild disease characterized by a low-grade fever, occasional conjunctivitis and sore throat, lymphadenopathy and a morbilliform rash that starts on the face and spreads to the rest of the body
Rubella
Virus shedding continues after the rash disappears and continues for ~1 month following initial exposure
Rubella
Most serious consequence of Rubella virus infection
is for the fetuses during the early stages of pregnancy -Mental retardation, Motor disabilities, Hearing loss, Congenital heart disease, Cataracts
Infection occurring during pregnancy can cause hydrops fetalis, intrauterine growth retardation, pleural and pericardial effusions, and death.
Parvo B19 Virus
Enteroviruses Differentiated from rhinoviruses by
Acid stability, Less stringent growth requirements: Can grow in human and primate cell lines, Grows well at 37OC
Asymptomatic infections are common with
enteroviruses
Occur mainly in the summer and fall
enterovirus infections
most common exanthem before age 2
Roseola 6 months - 4 years
HHV6/7
Roseola Can reactivate in immunosupp patients later in life
Virus is shed in the saliva ~6 days before onset of clinical disease
Mumps
causes erythema infectiosum (slapped cheek syndrome) and is most common in children 4-10 years old.
Parvo B19
