20 chapter viruses associated with respiratory infections. Department of pathogenic biology xie-shuixiang. ORTHOMYXOVIRUSES. pleomorphic influenza types A,B,C febrile, respiratory illness with systemic symptoms. ‘ FLU ’. True influenza
Department of pathogenic biology
RNA： -ssRNA, 8 fragments
RNA dependent RNA polymerase
sipke hemagglutinin(HA) 5
NA - neuraminidase
helical nucleocapsid (RNA plus
lipid bilayer membrane
type A, B, C : NP, M1 protein
sub-types: HA or NA protein
Host of origin
of HA and NA
HA protein - attachment, fusion
Ryan et al., in Sherris Medical Microbiology
Lycke and Norrby Textbook of Medical Virology 1983
Treanor JJ Infect. Med. 15:714
COLDS AND SARS
Pathologic cytoarchitectural changes indicative of diffuse alveolar damage, as well as a multinucleated giant cell with no conspicuous viral inclusions.
measles (rubeola) alveolar damage, as well as a multinucleated giant cell with no conspicuous viral inclusions.
Koplik's spots on mucosal membranes
Maculopapular rash (extends from face to extremities)
Histopathology of measles pneumonia. Giant cells. alveolar damage, as well as a multinucleated giant cell with no conspicuous viral inclusions.Lab Diagnosis
spherical or pleomorphic enveloped viruses (100-350 nm) with single-stranded, negative sense linear RNA
Infection of cells results in syncytium alveolar damage, as well as a multinucleated giant cell with no conspicuous viral inclusions.formation
Upper respiratory infection (‘bad cold’) in older children and adults
Lower respiratory infection- Bronchiolitis and/or pneumonia may occur after the upper respiratory infection
Severe infections occur in infants (2-6m)
at the vertices are 12 pentons, from which a fiber with a terminal knob projects. This complex is toxic to cells - causing rounding and death of cells through inhibition of protein synthesis.
Epidemic Keratoconjunctivitis (EKC), acute follicular conjunctivitis, pharyngoconjunctival fever
Common cold (rhinitis), pharyngitis (with or without fever), tonsillitis, bronchitis, pharyngoconjunctival fever, acute respiratory disease (LRI)
Acute hemorrhagic cystitis
Rash alveolar damage, as well as a multinucleated giant cell with no conspicuous viral inclusions.