2- Respiratory Viruses: (paramyxoviridae family) + rubella Flashcards
TAXONOMY OF PARAINFLUENZA
Paramyxoviridae paramyxovirus
TAXONOMY OF RUBELLA
Paramyxoviridae
Rubivirus
TAXONOMY OF MUMPS / Parotitis
Paramyxoviridae
Rubilivirus
morphology of parainfluenza
- Large spherical shape
-complex virus (enveloped/supra-capsid) - helical single stranded RNA (-ve); (unsegmented)
3 surface glycoproteins.
-hemagglutinin (H)
-neuraminidase (N)
-fusion (F) = for cell fusion
cultivation of parainfluenza
cell line cultures (human epithelial cells)
antigenic properties (+ virulence factors) of parainfluenza
*(factors of virulence)
- H (for adhesion)
- N (for binding)
- F (for penetration & fusion with CM - to form giant multi-nucleated cells)
pathogenicity of parainfluenza
- source =sick person
- trans. method =
1)air drop
2)contact mechanism
- gate = epithelia of mucosa of upper resp. tract
pathogenesis:
(cytopathogenic)
- H, N antigens attach to and bind host cell CM.
- virus penetrates cell by fusion using F antigen - forming giant multinucleated cells.
-(cytopathic) so virus exits cell by budding from CM
- virus affects upper resp tract causing croup and narrowing of trachea, which results in barking cough.
- infection can spread deeper to lower resp tract leading to pneumonia and bronchitis
clinical manifestations of parainfluenza
-CROUP (=barking cough + tracheal narrowing)
-bronchitis
-pneumonia
lab diagnosis of parainfluenza
- ELISA
- PCR
- immunofluorescence test (IFT).
treatment of parainfluenza
antiviral drugs
prophylaxis of parainfluenza
no vaccine (only treatment post exposure with antiviral drugs)
TAXONOMY of Measles
paramyxoviridae morbillivirus
morphology of measles
- large pleomorphic shape
-complex virus (enveloped/supra-capsid) - single stranded RNA (-ve); (unsegmented)
2 surface glycoproteins.
-Hemagglutinin (H)
-Fusion (F)
antigenic properties (+ virulence factors) of measles
-H = adhesion
-F = penetration by fusion
-M (matric) = virus assembly and budding
-N (Nucleoprotein) = encapsulating the mature virus
morphology of mumps / Parotitis
- spherical shape
-complex virus (enveloped/supra-capsid) - single stranded RNA (-ve); (unsegmented)
2 surface glycoproteins.
-Hemagglutinin-Neuraminidase (HN)
-Fusion (F)
antigenic properties (+ virulence factors) of mumps
-HN = adhesion &binding
-F = penetration by fusion
-N (nucleocapsid) protein = encapsulating/forming nucelocapsid of the mature virus
morphology of rubella
- spherical shape
-complex virus (enveloped/supra-capsid) - single stranded RNA (+ve); (unsegmented)
2 surface glycoproteins.
-E1 (hemagglutinin - fusion / RBC-clumping)
-E2 (adhesion)
antigenic properties (+ virulence factors) of rubella
-E1 & E2 (=adhesion & penetration)
-C (Capsid Protein) =forms nucelocapsids for mature viruses
-NS (non-structural) Protein = have a role in viral replication and transcription.
cultivation of measles /MUMPS
- vero cells (monkey kidney cells)
- human embryonic cells
cultivation of rubella
- vero cells
- RK-13 (Rabbit kidney cells)
pathogenicity of measles
- source =sick person
- trans. method =
1)airborne (airdrop)
- gate =mucous membranes of upper resp. tract
pathogenesis:
(cytopathogenic)
-H (attachment), F, capsid protein
- virus initiates lytic infection in cells of upper resp.tract
- they enter the blood, causing viremia and spread throughout the body reaching from mouth to skin, conjunctiva, GI tract, CNS
clinical manifestations of measles
- fever (high temp:39 40C)
- Maculopopular Rash; Koplik spots(starts on FACE and travels down to Torso then Limbs)
-conjunctivitis
pathogenicity of rubella
- source =sick person + congenitally
- trans. method =
1)airborne (airdrop)
2)vertical/transplacental
- gate =mucous membranes of upper resp. tract
pathogenesis:
(cytopathogenic)
- E1 &E2 Attach, penetrate
- virus replicates and starts spreading from resp tract to lymphnodes. then to skin causing a rash
- pregnant women can pass it to fetus causing CRS and future complications like cataracts and deafness
clinical manifestations of rubella
- mild fever + Mild catarrhal
symptoms - NON ITCHY Maculopopular Rash; Forcchheimer spots (starts on FACE and travels down
- enlarged posterior cervical & occipital lymph nodes
- Congenital Rubella Syndrome (CRS)
