University:
Coventry University
Course:
B940 | Biomedical Science
Academic year:

2023
Views:

350

Pages:

3
Author:

Badusha S.

* Poliomyelitis -Polio Viruses Morphology - enteroviruses simple in structure, Non enveloped, sumall sizy - (28-307mize] Spherical shaped & have icosahedral symmetry Capsid is composed of 60 subunits - Positive sense lineas SSRNA Anligenic hype - classified into wild polioviruses vaccine -whids cause Nartulal disease desived polsovirus which all vaccine strains that have regained neulovirulence and are capable defcase in man. of producing wild polio viru - WPV1, WPV2, WPV3 All three strains are identical, produces similas Manifestation & severity of illness But distinct genet cally &uumonologically deffes from cach other in VP1 region WPV1 is common selotype of poliomyelitis -Boty wpr 1 & WPV3 all eradicated Pathogenesis feco, oraly Malalion -MC -Droplets -Rallly conjunctival contact Multiply locally - - In Intellinal epithelial celly Submucosal Lymphoid tiss tonsils & payes's patches - Receptors •vical entry is possible by bindin to CD155 receptors spread to CNS/spinal cord •Hematogenous spread -MC -virus spread to Regional lymph nodes & spalls oves to the blood Stream Cio viremia) After fustres multiplying. in reticuloendothe system, the virus enled bloodstres again Causing 20 viremia. which is called to Spinal cord & brair • Neulal spread - It cous direally spread through nelves useraly duling tonisflectory whell the Virus may spocad via glossophalyngeal nerve Present in the tonsillar forsa site of action ie Anlessor final targel site-Mator nerve horn celll of the spiral which leadl to muscle weatness & flaccid paralysis ending Neuson, degenelalion-virus infealed neuson undergo degeneration. Easiest change in neulomit the degeneration of Nissie body -Patholog scal cal changel Extensive than the ase always most distribution paralys CM IP ys-Asymptocratic 7-14 days -Inapparent infection -(91-96%) sympto Abortive infedion -51 fenes, Malasia, to Palaty Stage Symphe -Non paralylic - 100 - presented as aseptic Meningitis paralytic poliomyclelis - less thou 1% - Chalaclesized by descending asymmetric aute flaccid paralysis Proximal muscles affected thandistict -site involved - spinal, bulbo spiral & bulbas According to nature of paralysis respiratory insufficiency are common or dysphagia Biphasic Coulse -in duldren biphase Aseptic meningitis ccuse first recovery] retules of feves with Palalytic features 1-2 days daly - cranial nerves involved occasionally No sensory loss Risk factor- Paralytic disease MC among -oldes children & Adult - Pregnant women. heavy muskulal Excelsise Tonsilectomy. - Im infection LAB -Virus isolation in i monkey kidney cell line from tsoat swab of stool samples -viral growth it detected by CPE, viral antigen or visal gene in coll lime - Ab detection-by neutraleation rest Vacal Boty is activated & 19ve attenuated polio vaccines are ovdiloble both have useful properties & draw boys