virology

RNA VIRUSES

Orthomyxoviruses
Epidemic influenza A , B , C  Due to Antigenic drift ( minor changes of HA )
Pandermic Antigenic shift ( major changes of HA )

influenza

Sings : fever , sorethroat , headache , cough , nasal
congestion & Resp. infection
Transmission : aerosol
Treatment & prevention :; Antiviral (Amantidine)
Vaccination : Difficult due to Ag changes

RNA Viruses: Orthomyxo (influenza)

Paramyxoviruses
Parainfluenza human Resp. disease affect young adult & infant
( laryngeotrachitis ) croup ; brocheolitis & pneumonia
Transmission : droplet

Mumps : common childhood parotitis one or both side are affected .

MMR vaccine solid immunity


Measles : infectious disease of childhood ; rash , virus enters Resp. tract regional LN viraemia
prodromal stage conjuctivitis , nasal discharge & fever .Sorethroat Kopliks Spots
Bluish white spots on buccal mucosa opposite molar teeth
then
Rash ( reactivation of virus & immuno system )
Koplik spots disappear

Complications of measeles

Resp. complication ; broncho pneumonia
Otitis media
Neurological
- encephalomyelitis
- SSPE progressive degenerative disease of brain
Gangrenous stomatitis & noma (Cancrum oris)
African child suffer from bad nutrition with ANVG
Destruction of orofacial tissue
Transmission of measles :
Resp. secretion & urine ( prodromal stage )
Prevention : MMR

Respiratory Syncytial virus ( RSV )

Lower resp. infection of infants & young adults

Picronaviruses A: Entero viruses
Polioviruses : poliomyelitis
Ingestion of contaminated food ( primary replication in oropharyngeal & intestinal mucosa ) mesenteric LN viraemia CNS


Coxsackieviruses : ( genra A , B ) cause mild disease
Herpangina : common in children
Sorethroat , ulceration an tonsil , soft palate grayish
white vesicles on posterior hard palate , self limiting
disease
Hand , Foot & mouth disease :
Coxa A , common in children
Oral bright red macules vesides pale center on hand & foot
Transmission : oral fecal , nasal route .

B: Rhino viruses :

Common cold upper resp. ; more than 100 group transmitted by inhalation ( Winter & Autumn )
Togaviruses

Rubella : German measles , childhood disease

similar to measles but milder .
Untreated during pregnancy lead to congenital abnormality
spread by nasal secretion
prevention : MMR

Other RNA viruses

Arena
Bunya Rota
Corona saris
Rhabdo Rabies


Viruses & Cancers
Papova HPV , SV40 cervical carcinoma
Adeno animals
Herpes HSV-2 , EBV , HHV-8 Kaposi
Hepatitis HBV & HCV hepatocellular carcinoma
Retro HTLVs ( AIDS )









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