Virology 1

PM2 Pathophysiology

Virus

• infectious particle• DNA or RNA as its

genetic material.• Needs to infect a

host cell for replication

• “toxic”, “poison”• virology

Tobacco mosaic virus

Baltimore classification of viruses

• based on the mechanism of mRNA production. • I: dsDNA viruses

Adenoviruses, Herpesviruses, Poxviruses• II: ssDNA viruses (+)sense DNA

Parvoviruses • III: dsRNA viruses

Reoviruses • IV: (+)ssRNA viruses (+)sense RNA

Picornaviruses, Togaviruses • V: (-)ssRNA viruses (-)sense RNA

Orthomyxoviruses, Rhabdoviruses • VI: ssRNA-RT viruses (+)sense RNA :Retroviruses• VII: dsDNA-RT viruses :Hepadnaviruses

Icosahedral

Helical viruses

• not grouped in capsomeres

• ribbon-like structure

       

Complex

Start

Forms of damage to the host cells

 

• 1. Cell lysis • 2. Production of toxic substances • 3. Cell transformation • 4. Induction of formation of substances • 5. Induction of structural alterations in the host cell ;

Nuclear (including chromosomal) or Cytoplasmic changes

PRIONS

• Contain protein only• small, proteinaceous

particles • Kuru• Creutzfeldt-Jakob

disease syndrome

DNA VIRUSES

• Herpes Virus

• Hepatitis B virus

• Adenovirus

• Parvovirus

• Polyomavirus

• Papillomavirus

Herpesvirus

• herpes simplex virus type 1• herpes simplex virus type 2• varicella-zoster virus• Cytomegalovirus• Epstein-Barr virus• human herpesvirus 6• human herpesvirus 7• Kaposi's Sarcoma herpesvirus.

HSV

• Causes encephalitis• DOC: Acyclovir

Varicella (chickenpox)

Herpes Zoster

CMV: 3 types of infections

• 1. Congenital cytomegalovirus infection retinitispetechial/purpuric skin rashcentral nervous system defects

• 2. Mononucleosis syndromefever, malaise, atypical lymphocytosis,

pharyngitis• 3. immunocompromised individuals

life-threatening disease from either primary or reactivated infection

EBV

• Epstein-Barr virus mononucleosis: most common that occurs in humans.

• Infectious mononucleosis

• Most cases: subclinical, (+) serology

• Main cause of malignant B-cell lymphoma in organ transplants

• PTLD:post-transplant lymphoproloferative disorder