Viral Pathogenesis 2 Virus ingested Bood ut asso iaid lymphoid tissue virus invades (va M cells?) endothelium Spinal cord (monocytes wYUS BxCUU Stages of Poliovirus Pathogenesis inc. Al rihts reserved
Viral Pathogenesis St f P li i P th i Stages o f P oliovirus P athogenes is
Common Routes of Human Pathogenic Viral Transmissions ROUTE OF SOURCE/ MODE OF EXAMPLES/VIRUSES ENTRY TRANSMISSION Respiratory Aerosol droplet inhalation Influenza virus, parainfluenza virus, respiratory syncytial virus, measles, mumps, rubella varicella-zoster virus. hantavirus Nose or mouth hand or object nose Common cold(rhinovirus, coronaviru adenovirus) Salivary Direct salivary transfer(eg, kissing) Herpes simplex virus(oral-labial herpes), Epstein-Barr virus(infectious mononucleosis) cytomegalovirus Gastrointestinal Stool hand mouth and/or stool Enteroviruses, hepatitis A virus, poliovirus, Skin Skin discharge air respiratory tract varicella-zoster virus, small pox virus Skin to skin Human papilloma virus(warts) Animal bite to skin Rabies virus Blood Blood products, transfusion or lepatitis B virus, hepatitis C virus, hepatitis D needle prick virus, human immunodeficiency virus(HIV) human T lymphotropic virus, cytomegalovirus
Common Routes of Human Pathogenic Viral Transmissions ROUTE OF ENTRY SOURCE/ MODE OF TRANSMISSION EXAMPLES/VIRUSES Respiratory Aerosol droplet inhalation Influenza virus, parainfluenza virus, respiratory syncytial virus, measles, mumps, rubella, vari ll ce a-zost i hti ter virus, hantavirus Nose or mouth hand or object nose Common cold (rhinovirus, coronavirus, adenovirus) Salivary Direct salivary transfer (eg kissing) Direct salivary transfer (eg, kissing) Herpes simplex virus (oral Herpes simplex virus (oral-labial herpes) labial herpes), Epstein-Barr virus (infectious mononucleosis), cytomegalovirus Gastrointestinal Stool hand mouth and/or stool Enteroviruses, he patitis A virus, poliovirus, object mouth , p ,p , rotavirus Skin Skin discharge air respiratory tract Varicella-zoster virus, small pox virus Skin to skin Skin to skin Human papilloma virus (warts) Human papilloma virus (warts) Animal bite to skin Rabies virus Blood Blood products, transfusion or Hepatitis B virus, hepatitis C virus, hepatitis D needle prick virus, human immunodeficiency virus (HIV), human T lymphotropic virus, cytomegalovirus
Common Routes of Human Pathogenic Viral Transmissions ROUTE OF SOURCE/ MODE OF EXAMPLES/VIRUSES ENTRY TRANSMISSION Blood Insect bite Arboviruses, dengue virus, yellow fever virus, West Nile virus, encephalitis causing rbi Genital Genital secretions Hepatitis B virus, HiV, herpes simplex virus Urine Urine Polyomavirus(BK virus) e Conjunctival Adenovirus, cytomegalovirus, herpes simplex virus 1 Zoonotic Animal bite Rabies Arthropod bite Arboviruses Mammals excreta Arenavirus. hantavirus filovirus Chicken, wild birds-aerosol Avian influenza virus(bird flu, H5N1) droplet
Common Routes of Human Pathogenic Viral Transmissions ROUTE OF SOURCE/ MODE OF EXAMPLES/VIRUSES ENTRY TRANSMISSION Blood Insect bite Arboviruses, dengue virus, yellow fever virus, West Nile virus, encephalitis causing arboviruses Genital Genital secretions Hepatitis B virus, HIV, herpes simplex virus, cytomegalovirus Urine Urine Pol i ( i) lyomavirus (BK virus) Eye Conjunctival Adenovirus, cytomegalovirus, herpes simplex virus 1 Zoonotic Animal bite Rabies Arthropod bite Arboviruses Mammals excreta Mammals excreta Arenavirus hantavirus filovirus Arenavirus, hantavirus, filovirus Chicken, wild birds–aerosol droplets Avian influenza virus (bird flu, H5N1)
Vertical Transmission of Human Pathogenic Viruses SOURCE/ MODE OF EXAMPLES/VIRUSES RANSMHSSHON Prepartum or transplacental Cytomegalovirus, parvovirus B19, rubella virus human immunodeficiency virus(HIV) Intrapartum or during delivery/birth Hepatitis B virus, hepatitis C virus, herpes simplex virus, HIV, human papilloma virus Postpartum or via breast feeding Cytomegalovirus, hepatitis B virus, human T lymphotropic virus, HIV
Vertical Transmission of Human Pathogenic Viruses SOURCE/ MODE OF TRANSMISSION EXAMPLES/VIRUSES Prepartum or transplacental Cytomegalovirus, parvovirus B19, rubella virus, human immunodeficiency virus (HIV) I t t d i d li /bi th I n trapar tum or during d elivery/bi rth H titi B i h titi C i h Hepatitis B virus, hepatitis C virus, herpes simplex virus, HIV, human papilloma virus Postpartum or via breast feeding Cytomegalovirus, hepatitis B virus, human T l h t i i HIV lymp h o tropic virus, HIV
Major Patterns of viral Infections o Abortive infection(no progeny viruses) Lytic infection o Persistent infection Chronic infection Latent infection Most persistent infections have some kind of acute phase followed by either being eliminated from the host or becoming latent or chronic ● Viral transformation
Major Patterns of Viral Infections z Ab ti i f ti ( i ) Abortive in fection (no progeny viruses ) z Lytic infection z Persistent infection ¾ Chronic infection ¾ Latent infection ¾ Most persistent infections have some kind of acute Most persistent infections have some kind of acute phase followed by either being eliminated from the host or becoming latent or chronic z Viral transformation