Infection 4) How viruses cause disease Flashcards
What is the basic reproduction number?
Approximate measure of how many infections one person will generate during their infectious period
What protective equipment is used in ebola?
Medical mask Surgical cap Goggles Overalls Scrubs Apron Double gloves Boots
What is a virus made of?
Nucleic acid
Protein coat
Enveloped / unenveloped
What is a virion?
Complete intact virus particle
Give examples of viral infections that can cause encephalitis / meningitis
JC virus Measles LCM virus Arbovirus Rabies HSV 1/2 VZV Enteroviruses Parechoviruses Mumps
Give examples of viral infections that can cause a common cold
Rhinovirus
Parainfluenza virus
Respiratory syncytial virus
Give examples of viral infections that can cause pharyngitis
Adenovirus
Epstein-Barr virus
Cytomegalovirus
Give examples of viral infections that can cause gingivostomatitis
Herpes simplex type 1
Give examples of viral infections that can cause cardiovascular infections
Coxsackie B virus
Give examples of viral infections that can cause hepatitis
Hepatitis A,B,C,D,E HSV 1/2 VZV CMV / EBV Enteroviruses Parechoviruses
Give examples of viral infections that can cause skin infections
Varicella zoster virus Human herpes virus 6 Small pox Molluscum contagiosum Human papillomavirus Parovirus B19 Rubella Measles Coxsackie A virus
Give examples of viral infections that can cause sexually transmitted diseases
Herpes simplex type 2
Human papillomavirus
HIV
Give examples of viral infections that can cause pancreatitis
Coxsackie B virus
Give examples of viral infections that can cause gastroenteritis
Adenovirus Rotavirus Norovirus Astrovirus Coronavirus
Give examples of viral infections that can cause myelitis
Poliovirus
HTV-I
Give examples of viral infections that can cause pneumonia
Influenza type A and B Parainfluenza virus Respiratory syncytial Adenovirus SARS coronavirus
Give examples of viral infections that can cause parositis
Mumps
Give examples of viral infections that can cause eye infections
Herpes simplex
Adenovirus
Cytomegalovirus
What are the 2 components of viral disease?
Effects of viral replication on host
Effects of host response on virus and host
What 4 requirements must viruses know to replicate?
What cells to enter and how
How to replicate inside cell
How to exit and move from 1 infected cell to a new cell and new host
Develop mechanisms to evade host defences
What are the 6 steps of viral pathogenesis?
Encounter Entry Multiplication Spread Damage Outcome
What is apical viral release?
Facilitates viral dispersal but virus doesn’t invade underlying tissues
What is basolateral viral release?
Provide access to underlying tissues and facilitates system spread
How can haematogenous spread occur?
Directly through capillaries
Replicating in endothelial cells
Through vector bite
By lymphatic capillaries
What is viraemia?
Presence of infectious virus in blood
What is neurotropic?
Virus can infect neural cells
What is neuroinvasive?
Virus can enter CNS following infection of peripheral site
What is neurovirulent?
Virus can cause disease of nervous tissue
What are the 3 determinants of tissue tropism?
Cell receptors
Cellular proteins that regulate viral transcription
Cell proteases
What is the Baltimore system?
Viral classification
Groups viruses into families depending on their type of genome and method of replication
Give examples of transmission routes
Exogenous Endogenous Skin / mucous membrane Respiratory tract Alimentary tract / faecal oral Urogenital tract Eye Blood borne Vertical transmission
Give an example of a virus that produces immunosuppressive cytokines
EBV
Describe influenza virus type A
Matrix protein Segmented RNA genome Neuraminidase Haemagglutinin M2 ion channel protein
How does influenza virus type A evade host defence mechanisms?
Change its surface antigens
Antigenic variation in HA and NA - antigenic drift and antigenic shfit
What is antigenic drift?
Accumulation of mutations within antibody-binding site
What is antigenic shift?
Sudden shift in antigenic of virus resulting from the recombination of genomes of 2 viral strains