Viruses Flashcards
What is the viral Genome encapsulated in
Capsomere
Virus size
From 15nm to 0.5 micro metres
Viral latency
Virus lies dormant within a cell
Viral pathogenesis
Process by which a viral infections cause disease
Requirements for infection
Enough virus, cells accessible, susceptible and permissive, local anti-viral defence absent or overcome
What is the most common route of entry for a virus
Respiratory tract – by aerosolise droplets from coughs/sneeze/saliva
Alimentary tract
Eating/drinking- an extremely hostile environment, virus must be evolved to with stand it
The Urogenital tract is protected by
Mucus and a low pH
The eye and entry routes for bacteria
Through the Sclera and conjunctiva- Infection occurs after injury/ophthalmology procedures
Skin outer layer the epidermis doesn’t support
Infection
Localised viruses are called
Disseminated
When many organs are affected by viruses it is called
Systemic
What is haematogenous spread
Where the virus enters the blood e.g. measles
What is viremia 
Presence of virus in the blood e.g. influenza, polio
What is neural spread
Viral entry into local nerve endings they invade the central nervous system e.g. polio virus, rabies
What is neurotropic
Virus can infect neural cells
What is tissue tropism
Tissues are affected by viruses
What is pantropic
Can invade many different tissues e.g. ebola
Determent of tissue tropism include
Cellular protease involved in maturation of virions
What is viral virulence
How bad is it going to get – the significance of the disease
What is LD50
Lethal dose 50 is quantitative- how long the appearance of symptoms have been, the mean time of death since infection, measurement of fever
If the virus can replicate quicker and spread more effectively it increases the
Virulence
Genius and as affects the variance because we send out
Virokines and viroceptors
Virus host interactions stops
Virus hijacking as the cells and virus both evolve
Zoonotic viruses spread from
Animals to humans
Tests for viruses
Use a microscope or culture
Detection of Antibody mounted against the virus or viral proteins of nucleic acid- Immunofluorescent and Elisa test Automation and random access analyser
Viral nucleic acid detection- PCR

How do you prevent the spread of viral disease
Use PPE, gloves and masks, vaccines, chemoprophylaxis, immunoprophylaxis, social intervention, hygiene
Seven stages of virus replication
Adsorption Entry Uncoating Transcription – mRNA production Synthesis of virus components Virgin assembly and release (liberation stage) Adsorption 
Horizontal transmission
Between members of the same species
Zoonotic transmission
Between members of different species
Latrogenic
Activity of healthcare worker leads to infection or patient
Nosocomial
When an individual is infected while in hospital or healthcare facility
Vertical transmission
Transfer of infection between parent and offspring
Germline transmission
Agent is transmitted as part of the genome