Transmission And Treatment Of Viral Disease Flashcards
Where do RNA and DNA viruses tend to replicate
RNA in cytoplasm whilst DNA viruses in the nucleus
List the 6 ways in which diseases can spread
1) respiratory through aerosols and droplets
2) contact through mucosal membranes such as HIV or herpes simplex. Or through cutaneous close skin-skin contact for HPV to spread
3) enteric via the oral-fecal route
4) percutaneous eg blood borne viruses such as HIV
5) mother to fetal spread that can either be congenital or perinatal
6) Zoonoses through ingestion of meat or excreta, animal bites or insects
Examples of respiratory viruses and how else can they spread apart from droplets
Eg flu COVID, rhinovirus or rashes as seen in measles, rubella
Can also be spread through saliva specifically CMV and EBV
Which viruses are spread through the enteric route
Hep A + E
Norovirus
Rotavirus
What are arboviruses
Viruses from insects and arthropods such as dengue, ticks, W Nile and Zika
Examples of viruses that are spread congenitally
CMV, rubella and varicella
Examples of viruses that spread perinatally
HIV,
Hep B
Herpes simplex
What are the 3 ways in which viral transmission can be prevented
Physical = condoms and DEET
Passive = antibodies
Active (vaccines)
Vaccines can contain the killed virus, an engineered antigen or the live attenuated virus
Examples of latent viruses
Herpes = herpes simplex, CMV, EBV and varicella zoster
HIV
Hep B
HPV
What is used to treat influenza
Tamiflu which is a neuroaminidase inhibitor
What is used to treat herpes simplex and varicella
Aciclovir which is a nucleotide analogue
What is used to treat CMV
Ganciclovir (nucleoside analogue)
What is used to treat RSV and Lassa fever
Ribavirin (RNA polymerase inhibitor)
What forms part of the cellular innate and adaptive response
Innate = neutrophils and macrophages
Adaptive = lymphocytes T cells. Antigens presented by MHC Class 1 which promotes killing by CD8 cells and this takes 7-10 days
What forms part of the humoral innate and adaptive response:
Innate = cytokines and interferon (alpha and beta)
Interferon is produced by fibroblasts and leukocytes which stimulates genes that produce host restriction factors (anti viral proteins that counteract viral replication)
Activation of NK cells and macrophages and release of other cytokines produces systemic response (fever)
In secondary infection IgG is highly elevated
IgM = aggregation whilst IgG are neutralising
