TRANSMISSION AND TREATMENT OF VIRAL INFECTIONS Flashcards
What happens in the attachment phase of viral replication?
viral proteins on the capsid or phospholipid envelope interact with specific receptors on the host cellular surface.
what happens in the penetration phase of viral replication?
This induces conformational changes in viral capsid proteins or the lipid envelope that results in the fusion of viral and cellular membranes. (some DNA viruses can enter the host cell through receptor-mediated endocytosis)
what happens in the un-coating stage of viral replication?
the viral capsid is removed and degraded by viral enzymes or host enzymes. The viral genomic nucleic acid is released
what happens in the replication stage of viral replication?
transcription or translation of the viral genome is initiated (in the cytoplasm for RNA viruses and in the nucleus for DNA)
what happens in the assembly stage of viral replication?
viral proteins are packaged with newly replicated viral genome into new virions that are ready for release from the host cell
what happens in the virion release stage of viral replication?
Lysis can occur to release the viruses. Enveloped viruses are typically released from the host cell by budding and so dont kill the infected cell- these are termed cytopathic viruses
what are some ways that viruses can be transmitted?
respiratory contact enteric percutaneous mother to child zoonoses
what are the problems of intervening with viral replication?
viruses vary in their metabolism and structure, have different cell receptors and its hard to intervene without damaging the host cells
what are the classes of antivirals?
non-specific replication inhibitor attachment inhibitors release inhibitors others e.g. protease inhibitors
what are some currently used antivirals?
neuraminidase inhibitors
nucleotide analogues
ribacvarin
ganiciclovirm vakganciclovimr, foscarnet, letermovir
what antivirals do we use for hepatitis C?
combination therapy of protease inhibits, NS5A inhibitors and NS5B inhibitors
what antivirals do we use for HIV?
combination therapy of nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and integrase inhibitors
how can we test to see if someones immune to something?
and how do we test to see if someone has the infection currently?
blood test to check for IgG
IgM for current infections
what is latency?
when viruses infect a cell but proliferation of the virus particles ceases so it remain dormant. however, the viral genome is not fully eradicated and may resume active replication after a period of time due to external stimulants
