Infections lecture 5: Viral infections and anti-viral drugs Flashcards
What is the baltimore system grouping
Genetic Material
Mode of replication
Structure and symmetry of capsid
Presence and absence of envelope
What is a DNA virus and give examples
Replicates in nucleus host
Examples:
Herpes
Varicella Foster
Adenovirus
What is a RNA virus and give examples
Replicates in cytoplasm
Examples: Rotavirus Enterovirus Rhinovirus Rubella virus Rabies virus
What are the six steps in a virus life cycle
Attachment
Penetration
Uncoating
Replication
Assembly
Release
What is an entry inhibitor and give examples
Prevents uncoating and release of viral RNA
example: Amantadine and Rimantadine
What is Pleconaril used for
Blocks uncoating and attachment against picorna, enterovirus and rhinovirus
(entry inhibitor type)
What does a nucleic acid synthesis inhibitor do and give examples
Prevents virus replication
Examples: Aciclovir- herpes virus and VZV Zidovudine- HIV Granciclovir- Herpes Lamivudine- Hepatitis B and HIV Ribavarin- influenza A, B and RSV
Give an example of a drug that is a integrase inhibitor
Raltegravir
Give an example of a drug that is a protease inhibitior
Ritonavir for HIV
Give an example of an exit/release inhibitor
Zanamivir (relenza)
OSETAMIVIR (tamiflu)
Explain the mechanism of action of AZT (anti-HIV drug) mechanism of action
Virus has RNA to create DNA- adds nucleosides to elongate chain
AZT is an analogue of a nucleoside which prevents DNA from being synthesised- blocks and prevents the elongation process
Give all the classes of antiviral drugs (5) NIPEE
Nucleic acid synthesis inhibitor
Integrase inhibitor
Protease inhibit
Exiting inhibitor
Entry inhibitor
How are the smaller droplets more deadly
Airborne longer and avoid ciliary nose action: more contagious (varicella zoster virus)
What are the three main respiratory viruses
Influenza
Rhinovirus/corona virus
Respiratory syncytial viruses (RSV)
What are the two different surface protein on influenza A,B and C and what do they do
Haemaglutinin (H)
Neuraminidase (N)
H and N change overtime hence classified H1N1- evolving and changing makes it difficult to target
How do you treat influenza patients
Self limiting
Elderly may develop secondary chest infection (pneumonia) that may need antibiotic treatment
Antiviral:
ZANAMIVIR AND OSELTAMIVIR (at risk patients only)
what are the risk groups that are available for a flu jab
Over 65 (elderly)
Chronic health problems: asthma, COPD, cardiovascular disease, diabetes, liver or kidney disease
Pregnant
Immunosuppesant
How are gastrointestinal infections usually passed on
Faecal oral route
How is rotavirus common caused and treatment options
Viral gastroenteritis (especially in children)
Self limiting
Rehydration
Babies vaccine: rotarix
Describe the Norwalk like viruses/noroviruses transmission, symptoms and treatment
Transmission: faecal oral, highly contagious
Symptoms: Diarrhoea, projectile vomiting
Treatment:
Self limiting (12 to 48 hours)
Hygiene
Rehydration
what are the symptoms of hepatitis A
Fever Nausea Diarrhoea Fatigue Appetite Loss
How do you diagnose Hepatitis A
Increased levels of SERUM TRANSAMINASE (ALT)
Explain the pathogenesis of hepatitis A and treatment
Affects LIVER
Virus replicates in hepatocytes and GI epithelial cells
Released into blood and bile by mechanism which doesn’t cause cell lysis
No permanent liver damage- any damage is normally a cell mediated immune response
REST, avoid fatty food and alcohol
What is the Hepatitis A vaccine called
AVAXIM- 10 year protection
What is the varicella zoster virus (VZV), symptoms, treatment and vaccines available
Caused by Herpes Virus
Symptoms: Chicken POX
Treatment: calamine lotion, antihistamines, NSAIDs
Vaccines: Varivax, varilrix, zostavax
What can varicella zoster virus (VZV) be reactivated as later in life and how do you treat it
Shingles
Rash and pain for 3 to 5 weeks
Long lasting problems: Neuralgia
Treatment: aciclovir or famciclovir
What can measles mumps and rubella do
Measles: mental retardation and death
Mumps: male sterility
Rubella: congenital defects
What causes a wart
Small tumours caused by human papilomavirus (HPV)
How do you treat a wart
Keratolysis
Salicylic acid and abrasion to remove dead cells
Silver nitrate
CRYOSURGERY- liquid nitrogen to freeze pores
