Module 8 - Viral Infections Flashcards
Creation of Influenza Vaccination:
-jan-may = virus selection
-june-july = fda testing
-aug = filling/packaging
-sep = product release and shipping
-oct-now = vaccination begins
Structure of Influenza:
-2 internal structural proteins: nucleocapsid (NP) and matrix (M) protein
-nucleocapsid proteins = dna packaging and protection
-matrix proteins = assembly release of viral particles
-influenza A/B viruses further subdivided based on surface antigen of 2 different types of protein spikes: hemagglutinin and neuraminidase
Hemagglutinin:
-binds to the target cell surface receptor (sialic acid) to initiate infection
-influenza
-antibody against the hemagglutinin neutralises the infectivity of the virus and prevents disease - therefore it is useful in vaccines
Neuraminidase:
-divides/cuts (sialic acid) to release virus from the infected cell
-degrades the protective layer of mucus in the respiratory tract
-enhances the ability of the virus to infect the respiratory epithelium
-antibody against the neuraminidase does not neutralise infectivity but does reduce disease
-flu antivirals target neurminidase
Influenza Antigenic Variation:
antigenicdrift/shift
-influenza viruses (especially 1A) show changes in the antigenicity (ability to bind to b/t cells) of their hemagglutinin and neuraminidase proteins - this can cause devastating worldwide epidemics
Two Types of Antigenic Changes:
(strains combine to become worse)
- Antigenic shifts: major/abrupt changes based on the re-assortment of segments of the 2 genomes , influenza A only
2.Antigenic drifts: minor/gradual changes based on mutations in the genome RNA, a and b
Influenza and Target Hosts:
Influenza type A viruses:
-can infect people, birds, pigs, horses
-wild birds are the natural hosts for these viruses
-most of severe epidemics and pandemics are type A
Influenza type B viruses:
-usually found only in humans
-it can cause morbidity and mortality among humans
-are associated with less severe epidemics than influenza A viruses
Influenza type C viruses:
-cause mild illness in humans and do not cause epidemics or pandemics
Influenza Virus Prevention:
-majority of currently used vaccines are inactivated (killed) preparations derived from influenza A and B viruses that circulated during the previous influenza season (in late season)
-the overall health risk following influenza outweighs the small potential risk associated with vaccination
-herd immunity provided by vaccination population is thought to prevent spread, and protect unvaccinated individuals
Abbreviations
DNA
CMV: cytomegalovirus
HSV: herpes simplex virus (HSV types 1 and 2)
VZV: varicella-zoster virus
EBV: epstein-barr virus
HEP: hepatitis virus
RNA
HEP: hepatitis virus
HTLV: human t lymphotropic virus (type 1)
HIV: human immunodeficiency virus (rubella)
ZIKV: zika virus
Latency and Herpes Viruses:
-in health individuals, HSV provoked by: certain febrile illness (common cold, pneumonia), direct sunlight, stress, trauma, menstruation, immunocompromised
Primary Causes of Chronic Liver Disease:
-hep c virus and alcohol
Recall how HIV Gets in and Replicates:
slide 45
Case Study: 6 month pregnant client has an outbreak of chicken pox in her students. What would you advise?
-ask and check if she’s been vaccinated for chickenpox (IGg immunoglobulin test to see if they have antibodies)
-if no antibodies, stay home because it transmits very easily, it is life threatening to baby as it can cross placenta
Influenza
-ssrna
-type a (human outbreak) also b and c
-through aerosols such as cough/sneeze
-cause fever, cough, sore throat, muscle ache
-can cause 2ndary lunge infection such as pneumonia
-antivirals for A/B
=zarimaivir (relenza) and oseltamivir (tamiflu)
-no transfer ti fetus
influenza vaccine is safe in prenancy and baby gets antivirals
HSV1
-Herpes Simplex Virus
-cold sores name
-dsDNA
-dindirect/direct contact
-latent, can reactivate in pregnancy
-causes cold sores
-in utero/perinatal is rare
-postnantl is yes
-rash/fever in infant
-antiviral acyclivir for mom and baby
–> decreases outbreak time, helps sores heal, less painful
HSV2
-Herpes Simplex Virus 2
genital herpes
-dsDNA
-oral/intercourse
-latent so can reactivate in pregnancy
-in utero = rare
-perinatal = yes
-postnatal = no
-rash/fever in infant
-prohylactic for mom
-acyclivir for baby
HSV3
VZV Varicella Zoster Virus
-chicken pox
-dsdna
-secretions/contact with vesicle
-latent, shingles as adult
-in utero, perinatal and postnatal transmission
-chicken pox for baby
-VZIG vaccine for mom/baby
-no vaccine in pregnancy
HSV4
EBV Epstein Barr Virus
-mononucleosis
0dsdna
-through saliva
-latent, can reactivate in pregnancy
-no trasnfer in utero or birth
-antibodies in breastmilk
-novaccine, can take acyclvir
CMV Cytomegalovirus
dsdna
-saliva, sex, organ transplant
-latent, can reactivate
-similar symtpoms to ebv
-can trasnder in utero
-perinatal and postnantl usually asymptomatoc baby
-can cause CNS issues, deaf, rash, fever in utero
-acyclivir baby, no vaccine
Hepatitis A
ssrna
fecal/oral
AcutE
in utero and perinatal
not postnatal
prophylactic mom vaccine
hep a immunglobulin for baby
Hep B
dsdna
-sex, blood
chronic carrier
in utero and perinatal transmission
no post natal trasnmisson
prophylactic for mon
HBsAg vaccine in pregnancy if mom is carrier
-hep b immunoglobulin for baby perinatl infection
Hep C
ssrna
blood/sex
-chronic 50% cases are hep c
-can lead to liver cancer
-in utero and perinatal transmisson
-not postnantl
-antiviral prophylatic
-Interferon and ribavirin antiviral for baby
avoid breast feeding if breast bleed occurs
Hep E
ssrna
fecal oral
acute
no vaccine
casue kdiney disfunction and clotting
not common in canda but issue in china
parovirus B19
ssdna
5th disease slapped cheek
resp and in uter trasnmissin
fever, headache, cough, rash, sore throat
no vaccine
acute or latent
rubella
german measels
resp droplets and in utero
teratogen
natural infection = lifelong immunity
-live attentutated MMR vaccine
routine child vaccine
heart disease, microcephaly, ete issues, deaf, patent ductus arteriosus
HTLV1
Human T lymptrohic virus
ssrna
intercourse, blood, breastmilk
can be latent
causes t cell leukemia
in utero is rare
no breastfeeding
spinal cord issues
no vaccine
HIV
human immunodeficiencyssrna
intercourse, blood, in utero, peri/posrnalt breastmilk
causes aids acquired immunodeficieny syndorme
desrtucts cd4 t cells
antiviral abacivir
low weight, sepsis, encephaly in newborn
zika
ssrna
mosquitos, blood, sex, placenta
rash, fever, conjuctivitus
vub foot, porr brain development, eye issues
wait 2-3 months after infection befroe geting pregnant
PCR and IgM antibodies
Sars/covid
ssrna
cough, fever, chills,
increased risk of stillbirth
vaccine safe in pregnancy so baby gets antibodies
not transmion through brestmilk but antibodies are
SARS-cov-2 binds to ace 2 on alveolar epithelial cells using spike protein
antibodies
G - through placenta, most abundant, long lasting (M)
A - secretions like bmilk, prevent attachmetn path to epithelial cells (D)
M - 1sr made (pentamer)
E - allergic respone (monomer)
D - b cell activation monomer
