Unit 4 - part 7 Viruses of medical importance: Vaccine-preventable viral disease (VPVD) Flashcards
what is the causitive agent of poliomyelitis
poliovirus types 1, 2, and 3 - all 3 can cause paralysis
what type of virus is the poliovirus
small ss RNA non-enveloped viruses
what family is the polio virus in
picornaviridae
what are the major reservoirs for polio
humans especially children
what are the modes of transmission for polio
PTP via feacl-oral route
contact with throat secretions
rarely spread by contaminated vehicles or formites
what is the Ro value for polio
5-7
what is the incubation period for polio
7-14 days
what is the period of communicability for polio
as long as the virus is excreted
1 week in the throat, 3 weeks in feces
4 phases of poliomyelitis pathogeneis
ailmentary phase
lymphatic phase
viremic phase
neurologic phase
what occurs in the ailmentary phase of polio
- virus replicates in the oropharyngeal and intestinal mucosa
- spreads to tonsils and multiplies in peyer’s patches, cervical and mesenteric nodes
what occurs in the lymphatic phase of polio
virus is absorbed into the bloodstream and spreads to the internal organs and lymph nodes
what are the two options in the viremic phase of polio
- no further of virus, pt. is asymptomatic or mild febrile
2. virus spreads to spianl cord and brain
if polio spreads to the spinal cord and brain what stage of pathogenesis occurs
neurologic phase
what occurs in the neurologic phase
paralysis
what are the 4 risk factors for polio
- living in the same house with an infected person
- unvaccinated and inadequately vaccinated people
- immunocompromised
- poor sanitation and hygeine
what does it mean when a disease has been eradicated
completely gone from earth
what does it mean when a disease is eliminated
gone at country level or continent level for at least 3 years
what are the S & S of polio
sore throat and vomiting fever and headache fatigue and muscle pain stiffness of neck limbs and back photophobia flaccid and asymmetric paralysis paralysis of respiratory muscles
what are common clinical features and complications of polio
quadrapeligic patient
paralysis
crawling
crouching gait
Polio vaccine used in canada is effective agaisnt what types of polio and what is it called
IPV (inactivated polio vaccine) all 3 (trivalent)
what 3 countries is polio still present in
afganistan
nigeria
pakistan
what is AFM
acute flaccid myelitis
mostly seen in children
poliomyelitis-like symptoms
what is the causative agent for the influenza virus
types A and B viruses
what type genome does the influenza virus have
ss RNA enveloped virus with segmented genome
what family is the influenza virus from
orhtomyxoviridae
what is the major resevoir for influenza
aquatic birds but also circulate in among other animals such as pigs
humans are a major reservoir for 3 subtypes
what are the main modes of transmission for influenza
droplet and contact
what is the Ro value for influenza
1.27-1.8
what is the incubation period for the flu
average 2 days
1-4 days
what is the POC of the flu
day before symptom onset until about 4 days after (7-10 days or longer for children)
what are complications for inluenza
pneumonia
febrile seizure
hospitalizations
death
4 steps of parthogenesis of the flu
- aerosol incubation of virus
- replication in respiratory tract
- desquamation of mucus-secreting ciliated cells
- influenza syndrome
5 risk factors for the flu
age immunocompromised chronic illness pregnancy obesity (BMI >40)
what is the causative agent for measles
measles virus
what type of genetic make up is the measles virus
ss RNA enveloped virus
what type of spikes does the mealses virus have
H spikes - different from those of the influenza virus
what is the major reservoir for measles
humans
what is the major mode of transmission for measles
PTP via airborne, droples, nasal or throat secrtions or contact with fomites
what is the Ro value for measles
12-18 one of the most contagious disease
what is the IP for measles
14 days
what is the POC for measles
usually 4 days before and after rash appears
what are S & S for measles
high fever cough runny nose conjunctivitis kopliks spots maculopapular rash
what does a maculopapular rash look like
small raised bumps may appear on top of the flat red spots - on face, neck, trunk, arms, legs and feet
what are the 4 risk factors for measles
lack or incomplete vaccination
international travel
vitamin A deficiency
immunocompromised
what is the measles vaccine commonly offered with
measles mumps and rubella
what is the measles vaccine made up of
attenuated (weakened) live viruses
what does attenuation mean
a process to make the live viruses non-pathogenic
what is the causative agent of mumps
mumps virus
true or false: measles and mumps are both part of the same family paramyxoviridae
true
what is the major reservoir of mumps
humans
what is the mode of transmission of mumps
droplet spread and direct contact with saliva of infected persons
what is the Ro value for mumps
4-7
what is the incubation period for mumps
16-18 days
what is the POC for mumps
7 days before the onset of parotitis to 9 days afterwords
what are the S&S of mumps
fever headache muscle aches fatigue parotitis
what is parotitis (as seen in mumps)
swollen and tender salivary glands under the ears on one or both sides
what are 4 complications of mumps
orchitis
oophoritis
meningitis and encephalitis
pancreatitis
what is orchitis (seen in mumps)
swelling of testes in 20-30% of post pubertal males (rarely causing infertility)
what is oophoritis (seen in mumps)
swollen ovaries, seen in about 5% of post-pubertal females
what is rubella commonly referred to as
german measles
what is the causative agent for rubella
rubella virus
what type of virus is rubella
ss RNA eveloped virus
what family is rubella in
togaviridae
what is the MR for rubella
humans
what is the MT for measles
PTP via droplet spread and direct contact with nasopharyngeal secreiona
what is the Ro value for measles
6-7
what is the Ip for rubella
14-17 days
whats the POC for rubella
7 days before the onset of rash to 4 days or longer afterwards
what are the S&S of rubella
similar to those of measles except:
low grade fever
absence of Koplik’s spot
rash - less intensely red
where is the rubella virus developed
nasopharynx
once the rubella virus is developed in the nasopharynx where can it spread to
respiratory tract skin lymph nodes joints placenta or fetus
the rubella virus in the respiratory tract can cause what symptoms
sore throat
cough
rubella virus spread to the skin what symptoms do you experience
rashes and lesions
the rubella virus in joints what S& S occur
mild arthralgia
arthrtitis
what S & S would you expect if rubella spread to the pacenta or fetus
pacentitis
fetal damage
A woman infecd with rubella during the first 3 months of pregnancy has up toa a____% chance of giving birth to a baby with congenital rubella syndrom
90%
congenital rubella syndrome can lead to what four problems
blindness
deafness
heart disease
other birth defects
what is the causative agent for hepatitus B
hepatitits B virus
what is the major resevoir for hep B
humans esp. chronic carriers (people who have been infected greater than 6 months)
what is the mode of transmission for hep B
PTP via contact with blood and body fluids (IV drug use, needle-stick, contaminated blood supply/products, sex and congenial transmission
what is the Ro value for hep B
2.4
What is the IP for HBV
2-3 months
what is the POC for HBV
as long as the infected erson is shedding the virus
what are the two different types of HBV
acute
chronci
what percentatge of HBV infections are acute
90-95%
chronic HBV infection is most likely the resutl of
infection at/around birth
What are the S&S of HBV
fever N/V fatigue abdominal & joint pain dark urine jaundice
what are 3 complications associated with HBV
cirrhosis
liver cancer
what type of vaccine is used for HBV
recombiant DNA product containing the surface antigen HBsAg
antibodies made against the ______ confers protect against
HBsAg
does HCV have a vaccine?
no
is their treatment available for HCV
yes, sofosbuvir inhibits viral replication of the enzyme
sofosbuvir in combination with other drugs have shown high cure rates
What is the causative agent for human papilloma virus (HPV)
> 120 types
what type of virus is the HPV virus
ds DNA non-enveloped virus
what family is the HPV virus
papilomavirdae
what is the MR for HPV
humans
what is the MT for HPV
PTP via direct contact shed such as sexual intercourse for genital warts and skin to skin contact or sharing of contaminated formites
what is the Ro for HPV
0.52
what is the IP for HPV
2-3 months
what is the POC for HPV
unknown
True or False most HPV infections are symptomtatic
false they are asymptomatic
infection resolved by immune response for HPV within a year?
2 years?
one year: 70%
90% within 2 years
What are the 6 complications of HPV
cancer of: cervix vagina penis anus rectum throat
What are 4 risk factors for HPV
increasing number of lifetime sexual partners and early age of sexual activity
risk of HPV infection
immunocompormised
co-infection with chlamydia and possibly HSV
The HPV vaccine is made from
subunit vaccines made by recombinant DNA technology
What is chickenpox caused by
varicella zoster virus *VZV
shingles is considered a ____ infection of what virus
latent
varicella zoster virus
what type of virus is varicella zoster virus
ds DNA enveloped virus
what is the MR for chickenpox
humans
what is the MT of chickenpox
PTP via droplets and direct contaact with vesicular fluid of blisters on people with chickenpox or shingles
what is the Ro value for chickenpox
7-12
what is the IP for chickenpox
12-21 days
what is the POC for chickenpox
4-8 days before lesions appear and 4-5 days after crusting
what are the S&S of chickenpox
rash fever fatigue headache loos of appetite
what type of rash appears in chickenpox
itchy, fluid filled blisters that eventually turn into scabs
what are the risk factors for chicken pox
age (infants, adolescents and adults)
unvaccinated persons
immunocompromised
pregnancy
what are 4 complications of chickenpox
secondary bacterial skin infections
pneumonia
encephalitis
sepsis
Chickenpox and shingles vaccine contains
live attenuated viruses
what % of children vaccinated with the chickenpox or shingles still get breakthrough varicella
15-20%
what vaccine is used for people who are over 60 for protection against chickenpox and shingles
herpse zoster vaccine
14X more potent
what is the causative agent for rotavirus diarrhea
rotavirus
what type of virus is the rotavirus
ds DNA non-enveloped virus
what family is hte rotavirus from
reoviridae
what is the MR for rotavirus
probably humans
what is the MT for rotavirus
PTP via contact with formites including food and water contaminated feces and possibly respiratory droplets
what is the Ro value for rotavirus diarrhea
17.6-19.2
what is the IP for rotavirus
1-3 days
what is the POC for rotavirus
up to 8 days
what are the 4 signs of gastroenteritis caused by rotavirus
fever
stomach pain
vomiting and watery diarrhea
loss of appetite
what are the risk factors for rotaviru
age 3-35 months old
immunocompormised
children in care settings
adults caring for children
what seasons is it more common to contract the rotavirus
winter and spring
what are the two common complications of rotavirus
hospitalizations and severe dehydration
in canada, about ____% of all severe cases of childhood diarrhea and vomiting can be attributed to rotavirus
20
what is provided to children for free to prevent rotavirus
oral vacccine
2 attenuated live vaccines available in canada (monovalent and pentavalent)
