Gastrointestinal Viruses Flashcards
Rotavirus
family —
most important cause of gastroenteritis among —
family retroviridae
infants and children <2 yrs old
Rotavirus
has a ssRNA anf the major cause of diarrheal illness in human infants and young animals like piglets and calves
true or false
false.
double stranded RNA icosahedral non-enveloped
classified into 5 species (A-E) + 2 tentative species (F-G)
Rotavirus
most frequent human pathogens which the only group that causes human disease
group A rotaviruses
Rotavirus
outer capsid proteins — carry epitopes important in neutralizing activitiy with — glycoprotein being the predominant antigen.
VP4 & VP7
VP7 - predominant antigen
Rotavirus
implicated in large outbreaks of severe gastroenteritis in adults in China
group B rotaviruses
rotavirus infections usually predominant during the winter season
Rotavirus
in retrovirus, genome codes for — and —
6 proteins: VP 1, 2, 3, 4, 6, 7
6 non-structural p: NSP 1-6
once in small intestine, the virus undergoes a change and becomes infective to th villi.
Rotavirus
rotaviruses infect cells in the — and multiply into cytoplasm. they multiply in the cytoplasm of enterocytes and damage their transport mechanisms.
infect cells in the villi of small infestine (gastric and colonic mucosa are spared)
Rotavirus
viral enterotoxin and induces secretion by triggering signal transduction pathway, in which those damage cells in the lumen of intestine will be release in stool
NSP 4
Rotavirus
Viral excretion usually last —
incubation period: —
viral excretion: 2-13 days
IP: 1-3 days
Rotavirus
enumerate the symptoms
- watery diarrhea
- fever
- abdominal pain
- vomiting (rapid loss of fluid leading to dehydration)
Rotavirus
diarrhea may be due to — as damaged cells on villi are replaced by nonabsorbing immature crypt cells
impaired sodium and glucose absorption
Rotavirus
this causes loss of electrolytes
nonabsorbing immature crypt cells
severe loss of electrolytes and fluids may be fatal unless it will be treated in infants and children.
Rotavirus
enumerate the rotavirus vaccines
what is the mechanism of the vaccine?
- oral live attenuated rhesus-based
- oral bovine-based
bovine-based was introduced on 2006
it delays the onset of the rotaviruses season
Rotavirus
the virus from the — is demonstrated by —
what is the sample needed?
sample: stool
demonstrated by enzyme immunoassay of real time PCR
PCR - most sensitive detection method
Rotavirus
management & prevention
IV fluids to correct the loss of water and electrolytes
replacement of fluids and restoration of electrolye balance
Calciviruses
family —
important agents of —- in humans
family CALCIVIRIDAE
important agents of viral gastroenteritis
Calciviruses
enumerate the 4 genera
- norovirus - norwalk viruses
- sapovirus - sapporo-like virus
- lagovirus - rabbit hemorrhagic disease
- vesivirus - vesicular exanthem virus of swine, feline calicivirus, and marine viruses
norwalk viruses is the most significant member
Calciviruses
small single-stranded RNA, round viruses of 27-30 nm in diameter. common cause of infectious gastroenteritis
incubation period: ?
norwalk virus
IP: 24-48 hrs
onset is rapid, and the clinical course is bried, lasting 12-60 hours.
Calciviruses
MOT of norwalk virus
- foodborne (common)
- waterborne
- person-person transmission
Calciviruses
all of the ff are the symptoms of norwalk virus, except:
- diarrhea
- nausea
- vomiting
- low-grade fever
- abdominal cramps
- headache
- malaise
none
all are included so FAMILIARIZE!
Calciviruses
genera that cannot be detected in culture and it relies on immune EM and RT PCR
Norovirus and Sapovirus
Norwalk - outbreak during 1968 in Norwalk, Ohayo
Sapovirus - discovered in Sapporo Japan, 1977
Calciviruses
based on recombinant virus-like particles that can detect antibody responses, with a fourfold sapovirus greater rise in IgG antibody titer
— is the indicative of a recent infection
ELISA immunoassays
convalescent-phase sera - indicative of a recent infection
Calciviruses
most used diagnostic test/assay for Norovirus bcos it detects — and can be used to detect stools, vomit and environmental samples
RT-PCR
detects viral RNA
Calciviruses
best sample to detect Norovirus. this should be collected from patients with acute illness or —
STOOL
patient with acute illness or within 48-72 hrs after onset of the symptoms
stool can be collected from 2 weeks after the recovery
Calciviruses
small virus that can range from 32-35 nm in diameter. it causes diarrheagenic viruses distinguished by a —
SAPOVIRUS
distinguished by a cup-shaped morphology
Calciviruses
for sapovirus, there is vaccine available and the treatment is supported based on the clinical symptoms.
true or false
FALSE.
there is NO VACCINE!
Calciviruses - S
prevention control
enumerate
- containment and disindection of soiled areas
- careful processing of food and education of food handlers
- purification of drinking water and swimming pool
handwashing is the most important method to prevent transmission
Astrovirus
family: —
with a — morphology in EM and it contains single-stranded RNA
FAMILY ASTROVIRIDAE
star-like morphology
Astrovirus
MOT
fecal-oral route through contaminated food or water
Astrovirus
recognized as pathogens for —
- infants
- children
- institutionalized patients
- immunocompromised persons
no.1 gastroenteritis in adults
Astrovirus
Astroviruses cause diarrheal illness and may be shed in extraordinarily large quantities in feces.
Astrovirus
all of the ff are the symptoms, except:
- diarrhea
- headache
- nausea
- vomiting
- low-grade fever
vomiting
Astrovirus
used for diagnosis (2)
Electron M. & Immune EM
small positive single-strand viruses and do not have lipid membrane, non-enveloped with icosahedral capsids. it is largest family in terms of number of genera.
nucleocapsids is 30 nm naked ssRNA
PICORNAVIRIDAE
Picornaviridae
in replication, it is usually 5-10 hours but approx. it takes 8 hours to replicate
true or false
TRUE.
pico means small
Picornaviridae
enumerate the genera/s
- enterovirus
- rhinovirus
- hepatovirus
- parechovirus
- aphtovirus
- cardiovirus
first four (HERP) are the human pathogenic genera
Picornaviridae
genera of foot-and-mouth disease viruses
Aphthovirus
Picornaviridae
genus Enterovirus include —
Polioviruses and Coxsackieviruses
Enteroviruses
this enterovirus causes paralytic poliomyelitis
Polioviruses 1-3
Enteroviruses
this enterovirus has 3 serotypes and causes superficial rashes in the foot, hand, and mouth
Coxsackieviruses A1-A3
Enteroviruses
this enterovirus has 6 serotypes internal symptoms
Coxsackieviruses B1-B6
Enteroviruses
this refers to an upper respiratory tract infection, fever, and sudden sharp pain in the intercostal muscle
BORNHOLM DISEASE
Enteroviruses
HEV A, HEV B, HEV, C, HEV D
Enteroviruses 68-104
Enteroviruses
echoviruses has — serotypes
33 serotypes
Enteroviruses
parechovirus has — serotypes
4 serotypes
Enteroviruses
MOT
- fecal-oral
- respiratory drop/aerosol inhalation
- fomite
Enteroviruses
portal of entry
- mouth/nose
- lymphoid tissue (pharynz and gut)
- initially will replicate > particles
- will go to the bloodstream viremia
- target organs of infection/disease spinal cord, heart, skin
Enteroviruses
vaccines are available for all enteroviruses.
true or false
FALSE.
no vaccines are available except for POLIO
endemic worldwide, common infection in children bcos of poor hygiene
enterovirus
Enteroviruses
incubation period and symptoms
enumerate
IP: 3 - 35 days
symptoms: mild nausea and diarrhea except for neonates
neonates can be severe bcos of the immaturity of their immune system
Enteroviruses
fever of unknown origin, aseptic meningitis, paralysis, sepsis-like illness, myopericarditis, pleurodynia
this is associated with infections of —
Coxsackie type B
Enteroviruses
conjunctivitis exanthemas is caused by —
enterovirus serotype 71
Enteroviruses
this has also been implicated in early on-set diabetes, cardiomyopathy, and fetal malformations
true or false
TRUE
portal or entry: alimentary or via mouth/nose
can result in the virus spreading from these locations to the spinal cord, heart, and skin. this refers to —
viremia
Enteroviruses
specimens of choice (5)
- stool (prolonged period of infection)
- rectal swabs
- throat swabs (replication)
- washings
- CSF
Enteroviruses
this is associated with acute hemorrhagic conjunctivitis
what could be the specimen of choice?
Enterovirus 70
specimen of choice: conjunctival swabs and tears
this virus has no group antigen so it is being identified individually by serum neutralization test
enterovirus
Enteroviruses
for specific confirmation (2)
- cell culture neutralization
- type-specific antisera
Enteroviruses
diagnosis is made by —
nucleic acid amplification (PCR)
CSF - PCR
Enteroviruses
used to detect presence of acute infection of enterovirus
ELISA: IgM (antibody titer)
flaccid muscle paralysis, this refers to —
paralytic poliomyelitis
Polio
this is a type of neurological conditions characterized by —
paralysis and reduced muscle tone
Polio
most diseases are from —
incubation period ?
Polio type 1
IP: 7-14 days
Polio
infection is restricted to the gastrointestinal tract and it is characterized by mild fever with diarrhea to flaccid paralysis. this refers to —
Asymptomatic polio infection
most common cases of infection
Polio
minor illness, first asymptomatic result is febrile disease, general malaise with vomiting and sore throat
Abortive poliomyelitis
Polio
mild diseases/infection (2)
Asymptomatic & Abortive
Polio
this disease occurs during the 1st week of infection of abortive polio
febrile disease
Polio
stiff neck and vomiting as a result of muscle spasm. it may progress to the brain and may upgrade to infect meninges > aseptic meningitis
this refers to —
non-paralytic polio
small percentage of this disease may advance to paralysis
Polio
resulting from a lower motor neuron damage, this refers to —
classic paralysis
Polio
arrange in order:
- affects anterior horn cells of the SN to the brain
- affects motor neurons/cortex of the brain
- spreads from the blood
- results to spinal paralysis/bulbar p
- spreads from the blood
- affects anterior horn cells of the SN to the brain
- affects motor neurons/cortex of the brain
- results to spinal paralysis/bulbar p
Polio
paralysis is more pronounced in very young and very old patients
t or f
true
Polio
complete flaccid paralyssi since one or more limbs are affected
spinal paralysis
Polio
affects the cranial nerves & respiratory
bulbar paralysis
Polio
result of physiologic and aging changes in a paralytic patient that already burdened by the loss of neuromuscular functions
progressive post-poliomyelosisits muscle atrophy
Polio
this is observed in individual decades after the experience of paralytic polio
muscle wasting
Polio
portal of entry: ?
primary multiplication site: ?
Portal of entry: mouth
multiplication site: oropharynx or intestine
Polio
virus can bee seen in — of patients with non paralytic polio and the virus invades a certain type of —
seen in blood of patients
invades in nerve cells
Polio
in the process of intracellular multiplication, it may damage or completely destroy these cells resulting in a —
loss of neuromuscular functions
Polio
Jonas Salk discovered what type of vaccine?
Intramuscular Polio Vaccine in U.S. since 2000
Polio
CDC recommended that children will get 4 doses of polio vaccine: 1 dose of each ff stages —
- 2 mnths old
- 4 mnths old
- 6-18 mnths old
- 4-6 yrs old
Polio
he discovered the Oral Polio Vaccine which is a live attenuated vaccine
Albert Sabin
OPV contains polio virus 1, 2, 3 serotypes
Polio
formalinized vaccine (Salk) is prepared form virus grown in —
monkey kidney cultures
Polio
killed virus vaccine induces humoral antibodies which induces local intestinal immunity.
t or f
FALSE
does not induce so that virus is still able to multiply in the gut
enteric cytopathogenic human orphan virus, this refers to —
Echoviruses
Echovirus
this infect human enteric tract associated with — (3)
- aseptic meningitis
- rashes
- infantile diarrhea
this has been isolated from patients with meningitis, encephalitis, and paralysis resembling poliomyelitis
enterovirus 71
enterovirus 71 causes the —
hand-foot-and-mouth disease
enterovirus 71
enumerate the symptoms
fever and blisters on the hands, palate, and feet