PICORNAVIRIDAE Flashcards
Enveloped; icosahedral, [?]-stranded
single
Small (from the Italian word [?], meaning small)
piccolo
Diameter:
27–30 nm
Non-enveloped
Capsid: naked icosahedral made up of [?] protein subunits
60
Genome: single linear molecule of
single-stranded RNA
First animal virus to be purified and obtained in crystalline form
POLIO VIRUS
Diameter: 27 nm
POLIO VIRUS
Virion: 60 subunits, each consisting of four viral proteins (VP1–VP4)
POLIO VIRUS
: major antigenic site for combination with typespecific neutralizing antibodies
POLIO VIRUS
Viral protein VP1
Viral genome: single-stranded positive-sense RNA
POLIO VIRUS
Absorbs only to the intestinal epithelial cells and motor neuron cells of the CNS
POLIO VIRUS
small nonenveloped viruses with an icosahedral configuration
COXSACKIE A AND B VIRUS
: 23 serotypes 124 (23 is missing)
coxsackievirus A
: 6 serotypes 1–6
coxsackievirus B
Small nonenveloped viruses with an icosahedral configuration
COXSACKIE
ECHO
Consisting of 29 serotypes
Optimal growth: pH 3-10
ECHOVIRUS
Resistant to ether and alcohol
ECHOVIRUS
Causative agents in outbreaks of aseptic meningitis
ECHOVIRUS
Epidemics of viral disorders with fever and rash in young children
ECHOVIRUS
MOT:
fecal oral route
aerosol inhalation
fomites
POLIO VIRUS
Body: Multiplies in the tonsils and Peyer’s patch of the ileum → Spreads to regional lymph nodes and enters the blood (primary viremia) → Multiplication of virus in the reticuloendothelial cells and invades the blood stream again (secondary viremia) → Crosses the blood–brain barrier → Destruction of motor neurons (paralysis of the muscles)
POLIO VIRUS
Generally initiated in the gastrointestinal tract
COXSACKIE A AND B VIRUS
MOT: fecal-oral transmission
COXSACKIE A AND B VIRUS
Prevalence: Poor sanitation, low socioeconomic status, crowded living conditions, immunocompromised patients
POLIO VIRUS
Mainly affects children
POLIO VIRUS
Major public health problem in developing countries
POLIO VIRUS
Endemic (2003): Afghanistan, Egypt, Niger, Nigeria, Pakistan, and India
POLIO VIRUS
Epidemic and endemic patterns
COXSACKIE A AND B VIRUS
ECHOVIRUS
Recovered much more frequently in the summer and early fall
COXSACKIE A AND B VIRUS
ENTERO
Age: Young children are the reservoir of the virus
COXSACKIE A AND B VIRUS
Epidemic and endemic patterns
COCX
ECHOVIRUS
Infection rates vary with the season, geography, and the age and socioeconomic status of the population sampled
ECHOVIRUS
ECHOVIRUS
was predominant
Echovirus 9
Age: children younger than 15 years (threequarters) – WHO
ECHOVIRUS
Sex: Male (50%)
ECHOVIRUS
Stable (does not withstand freeze-drying)
POLIO VIRUS
Inactivated at 55°C for 30 minutes (sensitive to heat)
POLIO VIRUS
Survive in feces for days to several weeks at room temperature, for months at 4°C, for years at -20°C
POLIO VIRUS
Incubation Period: 3 to 6 days (non-paralytic), 7 to 21 days (paralytic)
POLIO VIRUS
Acute infections: infections of the oropharynx and the gut
POLIO VIRUS
Chronic infections: viraemia and spread of infection to CNS
POLIO VIRUS
Incubation period: 10-14 days
COXSACKIE A AND B VIRUS
Symptoms:
- Fever
- Mouth Sores
- Sore throat
COXSACKIE A AND B VIRUS
Incubation period: 2-7 days
ECHOVIRUS
Symptoms:
- Croup
- Mouth Sores
- Skin rashes
- Sore throat
ECHOVIRUS
: appear within a week of infection, persist for nearly 6 months
Serum IgM antibodies
: persist lifelong
IgG antibodies
: provide mucosal immunity against the virus, protects the infants from infection (breast milk)
Secretary IgA antibodies
Isolation of virus: throat swabs, stools, rectal swabs, CSF
ECHOVIRUS
Immunofluorescence assay and ELISA
ECHOVIRUS
Viral cultivation: cell cultures
ECHOVIRUS
Reverse Transcription PCR (RT-PCR)
ECHOVIRUS
Congenital and neonatal diseases, myocarditis/pericarditis, febrile illness with rash, meningitis
ECHOVIRUS
90% or 90-95%
- Asymptomatic polio
Caused of viral infection to the oropharynx and intestine
- Asymptomatic polio
5%
- Minor Polio or Abortive Polio
Temporary fever, headache, sore throat, loss of appetite, vomiting, abdominal pain
- Minor Polio or Abortive Polio
Duration: 5 days
- Minor Polio or Abortive Polio
3% or 1-2%
- Non-paralytic Polio (Aseptic meningitis)
Viruses invading the CNS and meninges
- Non-paralytic Polio (Aseptic meningitis)
Symptoms: muscle spasms, back pain (Similar to abortive polio but more intense)
- Non-paralytic Polio (Aseptic meningitis)
0.1–2%
- Paralytic Polio
Paralytic poliomyelitis
- Paralytic Polio
Bulbar poliomyelitis
- Paralytic Polio
Viruses invade the spinal cord and motor cortex of the brain
limiting nerve impulse conduction (paralysis)
Paralytic poliomyelitis
Brain stem and medulla are infected
Bulbar poliomyelitis
Paralysis of limbs and respiratory muscles
Bulbar poliomyelitis
20-80%
- Postpolio syndrome (30 – 40 years after)
Crippling deterioration of the affected muscles due to age-related aggravation of nerve damage
- Postpolio syndrome (30 – 40 years after)
Acute aseptic meningitis
COXSACKIE A AND B VIRUS
Herpangina
COXSACKIE A AND B VIRUS
Hand-foot-and-mouth disease
COXSACKIE A AND B VIRUS
Good personal and hospital hygiene, proper sanitation
POLIO VIRUS
Inactivated polio vaccine (IPV) by Jonas Salk (intramuscular)
POLIO VIRUS
Oral polio vaccine (OPV) by Albert Sabin
POLIO VIRUS
Handwashing
COXSACKIE A AND B VIRUS
Currently, no vaccines are available
COXSACKIE A AND B VIRUS
ENTERO
RHINO
Administration of immune globulin for infants
ECHOVIRUS
No antiviral drugs
ECHOVIRUS
Also known as Hepatitis A virus
ENTEROVIRUSES
Small, approximately 25-30 nm in diameter
ENTEROVIRUSES
Icosahedral in shape
ENTEROVIRUSES
Non-enveloped
ENTEROVIRUSES
HEPATITIS A
Picornaviridae
HEPATITIS A
Single-stranded RNA genome
HEPATITIS A
small, non-enveloped icosahedral viruses, single-stranded RNA virus.
RHINOVIRUS
high genetic diversity, with more than 150 serotypes.
RHINOVIRUS
Sensitive to acid pH
RHINOVIRUS
Optimal growth at 33 C in pH 7
RHINOVIRUS
Causes mild nausea and diarrhea in adults
Diseases can be more severe in neonate
ENTEROVIRUS
MOT
-alimentary canal
-aerosol inhalation
-fomites
-fecal-oral
-virus can spread to the spinal cord, heart and skin
ENTEROVIRUSES
Targets the liver, causing inflammation.
HEPATITIS A
MOT
-fecal-oral route, entering the body through contaminated food or water
HEPATITIS A
primarily infect the upper respiratory tract
RHINOVIRUS
MOT
respiratory secretions, direct contact thru the nasopharynx
RHINOVIRUS
Host Defenses:
-Interferon
-gastric acidity
-temperature
RHINOVIRUS
Occurs during summer and early fall
ENTEROVIRUSES
More prevalent in areas with poor sanitation
ENTEROVIRUSES
Endemic worldwide
ENTEROVIRUSES
Global distribution
HEPATITIS A
Poor sanitation areas are more susceptible to outbreaks
HEPATITIS A
spread primarily through respiratory droplets
RHINOVIRUS
most common in the fall and spring, but they can occur throughout the year
RHINOVIRUS
Major cause of common cold (55% cases)
RHINOVIRUS
Cultured from pharyngeal specimens (1 to 2 weeks)
ENTEROVIRUSES
Isolated from feces for as long as 6 weeks
ENTEROVIRUSES
Specimens from the throat, feces, rectum, CSF, conjunctiva
ENTEROVIRUSES
Incubation period: few weeks
HEPATITIS A
Symptoms: fever, fatigue, nausea, abdominal pain, jaundice
HEPATITIS A
Asymptomatic
HEPATITIS A
Mild, self-limited condition to a more severe form
HEPATITIS A
Mild illness with symptoms appearing 2-3 days post-exposure
RHINOVIRUS
The incubation period for rhinovirus infection typically ranges from 1 to 3 days.
RHINOVIRUS
Symptoms:
o Profuse watery nasal discharge
o Headache
o malaise
o sneezing
o congestion
o sore throat
o cough
RHINOVIRUS
Serologic testing for the presence of IgM antibody with ELISA can be used for suspect cases of infection and has been used as an epidemiologic tool in outbreaks.
ENTEROVIRUSES
Lifelong immunity
HEPATITIS A
Not susceptible to reinfection
HEPATITIS A
Serological tests may detect antibodies
RHINOVIRUS
IgM antibodies are typically detectable within 1-2 weeks of infection
RHINOVIRUS
IgG antibodies are typically detectable for several months or years
RHINOVIRUS
Hepatitis with short incubation period
ENTEROVIRUSES
are responsible for a variety of diseases and conditions, including
Paralytic polio
Aseptic meningitis
Encephalitis
ENTEROVIRUSES
o most common among infants and children
Aseptic meningitis
o symptoms: headache, fever, nuchal rigidity
Aseptic meningitis
o patients may appear lethargic or obtunded
Aseptic meningitis
paralytic poliomyelitis
ENTEROVIRUSES
encephalitis
ENTEROVIRUSES
In addition to respiratory illness: myocarditis, and pericarditis
ENTEROVIRUSES
Common cold
RHINOVIRUS
Respiratory illnesses including otitis media, sinusitis, Exacerbations of asthma and COPD
RHINOVIRUS
Ensure safe water supply, proper waste disposal
ENTEROVIRUSES
No vaccines are availablem
ENTEROVIRUSES
Good personal and hospital hygiene and proper sanitation
ENTEROVIRUSES
Prevention:
Vaccination
HEPATITIS A
Prevention:
Effective and long-lasting protection
HEPATITIS A
Prevention:
Practicing good hygiene, especially proper handwashing
HEPATITIS A
Risk Groups: Travelers to regions with high endemicity, men who have sex with men, people who use injection or non-injection drugs
HEPATITIS A
Public Health Measures: Vaccination campaigns, improved sanitation, education on proper hygiene practices to reduce the risk of transmission
HEPATITIS A
No vaccine available
RHINOVIRUS
Hand hygiene to prevent spread
RHINOVIRUS
Respiratory etiquette
RHINOVIRUS
