Naked RNA Viruses

picornaviruses

large virus family - very small virus

Serum neutralization

RNA, small, naked, resistant

How can picornaviruses be described

naked icosahedral capsid

picornaviruses shape?

positive sense ssRNA

what do picornaviruses contain?

persist in the environment

Picornaviruses are very tough and resistant viruses, that can ____ __ __ _____

enteroviruses and rhinoviruses

Picornaviruses include two major groups of human pathogens:

hepatitis A virus

Moderately common picornaviruses associated with human illness:

VP1, VP2, VP3

where are the major antibody binding sites on typical picornavirus?

human enterovirus group

Humans are the only known reservoir for members of the:

shed

enteroviruses ____ for longer periods of time in stools

fecal contamination

what is the usual avenue of enterovirus spread?

polioviruses

causative agent of polio/poliomyelitis

acute

what kind of infectious disease is poliovirus?

CNS - destruction of motor neurons

what does poliovirus affect?

flaccid paralysis

what does poliovirus result in?

typical enterovirus stucture

what structure does polio have?

tissue range

poliovirus has a narrow ___ ____

oropharnyx and tonsils

where is the initial poliovirus infection?

blood and cross BBB

where does the poliovirus travel through

skeletal nerves to the brain

where can poliovirus also travel through?

asymptomatic limited to the oropharynx

most common type of infection of poliovirus

Abortive poliomyelitis

develop 3-4 days after infection - fever, headache, malaise, sore throat and vomiting

90

approximately what percentage is asymptomatic in poliovirus cases

direct pathogenesis

what pathogenesis does paralytic polio use?

civilized (vaccinated) world

paralytic polio is rarely seen in

Asymmetical flaccid paralysis with no loss of sensory perception

typical clinical presentation of paralytic polio

anterior horn cells of spinal cord

where does paralytic polio virus travel

postpolio syndrome

Late sequela, 30 - 40 years, after initial infection - Seen in 20 - 80 % of patients who suffer deterioration of originally affected muscles

virus

within postpolio syndrome there is no what present

original destruction of neurons

postpolio syndrome mechanism

lymphatic pleocytosis

with poliovirus, the CSF has ____ ____

neutrophils

within poliovirus there are no

antibody

polioviruses are ____ mediated

passive immunity

within poliovirus, ____ ______ is transferred from mother to offspring

pleconaril

treatment drug for poliovirus?

blocks penetration of virus

how does pleconaril work to treat polio

strains of poliovirus

Killed vaccine incorporates all three ____ ____ ____

IPV and OPV

_____ _ ____ used in mass immunization programs in areas of high poliomyelitis

Coxsackieviruses

large subgroup of the enteroviruses

Coxsackie "A" viruses

associated with vesicular lesions

Coxsackie "B" (body)

associated with myocarditis and pleurodynia (devil's grip)

echoviruses

Enteric cytopathic human orphan

alimentary tract

Primary anatomic site of multiplication of echoviruses

typical enterovirus structure

Coxsackieviruses and Echoviruses structure

natural infection in humans

Coxsackieviruses and Echoviruses can be recovered from the blood in the early stages of

5-6 weeks

Coxsackieviruses and Echoviruses detected in the throat for a few days early in the infection and in thestools for up to

herpangina

An oral vesicular disease caused by Coxsackievirus type A

hand foot and mouth disease

First lesions (oral ulcerations and vesicular rashes) appear in the oral cavity - later small lesions appear on hands, feet and mouth - resolves in a few days & can lead to neurological complications and infant deaths

Coxsackievirus A16 (also Human Enterovirus-71)

what virus causes hand foot and mouth disease?

viral meningitis

acute febrile illness accompanied by rash or petechiae

aseptic meningitis

viral meningitis is also called

Coxsackievirus A or B and some Echoviruses

what is viral meningitis caused by?

low neutrophil count in CSF

viral meningitis can be differentiated from bacteria meningitis by

feces and throat

viral meningitis can be isolated from where

Viral Exanthems

non infectious rash, fever and dehydration, non scarring rash

myopericarditis

Cox B is a major cause, in infants it presents with fever and heart failure - MORTALITY IS HIGH

no effective vaccine as there are too many serotypes

treatment for Coxsackieviruses and Echoviruses

flaccid paralysis

for Coxsackieviruses and Echoviruses HEV-71 is licensed in china but it can cause what in children:

HEV-71

Outbreaks of hand-foot-and-mouth disease, characterized by oral ulcerations and vesicular rashes, occur and may result in infant deaths. The disease is caused by:

rhinovirus

common cold virus - mild upper respiratory illness

nasopharyngeal secretions, throat and oral secretions

where is rhinovirus isolated from

asthma exacerbations

rhinovirus can also cause

acid

rhinovirus is ____ labile (unlike other enterovisuse)

pH 6

rhinoviruses inactivated at

ph 3

rapid and complete inactivation of rhinovirus at

the stomach

rhinovirus cannot survive the

indirect pathogenesis

what type of pathogenesis is rhinoviruses?

interferon and cytokines

rhinoviruses have flu-like symptoms due to

enterovirus, coronavirus, adenovirus

rhinoviruses are not distinguishable from common cold caused by:

remain hydrated

supportive therapy to treat symptoms of rhinovirus?

antiviral

there is no good ______ therapy for rhinovirus

calicivirus

positve sense - single stranded RNA - not segmented

gastroenteritis

what does calicivirus cause in humans?

norovirus, noro-like virus

viruses of medical importance (for humans) from calicivirus

small round gastroenteritis viruses

what are noroviruses also called:

winter vomiting disease

what is the causative agent of noroviruses?

picornaviruses

noroviruses are slightly larger than

fecal oral mode

what is the mode of transmission of noroviruses?

cellular receptors involved in norovirus

Histocompatibility blood group antigens that are expressed on the mucosal epithelia of the digestive tract.

GI, GII, GIV

Three genogroups are associated with human gastroenteritis designated:

brush border epithelial cells in the intestine

what do noroviruses disrupt the function of?

proper absorption of water and nutrients causing gastroenteritis

what do noroviruses block and cause?

travelers diarrhea

norovirus is a common source of?

single source transmissions (food, water, shellfish)

norovirus cause outbreak as

highly contagious

norovirus is

Norovirus

What virus cannot be cultivated

antibody

norovirus can be directly detected in stool by ______

IEM

Mix anti-viral antibody with stool sample & allow antibody viral complexes to form

no

are there any vaccines or antiviral available for norovirus?

the large number of rhinovirus serotypes

The major barrier to the control of rhinovirus upper respiratory infections through vaccination is: