Enteroviruses Flashcards

1
Q

Describe the characteristics of picornaviruses

A

recall that these are small, non-enveloped, icosahedral capsid, +ve sense ssRNA viruses

they replicate in cytoplasm, the viral RNA is translated into polyprotein and cleaved into enzymes and structural proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are enteroviruses transmitted?

What time of the year would you expect a pt to present with symptoms of an enterovirus infection?

A

Transmission: Person-to-person via fecal-oral route; respiratory droplets; fomites

Seasonality: late summer/autumn in temperate climates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the pathogenesis of enterovirus

A

Enteroviruses are ingested or inhaled >> enter and replicate in oropharynx >> intestines >> regional lymph nodes >> blood stream (cause primary viremia – illness ends here if pt has immunity) >> sustained viremia (virus targets tissues) >> can disseminate to liver, brain, meninges, skin, muscle etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What conditions can occur when enteroviruses spp enter the organs shown in the schematic below?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Poliovirus targets the ___ cells of the spinal cord, causing a (asymmetric/symmetric) ___ paralysis without sensory loss

A

Poliovirus targets the anterior horn cells of the spinal cord, causing an asymmetric flaccid paralysis without sensory loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The presentation of polio includes __, intense myalgia and loss of ___

Describe the 2 phases of the disease

Which groups of muscles are mainly affected by polio?

A

Presentation: high fever, intense myalgia and loss of deep tendon reflexes

Phases: initial phase = minor illness; later phase = sudden onset of asymmetric paralysis or paresis

Muscle groups affected: proximal and lower limb muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is polio diagnosed? (5 ways)

A

Clinical presentation

Aseptic meningitis

MRI ventral horn defects

PCR

Cell culture** - best way to Dx polio (can differentiate wild type strain from vaccine strain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the Salk polio vaccine

A

K in Salk = killed vaccine (delivered by injection – gives good systemic immunity but gives less local mucosal immunity)

(inactivated killed poliovirus vaccine)

advantages: can be given to the immunocompromised since its killed, combined w other vaccine and efective in tropical areas

**used in US and other developed countries**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Contrast the Salk poliovirus vaccine with the Sabin poliovirus vaccine

A

Sabin poliovirus vaccine is oral, live attenuated so:

can give good systemic AND local immunity, and life-long immunity

but: because it’s live attenuated, the virus can revert back to a disease-causing form and cause disease in the pt; also can’t be used in the immunocompromised and has low response to type 3 polio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

3 types of paralytic poliovirus that can occur from the oral polio vaccine are ___

A

VAPP (vaccine associated paralytic polio)

VDPV (vaccine-derived poliovirus)

cVDPV (circulating VDPV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe VAPP, VDPV and cVDPV

A

VAPP – when the attenuated form converts to a mutated, disease causing form and causes paralysis

VDPV – disease occurs in someone that is unvaccinated and they somehow acquired the vaccine, which reverts back to a disease causing form

cVDPV –happening in the community and there’s more than one strain of VDPV circulating in community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which strains of poliovirus are in the oral polio vaccine vs the inactivated polio vaccine?

Which strain is currently circulating in the global community?

A

OPV: all three strains (types 1-3)

IPV: types 1 and 3 because noone’s reported a case of type 2 since the 90s

Only polio type 1 is now circulating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The most common manifestation of non-polio enterovirus infection is ___

A

Most common manifestation is asymptomatic infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name 3 types of non-polio enteroviruses

A

ECHOvirus (Enteric cytopathic human ophan viruses)

Coxsackievirus

Other enteroviruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Non polio enteroviruses can cause a variety of infections.

Name the skin infections that are seen with these viruses and which virus causes them

A

Herpangina/stomatitis: painful vesicles on soft palate & post. pharynx;

pt presents with the above and fever, headache, sore throat; caused by Coxsackie A (like A herpangina)

Hand-foot-mouth disease: vesicular stomatitis; vesicles or papules on hands, feet, groin

pt presents with above and fever, headache, sore throat; also caused by Coxsackie virus spp and Enterovirus 71, which is actually ass’d w/ outbreaks in India

Pts can also develop mobiliform rash

**note that these 2 have the same general presentation but what’s different is where the vesicles are on the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What CNS dysfunctions can result from infection with non-polio enterovirus infection?

A

Aseptic meningitis

Encephalitis

Poliomyelitis-like syndrome

Others: Guillain Barré, transverse myelitis

17
Q

What are the muscle infections that can occur with non-poliovirus enterovirus infection?

A

Pleurodynia

Myositis

Myopericarditis

18
Q

Name the effect of non-polio enterovirus infection of the eye

A

Acute hemorrhagic conjunctivitis

19
Q

Which condition is illustrated below?

A

hand foot and mouth disease caused by coxsackie A virus

20
Q

The most common cause of meningitis in adults and kids is ___ and infection with this is usually asymptomatic but folks recover usually with no defects

A

Entetovirus (all of them can cause meningitis)

21
Q

Describe the lab findings for a pt with aseptic meningitis

A

Mild increase in white cells in CSF

Mild increase in protein

Normal glucose

Negative gram stain (aseptic)

22
Q

Non polio enterovirus infection of the chest wall causes __ which presents as a sharp, spasmodic pain in chest wall or abdomen with a fever

Which coxsackie virus can cause this?

A

Pleurodynia

Coxsackie B 1-5

23
Q

Describe the presentation of myositis. Which Coxsackie virus is implicated in this syndrome?

A

Fever, chills, focal (usu. thighs) or generalized muscle pain

Myoglobinemia/uria, elevated muscle enzymes

**

Coxsackie B 1-5

**seems like Coxsackie B1-5 cause anything muscle related**

24
Q

What condition arises from nonpolio enterovirus infection of the heart muscle?

A

Myopericarditis (inflammation of cardiac muscle)

25
What condition is depicted below and which virus causes it?
Acute Hemorrhagic Conjunctivitis can be caused by Coxsackie A24 and Enterovirus 70 but can also be caused by adenovirus, etc
26
Describe the manifestation of neonatal infection with nonpolio enterovirus
Basically its a sepsis like syndrome that's transmitted from mother to child \*\* •Onset in first 10 days of life; multisystem: sepsis-like: (hypotension) Myocarditis Encephalitis Hepatitis Pneumonia Often fatal (no Rx, often just supportive care) Echoviruses or Coxsackie B
27
The most common test to Dx non-polio enterovirus infection is:
PCR Other methods: isolate virus from infection site; stool/respiratory tract isolation; serology
28
How do you treat nonpolio entervirus infections?
For the most part, treatment is supportive care then sometimes IVIG for myopericarditis and the immunocompromised