True or false? Polio virus a is an enterovirus b is mainly transmitted

True or false? Polio virus a) is an enterovirus b) is mainly transmitted by respiratory droplets c) can cause aseptic meningitis d) is an important cause of gastroenteritis in children e) causes the disease by producing toxin

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Here is the full, textbook-verified breakdown:

Poliovirus - True or False

a) Is an enterovirus - TRUE

Poliovirus is a spherical, unencapsulated RNA virus belonging to the Enterovirus genus, family Picornaviridae. It shares this genus with coxsackieviruses, echoviruses, and others. (Robbins & Cotran Pathologic Basis of Disease; Medical Microbiology 9e)

b) Is mainly transmitted by respiratory droplets - FALSE

Poliovirus is transmitted primarily by the fecal-oral route. Pharyngeal (respiratory) secretions can play a secondary role, but this is far less common. As Robbins states: "Poliovirus, like other enteroviruses, is transmitted by the fecal-oral route or, less often, by pharyngeal secretions." (Robbins & Cotran)

c) Can cause aseptic meningitis - TRUE

Poliovirus belongs to the enterovirus group, and enteroviruses as a class are the leading cause of aseptic (viral/non-bacterial) meningitis. Poliovirus itself can cause a non-paralytic form of polio that presents as aseptic meningitis. (Harrison's Principles of Internal Medicine 22e)

d) Is an important cause of gastroenteritis in children - FALSE

Poliovirus is not a recognized important cause of gastroenteritis. While it replicates in the gut and is shed in stool, it does not cause diarrheal illness. Other enteroviruses (e.g., coxsackievirus A) and unrelated viruses (rotavirus, norovirus, adenovirus 40/41) are the main viral causes of childhood gastroenteritis. (Robbins & Cotran)

e) Causes disease by producing a toxin - FALSE

Poliovirus causes disease through direct cytopathic destruction of neurons - specifically the motor neurons of the anterior horn of the spinal cord and the brainstem. It does not produce any exotoxin or endotoxin. The virus binds CD155 on cell surfaces, enters, replicates, and lyses the cell. (Robbins & Cotran; Harrison's)

Summary Table

Statement	Verdict	Key Point
a) Is an enterovirus	TRUE	Genus Enterovirus, family Picornaviridae
b) Mainly respiratory droplet transmission	FALSE	Fecal-oral is primary route
c) Can cause aseptic meningitis	TRUE	Non-paralytic polio presents as aseptic meningitis
d) Important cause of gastroenteritis in children	FALSE	Replicates in gut but does not cause diarrhea
e) Causes disease by toxin production	FALSE	Direct cytopathic destruction of motor neurons

Poliomyelitis can be cured by early antiviral treatment

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FALSE - Poliomyelitis cannot be cured by early antiviral treatment

Multiple authoritative textbooks are unambiguous on this:

"No specific therapy has been shown to be of proven benefit"

Bradley and Daroff's Neurology in Clinical Practice

"No specific therapy exists for the treatment of enteroviral infections, but vaccines are effective for the prevention of poliovirus and enterovirus A71."

Goldman-Cecil Medicine

Why there is no antiviral cure

No approved antiviral exists - Unlike influenza (oseltamivir) or herpesviruses (acyclovir), there is no licensed antiviral drug effective against poliovirus.
Timing problem - By the time paralysis is clinically apparent, the virus has already caused irreversible destruction of anterior horn motor neurons. The neurological damage is established before treatment could theoretically begin.
Mechanism of injury is cytopathic - Poliovirus directly lyses motor neurons. Dead neurons cannot regenerate, so even eliminating the virus after the fact cannot restore lost function.
Pleconaril - This broad-spectrum antipicornavirus drug was investigated for enterovirus infections but was never approved, and there is no evidence it prevents paralysis in established polio.

What management actually involves

Approach	Examples
Supportive care	Bed rest, analgesia, fever management
Respiratory support	Mechanical ventilation in bulbar/respiratory polio
Rehabilitation	Physiotherapy, orthoses, assistive devices
Prevention	IPV (injected) or OPV (oral) vaccine - the only effective strategy

The key teaching point

Prevention through vaccination is the only effective intervention. Once paralytic poliomyelitis develops, the damage is permanent. This is why the global polio eradication program relies entirely on vaccination, not treatment.

Hand, foot and mouth disease a) is a zoonotic infection b) commonly occurs in elderly c) is commonly caused by Coxsackie A virus d) can be transmitted by indirect contact through contaminated surfaces and objects e) infection can be prevented by vaccination

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hand foot mouth disease zoonotic transmission fomites vaccine EV71 overview

Here is the full, evidence-based breakdown:

Hand, Foot and Mouth Disease (HFMD) - True or False

a) Is a zoonotic infection - FALSE

HFMD is caused by human enteroviruses (primarily Coxsackievirus A16 and Enterovirus A71) and is strictly a human-to-human infection. There is no animal reservoir and no animal-to-human transmission. It is not zoonotic in any sense. (Tintinalli's Emergency Medicine; StatPearls/NCBI)

b) Commonly occurs in the elderly - FALSE

HFMD predominantly affects infants and children under 5 years old. As the Texas DSHS notes: "HFMD is a common illness that usually affects infants and children younger than 5 years old." Older children and adults can occasionally be affected (particularly with newer strains like CVA6), but it is emphatically not a disease of the elderly.

c) Is commonly caused by Coxsackievirus A - TRUE

Coxsackievirus A16 (CVA16) is the classic and most common cause of HFMD worldwide. Coxsackievirus A6 (CVA6) has emerged as a common cause of "atypical HFMD" in recent years. Enterovirus A71 (EV-A71) causes a more severe form seen especially in Southeast Asia. (Andrews' Diseases of the Skin; Tintinalli's; StatPearls)

d) Can be transmitted by indirect contact through contaminated surfaces and objects - TRUE

Enteroviruses are hardy viruses that survive on surfaces (fomites). HFMD spreads via:

Fecal-oral route
Respiratory droplets / oral secretions
Direct contact with blister fluid
Indirect contact via contaminated surfaces and objects (doorknobs, toys, etc.)

The CDC explicitly states transmission occurs by "touching objects and surfaces that have the virus on them, like doorknobs or toys." (CDC; Texas DSHS)

e) Infection can be prevented by vaccination - TRUE (with important context)

This is true, but geographically limited:

China approved the first inactivated EV-A71 vaccine in December 2015, with demonstrated efficacy of ~94.7% in clinical trials (n = 10,077)
This vaccine is approved and in widespread use in China
No vaccine is currently approved in the United States or most Western countries (CDC, 2024)
There is no vaccine covering Coxsackievirus A16 yet

For exam purposes in most contexts (e.g., UK/European syllabi), the answer leans True - a licensed vaccine does exist - but it is only for EV-A71 and only in China. (PubMed PMID: 26732723; CDC; StatPearls)

Summary Table

Statement	Verdict	Key Point
a) Is a zoonotic infection	FALSE	Strictly human-to-human; no animal reservoir
b) Commonly occurs in the elderly	FALSE	Predominantly children under 5 years
c) Commonly caused by Coxsackievirus A	TRUE	CVA16 is the classic cause; CVA6 increasingly common
d) Transmitted via contaminated surfaces/objects	TRUE	Fomite transmission is well-established
e) Can be prevented by vaccination	TRUE*	EV-A71 vaccine approved in China (2015); not available in the US/UK

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