Microbiology trans - RNA Viruses I

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Questions and Answers

What is the primary route of transmission for Hepatitis E virus?

Fecal to oral route (correct)

Airborne particles

Contact with infected blood

Sexual contact

What type of virus is Hepatitis A classified as?

Retrovirus

Single-stranded RNA virus (correct)

Enveloped virus

Double-stranded DNA virus

What is the mortality rate associated with Hepatitis A?

Less than 0.1% (correct)

0.1% to 2.1%

Above 10%

About 5%

Which laboratory marker is commonly elevated during a Hepatitis A infection?

IgM antibodies Signup and view all the answers

Which of the following complications is associated with Hepatitis A?

Complications are uncommon Signup and view all the answers

What is the diameter range of the Hepatitis A virus?

27 to 34 nm Signup and view all the answers

What is the primary complaint associated with paralytic poliomyelitis?

Acute flaccid paralysis with pain Signup and view all the answers

Which type of motor neuron damage is associated with paralytic poliomyelitis?

Lower motor neuron damage Signup and view all the answers

What symptoms may occur due to brain stem invasion in paralytic poliomyelitis?

Incoordination and painful spasms Signup and view all the answers

In patients with paralytic poliomyelitis, which muscles are usually affected?

Proximal muscles Signup and view all the answers

What is a characteristic feature of the muscle tone in patients with paralytic poliomyelitis?

Reduced muscle tone asymmetrically Signup and view all the answers

What type of virus causes paralytic poliomyelitis?

RNA Virus Signup and view all the answers

What is an additional symptom that may accompany paralysis in paralytic poliomyelitis?

Incoordination Signup and view all the answers

Which muscle group is primarily affected in paralytic poliomyelitis?

Proximal muscles Signup and view all the answers

What can contribute to painful spasms in non-paralyzed muscles during paralytic poliomyelitis?

Brain stem invasion Signup and view all the answers

What is the primary method of virus spread for echoviruses and enteroviruses?

Fecal contamination Signup and view all the answers

Which enterovirus is primarily associated with acute hemorrhagic conjunctivitis?

Enterovirus 70 Signup and view all the answers

What characteristic do Enterovirus 68 and rhinoviruses share?

Acid liability Signup and view all the answers

What is a significant source of virus contamination in water supplies?

Human wastes in sewage Signup and view all the answers

How long can the incubation period for infections caused by Enterovirus strains be?

1 day Signup and view all the answers

Which of the following preventive measures is NOT recommended for echovirus and enterovirus infections?

Consuming raw shellfish Signup and view all the answers

What condition is Enterovirus 71 known to cause?

Meningitis and encephalitis Signup and view all the answers

What type of outbreaks are challenging to recognize due to their mode of transmission?

Waterborne outbreaks Signup and view all the answers

What is a potential consequence of poorly treated sewage?

Long-distance virus travel and infection Signup and view all the answers

What is one of the main causes of central nervous system (CNS) disease linked to enterovirus infections?

Meningitis Signup and view all the answers

What is the main incubation period for human rhinovirus infection?

2-4 days Signup and view all the answers

What receptor does the major receptor group of human rhinovirus primarily bind to?

Intracellular adhesion molecule-1 (ICAM-1) Signup and view all the answers

How does human rhinovirus most commonly infect the host?

By self-inoculation Signup and view all the answers

What general step does NOT occur during the replication of human rhinovirus?

Formation of viral DNA from RNA Signup and view all the answers

What is the duration for which passively administered antibodies last?

3-5 weeks Signup and view all the answers

Which of the following statements about human rhinovirus transmission is TRUE?

Can be transmitted via contact with contaminated surfaces Signup and view all the answers

What triggers the recrudescence of paralysis and muscle wasting in individuals with a history of paralytic poliomyelitis?

Physiologic and aging changes Signup and view all the answers

How many serotypes of wild poliovirus are there?

3 Signup and view all the answers

What happens to the structural proteins during the maturation of the human rhinovirus?

They assemble into empty capsids Signup and view all the answers

For how long can human rhinovirus be present in nasal secretions after infection?

2-3 weeks Signup and view all the answers

Which serotype of wild poliovirus was declared eradicated in September 2015?

Type II Signup and view all the answers

What is the main factor that allows immunity to one serotype of poliovirus?

No cross-immunity with other serotypes Signup and view all the answers

Which step of rhinovirus pathogenesis occurs first?

Uncoating at pH ≤ 5.6 Signup and view all the answers

What major effect does human rhinovirus have on asthma patients?

Responsible for about half of asthma exacerbations Signup and view all the answers

When should stool samples and swabs be collected for laboratory testing after the onset of limb weakness?

At least 24 hours apart during the first 14 days Signup and view all the answers

What is the duration of the replication process of human rhinovirus?

8-12 hours Signup and view all the answers

What is the last year in which type 3 wild poliovirus was detected?

2012 Signup and view all the answers

Which type of antibodies are formed immediately after exposure to the poliovirus?

Virus-neutralizing antibodies Signup and view all the answers

Which of the following statements is true regarding wild poliovirus?

Only type 1 wild poliovirus remains Signup and view all the answers

Study Notes

Paralytic Poliomyelitis

Characterized by acute flaccid paralysis and muscle pain due to lower motor neuron damage or anterior horn cell injury.
Incoordination can occur from brain stem invasion, leading to painful spasms in non-paralyzed muscles.
Muscle tone is typically reduced asymmetrically, with proximal muscles most commonly affected.

Microbiology

Caused by an RNA virus; paralysis and muscle wasting can recur decades after initial poliomyelitis due to aging and physiological changes.
Natural strains are called wild polioviruses, which include three serotypes: type I, type II (eradicated in 2015), and type III (eradicated in 2019).
Type I wild poliovirus is the only remaining serotype, with community spread primarily through fecal contamination.

Laboratory Diagnosis

Specimens must be collected at least 24 hours apart within the first two weeks of limb weakness onset.
Diagnosis involves stool samples and swabs to detect poliovirus, which survived in sewage and contaminated water sources.

Enterovirus Types

Enterovirus 68 shares traits with rhinoviruses, highlighting acid liability and temperature preferences, affecting both infants and adults.
Enterovirus 71 can cause severe CNS diseases, including meningitis and paralysis, with outbreaks linked to hand, foot, and mouth disease (HFMD) in 2008.

Human Rhinovirus

Recognized as the common cold virus, primarily infects the upper respiratory tract, found in nasal secretions for up to three weeks.
Incubation is typically 2-4 days; transmission occurs mainly through self-inoculation and aerosol droplets.
Over 150 types exist, categorized into major (ICAM-1 receptor) and minor (LDL-R family) receptor groups.

Pathogenesis of Human Rhinovirus

Enters epithelial cells via endocytosis, uncoating occurs at pH ≤ 5.6, leading to viral RNA transcription and replication.
Replication and assembly of viral proteins and genomes are swift, taking about 8-12 hours; the process can lead to cell lysis or non-lytic exocytosis for particle release.

Hepatitis E Virus

Classified in the Hepeviridae family and genus Hepevirus; it is a small, nonenveloped single-stranded RNA virus.
Transmitted via the fecal-oral route, outbreaks have occurred in resource-limited countries due to contaminated drinking water.
Symptoms include elevated liver enzymes (aminotransferase levels) with a mortality rate of approximately 0.1%.

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This quiz covers key concepts related to Paralytic Poliomyelitis, focusing on its symptoms and severe illness implications. It aims to enhance understanding of acute flaccid paralysis and associated pain. Perfect for students and healthcare professionals interested in infectious diseases.