LECTURE #4 Neurological Viruses Flashcards by Tala Ebrahimian

To what family does the Eastern equine encephalitis virus (EEE) belong?

Togaviridae

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To what family does the Venezuelan equine encephalitis virus (VEE) belongs?

Togaviridae

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To what family does the West Nile virus belongs?

Flaviviridae

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To what family does Rabies virus belongs?

Rhabdoviridae

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What is the genome of Eastern equine encephalitis (EEE) virus?

(+)ssRNA

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What is the genome of Venezuelan equine encephalitis virus?

(+)ssRNA

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What is the genome of West Nile virus?

(+)ssRNA

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What is the genome of Rabies virus?

(-)ssRNA

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Does the virion of Eastern equine encephalitis virus contain envelope?

Yes

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Does the virion of Venezuelan equine encephalitis virus contain envelope?

Yes

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Does the virion of West Nile contain envelope?

Yes

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Does the virion of Rabies virus contain envelope?

Yes

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How is the transmission occurs for those virus of the flavivirus and togaviruses families?

Through a vector (Arthropod transmission)

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What are some common vectors for transmission?

Mosquitoes: culiseta, aedes, culex, ticks

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What are considered reservoirs of virus to be transmitted by vector?

Birds & Small mammals

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What is a requirement for transmission of virus through a vector?

Requires replication in the vector first

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What are the proteins found in Eastern equine encephalitis (EEE) virus and Venezuelan equine encephalitis (VEE) virus?

E1&E2: cell attachment and entry, capsid protein and various non-structural proteins

How does the transmittion of Eastern equine encephalitis virus and Venezuelan equine encephalitis occur?

Virus introduced through bite of infected arthropod, infect cells locally and/or carried by Langerhans cells to LN (lymph nodes), then replication and releases into the blood stream (infection in other target organs such as CNS)

What is the incubation period of Eastern equine encephalitic virus and Venezuelan equine encephalitis virus?

4-10 days

What are the symptoms associated with Eastern equine encephalitic virus and Venezuelan equine encephalitis virus infection?

Chills, fever, malaise, arthralgia, myalgia (1-2 weeks to recover)

What are the symptoms of encephalitis caused by Eastern equine encephalitic virus and Venezuelan equine encephalitis virus?

Fever, headaches, irritability, restlessness, vomiting, diarrhea, convulsions, and coma (1/3 cases die from disease 2-10 days after onset)

Can someone recover from encephalitis infection?

Yes, but have long term sequelae such as seizures, personality disorders, paralysis

How to prevent Eastern equine encephalitic virus and Venezuelan equine encephalitis virus infections?

A single vaccine is available TC-83 which is a live attenuated vaccine (given to military personnel and researchers)/also available for veterinary use.
C-84 is inactivated.
Mosquito control/repellant

Once infection occurs is there any treatment available for Eastern equine encephalitic virus and Venezuelan equine encephalitis virus infection?

No treatment, supportive care

How long is the incubation time for West Nile virus?

2-14 days (80% asymptomatic)

What are the symptoms associated with West Nile virus infection?

Fever, headaches, fatigue (3-6days)

Can West Nile virus infection cause Neuroinvasive disease?

Yes, only on less than 1% | aseptic meningitis, encephalitis, flaccid paralysis, altered mental state, tremors

How to prevent west nile virus?

No vaccine available, no treatment-supportive care, mosquito control/repellant

What are the proteins of Rabies virus?

N-nucleoprotein, P-phosphoprotein, M-matrix, G-glycoprotein (attachment and entry), L-polymerase

What is a characteristic of the Rabies virus?

Broad tropism (in response to environment)

Where does replication of Rabies virus occurs?

In the cytoplasm only!

How does the replication occur of Rabies virus?

Genome order dictates abundance of transcripts and proteins, binding of N to RNA triggers genome replication, it can frequently produce defective interfering particles

How is Rabies virus spread?

Transmission by bite of infected animal

What percentage of those bitten with infected rabies animal will cause disease?

15% can cause disease, 60% if on face or head

What type of animals are reservoirs of Rabies virus?

Bats, skunks, raccoons (common disease of dogs in developing countries that leads to human rabies)

How long is the incubation period for Rabies virus?

1-3months

How is the Rabies spread inside the body?

Replicates locally until it finds neurons, moves passively in axoplasm of peripheral nerves to spinal ganglia, spinal cord and brain, can spread back to periphery, highly innervated salivary glands and replicates

What are symptoms of Rabies virus infection?

Prickling or itching where bitten, fever, headaches, hydrophobia (difficult swallowing, “foaming mouth”) cerebral dysfunction, anxiety, confusion, delirium, hallucinations and insomnia

What are the outcomes of a person infected with Rabies?

Once symptoms appear, disease is nearly always fatal

What are prevention methods for Rabies?

Vaccine available, post exposure prophylaxis,