Zoontic Viruses, Arboviruses and Smallpox

Question 1

What is an Arbovirus?

Answer 1

A virus that can be transmitted by an insect.

Question 2

Where does a Togavirus replicate? Flavivirus?

Answer 2

Togaviruses replicate in the cytoplasm and bud through the plasma. Flaviviruses replicate in cytoplasm and bud through intracellular membranes.

Question 3

Explain yellow fever life cycle

Answer 3

1. Female mosquito acquires virus during feeding on viremic vertebrate host.
2. Virus infects mid-gut of mosquito, then salivary gland.
3. Transmitted to new vertebrate host.

Question 4

Discuss Dengue symptoms

Answer 4

Fever, headache, back/bone pain lasting a week.

Question 5

Discuss Chikungunya virus symptoms.

Answer 5

Fever, rash on trunk and limbs, arthralgia. Acute symptoms resolve in a week. Arthralgia may last for years

Question 6

What is the life cycle of rabies?

Answer 6

1. Virus inoculation
2. Replication in muscle, then PNS
3. Ascent via sensory fibers
4. Replication in DRG, ascent in spinal cord to brain.
5. Infection of brain, eye, salivary glands.

Question 7

Discuss Rabies symptoms

Answer 7

Virtually always fatal. Hydrophobia, fever, malaise. Negri bodies seen in brain tissue.

Question 8

Discuss Filoviruses

Answer 8

Filamentous enveloped virion that causes severe hemorrhagic fevers. Replicates in macrophages eliciting a cytokine storm. Anmial resevoir

Question 9

What are the clinical symptoms of Variola virus?

Answer 9

Lesions develop in mucous membranes of the nose, mouth and skin.