Lec 11: Rhabdoviruses (& other -ssRNA viruses) Class V

Question 1

The name is derived from

Answer 1

the Greek word rhabdos, which means a rod.

Question 2

(Rhabdovirus Virion Shape)
Those infecting plants =
Those infecting animals =

Answer 2

plants = rods with rounded ends
animals = bullet shaped

Question 3

Rhabdoviruses host range =

Answer 3

(wide)

mammals, fish, plants and insects

Question 4

Many rhabdoviruses replicate in the cells of

Answer 4

diverse types of host, especially the so-called ‘plant’ rhabdoviruses, which replicate in their insect vectors AND in their plant hosts

Question 5

Rhabdovirus we talk about =

Answer 5

RABIES

Question 6

Rabies Infection normally occurs as a result of…

The rabies infection spreads to…

Answer 6

…virus in saliva gaining access to neurons through damaged skin
…other neurons in the central nervous system, then to cells in the salivary glands, where infectious virus is shed into the saliva

Question 7

Each year rabies kills

approx =

Answer 7

large numbers of humans, and animal species

= 60K human deaths/year

Question 8

Most human infections are acquired via

Answer 8

bites from rabid dogs

Question 9

Rabies Vaccines have been developed to provide

Answer 9

protection to humans, domestic animals (especially dogs) and wild animals.

Question 10

Vaccination against rabies is used in 2 distinct situations:

Answer 10

1. ) to protect those who are at risk of exposure to rabies (ex: pre-exposure vaccination)
2. ) to prevent the development of clinical rabies after exposure has occurred, usually following the bite of an animal suspected of having rabies (ex: post-exposure vaccination)

Question 11

The rabies vaccines used for pre-exposure and post-exposure vaccination are

Answer 11

the same, but the immunization schedule differs.

Question 12

Rabies immunoglobulin is used only for

Answer 12

post-exposure prophylaxis.

Question 13

For post exposure, best to get vaccine in

Answer 13

<24 hr

Question 14

(Rabies) Post-exposure prophylaxis should not be

Answer 14

denied due to a prolonged time interval between exposure and starting treatment

Question 15

Rabies Incubation period =

Answer 15

well in excess of one year have been reported.

Question 16

The actual time between infection and when you get sickranges from

Answer 16

10 days - 7 years (incubation period).

Averageperiod = 3 -12 weeks.

Question 17

Rhabdovirus virion shapes (3)

Answer 17

enveloped, rod- or bullet-shaped structure containing 5 protein species

Question 18

Rhabdovirus genome has

Answer 18

a leader sequence and the genes for the five structural proteins.
(The genes are separated by short intergenic sequences)

Question 19

short intergenic sequences function

Answer 19

separates genes of rhabdovirus structural proteins within genome

Question 20

Rhabdovirus entry method =

Answer 20

endocytosis

Question 21

(Rhabdovirus entry)

After endocytosis…

Answer 21

…the nucleocapsid is released into the cytoplasm by fusion between the membranes of the virion and the endosome.

Question 22

(Rhabdovirus transcription) :

Answer 22

The (-) strand genome is transcribed into 6 (+) strand RNAs: a leader RNA and five mRNAs.

Question 23

(Rhabdovirus Assembly and exit) :

Answer 23

M protein coats nucleocapsids, which then bud from regions of the plasma membrane that have been modified by the insertion of G protein.

Question 24

Rhabdovirus spreads through…

tf…

Answer 24

…the air through coughing and sneezing

tf, highly contagious virus

Question 25

Measles starts with…

Children are protected with…

Answer 25

…fever, runny nose, cough, red eyes, and sore throat, followed by a rash that spreads over the body.
…measles, mumps, and rubella (MMR) vaccine.