Neglected tropical diseases 3

Question 1

What % of reported rabies infections are in children?

Answer 1

40%

Question 2

Which communities are mainly affected by rabies?

Answer 2

Poor rural communities in asia and africa

Question 3

What causes rabies?

Answer 3

Lyssavirus

Question 4

How is rabies transmitted?

Answer 4

Via saliva from infected animals i.e. dogs

Question 5

What % of human cases of rabies are caused by dog bites?

Answer 5

99%

Question 6

How does rabies affect the brian?

Answer 6

Causes inflammation

Question 7

What are the two types of rabies?

Answer 7

Furious and paralytic

Question 8

Treatment of rabies?

Answer 8

Thorough washing of would

Question 9

Rabies prevention?

Answer 9

Active vaccination of humans and dogs
Passive immunisation: immunoglobulins against lyssavirus can be used as an “antidote”

Question 10

What is on the outside of lyssavirus particles?

Answer 10

Glycoproteins

Question 11

Lyssavirus shape?

Answer 11

Bulleted structure

Question 12

What is inside lyssavirus?

Answer 12

helical ribonuclease protein

Question 13

What is the target of virus neutralising antibodies used for passive immunisation of rabies?

Answer 13

Glycoproteins on the surface

Question 14

How is lyssavirus adapted for replication in the mammalian CNS?

Answer 14

Glycoproteins on its surface

Question 15

How do the glycoproteins on the surface help lyssavirus replicate in the mammalian CNS?

Answer 15

They bind to receptors found specifically on nerve cells, e.g. nicotinic ACh receptor and low affinity nerve growth factor receptors, and ganglyocytes

Question 16

Incubation period of lyssavirus?

Answer 16

1-3 months

Question 17

What occurs during lyssavirus incubation period?

Answer 17

Virus replicates in the muscle

Question 18

Symptoms during incubation of lyssavirus?

Answer 18

None, fever, vomiting, loss of appetite, headaches

Question 19

At which nicotinic ACh receptors does lyssavirus bind to?

Answer 19

Those at the neuromuscular junction

Question 20

Where does the virus go after binding to the neuromuscular junction?

Answer 20

Travels up the axons of peripheral nerves, into neurons of the CNS, the brain and the SC

Question 21

What happens after lyssavirus enters the SC and brain?

Answer 21

It replicates in the motor neurons

Question 22

What happens as a result of lyssavirus replicating within the motor neurons of the brain and SC?

Answer 22

Neuronal damage, dysfunction and inflammation

Question 23

Final step of lyssavirus infection?

Answer 23

Infection spreads along cranial nerves into salivary glands, skin, cornea and other organs

Question 24

What causes the excessive salivation seen in furious rabies?

Answer 24

Infection of salivary glands

Question 25

When are negri bodies seen and what is their appearance?

Answer 25

Small darker spots seen in staining

Question 26

What are negri bodies?

Answer 26

Abnormal structure in the nucleus or cytoplasm composed of protein Composed of viral N and P proteins Result of accumulation of large quantities of protein

Question 27

What can be used to confirm rabies post-mortem?

Answer 27

Direct fluorescence antibody test

Question 28

%s of the two types of rabies?

Answer 28

furious--> 80%, paralytic--> 20%

Question 29

Presentation of furious rabies?

Answer 29

Hyperactivity and hydrophobia, death after a few days

Question 30

Presentation of paralytic rabies?

Answer 30

Gradual muscle paralysis, slow develop of coma, death

Question 31

What is encephalitis?

Answer 31

Inflammation of the brain

Question 32

Theories as to why rabies leads to two diff presentations?

Answer 32

Type of animal vector, wound site, incubation period, history of rabies vaccine

Question 33

Main infection sites for furious rabies?

Answer 33

Function of anterior horn of spinal cord is disrupted, cells damaged

Question 34

Main infection sites for paralytic rabies?

Answer 34

Peripheral nerves are demyelinated (muscle weakness)