Lecture 26 - Bats as Sources of Zoonoses

Question 1

Most-secure BC4 facility in Australia

Answer 1

Australian Animal Health Laboratory (Geelong)

Question 2

Linnean order of bats

Answer 2

Chiroptera

Question 3

Suborders of chiroptera

Answer 3

Microchiroptera, megachiroptera

Question 4

When did hendravirus emerge in Australia?

Answer 4

1994

Question 5

Examples of viruses whose natural reservoir might be bats
1)
2)
3)
4)
5)
6)
7)

Answer 5

1) Hendravirus
2) Lyssavirus
3) Menanglevirus
4) SARS coronavirus
5) Ebolavirus
6) Marburgvirus
7) MERS coronavirus

Question 6

Why might bats be asymptomatically infected with diseases that cause significant pathology in other species?
1)
2)

Answer 6

1) Flight might cause body temperature increase.

2) IFN system operates differently in bats. Much higher baseline levels of IFN.

Question 7

Number of flying fox species in Australia

Answer 7

Four

Question 8

Distribution of flying fox species in Australia
1)
2)
3)
4)

Answer 8

1) Grey headed flying fox - south eastern Australia
2) Little red flying fox - East, north coasts
3) Black flying fox - North coast
4) Spectacled flying fox - Cape York

Question 9

How are bats sampled for viruses?

Answer 9

Often non-invasively (urine, faeces samples)

Rarely bats are killed and examined

Question 10

How similar are hendra and nipahviruses?

Answer 10

Extremely similar. They are essentially the same virus

Question 11

Bat suborder that is a reservoir for Hendravirus

Answer 11

Megachiroptera

Question 12

Viral family that henipaviruses belong to

Answer 12

Paramyxoviridae

Question 13

First hendravirus outbreak

Answer 13

Horse stable in Hendra, Brisbane, 1994

Question 14

Number of Hendravirus outbreaks in Australia

Answer 14

13

Question 15

Is there a hendravirus vaccine?

Answer 15

Yes. It is an equine vaccine. Not tested in humans.

Question 16

Virus that is very similar to bat lyssavirus

Answer 16

Rabiesvirus

Question 17

Paramyxovirus of bats that results in reproductive problems in pigs

Answer 17

Menanglevirus.
Severe decline in farrowing rate.
High incidence of stillborn piglets.

Question 18

Menanglevirus symptoms in humans

Answer 18

Severe influenza-like illness

Question 19

Nipahvirus symptoms in humans.

Answer 19

Febrile encephalitis.
~40% mortality.
Survivors can have permanent brain damage

Question 20

Henipahvirus that is spreading human-human in Bangladesh

Answer 20

Nipahvirus.

Outbreaks occur almost annually.

Question 21

Typical hendravirus transmission pattern

Answer 21

Bats->horses->humans

Question 22

Typical Malaysian nipahvirus transmission pattern

Answer 22

Bats->pigs->humans

Question 23

Typical Bangladeshi nipahvirus transmission pattern

Answer 23

Bats->humans->humans

Question 24

Effect of nipahvirus on pigs

Answer 24

Mild respiratory illness

Question 25

Novel henipavirus that doesn't cause disease in humans

Answer 25

Cedarvirus

Question 26

Why mightn't cedarvirus cause significant pathology?

Answer 26

V, W proteins are made via RNA splicing of P gene, and are antagonists of IFN system. V, W proteins are absent in cedarvirus. Therefore IFNa, b levels are high in response to virus.

Question 27

Two genera of filoviruses

Answer 27

Ebola, Marburg

Question 28

Five identified ebola species

Answer 28

1) Zaire 2) Sudan 3) Tai Forest 4) Reston 5) Bundibugyo

Question 29

Strains of Marburgvirus

Answer 29

Only Marburg Marburgvirus

Question 30

Mortality rate of Marburg virus

Answer 30

~80%

Question 31

``` Ebolavirus disease characteristics 1) 2) 3) 4) ```

Answer 31

1) Begins with influenza-like illness 2) Followed by vomiting, diarrhoea, kidney and liver damage 3) Bleeding can occur, but only happens ~10% of the time. Bleeding often occurs into GIT. 4) Death often occurs due to kidney and liver failure, not blood loss.

Question 32

Ebolavirus strain that doesn't cause human disease

Answer 32

Reston ebolavirus