Week 9

Question 1

Bats

Answer 1

• 20% of all classified mammalian species
• Variable thermoregulation - torpor
• 30 yr life span
• Pollination and insect control

Question 2

Bats and disease

Answer 2

• Only known disease to make bat sick is rabies
• Metabolic demands
• Ability to fly
• Torpor: immunological impact?
• High density populations: infection transmission
• Season for pregnancy

Question 3

Bat species in Aus

Answer 3

1. Microbats
2. Megabats, include flying foxes

Question 4

Sampling bats

Answer 4

Non-invasive preferred: urine and faeces

Occasionally sacrifice animals for tissue collection

Question 5

Hendra/Nipah virus

Answer 5

• Henipavirus genus, Paramyxoviridae family
• 1994 Brisbane horse outbreak + 2 human infections
• Vaccine used in horses –> prevent human cases
• Bats natural reservoir

Question 6

Australia Bat lyssovirus

Answer 6

• Isolated from flying fox while surveying for hendra virus
• All fatal
• Direct contact with bats
• Have infected horses

Question 7

Menangle virus

Answer 7

• Paramyxovirus
• Found in commercial piggery –> stillborn piglets
• Severe influenza-like illness (not fatal)
• Isolated from flying foxes

Question 8

Malaysia Nipah virus

Answer 8

Outbreak of respiratory and neurological disease in pigs

Isolated from local flying foxes

Re-emergence in Bangladesh:

• Febrile encephalitis
• Human-human transmission
• Isolated from flying foxes

Question 9

Hendra/Nipah transmission patterns

Answer 9

Question 10

Nipah in pigs

Answer 10

causes respiratory illness, not really fatal

Question 11

Global distribution of henipavirus

Answer 11

South and Central America

Africa

South east Asia

Question 12

Cedar virus

Answer 12

Looking for Hendra virus

Most are 10% seropositive, but in 2009 Hendra positive (30%)

Showed syncytia –> PCR –> n protein sequences –> was not Hendra, but very closely related

Could cause significant human disease, but no disease seen in animals

P gene not edited to produce V or W proteins, does not antagonise IFN response in infected cells

V and W protein made by RNA editing

Strong upregulating of IFN response

Question 13

Filoviridae

Answer 13

• Order: mononegavirales
• ss -ve RNA
• Ebola and Marburg genera
• Haemorrhagic fever
• 5 Ebola species
• 1 Marburg species

Question 14

Marburg virus

Answer 14

Identified in Germany

• Primary infections: lab staff exposed while working with monkeys (kidneys)

Question 15

Ebolavirus

Answer 15

• 2 viruses - independent outbreaks at same time
• Fatality rate: 72%
• Influenza-like illness (sore throat, muscle pain, headaches) –> vomiting, diarrhoea, decreased kidney/liver function –> death
• 10% showing signs of haemorrhagic fever

Question 16

WHy is ebola highly pathogenic?

Answer 16

• Evade host immune response - shut down interferon pathways
• Infects white blood cells

Reston ebola: infects people, but doesn’t cause disease, except generate neutralizing response to virus