Barmah Forest Virus

Question 1

What is your opening line for BFV?

Answer 1

BFV is a nationally notifiable vector-borne disease endemic to regional Victoria though cases have been notified across most of mainland Australia & Tas. Cases are often asymptomatic though some develop rash, arthralgia, myalgia and fever. High-risk groups for infection include those living / working in endemic areas, parklands or where mosquito breeding / activity is high.

Question 2

Is BFV nationally notifiable?

Answer 2

Yes

Question 3

How is BFV transmitted?

Answer 3

Mosquito vector.
C. annulirostris (inland)
Ochlerotatus spp (coastal seawater)

Question 4

Which animals are the principal hosts for BFV?

Answer 4

Macropods and other marsupials

Question 5

What are the clinical features of BFV?

Answer 5

• Asymptomatic (often)
• Rash (incl. palms)
• Polyarthritis / arthralgia
• Myalgia
• Lethargy
• Fever

Clinical features can be indistinguishable from RRV. Self-limiting illess. Lifelong immunity.

Question 6

Which groups are at high risk of BFV infection?

Answer 6

• Live / travel in endemic area
• Activities near mosquito breeding sites

Question 7

What is the definition of a confirmed case of BFV?

Answer 7

Isolation / detection / seroconversion

Question 8

What is the definition of a probable case of BFV?

Answer 8

IgM and IgG, unless IgG detected > 3 months earlier

Question 9

How is BFV diagnosed?

Answer 9

PCR or serology (acute and convalescent)

VIDRL reference lab

Question 10

What is the incubation period for BFV?

Answer 10

3 - 21 days
(usually 7-10 days)

Question 11

What is the infectious period for BFV?

Answer 11

Humans are infectious to mosquitoes first few days of illness.

Question 12

What is the outbreak definition of BFV?

Answer 12

**Observed > expected **- increase in notifications from geographical area within specific time period.

New emerging area - >= 2 cases from non-endemic area in same mosquito season with no travel hx.

Question 13

Epidemiology: where has BFV been detected in Australia?

Answer 13

Most of mainland Australia

Serological surveys confirm widespead human infection.

Question 14

Epidemiology: where is BFV considered endemic?

Answer 14

All of regional Victoria.

Question 15

Epidemiology: when to BFV epidemics / outbreaks occur?

Answer 15

Usually after heavy rains, high tides that inundate salt marshes or costal wetlands.

Sporadic cases / small outbreaks usually on mainland. Low notifications in Tas expect 2019 - 13 cases.

Question 16

How is BFV prevented?

Answer 16

Standard vector-borne disease prevention:
* Mosquito control
* Bite prevention
* No vaccine

Question 17

What resources are available for BFV public health response?

Answer 17

DoH guideline. No SoNG.

Question 18

How are cases of BFV managed?

Answer 18

• Supportive care
• Case interview - DRSVECTA
• Education

Demo, RFs, Sx, Vax (NA), Exp (endemic area, mosquitoes, environment/parklands), Contacts/co-exposed, Travel hx, Animals

Question 19

How are contacts of BFV managed?

Answer 19

Nil.

Co-exposed may require education but no follow-up indicated.

Question 20

What is the environmental management for BFV?

Answer 20

Standard environmental measures to prevent mosquito exposure.

Question 21

What public health actions are required for new / emerging areas?

Answer 21

• Liaise with stakeholders
• Review recent data (mosquito/human)
• Enhanced surveillance
• Mosquito surveys
• Promote mosquito management
• Clinician alert / advisories
• Health alerts
• Health promotion measures

Question 22

What public health measures are required for outbreaks?

Answer 22

• Prevention activities
• Community education
• Surveys - animal reservoirs, vector species
• Identify breeding places + eliminate
• Enhanced vector control measures
• Predictive modelling
• Enhanced human surveillance (test/notify)
• Closing public land to human access if high risk of acquisition
• Consult NAMAC

National Arbovirus and Malaria Advisory Committee