JEV

Question 1

What is your opening statement for JEV?

Answer 1

JEV is a nationally notifiable, vaccine preventable disease transmitted by mosquito vector (Culex annulirostris primarily). Infection is largely asymptomatic but rarely can cause encephalitis with chronic neurological sequalae. Priority populations include children < 5yo, elderly, pregnant, immunocompromised, people who live close to or work with mosquitoes, pigs.

Question 2

Is JEV nationally notifiable?

Answer 2

Yes

Question 3

What is the infectious agent for JEV?

Answer 3

JEV is a mosquito-borne flavivirus closely related to Yellow fever, MVEV and West-Nile virus (Kunjin).

Question 4

What is the clinical presentation for JEV?

Answer 4

• 99% asymptomatic.
• Of symptomatic, < 1% to 4% develop symptoms (fever, headache, vomiting etc.)
• Of those infected < 1% develop neuroinvasive disease (acute encephalitis)

Question 5

What are the complications of JEV encephalitis?

Answer 5

Acute encephalitis can result in:
* Confusion / agitation
* FND e.g. CN palsies, paralysis
* Convulsions, seizure
* Coma
* Permanent cognitive, behavioural or neurological complications (30-50%)
* CFR: 20-50%

Question 6

What is the clinical management of JEV?

Answer 6

Supportive care in hospital.

Question 7

What is the public health importance of JEV?

Answer 7

Vaccine-preventable disease with high morbidity and mortality of those who develop encephalitis.

Requires monitoring, reporting, One Health approach, planning for outbreak management.

Question 8

How is JEV transmitted?

Answer 8

Mosquitoes after they have fed on infected waterbirds or pigs.

Question 9

Which is the main vector of JEV in Australia?

Answer 9

Culex annulirostris in Australia but several other species implicated.

Inland riverine areas; bites dawn and dusk

Question 10

Which animal is the primary host of JEV?

Answer 10

Wildbirds - Ardeidae family (herons, egrets)

Question 11

Which species are dead-end hosts for JEV?

Answer 11

Humans and horses.

Don’t develop high enough viraemia.

Question 12

What is the incubation period for JEV?

Answer 12

5 - 15 days

Question 13

What is the infectious period for JEV?

Answer 13

Is not transmitted from person to person.

Question 14

Epidemiology: in which region is JEV a major public health problem?

Answer 14

Asia and western Pacific

Question 15

Epidemiology: is/was JEV a CDINS?

Answer 15

Yes, 2022-23

Question 16

Epidemiology: how was JEV likely introduced to the Australian mainland?

Answer 16

Migratory waterbirds following climatic drivers - El Nino then La Nina.

Question 17

Priority populations: which groups are at greater risk of severe disease?

Answer 17

Anyone but some groups at greater risk:

• Children < 5yo
• Non-immune adults
• Immunocompromised
• Pregnant people

Question 18

Priority populations: which groups are at greater risk of exposure?

Answer 18

• Travel, live or work in areas with JEV
• Outdoor work / leisure activities
• Work with or live close to pigs/waterbirds/
• Work with mosquitoes (EHO/entomologist)
• Travel to endemic areas
• Live or work on outer islands of Torres Strait

Question 19

Priority populations: which settings at increased risk of spread?

Answer 19

Piggeries, pork abattoirs and pork rendering plants.

Question 20

What is the definition of a confirmed JEV case?

Answer 20

Isolation / detection / seroconversion.
JEV-specific IgM in CSF.

Question 21

What is the definition of a probable case of JEV?

Answer 21

Clinical (encephalitis - Sx, imaging, CSF pleocytosis)
AND
Lab suggestive

Question 22

What resources are available for JEV?

Answer 22

DoH guideline. No SoNG

Question 23

How can JEV be prevented?

Answer 23

• Vaccination
• Protect against mosquitoes
• Mosquito control

Question 24

Who is routine vaccination againist JEV recommended for?

Answer 24

• Laboratory workers exposed to virus
• Travellers spending > 1 month in endemic areas during transmission season
• Live or work in outer islands of Torres Strait
• Work with or live close to pigs/waterbirds
• Works with mosquitoes (EHO/entomologist)

Question 25

How can people protect against mosquitoes?

Answer 25

* Insect repellent containing DEET or picaridin * Long, loose-fitting, light clothing * Mosquito netting / screens * Insecticide sprays / vapour dispensing units / mosquito coils * Remove standing water * Clean out permanent water containers * Keep gutters clear * Covering openings to water storage (rainwater, septic tanks) * Avoid areas of high mosquito activity - dawn and dusk

Question 26

How is JEV diagnosed?

Answer 26

PCR (CSF, blood, urine) Serology (repeat 2-4 wks post illness) ## Footnote Also test for MVEV, WN/Kunjin, other causes of meningitis. Samples to VIDRL

Question 27

Public health response: what is the general approach to JEV management?

Answer 27

One Health - the connection between human, animals and the environment.

Question 28

What do JEV public health actions focus on?

Answer 28

* Find source of exposure * Support communities to control mosquitoes * Advice on preventing mosquito bites * Vaccinating eligible people

Question 29

How are cases of JEV managed?

Answer 29

* Urgent investigation * Case interview - DRSVECTA * Determine likely source * Co-exposed should be provided information about JEV * No need for isolation ## Footnote Demo, RFs, Sx, Vax, Expo, Contacts, Travel, Animals

Question 30

How are contacts of JEV managed?

Answer 30

* Potentially co-exposed individuals * Education - transmission, signs/symptoms, vaccination, bite prevention

Question 31

What is the environmental management for JEV?

Answer 31

* Mosquito surveillance existing? * Vector control activities - work with local council

Question 32

What is the response to a JEV outbreak?

Answer 32

* Joint national JEV response outbreak plan (One Health) Control measures: * Animal surveillance * Mosquito control measures * Health education / mosquito bite prevention * Vaccination of people at high-risk of exposure

Question 33

True or False: JEV is a vaccine-preventable disease?

Answer 33

True. JESpect - inactivated; 2 doses Imojev - live attenuated; 1 dose; preferred

Question 34

True or False: JEV is the most important vaccine-preventable cause of human encephalitis in Asia

Answer 34

True ## Footnote 01. to 1.0% of infections

Question 35

Were there any JEV pig infections in the years 22-23 or 23-24?

Answer 35

No.

Question 36

What are the clinical signs of JEV in pigs?

Answer 36

* Reproductive signs - mummification, abortions, still births * Boars - testicular/epididymal infection with swelling, fever, poor semen quality ## Footnote Sows only affected in particular periods of pregnancy.

Question 37

What are the clinical signs of JEV in horses?

Answer 37

Fever and neurological signs. ## Footnote Usually recover in 2-3 days but some may day. No horse cases have been identifed in Australia.

Question 38

What is AUSVET Plan?

Answer 38

AUSVETPLAN contains the nationally-agreed approach for responding to emergency animal disease (EAD) incidents in Australia. The plan is captured in a series of manuals and supporting documents.

Question 39

What are some preventative measures for JEV for workers?

Answer 39

Protective clothing, mosquito control, vaccination

Question 40

How are pigs surveilled for JEV?

Answer 40

Oral fluid collection - test for virus and antibodies. ## Footnote Blood collection is technically difficult.