JKO Japanese Encephalitis Virus Course

A woman presents to an immunization clinic requesting JE-VC (Ixiaro) before planned travel to Japan. She has a fever of 102F which she attributes to a kidney infection. The immunization clinic should:

Temporarily exempt from JE-VC (Ixiaro) due to current moderate illness (correct)

Because encephalitis from JEV infection is easy to treat, vaccination of people travelling to high-risk areas is not necessary

False (correct)

Which animals are important in the propagation and transmission of JEV?

All of the above (correct)

A man returns to the immunization clinic for his 2nd dose of JE-VC (Ixiaro). He reports that he had a 1-inch area of redness and swelling on his arm after his 1st dose. The immunization clinic should:

Reassure him regarding this common reaction and administer the standard JE-VC (Ixiaro) dose (correct)

Which factors should be considered when determining if a traveler will be at risk for JEV and therefore a good candidate for JE-VC (Ixiaro)?

All of the above (correct)

A woman returns to the immunization clinic for her 2nd dose of JE-VC (Ixiaro). She reports that she had two days of low-grade fever and headache after her 1st dose. The immunization clinic should:

Reassure her regarding this possible systemic reaction and administer the standard JE-VC (Ixiaro) dose, as long as she is well on the day of vaccination (correct)

A family will be relocating to Japan for the next three years. The family includes a 25-year-old active duty woman, her 24-year-old civilian husband, and their 1-year-old baby. They enjoy hiking and camping. When considering JE-VC (Ixiaro) for this family, the immunization clinic should:

Offer vaccine to all of these family members. (correct)

In what part of the world is JEV endemic (common)?

Asia (correct)

Most people infected with JEV will develop:

No symptoms or mild flu-like illness (correct)

A woman presents to an immunization clinic requesting JE-VC (Ixiaro) before planned travel to Japan. She is 6 months pregnant. The immunization clinic should:

Consult with her provider on risk, benefit, and timing of JE-VC (Ixiaro) for this patient. (correct)

A severe clinical presentation of JEV infection is encephalitis. JEV encephalitis is characterized by

All of the above (correct)

12) JE-VC (Ixiaro) is a live-virus vaccine.

False (correct)

JEV is transmitted to humans via:

Mosquito bites (correct)

The effectiveness of JE-VC (Ixiaro) in preventing JEV infection is described as follows:

Two doses of vaccine are estimated to be effective in protecting >95% of adults and children (correct)

Most people infected with JEV have no symptoms or mild flu-like symptoms.

True (correct)

The correct dose and route for administering JE-VC (Ixiaro) in patients ages 3-years and older is:

0.5 mL intramuscularly (correct)

A man who developed hives and throat swelling after his 1st dose of JE-VC (Ixiaro) should be considered permanently exempt from future doses of this vaccine

True (correct)

What is the recommended dosing schedule for JE-VC (Ixiaro) vaccine?

Two doses, at least 28 days apart (correct)

JE-VC (Ixiaro) is an inactivated (not live) vaccine.

True (correct)

japanese encephalitis taxonomy

flavivirus
flaviviridae
+ssRNA

JE is transmitted by

Culex spp
(C. tritaeniorhynchus)

C tritaeniorhynchus is the primary vector of JE in ___

Asia

why is culex spp a bridge vector of JE?

ornithophilia
mammalophilia

overwintering definition (in the context of JEV)

maintenance during non transmission seasons (hibernating) of female Culex spp. or egg stages of Aedes spp.

the first case of JE was documented in Japan in ___

1871

JEV is the main cause of ____ in many asian countries with an estimated ____ clinical cases annually

viral encephalitis
68000

JEV hosts during primary and maintenance cycle

ardeid birds (herons, egrets)

JEV hosts during amplification cycle

pigs

dead end/incidental hosts of JEV

humans
horses
donkeys

in the maintenance cycle in _____, ____ infection is the main type of JEV infection to humans

rice fields
rural infections

in the amplification cycle in _____, ____ infection is the main type of JEV infection to humans

farms
rural and peri-urban infections

main vector for JEV in endemic cycle

culex spp. (culex tritaeniorhynchus)

main vector for JEV in amplification cycle

culex spp. (culex tritaeniorhynchus)
aedes spp.

main reservoir hosts for JEV

herons and egrets

t or f. herons and egrets forage in the same rice-field sites where JE vectors undergo development.

true

t or f. water fowls produce low viremia in JEV infections so only mosquitoes are affected.

false - water fowls produce high enough viremias such that mosquitoes can be infected

heron migration causes _____ in JEV

introduction of genetic variants

amplifying hosts include (____ and ____ pigs) and ____

domestic
feral
boars

places with pig rearing and rice production have ____ impact of JEV transmission

higher

why are swine infected wih JEV in the first place?

they are attractive to JE vectors

swine infecton rate for JEV

98-100%

T or F. Only swine produce high viremia during JEV infection

false - both swine and waterfowls

4 general roles of other animals in the JEV life cycle

-ZooZooPS-
zooprophylaxis
zoopotentiation
possible transmission
sentinel species

in zooprophylaxis, there is ___ (JEV)

diversion of pathogen-carrying biting arthropods from one organism to another organism not involved in the pathogen transmission cycle.

animals involved in zooprophylaxis include (JEV)

cattle and other ruminants

in zoopotentiation, there is a ___ (JEV)

spill over of pathogen carrying biting arthropods from one organism to another

animals involved in zoopotentiation (JEV)

swine

animals that could possibly transmit JEV but are not preferred for feeding by vectors (5)

-BaSLiFF-
bats
snakes
lizards
frogs
flying foxes

JEV sentinel species ______ (hindi enumeration)

provide prior warning for seasonal occurrence of the disease.

JEV sentinel species include

poultry
dogs
goats

JEV clinical manifestations

-CEFFHAD-
convulsions
encephalitis
flu-like symptoms
fever
headaches
altered state of mind
death

JEV incubation period

4-14 days (sometimes longer)

t or f. majority of JEV infections are clinically inapparent

true

ratio of adult clinical JEV cases to inapparent cases

1:25

death rate for JEV

20-50% percent

where does JEV death rate variability come from?

differences of pathogenicity of various strains

in swine, JEV is considered a significant reproductive problem which causes ______ (3)

abortion
still-birth
birth defects

non-pregnant swine JEV symptoms

asymptomatic OR
transient febrile illness

piglets up to 6 mos of age born to JEV infected sows can display _____ (2)

neurological disease
wasting syndrome

in boars, JEV causes ___

disturbance of spermatogenesis leading to infertility

equine JEV mild clinical signs

-EMALeC-
*encephalitis
mild illness with transient fever
anorexia
lethargy
congestion of or jaundiced mucous membranes

equine JEV severe symptoms

-HHAViPDe-
high fever
hyper excitability
aimless wandering
violent and demented behavior
profuse sweating and muscle tremors
death

JEV avian symptoms

no clinical disease

JEV geographical distribution

South Asian + SEA countries
China
Russian Far East
Australia

JEV hotspot in Philippines (1958-2013)

Nueva Ecija

JEV tropical temporal patterns (3)

endemic
appear sporadically throughout the year;
outbreaks during rainy season

JEV temperate temporal patterns (2)

epidemic
seasonal: late summer and early autumn

demographic most susceptible to JEV (PH)

10-15 y/o (basta less than 18)

why are mostly young people affected by JEV in the Philippines?

morbidities decline later in life because of immunity acquired from apparent and inapparent infections

most common domestic animal with JEV and is an important source of virus amplification

pigs

animals with high JEV antibody titers (4)

pigs
horses
cattle
birds

in a 2003 study in the Philippines, what percentage of what studied animal was positive for IgM to JEV using IgM-capture ELISA?

35% of monkeys

JE transmission is high in agriculturally irrigated land (rice fields) due to (2)

location for larval development of mosquitoes
location of forage of water birds

treatment for symptomatic JEV

administration of recombinant alpha interferon

prevention and control of JEV (2)

vector control
vaccination

vector control methods for JEV (3)

-ECB-
Environmental
-stabling animals during peak mosquito biting activity
-screened barns
-barn farms
-intermittent irrigation

Chemical
-insecticides
-repellents

Biological
-microbial, plant-based insecticides
-predators (larvivarous fish, nematodes, insects)

2 chemical repellents for mosquitoes for JEV

DEET
picridin

most effective and efficient method of JEV transmission control in humans

mass vaccination

t or f. vaccination of swine does not affect human transmission rates for JEV

false

most common diagnosis technique for JEV in humans and animals

ELISA

1. antibody used for detection of JEV;
2. it is detected in ____ and ____ within ____

IgM
serum, CSF, 7 days of infection

other JEV diagnosis techniques

IIFT
HI
CFT
RT-PCR
RT-LAMP
Viral isolation

JEV can be isolated from ___

brain of:
humans
dead animals
porcine fetuses