JE ppt

MD.KABIUL AKHTER ALI
Vector Borne Disease Consultant
NVBDCP, NRHM
District Heath & Family Welfare Samiti
Uttar Dinajpur

Overview
Economic impact
History
Epidemiology
Transmission
Clinical Signs
Diagnosis and Treatment
Disease in Humans
Prevention and Control
Actions to Take/Program mode

Japanese Encephalitis
Flaviviridae
Flavivirus
The name is derived from
the Latin ‘flavus’
Flavus means “yellow”
 Refers to yellow fever virus
Enveloped
Single stranded RNA virus
Morphology not well defined

History
 1870s: Japan
 “Summer encephalitis” epidemics
1924: Great epidemic in Japan
 6,125 human cases; 3,797 deaths
1935: Virus first isolated
 From a fatal human encephalitis case
1938: Isolated from Culex tritaeniorhynchus
1952: First evidence of J E
1955:First case in India
1958:First viral isolation in India
1973:First outbreak inBankura/Burdwan
1978:widespread occurance/monitoring NMEP
Initiation of immunisation –killed mouse brain vaccine

Economic Impact
Animals
Porcine
 High mortality in piglets
Equine
 Up to 5% mortality rate
Humans
 Cost for immunization and medical treatment

Geographic Distribution
Endemic in temperate and
tropical regions of Asia
Reduced prevalence in Korea Japan

Japan China

Has not occurred in U.S. India Philippine
s

Indonesia

Morbidity/Mortality
Swine
High mortality in piglets
Death rare in adult pigs
Equine
Morbidity: 2%, during an outbreak
Mortality: 5%
Humans
Mortality: 5-40%
Serious neurologic sequelae: 45-70%

Transmission
Vector-borne disease
Enzootic cycle
Mosquitoes: Culex species
 Culex vishnuii/pseudovishnui/tritinorinchus
 Paddy fields

Reservoir/Amplifying hosts
 Pigs, bats
 Ardeid (wading) birds
 Possibly reptiles and amphibians

Incidental hosts
 Horses, humans,(dead end)

Global Problem
Leading cause of viral encephalitis
3 billion live in endemic areas
50000 cases reported annually
10-15 thousand deaths annually
INDIA-33o million live in endemic areas in 15
states/ut
135 districts are affected

Clinical Signs: Swine
Incubation period not known
Exposure early in pregnancy more harmful
Birth of stillborn or mummified fetuses
Piglets: Neurological signs, death
Boars: Infertility, swollen testicles

Post Mortem Lesions
Horses
Non-specific
Nonsuppurative
meningoencephalitis
Swine
Fetuses
 Mummified and dark in appearance
 Hydrocephalus

 Cerebellar hypoplasia

 Spinal hypomyelinogenesis

Differential Diagnosis
Equine
 Other viral encephalitides, Hendra, rabies,
neurotoxins, toxic encephalitis
Swine
Myxovirus-parainfluenza 1, coronavirus, Menangle
virus, porcine parvovirus

Sampling
Before collecting or sending any samples, the proper
authorities should be contacted

Samples should only be sent under secure conditions
and to authorized laboratories to prevent the spread
of the disease

Diagnosis
Clinical
Horses: Fever and CNS disease
Swine: High number of stillborn piglets
Laboratory Tests
Definitive: Viral isolation
 Blood, spinal cord, brain, CSF
Rise in titer
 Neutralization, HI, IF, CF, ELISA
 Cross reactivity of Flaviviruses

Treatment
No effective treatment
Supportive care

Clinical Signs-Humans
Incubation period: 5 to 15 days
Most asymptomatic or mild signs
Children < 15 years and Elderly
At highest risk for severe disease
 Elderly: High case fatality rate (30%)
 For every case 200-1000 undetected/asymptomatic cases

 Disease clinical perspective divided into
mild/moderate/severe/asymptomatic cases

Clinical Signs: Severe
Acute encephalitis
Headache, high fever, stiff neck, stupor
Severe encephalitis
Paralysis, seizures, convulsions, coma, and death
Neuropsychiatric sequelae
45-70% of survivors
In utero infection possible
Abortion of fetus

Post Mortem Lesions
Pan-encephalitis
Infected neurons scattered
throughout CNS
Occasional microscopic
necrotic foci
Thalamus generally severely
affected

Diagnosis and Treatment
Clinical
Laboratory Tests
Tentative diagnosis
 Antibody titer: HI, IFA, CF, ELISA
 JE-specific IgM in serum or CSF

Definitive diagnosis
 Virus isolation: CSF sample, brain
No specific treatment
Supportive care

Public Health Significance
Strengthening of surveillance
Capacity building for diagnosis/case management to
reduce fatality
Clinical laboratory support/adequacy of medicines in
hospitals
Vector surveillance strengthening
Focused IEC for early reporting
Increasing indigenous capacity of vaccine production

Disinfection
Biosafety Level 3 precautions
Chemical
Ethanol, glutaraldehyde, formaldehyde
Sodium hypochlorite (bleach)
Iodine, phenols, iodophors
Physical
Deactivation at 133oF (for 30 minutes)
Sensitive to ultraviolet light and gamma radiation

Prevention
Vector control
 Eliminate mosquito breeding areas
 Adult and larvae control( chemical larvicides, Biolarvicides,
larvivorous fish)
 Environmental management
Vaccination
 Equine and swine
 Humans
Personal protective measures
 Avoid prime mosquito hours/IVM
 Space spray-Fogging with pyrethrum/malathion
 Use of repellants /ITN/curtains

Prevention(Program mode)
Strengthening JE surveillance- identifying /setting of
50 sentinel sites
12 Apex Referral laboratories(Diagnosis)
Guidelines for AES/JE surveillance
VBD Control Surveillance Unit at BRD Medical
College Gorakhpur
Sub office ROHFW Lucknow at Gorakhpur
NIV Pune unit at BRD Medical College
Gorakhpur(funded by GOI/ICMR)

Vaccination
Live attenuated vaccine
Used in equine and swine
Successful for reducing incidence
Inactivated vaccine (JE-VAX)/SA 14-14-2 Chinese-
Single dose IM(Children 1-15 years)
 Used for human beings
 2006-11 districts in 4 states(Assam,Karnataka,WB &UP)

 2007 – Expanded to 27 districts in 9 states

 2008- 23 districts in 9 states covered

 Left out and new cohorts covered in routine immunisation

JE ppt

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to JE ppt (20)

Recently uploaded (20)

JE ppt

Editor's Notes