This document summarizes information about Japanese encephalitis (JE), including: - JE is a mosquito-borne viral disease that causes brain inflammation and is a major public health problem in Asia. - It is transmitted by Culex mosquitoes and has pigs and wading birds as amplifying hosts. - Up to 50,000 cases and 10,000-15,000 deaths are reported each year globally. Many survivors are left with long-term disabilities. - Control relies on surveillance of cases and vectors, vaccination programs, and reducing mosquito breeding sites.

1. JAPANESE ENCEPHALITIS

2. • mosquito-borne encephalitis caused by a group B
arbovirus (Flavivirus) and transmitted by Culicine
mosquitoes
• More than 3 billion people live in areas where JE is
transmitted.
• Up to 50,000 cases of JE are reported to WHO each
year.
• Up to 10,000 to 15,000 deaths are reported each
year.
• nearly 15,000 disabled

3. Why is JE a problem?
• JE is the leading cause of viral neurological
disease in Asia, now that poliomyelitis has nearly
been eradicated.
• case fatality rate 20-40 %
• For those that survive the illness, 30% to 75%
cases are left with disability.
• Disability is both physical and cognitive.
Epidemic potential , high case
fatality and life long sequelae

4. Animal Hosts
• mainly include pigs and water birds e.g.
pond herons, cattle egrets, poultry birds and
ducks
• studies of the presence of JE antibodies in the
sera of birds have indicated that Ardeola grayii
(pond heron) and Bubulcus ibis (cattle egret)
play a definite role in maintenance of JE virus
in nature

5. Ardeola Grayii-indian pond
heron

7. • Pigs act as amplifying hosts
• Cattle and buffaloes –mosquito attractants-no
role in transmission
• Man-incidental host

8. VECTORS
• C.tritaeniorhynhus,C vishnui ,C.pseudovishnui and
C.gelidus
• Breed in irrigated rice fields,pools and ditches
• Mosquitoes are zoophilic
• Epidemics usually coincide with monsoons and post-
monsoon period when the vector density is high.
• extrinsic incubation period of 9 to 12 days.
• mosquitoes remain infected for life. The average life
period of a mosquito is about 21 days. Culex
mosquito can fl y for long distances (1-3 kms. or even
more).

9. • Principal vector in kerala
• Mansonia annulifera, Mansonia uniformis and
Mansonia indiana- 'bridge vector' of JE in Kuttanadu
area where these mosquitoes are abundant.
C.tritaeniorhynchus

10. TRANSMISSION CYCLE

11. Clinical manifestations
• incubation period in man- 5 to 15 days.
• Only 1 in 250–500 JE viral infections are symptomatic.
• JE manifestations divided into
• A Prodromal Stage
• An Acute encephalitic Stage
• and a late stage

12. Prodromal Stage :
• Fever
• malaise
• Rigors
• Headache
• Nausea
• and Vomiting
• The Prodromal stage usually lasts for 1 to 6 days.

13. An Acute Encephalitic Stage:
Begins by the third to fifth day. The symptoms
include:
• Convulsions
• Altered sensorium, unconsciousness, coma
• Stiff Neck
• Muscular Rigidity
• Tremors in fingers, tongue, eyelids and eyes.
• Abnormal movements of limbs
• Speech impairment

14. A Late Stage:
Characterised by
• Improvement/the persistance of signs of CNS
injury such as
• Mental impairment.
• Increased deep Tendon reflexes
• Paresis either of the upper or lower motor neuron
type.
• speech impairment
• Epilepsy, Abnormal movements, Behaviour
abnormalities.

15. Laboratory diagnosis
• IgM antibodies appear after the first week of
onset of symptoms and are detectable for one to
three months
• A four fold rise in IgG antibody titre in paired sera
taken at an interval of 10 days or more is confi
rmatory.
• Virus isolation from brain tissue
• Antigen detection by immunofluroscence
• Nucleic acid detection by PCR

16. treatment
1.) Management of Airways and Breathing.
2.) Management of Circulation.
3.) Control of Convulsion and Intracranial pressure
4.) Control of Temperature
5.) Fluid and Electrolytes and Calories/ Nutrition
6.) General management
7.) Specific treatment of any for treatable cause
8.) Investigations, Samples Collection
9.) Reporting of a case
10.) Rehabilitation.

17. JE CONTROL STRATEGY
• Early Case Detection and Treatment
• Vector Control
a)reduction of breeding source for larvae
b) reduction in man-mosquito contact
c) control of adult mosquitoes
• Prevention
a) je vaccination
• Surveillance

18. Prevention & Control
• Reservoir Control
• Surveillance
• Early case detection and treatment
• Interruption of Transmission – Vector Control
• Protecting host - Vaccination

19. Objectives of JE Surveillance
• Detect early warnings signals
• Strengthen lab services
• Assess impact of vaccination

20. Strategies of JE Surveillance
• Epidemiological Surveillance for AES
• Entomological Surveillance
• Veterinary based Surveillance

21. Epidemiological Surveillance for AES
Case Definition of AES
• A person of any age, at any time of the year
with acute onset of fever and a change in
mental status (including confusion,
disorientation, inability to talk or coma) and/
or new onset of seizures (excluding simple
febrile seizures).

22. Suspected
JE (AES)
Adequate
blood/CSF
IGM -ve
Other
diagnostic
test
AES – other
agent
AES
unknown
IGM +ve Lab confirmed JE
No
adequate
blood/CSF
Geographical/temp link
to lab confirmed
Probable JE
No
geographical/temporal
link
AES
unknown

23. Case Classification
A case that meets the clinical case definition for
AES – classified in one of the four ways
Laboratory confirmed JE:
A suspected case that has been laboratory
confirmed as JE
Probable JE:
A suspected case that occurs in close
geographic and temporal relationship to a
laboratory confirmed case of JE, in the context
of an outbreak.

24. Case Classification
Acute Encephalitis Syndrome (due to other
agent)
– A suspected case in which diagnostic testing is
done & an etiological agent other than JE is
confirmed
Acute Encephalitis Syndrome (due to unknown
agent)
– A suspected case in which no diagnostic testing is
performed or in which diagnostic testing is
performed but no etiological agent was identified
or in which the test result was indeterminate

25. Implementation of JE / AES Surveillance
• Sentinel Surveillance Sites with Laboratories
facilities. (SSSL)
• Sentinel Surveillance Sites without
laboratories facilities.(SSS without Lab.)
• Other Informer Units.

26. Sentinel Surveillance Sites with Laboratories
facilities. (SSSL)
• Tertiary care hospital – MC, Regional, DH
• Nodal Officer -> District Malaria Officer
• Records and report – maintain documentation
SSSL - JEF3, JEF4, JEF5
• Monthly basis – Inter epidemic period
• Weekly basis – transmission season
• Daily basis – during outbreak

27. Sentinel Surveillance Sites without laboratories
facilities (SSS without Lab.)
• DH, CHC, PHC
• Linked with nearest SSSL
• Linelist of AES case / Record of JE maintained
• Submitted to DMO / State Programme Officer
• Format – JEF3 & JEF4
• Frequency – Daily , weekly & monthly to DMO

28. Other Informer Units.
• Smaller health facility , private practioners
• Inform DMO / SMO
• Do not maintain detailed documentation of
patients.
• AFP surveillance network

29. JE Surveillance Activities – District
Level
• DMO – study & monitor the
daily/weekly/monthly/nil reports from all units
• Reconcile data with IDSP – forward to
SPO(senior programme officer)
• Compile all reports - interpretation and action.
• Supervision & monitoring of all levels.

30. 1. Case Investigation
a) Verification of case definition – personally see
the case and discuss with reporting physician.
b) Patient code number assigned – 11 alphabet with
seven digit numerical code(IND-AESUP-XXX-01-001)
c) JEF4 – history,conduct the physical examination, fill
JEF5 and AES case identification, coordinate collection
of serum and CSF specimen.

31. 2. . Visit to Sentinel Surveillance Sites
• Meet the Nodal Officer
• Visit IP / OP – scan the registers
• Identify training needs

32. 3. Visit to AES Informers
• Regular visit by DMO / SPO
• Monitor surveillance activity
• Sensitize the staff
• Update informers on the importance of AES
reporting

33. Surveillance activities at State level
• All reports from the district is merged and
collated
• Transmit to director, NVBDCP in JEF1 & JEF1A
forms.
• Daily reporting –> JEF1A
• Take rapid action for containment

34. NVBDCP
STATE
DISTRICT
SSSL
SSS
IU
AESF1,1A
AESF2,2A
AESF3,4,5 AESF3,4
INFORMATION FLOW

35. Process of AES Surveillance
Febrile illness with altered sensorium
Detection & notification
Case investigation Specimens arrive
Serological
blood & CSF collection at laboratory results
Line listing Classification of
isolated cases
Implications of control measures
Data analysis &
interpretation
Compile JE outbreak
Investigation report

36. Surveillance activities - National
• Data from districts compiled - national report
with epidemiological inferences
• Data shared with international organisation
• Report – basis for planning , containment
activities and allocation of resources

37. Entomological Surveillance
• To identify JE vector mosquitoes in the area
• To monitor the vector abundance
• To detect JE virus in vector
• To suggest appropriate vector control
measures.

38. Procedure of entomological
surveillance
• Index village selected – 3 JE occurred in the
recent past + 2 unaffected will be monitored
• Sampling carried out on fortnightly basis
• Surveillance carried out round the year – JE
vector density, feeding & resting behaviuor –
detection and isolation of virus from vector

39. Veterinary based surveillance
Objectives
• Prevalence of Pigs / Ducks, Ardeid Birds in an
area
• To Detect viral Activity in susceptible hosts
Animal Husbandry Dept.
• Pigs – antibody titer – viral activity
• 5 – 8 month old piglets blood samples – IgM
antibody – recent infection

40. Vector Control
Indoor residual spray
Fogging
Personal protective measures
Anti larval operations
Reduction of breeding source of larvae
Larvivorous fish
Biolarvicides
Reduction in man vector contact

41. Control of Pigs
• Immunisation
• Slaughtering
• Use of mosquito proof piggeries
• Segregating pigs 4-5 km away

42. Behavior Change Communication
Imparted through all probable approaches
Personal prophylaxis against vector
Segregation of amplifier host
Early reporting of cases

43. JE Vaccination
3 Types of vaccines
o Inactivated mouse brain
o Inactivated primary hamster kidney cells
o Live attenuated SA-14-14-2 – single dose, s/c

44. JE Vaccination Strategy-India
• One time mass campaign in 1-15yrs in
endemic districts
• Integrate into routine immunisation to cover
new cohort along with DPT booster
• Coverage both urban & rural children
• 2008 –Alappuzha – 42 %
• 2009 – Thiruvananthapuram- 39 %

45. Criteria to identify district
• Case load of JE
• Incidence of JE
• Evidence of recent transmission
• Serological evidence fom studies
• Epidemiological link to known areas of
transmission

46. THANK YOU