This document discusses several cases of acute encephalitis syndrome (AES) along with background information on AES etiologies and Japanese encephalitis (JE) epidemiology. Case 1 involves a 15-year-old boy with JE diagnosed by CSF IgM antibody testing who required ventilatory support and developed aphasia. Case 2 is a 65-year-old man with varicella zoster virus encephalitis diagnosed based on clinical presentation. Case 3 is a fatal case of dengue encephalitis diagnosed based on CSF findings and clinical course. Case 4 involved HSV encephalitis confirmed by PCR testing who recovered with acyclovir treatment. Case 5 involved mumps meningoencephalitis presenting with par

1. Acute Encephalitis Syndrome
Yogiraj Ray
MD (Tropical Medicine)
Assistant professor
Calcutta School of Tropical Medicine

2. Case 1
• 15 years old boy from Dhapa, near Kolkata
• Fever for 7days- initially low grade, then high grade
from next day with chills
• Headache
• 5 episodes of GTCS in 3 days.
• Unconscious for 3 days
• No rash/bleeding/ cough/ pain abdomen/ loose
motion/ dysuria/ history of travel.

3. On Examination
• GCS: 5
• Pupil : pin point (B/L)
• Doll’s eye : Present
• B/L basal crepts
• Pulse: not palpable
• Respiration: shallow, 38/min
• Blood Pressure : Not recordable

4. Your opinion & management

5. Case Definition of Suspected case
• Acute onset of fever, not more than 5-7 days duration.
• Change in mental status with/ without
 New onset of seizures (excluding febrile seizures)
 (Other early clinical findings – may include irritability,
somnolence or abnormal behaviour greater than that seen
with usual febrile illness)
Important
• In an epidemic situation fever with altered sensorium persisting for more than two hours with a focal
seizure or paralysis of any part of body, is encephalitis.
• Presence of rash on body excludes Japanese Encephalitis.
• AES with symmetrical signs and fever is likely to be cerebral Malaria.

6. Case Classification
Probable Cases
• Suspected case in close geographic and temporal
relationship to a laboratory-confirmed case of AES/JE in an
outbreak
Acute Encephalitis Syndrome due to other agent
• A suspected case in which diagnostic testing is performed
and an etiological agent other than AES/JE is identified
Acute Encephalitis Syndrome due to unknown agent
• A suspected case in which no diagnostic testing is
performed / no etiological agent is identified / test results
are indeterminate

7. Laboratory-Confirmed case
A suspected case with any one of the following markers:
• Presence of lgM antibody in serum and/ or CSF to a
specific virus including JE/Entero Virus or others
• Four fold difference in lgG antibody titre in paired sera
• Virus isolation from brain tissue
• Antigen detection by immunofluroscence
• Nucleic acid detection by PCR
In the sentinel surveillance network, AES/JE will be diagnosed by lgM Capture ELISA, and virus
isolation will be done in National Reference Laboratory

8. encephalitis
Vector borne
• Japanese B
• West Nile
• Chandipura
• Tick borne
• Chikungunya
• Dengue
Important others
• HSV
• Rabies
• Nipah
• VZV
• Mumps
• Measels
• Enteoviruses
• Poliomyelitis
• HIV

9. JE Epidemiology

10. Mosquito
• In India, JE virus has been isolated from 17 mosquito species
in wild caught specimens from different parts of the country.
• Maximum isolations have been recorded from Culex vishnui
group consisting of Cx.tritaeniorhynchus, Cx.vishnui and
Cx.pseudovishnui.
• Female mosquitoes get infected after feeding on a vertebrate
host harbouring JE virus and after 9-12 days of extrinsic
incubation period, they can transmit the virus to other hosts.

11. • The ratio of overt disease to inapparent infection
varies from 1:250 to 1:1000.
• Thus the cases of JE represent tip of the iceberg
compared to the large number of inapparent
infections.
• Usually the number of overt disease cases reported
from each village is 1 or 2.

12. Post Mortem Lesions JE
• Pan-encephalitis
• Infected neurons scattered
throughout CNS
• Occasional microscopic
necrotic foci
• Thalamus generally
severely affected
• Basal ganglia, brain stem,
cerebellum, hippocampus
& cerebral cortex

13. SYMPTOMS
• Incubation period: 5-15 days
• Fever, headache, nausea, vomiting, myalgia
• Altered mental status follows
• Seizures in 66% esp. children. headache & meningismus more
common in adults
• Tremor & involuntary movements common.
• Mutism reported.
• Fever subsides by 2nd week
• Extrapyramidal symptoms develop later

14. SIGNS
• Varied neurologic signs
• Generalised weakness, hypertonia, hyperreflexia
• Papilloedema in <10%
• Cranial nerve findings –33% (disconjugate gaze,cr. nv. palsy)
• Extrapyramidal signs frequent(mask like facies,tremor, rigidity.
choreoathetoid movement)
• May be loss of bowel & bladder control

15. Mortality & morbidity
• An estimated 25% of the affected children die
• Among those who survive, about 30-40% suffers
from physical & mental impairment

16. MRI of brain-JE

18. Schematic antibody responses in JE
infection
All samples must be sent in cold chain

19. Specimen collection and
transportation
• Blood (serum) and Cerebrospinal fluid (CSF) are the
specimens to be collected for JE diagnosis.
• Blood samples should be collected from suspected JE cases
within 4 days after the onset of illness for isolation of virus
and at least 5 days after the onset of illness for detection of
IgM antibodies.
• A second, convalescent samples should be collected at least
10-14 days after the first sample for serology.

20. Probable JE
• Encephalitis syndrome
• CSF consistent with Viral Encephalitis
• Elevated IgM antibody
• Stable antibody

21. Confirmed Case
• Suspected case plus
• Any one or more of the following
 JE IgM in CSF
 Or 4 fold or greater rise of antibody titers in paired
sera (acute /convalescent)
 Or detection of virus, antigen or genome in tissue,
blood or other body fluids.

24. Indications of Ventilatory Support
1. GCS<8
2. Very Shallow Respiration/ Severe Respiratory Distress
3. Capillary Refilling time/ colour of Patient Not Improved
4. Dusky Colour of body/ Cyanosis
5. Needs continuous Bag and Mask (Ambu) respiration
6. ABG Parameters
7. ARDS with or without Sepsis

25. Management of convulsions
Give anti convulsants if there was a history of convulsions and not given earlier, or convulsions are present.
Number one to three are first drug of choice, if convulsions are not controlled.

26. Maintenance Dose
• Phenobarbitone 3-8mg/kg/day I/V or oral
• Phenytoin 5-8 mg/kg/day I/V or oral
• Sodium Valproate 40-60mg/kg/day Oral
• Levetiracetam 10 mg/kg twice a day

27. Management of case 1
• ABC
• Anticonvulsunt
• Confirmed JE by CSF anti JE IgM antibody
• Sepsis manage
• Tracheostomy
• Feeding jejunostomy
• Pysiotherapy
• Discharged with recovery (aphasia still there)

28. Case 2
• 65 year male from Bankura H/O fever with
vesicular eruption for 5 days
• Seizure 2 episode
• Bizarre behavior with involuntary movement
• ???? Diagnosis

29. Treatment
• No need for ventilator
• Isolation
• Aciclovir
• Cured and discharged after 10 days

30. Case 3
• Fever 3 days
• Diffuse macular rash with island of clear skin 1
days
• Sudden unconciousness 6 hours
Diagnosis??????

31. • Diagnosed as dengue
• CSF pleocytosis only
• Looked for many causes
• Iv antibiotic as per meningitis
• Aciclovir
• Died after 3 days

32. Case 4
• Fever for 15 days
• Altered sensorium 3 days
• Bizarre movement 10 days back which
recovered after 3 days
• Admitted with GCS 10
• No need for CCU care

33. • CSF s/o viral encephalitis
• HSV PCR positive
• IV Aciclovir for 21 days
• Physitherapy
• After 21 days: aphasia, ophthalmoplegia,
chorieform movement
• Complete recovery after 40 days

34. Case 5
• 25 yr old male b/l parotid enlargement with
fever 7 days
• Testicular pain for 3 days
• GCTS with status
• Admitted at CCU

35. • Iv lorazepum
• Phenytoin loading & maintenance
• Add on Levetiracetam
• GCTS controlled but unconscious
• O2 by T-piece

36. Recovery
• Supportive care
• Physiotherapy
• RIBAVIRIN

37. AES
• JE
• HSV
• VZV
• Mumps
• WNV
• HIV related
• Unclassified (???????) : keep them as AES

38. Thank you