Japanese Encephalitis

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Japanese Encephalitis

• Rahul Kapoor

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Japanese Encephalitis

• Affects CNS and can cause severe complications
  and even death.
• Cause Japanese Encephalitis virus (arbovirus)
• Vector Rice field breeding mosquito primarily
  Culex tritaeniorhynchus
• No human to human transmission.
• It is most seen in Southeast Asia and the Far
  East.
• 30,000-50,000 cases are reported annually.

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Basic Transmission Cycle

• Mosquitos become infected by feeding on pigs and
  wild birds infected with JEV.
• The JE virus is amplified in the blood of pigs
  and wild birds.
• The infected mosquitos transfer the amplified
  virus to humans and animals.

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Pathophysiology

• The virus initially propagates at the site of
  the bite and the regional lymph nodes.
• Viremia develops causing inflammatory changes in
  heart, liver, lungs and reticuloendothelial
  system.
• Neurologic invasion can develop, possibly by
  growth of the virus across vascular endothelial
  cells.
• Large areas of brain can be involved including
  basal ganglia, thalamus, brains stem, hippocampus
  and cerebral cortex

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Signs and Symptoms

• Symptoms usually appear after 6-8 days after the
  mosquito bite.
• MILD INFECTION No apparent symptoms except
  fever headache
• SEVERE INFECTION Quick onset of high fever,
  headache, neck stiffness, disorientation,
  tremors, coma, occasional convulsions and spastic
  paralysis.
• If it progresses to encephalitis, it can be fatal
  in 30 of the cases.
• Among the survivors, 30 have serious brain
  damage, including paralysis.
• Diagnosis is based on tests of blood or CSF.

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Occurrence around the Globe

• JE is the leading cause of viral encephalitis in
  Asia.
• 30,000-50,000 cases each year.
• Countries which have had major epidemics in the
  past, but which have controlled the disease
  primarily by vaccination, include China, Korea,
  Japan, Taiwan and Thailand.
• Countries that still have periodic epidemics
  include Vietnam, Cambodia, Myanmar, India, Nepal,
  and Malaysia.

Japanese Encephalitis is seen in southeast Asia
and far east
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Treatment and Prevention

• No anti viral drugs have been discovered against
  JE so far.
• Intensive Supportive Therapy (nutrition, control
  of infection, intensive care) is indicated.
• Vaccines against JEV provide immunity against the
  virus.
• Can also be prevented by preventing mosquito bite
  (use of repellents etc)
• Drainage of stagnant water.

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Acknowledgement

• www.google.co.in
• http//gkpdiv.up.nic.in
• www.cdc.gov/ncidod/dvbid/jencephalitis/qa.htm
• www.sumerdoc.blogspot.com
• www.arbovirus.health.nsw.gov.au

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fin

• Thanks for your attention ?