What is the treatment and prevention for Japanese encephalitis?

Treatment and Prevention of Japanese Encephalitis

Treatment for Japanese encephalitis (JE) consists solely of supportive care and management of complications, as no specific antiviral agent or medication has been proven effective against JE virus infection. 1

Treatment Approach

Supportive Care

• JE treatment is limited to supportive care focusing on managing symptoms and complications 1
• Management includes:
  • Maintaining adequate hydration with intravenous fluids 1
  • Respiratory support in severe cases with declining consciousness 1
  • Monitoring and management of increased intracranial pressure 1
  • Anticonvulsants for seizure control if needed 1

Ineffective Treatments

• Clinical trials have demonstrated that the following treatments do not improve outcomes:
  • Corticosteroids 1
  • Interferon alpha-2a 1
  • Ribavirin 1
  • Minocycline 1
  • Intravenous immunoglobulin 1

Prevention Strategies

Vaccination

• Vaccination is the most effective prevention strategy for JE 1
• JE vaccines are recommended for:
  • Residents in endemic areas, particularly children 1
  • Travelers staying for prolonged periods in rural areas with active JE virus transmission 1
  • Travelers with extensive outdoor or nighttime exposure in rural areas during periods of active transmission 1
  • Laboratory workers with potential exposure to JE virus 1

Mosquito Precautions

• Personal protective measures include:
  • Using insect repellents containing DEET, picaridin, or IR3535 1
  • Wearing long-sleeved shirts and long pants 1
  • Staying in accommodations with air conditioning or window/door screens 1
  • Using permethrin-treated clothing and gear 1
  • Avoiding outdoor activities during peak mosquito biting times (dusk to dawn) 1

Risk Assessment for Travelers

• Risk factors to consider include:

  • Destination (rural vs. urban areas in endemic regions) 1
  • Duration of travel (longer stays increase risk) 1
  • Season (higher risk during rainy season in tropical areas, summer in temperate areas) 1
  • Activities planned (outdoor activities increase risk) 1
  • Accommodations (lack of air conditioning or screens increases risk) 1

• Short-term travelers (<1 month) whose visits are restricted to major urban areas are at minimal risk for JE 1

Prognosis and Sequelae

• JE has a case-fatality ratio of 20-30% 1
• Among survivors, 30-50% experience neurologic or psychiatric sequelae even years after infection 1
• Common sequelae include:
  • Seizures 1
  • Upper and lower motor neuron weakness 1
  • Cerebellar and extrapyramidal signs 1
  • Flexion deformities of the arms 1
  • Hyperextension of the legs 1
  • Cognitive deficits 1
  • Language impairment 1
  • Psychiatric issues 1
  • Learning difficulties 1
  • Behavioral problems 1

Common Pitfalls in Management

• Delayed diagnosis due to nonspecific initial symptoms 1
• Misdiagnosis due to similarity with other viral encephalitides 1
• Failure to consider JE in travelers returning from endemic areas with neurological symptoms 1
• Reliance on insensitive diagnostic methods (virus isolation and nucleic acid amplification tests) 1
• Inadequate preventive measures for travelers to endemic regions 1

Diagnostic Approach

• IgM antibody-capture enzyme-linked immunosorbent assay (MAC ELISA) is the preferred diagnostic test 1
• JE virus IgM antibodies can be detected in:
  • CSF within 4 days of symptom onset 1
  • Serum by 7-8 days after symptom onset 1
• Presence of JE virus IgM antibodies in CSF provides evidence of JE virus as the cause of neurologic illness 1
• Plaque reduction neutralization tests (PRNTs) can be performed to confirm recent infection 1