Travel frequently to Asia countries? Protect your child against Japanese Encephalitis - a leading viral encephalitis in Asia

A healthy child is a blessing. Parents do everything in their power to ensure that their children have a disease-free childhood so that they have a strong foundation for good health and success in their adult lives.

An important step in facilitating this, is being aware of common childhood diseases, being able to to recognize their symptoms and knowing preventive measures against them.

This article looks at Japanese Encephalitis (JE), a disease that is caused by a virus spread by infected mosquitoes. It is a potentially severe disease that can lead to inflammation of the brain (encephalitis) and is often accompanied by seizures. In some cases, coma and paralysis can also occur.^1,2,3

About 20-50% of encephalitis cases result in death.¹

Japanese Encephalitis is caused when an infected Culex Tritaeniorhynchus mosquito bites a human being.

What is Japanese Encephalitis and how does it spread?

Japanese Encephalitis is a viral brain infection caused by JE virus. JE is closely related to West Nile encephalitis, dengue, and yellow fever.

Mosquitoes, particularly the Culex Tritaeniorhynchus mosquito, pick up the virus from feeding on infected birds and pigs. Infected mosquitoes can then transmit the virus to humans through their bites.^1,2

The disease has a long history, with the first clinical case of Japanese Encephalitis being documented in Japan in 1871.³ Despite this fact, there is no specific treatment for it to date.¹

Recognizing the symptoms

Most human infections are asymptomatic or result in only mild symptoms.^1,2,3

However, 1 out of 250 infections will rapidly progress into severe complications such as inflammation of the brain (encephalitis)^1,2,3.

Symptoms typically develop 5 to 15 days after the bite of an infected mosquito and include^2,3:

• Fever
• Chills
• Headache
• Fatigue
• Nausea
• Vomiting
• Seizures (especially in children)
• Coma
• Loss of speech
• Disorientation

Click on the next page to find out more about the prevention of Japanese Encephalitis.

Treatment and prevention

In temperate areas of Asia, transmission usually peaks in the summer and fall. In the subtropics and tropics, transmission can occur year-round.² JE is the main cause of viral encephalitis in Asia with an estimated 68 000 cases every year³. JE virus transmission occurs primarily in rural agricultural areas. However, in some areas of Asia, these conditions can occur near urban centers too.⁴

There is no specific treatment for JE and patient management focuses on supportive care and management of complications.^2,3 This implies hospitalization and close observation of the person infected with JE.

The diagnosis is based on a combination of clinical signs and symptoms and specialized laboratory tests of blood or spinal fluid. These tests typically detect antibodies that the immune system makes against the viral infection.²

The treatment focuses on dealing with the symptoms and use of pain relievers and medication to reduce the fever are common. Although some symptoms improve after the acute illness, 20%-30% of survivors continue to have neurologic, cognitive, or psychiatric symptoms.^2,3

There are two measures that can be taken to prevent JE and these are to firstly use personal protective measures to prevent mosquito bites and secondly get vaccinations, especially when travelling to JE risk areas.

There is no specific treatment to date for Japanese Encephalitis. The best way to combat it, is to prevent it and being vaccinated against it is one such measure.

Avoid mosquito bites

1. Use insect repellent.
2. Wear proper clothing such as long-sleeves and long pants.
3. Sleep indoors and as far as possible under mosquito nets.
4. Reduce exposure to mosquitoes during peak biting hours, by staying indoors during cooler hours from dusk to dawn.

Get vaccinated

JE vaccine can further reduce the risk for infection. ^2,3 As Asia is often our frequent travel destination, prevention is key. Talk to your pediatrician or healthcare providers about the available vaccines and other ways to protect against Japanese Encephalitis.

Glossary:

Encephalitis – inflammation of the brain, caused by infection or an allergic reaction

References:

1. Ministry of Health Website: https://www.moh.gov.sg/content/moh_web/home/pressRoom/pressRoomItemRelease/1999/Frequently_Asked_Questions_On_Japanese_Encephalitis.html Last Accessed March 2016

2. Centers for Disease Control and Prevention, USA. Japanese encephalitis. Available at https://www.cdc.gov/japaneseencephalitis/qa/index.html Last accessed March 2016

3. World Health Organisation Fact Sheet on Japanese Encephalitis: https://www.who.int/mediacentre/factsheets/fs386/en/ Last accessed March 2016

4. K Chokephaibulkit et al, Expert Review of Vaccines, 2016

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