Japanese B Encephalitis - The Disease
This is a rare but serious viral (Culex) mosquito-borne disease endemic in the Far East and South East Asia. Between 30,000 and 50,000 cases are reported annually. Mosquitoes which breed in rice paddies become infected through contact with domestic pigs and wild birds, and pass on that infection to humans. Encephalitis is inflammation of the brain. The disease causes headache, fever, stiff neck, meningeal irritation, cranial nerve paralysis, disorientation, coma, tremors, convulsions.
Incubation period
The incubation period is between 5 and 15 days.
Vaccination with JE-VAX® (Aventis Pasteur)
Vaccination is recommended for stays of longer than one month in rural areas during and just after rainy seasons. These are the periods when mosquitoes are most active. The vaccine is NOT licensed and is issued on a named patient basis. It is given as a series of 3 injections over a period of 2-4 weeks; a booster can be given after 2-3 years. The minimum age for vaccination is one year. The vaccine confers protection for a period of about 2 years. It is NOT recommended for all travellers to Asia, since the risk of infection for short-term travellers is one in a million. The disease is uncommon in urban areas, with residents of rural areas being most at risk. Travellers are rarely affected.
The vaccine is taken in 3 doses, on days 1, 7 and 14, at least 6 weeks before departure. Boosters are offered every 2 years.
Contents of the vaccine
- Inactivated Nakayama-NIH strain of
Japanese encephalitis virus
- Mouse brain protein infected with the disease
- Thiomersal (Mercury) added as a preservative
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- Gelatin added as a stabiliser
(from boiled pig)
- Formaldehyde
- Polysorbate 80
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Contra-indications
- Previous allergy to vaccine, or allergy to rodents (but how would you know?!)
- Any allergy or hypersensitivity to bees or insect bites
- Any febrile illness
- Alcohol should be avoided for 48 hours following vaccination
- Hypersensitivity to thiomersal (mercury)
- The vaccine should not be used in pregnancy
Side effects of the vaccine
- Redness, pain and
swelling at injection site
- Headache, fever
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- Muscle aches
- Chills, wheezing
- Dizziness, nausea
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- Vomiting, abdominal pain
- Facial swelling
- Hives, itchiness
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Homeopathic prophylaxis
Take Japanese B Encephalitis Nosode 30c weekly while travelling in high risk areas - this can help prevent the disease. Avoidance of mosquitoes is essential.
- Avoid places where there is stagnant water.
- Stay indoors when mosquitoes are most likely to bite, i.e. dusk to dawn.
- Use insect repellent and sleep under mosquito nets.
- Avoid using perfumes and after shave.
- At evening time, wear long-sleeved shirts, trousers and hats (light colours are best).
- Eat lots of garlic (raw if possible).
- Take 50mg of vitamin B1 morning and evening to deter mosquitoes from biting. Also take vitamin B complex.
- Take Ledum 30c 3 times a week to help prevent bites.
- If you are particularly prone to being bitten, take Caladium 6c and Staphysagria 12c daily in addition to Ledum.
- Citronella oil deters mosquitoes: either burn it in your room, or add it to a light cream or oil to rub on your body.
- Lavender oil applied to bites helps to relieve itchiness.
References
[JAPANESE1] © Liz Bevan-Jones SRN LCH RSHom: updated August 2007