Japanese Encephalitis: New Vaccine and Advice
WORLDWIDE | Monday, 1 June 2009 | Views [1368] | Comments [1]
For travelers headed to Asia, avoidance of Japanese Encephalitis should be a priority as high as finding a decent noodle bar.
WorldNomads.com's roving medical expert Dr. Erik McLaughlin MD tells us about new developments in a vaccine and once again reminds us to avoid mozzies!
What is Japanese Encephalitis?
A traveler does not need to have a degree in infectious diseases to know that Japanese Encephalitis is found in Asia. This is because, unlike so many of the other viral illnesses, the name is quite simple when broken down. Encephalitis features the Greek root word “encephalo” meaning brain and “itis” meaning inflammation or infection. So we have an inflammation/infection of the brain that is found in Japan and Asia.
Where is it found?
Japanese Encephalitis is found in a large area, covering much of Asia and specifically South East Asia - see the map below. This is considered primarily a disease of rural environments and those traveling to farming areas are considered at special risk.
The time of year is a special concern, as well. Although the disease is active year-round, rainy seasons increase mosquito populations, generally causing an increase in the number of cases.
JE is very important to travelers because approximately 30,000-50,000
cases are diagnosed each year, in the regions it is found. Of these
cases, the majority are asymptomatic but of those infections with
symptoms, up to 30% are fatal. Also, most experts agree that the
number of reported cases is much less than actual cases.
How do I get it and what does it cause?
This viral illness is a frequent problem for travelers, not necessarily because of the infection itself but because the vaccine against it is quite controversial.
JE is spread through the bites of infected mosquitoes making it very difficult to prevent - and treatment once acquired, is only supportive. This means that once you actually get the illness, there is not a lot that can be done about it, other than keeping the victim comfortable with adequate hydration, fever reduction and pain control. Symptoms of JE typically include high fevers, headaches, disorientation and sometimes seizures.
How do I prevent it?
Preventing infection with JE still centers on avoiding mosquito bites. Bite prevention is best accomplished with a two-fold approach including barrier methods such as bed nets, long sleeves and long pants. Second, using chemical insect repellents such as DEET body spray and permethrin treated clothing are strongly advised. Avoidance of outdoor activity during peak mosquito biting times (dusk/dawn) should also be attempted.
Vaccines against JE
Recently, a new vaccine against Japanese Encephalitis has become approved in the USA named Ixiaro. This vaccine is currently awaiting approval in the EU. This is a major step forward in protecting travelers because the previous vaccine was often difficult to obtain and had many side effects.
The old vaccine was made with mouse-brain tissue and carried a lot of risk with it, prompting travel docs to be hesitant when advising those to use it. The old JE vaccine was especially known to cause severe allergic reactions. Previously, the vaccine was advised for those traveling to rural areas and planning extended travels, for a month or more. Also, those planning camping and outdoor sleeping were considered good candidates for the vaccine.
However, all things change and with the development of a new and safer vaccine against JE, so have the recommendations to travelers in these areas. A recent article in the Journal of Travel Medicine looks at this new vaccine and analyzes the recommendations from an “expert group” looking at travel vaccines. From their meeting, the following advice was generated about who should be receiving the new and safer JE vaccine.
Who should receive the new JE vaccine?
- All expatriates
- Repeat travelers who frequent the area and have prolonged stays
- Any person traveling to rural areas
- Travelers wishing maximum protection
Persons who should consider the new JE vaccine include:
- Those with increased outdoor exposure
- Persons over 50 years of age
- Children less than 10 years of age
- Those with chronic medical conditions
What does this all mean for travelers?
Previously, the risk of severe reaction to a JE vaccine caused many travelers to avoid this protective measure. Currently, a new and safer vaccine appears to be free of these previous side-effects. This means travelers have a better weapon against preventing this potentially fatal illness. Hopefully, this will prompt travelers headed to Asia to discuss this new vaccine with their travel doctors and have more peace of mind with a safer vaccine.
Spread of Japanese Encephelitis across Asia (Map graphic courtesty of Wikipedia.com)
Tags: travel health, vaccination, medical health, travel medical, mosquitos, vaccine
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