Japanese encephalitis: it's preventable

Japanese encephalitis is a deadly disease that is caused by a virus and transmitted by mosquitoes from infected animals, usually pigs or wild birds. It occurs primarily in rural areas of South and East Asia. 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. Other countries such as Viet Nam, Cambodia, Myanmar, India, Nepal, and Malaysia still have periodic epidemics. With a few precautions, travelers to these areas should not have to worry about contracting the disease. Although 30,000 to 50,000 cases of Japanese encephalitis are reported annually, less than one case per year is reported in U.S. civilians and military personnel living in or traveling to Asia. Most people who are infected with Japanese encephalitis show only mild symptoms such as fever and a headache. More severe infections can produce symptoms such as a stiff neck, gastrointestinal problems, vomiting, confusion, tremors, stupor, and coma. In about one out of every 200 cases, advance stages of the illness cause inflammation of the brain, and more than half of those cases end in permanent disability or death. Since Japanese encephalitis is transmitted by mosquitoes, the best way to avoid contracting the disease is to avoid being bitten by mosquitoes. In tropical areas, the rainy season and early dry season is the time when the disease is most likely to be transmitted. In temperate areas, the critical time is during the summer months. But regardless of the season, you should avoid being outside during the dusk and dawn hours, when it's cool and mosquitoes are most actively feeding. Also use mosquito repellent and aerosol room insecticides. If your bedroom doesn't have screens or air conditioning, the use of a mosquito net is a must. Don't worry about contracting Japanese encephalitis from another person, even a health care worker who has treated someone with the disease, because the disease is transmitted only by mosquitoes, not from person to person. You can get vaccinated against Japanese encephalitis, but in a small number of cases there have been reports of serious allergic side effects. About one in ten people who receive the vaccine also experience chills, muscle pain, nausea, vomiting or abdominal pain. The National Center for Infectious Diseases does not recommend the Japanese encephalitis vaccine for most travelers to Asia, unless they will be spending more than a month in endemic areas during the transmission season, and especially if their travel will include rural areas. The Center does recommend the vaccine for expatriates who plan to live in areas where Japanese encephalitis is found. Interested in this subject? Try this link for more of the same.