JE immunization is recommended at the population level in all regions where the disease is a recognised as a public health problem. In India, out of the 171 JE endemic districts, 132 districts have been brought under vaccination by giving single dose of SA 14-14-2 vaccine to all children 1-15 years of age. In addition, two doses of vaccines are given under routine immunization under the Universal Immunization Programme with the first does at the age of nine months and second dose with the booster of DPT.
JE vaccine is recommended also for travellers who plan to spend at least one month in endemic areas during the JE virus transmission season. Vaccines should be considered for the following:
• Short-term (less than 1 month) travellers to endemic areas during the transmission season, if they plan to travel outside an urban area and their activities will increase the risk of exposure. Higher-risk activities include participating in extensive outdoor activities (such as camping, hiking, trekking, biking, fishing, hunting, or farming) and staying in accommodations without air conditioning, screens, or bed nets.
• Travellers to an area with an ongoing outbreak.
• Travellers to endemic areas who are uncertain of specific travel destinations, activities, or duration.
Safe and effective JE vaccines are available to prevent disease. In addition, proper mosquito protection is important. Minimise your outdoor exposure to mosquitoes, especially in the early evening when their activity is the greatest. Wear long pants and long-sleeved shirts when outside and use DEET insect repellents.
In case of development of typical symptoms during transmission season in endemic areas, contact the nearest health care worker or health centre immediately.
Usually 5 to 15 days.
Most people who are infected develop mild symptoms or no symptoms at all. In people who develop severe disease, initial symptoms include fever, chills, headache, fatigue, nausea and vomiting. The disease can progress to inflammation of the brain (encephalitis) and is often accompanied by seizures. Coma and paralysis occur in some cases. When clinical signs are seen they have a quick onset with high fever, headache and neck stiffness. Infection of the brain (encephalitis) can cause disorientation, tremors or convulsions (especially in infants), paralysis and coma. Also, infections are generally more severe in infants and the elderly.
Yes, people can get JE from the bite of an infected mosquito (vector). The virus
is not spread directly from infected animals or people. Most human infections have limited or no signs of illness.
The JE virus causes disease in horses, donkeys and pigs. Other animals can be infected, but typically do not show signs of illness. These include cattle, sheep, goats, dogs, cats, wild mammals, reptiles, amphibians and birds.
Since JE virus is spread by certain species of mosquitoes, proper mosquito control can help minimise the spread of the disease. Designing pig shelters that minimise the swine-vector contact and use of bednets on pig shelters have been found to be effective in reducing JE infection in pigs.
Vaccines have been used for control of JE in swines in some countries such as Japan and Taiwan. However, vaccination is not used as a strategy in India mainly for two reasons. First, the high turnover in pig populations would require annual vaccination of newborn pigs, which would be costly and operationally challenging. Second, the effectiveness of live attenuated vaccines is decreased in young pigs because of maternal antibodies.
JE outbreaks are being reported from previously unknown foci. Further, encephalitis outbreaks of other aetiologies in endemic areas have only added to their complexity. For programme managers, researchers and community health professionals, access to accurate and updated information is key to planning interventions and other relief measures.read more