Prevention and control measures of Japanese encephalitis

Personal protective measures

Different kinds of vaccines (inactivated, attenuated and chimeric) are available and used in several Asiatic countries. In Europe an inactivated vaccine is currently available.

Several inactivated and live attenuated Japanese encephalitis vaccines are manufactured and used in Asia, mostly in children. One inactivated vaccine produced on Vero-cells is available in Europe for use in > 18 years adults. Paediatric clinical trials are being conducted to enable licensure this vaccine for use in children.

The implementation of attenuated vaccine in unvaccinated populations will continue to decrease the incidence of the disease in endemic areas.

Another way to prevent Japanese encephalitis infection is to avoid mosquito bites in endemic rural areas more specifically close to irrigated rice fields and pig farms. Many mosquitoes are most active at dusk and dawn. People can use insect repellents when they are outdoors and wear long sleeves and trousers at these times, or consider staying indoors during these hours.

As there is no specific treatment, the best way to prevent Japanese encephalitis infection is to avoid mosquito bites. Inactivated vaccine is available under restrictive regulations for adults with potential risk of exposure (e.g. travel for more than 1-2 months in rural areas).

Public health measures

It seems that the change of agricultural practices has substantially decreased the risk of transmission to humans. Measures aiming to control adult mosquito vectors can be applied in an outbreak situation but its impact is not well known.