Japanese Encephalitis (JE)
Introduction
Japanese encephalitis is a viral disease which is transmitted by mosquitoes. JE is commonly a rural disease because the mosquito mainly breeds in paddy fields. Pigs and water birds play an important role in transmission of this virus. JE is a disease which affects mainly children. It causes infection of the brain and it’s covering membranes (meninges). Out of the patients who get this disease about 30% die. Out of those that survive about 50% are left with neurological or psychiatric disability. Presently in Sri Lanka patients are reported in small numbers in Colombo, Gampaha, Kurunagala and Ratnapura districts. Although Sri Lanka had 2 -3 epidemics now due to successful vaccination the number of cases recorded are reducing.
Japanese encephalitis virus which belongs to the Flavi virus family.
It is transmitted by the bite of the Culex tritaeniorhynchus mosquito. This mosquito bites humans out doors although it prefers the blood of animals more.
The virus breeds and multiplies in pigs, bats, pigeons, cranes etc. When the virus enters a human it takes about 3 -15 days for symptoms to occur.
According to symptoms the illness can be divided to 3 stages.
- Prodromal stage - rapid onset of high fever and shivering can occur during this stage. Severe headache, nausea and vomiting can occur.
- Acute encephalitis stage - Developing seizures (fits), neck stiffness, loss of consciousness or reduced level of consciousness, disorientation, restlessness paralysis or even coma
- Late stage - The patient may get back to normal or have long term neurological and psychological symptoms.
If not treated early JE becomes a killer disease. 30% of those who develop the illness die. Out of the survivors many as 50% may end up with disabilities both neurological and psychiatric. It is a burden to the family as well as the country.
JE is a medical emergency. Rush the person who has suggestive symptoms of JE to the nearest hospital. The disease is confirmed by checking blood or a sample of cerebro-spinal fluid. There is no specific antiviral treatment for JE. But intensive supportive medical and nursing care may lead to complete recovery or minimal neurological complications.
Effective vaccines against JE are available in Sri Lanka both in government and private sector.
If traveling to endemic areas protect against mosquito bites by using repellants and / or mosquito nets. Wear clothing which covers arms and legs especially when out doors.