Japanese Encephalitis (JE) is a little-known mosquito-borne disease that can have devastating consequences. Although cases are isolated in Singapore, you can still protect your family with a vaccine.
Getting bitten by insects is not uncommon in our tropical climate. Most insect bites are harmless and can be quickly and easily treated, but certain types of insects carry diseases, and their bite can prove fatal. Mosquitoes are a good example. These tiny insects are known to transmit diseases like malaria and dengue fever, but there is one mosquito-borne disease that you may not have heard of: Japanese Encephalitis (JE). The incidence of JE in Singapore is rare, but that is no reason to leave your family unprotected.
WHAT CAUSES IT?
The first case of JE was documented in 1871 in Japan. The disease is caused by a flavivirus, which is closely related to the dengue, yellow fever and West Nile viruses. It was transmitted to humans via Culex mosquitoes in Asia. The World Health Organization (WHO) reports that JE is the main cause of viral encephalitis in many countries in Asia – near to home and popular destinations we travel to – with nearly 68,000 clinical cases ever year.1
The virus lives in host animals such as pigs and wading birds. Culex mosquitoes feed on the blood of these animals and then transfer the virus to humans through bites. Although Culex mosquitoes’ favourite breeding grounds are flooded rice fields and marshes, these insects have also been found in urban environments.
INCIDENCES OF JE HERE
Occurrences of JE used to be regular in Singapore, but incidences of the disease have decreased ever since pig farming was phased out in 1992, with only six cases reported between 1991 and 2005. Still, findings suggest that the virus remains active on our island.2 The disease also occurs in neighbouring countries where pig farming is prevalent and, as such, it is important not to take the threat for granted.
WHAT ARE THE SYMPTOMS?
The JE virus causes either no symptoms or mild, short-lived symptoms, which are often mistaken for those of the fl u. Typically, these symptoms include fever, headache, diarrhoea and muscle pain.
In extreme cases, the infection can spread to the brain, causing symptoms of encephalitis such as seizures, stiff neck, muscle weakness, uncontrollable shaking of body parts, the inability to speak, paralysis, and changes in mental state that can range from mild confusion to coma. Death may result in very severe cases. For those who survive, recovery tends to be slow.3
PREVENTING JE
According to WHO, there is no specific cure for JE. Treatment is focused on relieving severe clinical signs and supporting the patient to overcome the infection.3 The good news is that you can protect your family with the JE vaccine. There are different vaccines available for infants, children and adults. For more details, speak to your paediatrician or health-care provider.
1 WHO Media Centre. Japanese Encephalitis. Available at www.who.int/mediacentre/factsheets/fs386/en. Last accessed September 2015.
2 Yin-Ling Koh et al. Emerging Infectious Diseases, www.cdc.gov/eid, Vol. 12, No. 3, March 2006.
3 The National Health Service in the UK. Available at www.nhs.uk/Conditions/Japanese-encephalitis/Pages/Symptoms.aspx. Last accessed September 2015.
