Health officials in northern India report that a serious outbreak of Japanese encephalitis has infected hundreds of children. The viral brain disease, which can cause permanent disabilities and sometimes death, is a common seasonal disease in Asia. Experts say it is likely the virus also is spreading in other countries in the region, but is going undetected due to inadequate surveillance and diagnostics.
In India every year, during the rainy monsoon season, hundreds of children die or become disabled, physically or mentally, after contracting Japanese encephalitis. Doctor K. P. Kushwaha is a senior pediatrician at a government hospital in Gorakhpur, in the Indian state of Uttar Pradesh.
"We have the highest number of patients admitted in one day, which is 550 patients," said Kushwaha. "We have never got such figures in the past. In the current cases of encephalitis, the children not only have swelling in their brains, but their skin, kidney, liver and heart also show swelling.”
"Japanese encephalitis is interesting because it is in animals as well as in people. This is a virus that will never be eradicated or eliminated,” said Dr. Julie Jacobson, who is trained in clinical tropical medicine and is a senior program officer at the Gates Foundation, a private philanthropy.
She explained that encephalitis is a zoonotic infection that is found in humans, as well as in a variety of domesticated and wild animals. Pigs and migratory birds pose a special danger because they are so-called "amplifying hosts" - they store the virus in large amounts in their systems without getting sick.
When mosquitoes bite an infected pig or bird, they pick up the virus and can transmit it to humans when they bite them.
Jacobson said Japanese encephalitis, when it is not fatal, can leave victims with severe physical and mental damage.
“People’s personality changes - they have behavioral issues," she said. "A very striking finding is that within families when you are talking to them, the children who have survived, kids will not recognize a family member. So they will be crying, crying to talk to their sister, 'I want my sister, I want my sister I want to talk to my sister' - it is very devastating for families to have that kind of disability that comes to the household.”
Health experts say the best way to protect people against this crippling disease is to immunize them with the encephalitis vaccine. They recommend that children especially be routinely vaccinated. Jacobson said there also is an urgent need for public health agencies to step up surveillance and diagnostic operations in endemic countries - to look for early signs of encephalitis and take steps to limit its terrible toll.