Dec 14, 2012
The new strain tracked by Indian scientists is difficult to counter and accounts for the vast majority of JE-related deaths in India
Faced with flak over its failure in combating Japanese Encephalitis (or JE, causing brain fever) that has claimed 884 deaths across India, health planners are flabbergasted with fresh news of a new strain of the Japanese Encephalitis Virus (JEV) circulating in India's eastern state of West Bengal.
JE is rampant in many states of India, despite an active vaccination programme. The stubbornness of disease is also attributed to this strain of virus.
According to a study published in the online journal, Virology Journal, researchers confirmed noticing a new strain of the virus. This new strain coexisted with the existing strain and was found in over a quarter of 135 patients hospitalised for AES. This strain was first detected three years ago in the Gorakhpur district of the northern state of Uttar Pradesh.
The unusual strain of the JE virus has challenged the efficacy of vaccines currently used against JE derived from the dominant strain. "In future, JE outbreak is quite likely in the state if this vaccine fails to protect sufficiently against GI of JEV," the researchers noted in their study.
This strain is difficult to counter and accounts for the vast majority of JE-related deaths in India. Researchers from the Indian Council for Medical Research (ICMR) have confirmed the strain in the samples of blood, and fluid from brain and spinal column, of patients admitted to government hospitals in eight West Bengal districts.
The ICMR scientists, who were joined by scientists from the microbiology department of the University of Burdwan, were unable to ascertain how the GI strain, earlier reported circulating in South Korea, Thailand and China, had reached India.
It was possible, researchers said, that the GI strains were brought in by travellers, migratory birds (such as herons) or mosquitoes blown in by cyclonic winds. Domestic pigs are known reservoirs of JEV.
Transmitted to humans by the culex mosquito, the symptoms of JE include severe rigors, convulsions and high temperature. Patients may go into coma and the fatality rate is high among child victims.
First isolated in Japan in 1935, JEV has become a major public health menace with a worldwide case-fatality rate of 30 per cent and 30–50 per cent of survivors develop permanent brain damage.
In October, India's Union Cabinet -- its highest executive decision making authority -- approved a proposal for a comprehensive multi pronged strategy for the prevention and control of Japanese Encephalitis and Acute Encephalitis Syndrome entailing some US $ 730 million.