Gorakhpur encephalitis mystery may soon be cracked
Diagnostic kit developed by B’lore scientists looks for 23 pathogens
Desperately seeking an answer to the Gorakhpur encephalitis mystery, the Union health ministry has now turned to a group of Bangalore-based researchers to find out if their diagnostic kit can finally crack the code.
The indigenous test kit looks for as many as 23 pathogens – all causing acute encephalitis syndrome (AES) – in a single sample and identifies the culprit within seven hours.
Notwithstanding the recurring nature of AES outbreaks in Uttar Pradesh in the last seven years, medical investigators still have not been able to identify the causative organism. The ongoing Gorakhpur outbreak has affected close to 3,000 children and killed more than 400.
Even though doctors don’t know what is causing the outbreak, they are treating children for encephalitis symptoms. After reviewing the Gorakhpur scenario on last Friday, the Indian Council of Medical Research decided to send samples to V Ravi of National Institute of Mental Health and Neuroscience who along with B V Ravi Kumar of Xycton Diagnostics Ltd claimed to have developed the detection kit with funding from Council of Scientific and Industrial Research (CSIR). “We hope to receive the samples within a week. This is the first time we will test it in an outbreak. There is no other diagnostic kit that can search 23 pathogens in a single sample,” Ravi told Deccan Herald.
Even though Japanese Encephalitis was originally the main cause of UP outbreaks, over the years, JE positivity in AES cases has come down to a mere seven percent in 2011 as against 36 per cent in 2005.
At the same time, the proportion of AES cases increased from 64 per cent in 2005 to more than 90 per cent in 2011, making the situation alarming. Scientists at the National Institute of Virology, Pune showed that a large part of AES is due to entero-viruses, transmitted through contaminated water.
Ravi said globally there are 75-100 organisms that cause AES, out of which 22-25 are found in India. The Xycton-NIMHANS diagnostics can detect almost all of them. The multiplex polymerase chain reaction (PCR) kit had been successfully validated with 425 samples at NIMHANS, Kumar said. When multiplex PCR was applied in 127 samples that tested negative in conventional tests, the diagnostics identified 83 of them.
Cerebrospinal fluid of AES patients would be collected in such a manner that the genetic material remains intact. Only a tiny drop of sample (0.5 cc) is required for the elaborate laboratory test that lasts for seven hours. The genetic material from the sample is first isolated and subsequently amplified in a PCR. Then it is put on a specially designed chip that contains probe for all the 23 pathogens, which include a large number of virus and bacteria as well as a solitary fungus and parasite. The test has high specificity and sensitivity.
“We are in the process of filing a patent on this technology,” said a CSIR official.
