New Delhi: A disease outbreak in western Uttar Pradesh, which has claimed at least 200 children according to the last official count in 2005, may not have come from a virus at all as government reports maintain, but from poisoning by a wild, abundantly growing weed called coffee senna (cassia occidentalis), say a series of papers in the peer-reviewed Indian Journal of Medical Research and Indian Paediatrics.
The outbreak in these regions, according to the authors involved in the research, is not encephalitis, generally caused by a virus, but actually an acute hepatomyoencephalopathy syndrome. Such a syndrome, typically a set of symptoms reported by a patient and signs analysed by a doctor, need not have a viral or bacterial cause, but could very well have originated from the environment.
Fatal Disease: A September 2005 file picture of a mother with her child suffering from Japanese encephalitis, as he lies at the Medical College in Gorakhpur, some 300km east of Lucknow
The National Institute of Virology (NIV), Pune, is the nodal government organization that collected field samples from patients to determine the cause of the disease. Since 2002, when media reports of a fatal fever in Saharanpur, Bagphat and Bijnor—all districts in western UP—started gaining ground, teams from the NIV collected and studied samples from infected patients.
But though the scientists say that it’s a virus—one of them even calling it a measles strain—nobody has actually found any trace of either a virus or any other micro-organism.
Jacob John, one of the authors involved in the research, said that detailed MRI (magnetic resonance imaging) scans on 55 children who showed symptoms of the disease disclosed that there was no inflammation of the brain. Encephalitis, by definition, means swelling of the brain, and further tests on the liver tissue of 21 children, showed that 17 of them had abnormalities, he added.
“Most striking were the presence of cell necrosis—or dead cells—in the liver, which were very typical of symptoms of poisoning. You never find such necrosis in encephalitis cases,” said Vipin Vashishtha, a paediatrician in Bijnor.
Moreover, the researchers claimed that the onset of the fever between September and November coincided with the annual blooming season of the weeds. Vashishtha also conducted a case-control study in 2005 and interviewed parents of 18 children, eight of whom confirmed that they had seen children consume pods of a weed called coffee senna.
“We did a similar study on 10 children, who fell sick with the same symptoms in 2006,” said Vashishtha. “Parents of all confirmed that they had seen the children eat the pods prior to falling sick.”
The parents of these children were daily wage labourers and malnutrition among these children was common, said Vashishtha. He attributed the consumption of these weeds to lack of parental supervision, hunger and pica (an eating disorder characterized by a craving for non-nutritive food).
“We actually found a strong case history of pica in these children,” he added. But Vashishtha said they couldn’t determine the quantity of pods that could be fatal to children, but consuming a few pods is fine. “I tasted it myself, and while I can’t say it’s tasty, it’s not repulsive either.”
However, peer-reviewed international journals, such as Veterinary and Human Toxicology and the American Journal of Veterinary Research, have documented the effects of coffee senna on animals. One of these reports says that quantities of the weed exceeding 0.5% of the body weight induced severe muscle and liver degeneration in cattle, and the other said that the weed induced severe diarrhoea and abdominal pains in adults.
“Studying the toxicity effects of a herb on other plants and animals are how we generally go about determining the potency of any weed, because we can’t do human tests,” said Ashwani Kumar, acting director of the Industrial Toxicological Research Centre. “If there are studies that already show the effects of toxicity of coffee senna on animals, and parents attest to seeing the child eating it, I guess the researchers have a strong case.”
Kumar added that he himself wasn’t aware of such a weed. But D. Subramaniam, principal scientist at the National Research Centre for Weed Science (NRCWS), said that though plants of the cassia family, such as cassia toras were known, no specific database was maintained on the growth of cassia occidentalis in India.
“After all a weed is just another plant, and you study a plant only if it has some direct use to us,” said Subramaniam. NRCWS, he added, specifically studied weeds that could harm rice, wheat and other important food and cash crops of India.
In an email, Pankaj Oudhia, an agricultural scientist at the Raipur University who specializes in the toxic effects of a wide range of herbs in the country, wrote that five species of the cassia family were found in India, though there was no specific information on the spread and occurrence of the cassia occidentalis. “Cassia toras is common in Chhattisgarh and widely used as a medicinal plant, but it’s known, even locally, that over consumption can cause severe diarrhoea,” he wrote.
N.S. Wairagkar, a scientist at the NIV, who has been part of the team studying the epidemic in research papers, had previously argued that a measles (viral) strain was the culprit. “I haven’t read their paper, and though I have my opinion on the issue, I can’t elaborate on it because I am not authorized to speak to the media,” he told Mint while sticking to his original assertion that it is encephalitis.
A presentation by N.K. Ganguly, the director of the Indian Council of Medical Research (ICMR), at the 2nd Asian Science and Technology Forum in Tokyo in September, summarized the latest official response to the outbreak. It says that of the cases studied, “few tested positive for an entero or aden virus, but cultures and PCR (polymerase chain reaction) were negative for all viruses. Diagnosis inconclusive”. Calls and emails to A.C. Mishra, director of the Pune institute were not returned.