In mid-January, a 50-year-old woman from Pune’s Kirkatwadi locality was admitted to the Poona Hospital and Medical Research with a numbness and tingling in her lower limbs that had progressed into paralysis.
Infectious disease expert Dr Ameet Dravid felt something was amiss when the woman’s husband told him that several residents in their township near Pune’s Sinhagad Road had suffered from diarrhoea a week earlier.
Soon after, three more residents from the township were hospitalised under Dravid’s care with the same symptoms: numbness and eventual paralysis.
All four patients were diagnosed with Guillain-Barré syndrome, or GBS, a rare auto-immune disease usually triggered by viral or bacterial infections. A test of the first patient’s stool sample detected a bacterial infection caused by the pathogen, campylobacter jejuni.
Campylobacter jejuni is a bacteria that spreads through contaminated water, raw milk or contaminated meat that is consumed uncooked.
Over the next two weeks, Pune recorded a surge in GBS patients.
Since early January, there have been 110 suspected cases of Guillain-Barre Syndrome in the city. On Sunday, a patient who had travelled to Pune died in Solapur due to complications from breathing difficulties while being treated for the syndrome. Thirteen other patients are on ventilator support in Pune. Twenty of the total patients are children below the age of nine.
Of 44 patients whose stool samples were tested by the National Institute of Virology, five had campylobacter jejuni infections while 14 were found to have norovirus. Norovirus spreads from one infected person to another through physical contact or the air, or through contaminated surfaces.
Both pathogens cause fever, abdominal pain and diarrhoea. “After two to three days, these symptoms subside. Then, for three days, patients are asymptomatic,” said Dravid. A few days after this, a small number of patients can feel weakness and numbness in the lower limbs that progresses into GBS, he added.
In Guillain-Barre Syndrome, a person’s immune system attacks its own nerve cells, which it mistakes for a pathogen, leading to paralysis, numbness or weakness that can last for days or even years. The syndrome is mostly reversible, but in some cases it can cause death.
Epidemiologists and health experts are concerned for two reasons: first, since Guillain-Barre Syndrome is extremely rare and only a small number from a large infected pool develop the syndrome, the situation points to a much larger outbreak of campylobacter and norovirus infections in Pune.
About one in every 1,000 patients infected by campylobacter develops this syndrome, according to the US Centers for Disease Control and Prevention states. In the case of norovirus, GBS is even more rare.
Second, Guillain-Barre Syndrome may be becoming more common than its recorded incidence, which indicates a shift in how the virus or bacteria is infecting people. So far, there is no evidence in Pune to show that the increased incidence is due to a mutation in the virus or the bacteria, said state epidemiologist Dr Babita Kamlapurkar.
The sources of the campylobacter and norovirus infections have not yet been found. “Our health teams are visiting affected areas daily,” said Kamlapurkar.
Former state epidemiologist Dr Pradeep Awate said that since both pathogens are widespread, it is unclear what is leading to the “astonishing and unusual spike” of GBS cases.
Contaminated water
The outbreak in Pune may have begun in early January. The first case was reported on January 9. The state health department showed that as of Sunday, 88 patients were from Pune Municipal Corporation limits, 15 from Pimpri Chinchwad next door and seven from nearby rural areas.
So far, most cases have been from the city’s Sinhagad Road area, which has urban settlements, villages, agricultural land and poultry farms. Sixty per cent of the GBS patients from Sinhagad Road had suffered from diarrhoea, said a state health official.
The official suggested that contaminated water, possibly from poultry farms being close to human settlements, was to blame for infections.
Another state health official said that the area affected by the outbreak was included in the Pune Municipal Corporation limits only recently. State officials, during a meeting on Sunday, voiced concern that there is no drinking water filtration plant in the area and not enough staff to ensure chlorination.
But campylobacter spreads in other ways too. “It can also be through uncooked or raw meat,” said former Maharashtra epidemiologist Dr Pradeep Awate. “And the affected area has poultry farms.”
A larger outbreak?
With Pune’s high tally of GBS cases, Dravid said it is possible that there is a widespread norovirus or campylobacter jejuni infection – possibly in “thousands and thousands”. “What we are getting is a small pool of patients whose condition worsened after they developed GBS,” said Dravid. “There are many more who have diarrhoea, abdominal pain and vomiting.”
Research says that 0.3 per one lakh patients infected with campylobacter jejuni, a sub-category of campylobacter, will develop GBS. At the current rate of GBS incidence in Pune, there could be more than a lakh infections of either campylobacter or norovirus in the city.
Awate, however, said that is unlikely. “That would have come up in the health system radar,” he told Scroll. “We would have many more diarrhoea cases.”
A door-to-door survey of 64,238 residents in the affected area had found only 124 cases of diarrhoea until January 25. “There has to be some other reason why GBS cases are so high,” Awate said.
At Pune’s Deenanath Mangeshkar Hospital and Research Centre, intensivist Dr Sameer Jog is treating 26 GBS patients: private testing detected a campylobacter jejuni infection in one while three others were found to have contracted the norovirus. “To me it seems like a combination of infections have affected people which has led to GBS cases,” Jog said.
Dravid suspects that the campylobacter infection is likely to have been transmitted through contaminated drinking water. His first patient had mentioned that their township depended on tankers for drinking water. State health officials have said the municipal corporation treats drinking water sources with chlorine for disinfection. “But there has to be some breach in sterility of water,” said Dravid.
State Director of Health Services Dr Nitin Ambadekar said a team of health officials has been visiting affected areas every day. Till Monday, officials found that seven of 34 water samples tested had contamination.
Some international researchers have established that some isolates of campylobacter jejuni is resistant to chlorine. But Ambadekar said state health officials are yet to investigate if there is any mutation in the virus or bacteria or resistance. “We don’t think there is any resistance at this point to talk about,” said state epidemiologist Kamlapurkar.
In August 2024, Gayani Weersooriya, a researcher at the Veterinary Research Institute in Sri Lanka, had found that campylobacter isolates were resistant to chlorine when poultry is being processed – meat is usually disinfected using chlorine before it is packaged. Weersooriya confirmed these findings with Scroll.
Dr Anurag Agrawal, dean of the Trivedi School of Biosciences at Ashoka University, said faecal contamination of drinking water is most likely the source of the campylobacter infection. “I don’t think it is in the central water supply though – the contamination could be in some other points,” he said.
Agrawal said that if standard chlorination is not working, the civic authorities should undertake super chlorination, a process that requires additional chlorine, to kill pathogens.
Waste water surveillance
Since campylobacter and norovirus are common pathogens, it is unclear what is driving the increase in GBS cases in Pune. Dr Nerges Mistry, director of the Foundation for Medical Research, said that routine analysis of waste water in Mumbai has found campylobacter jejuni circulating within the community. It causes only mild illness.
In Hyderabad and Bangalore, the Tata Institute of Genetics and Society has regularly found norovirus and campylobacter in waste water. “This means that we have a reasonable abundance of them among our population,” said director Dr Rakesh Mishra. “I am not sure how to link it with the outbreak [in Pune] when it [norovirus and campylobacter] is there all the time.”
Kamlapurkar, however, said neither state nor Pune officials were alerted about the presence of norovirus or campylobacter by laboratories conducting sewage surveillance. Dr Mahesh Dharne, scientist at the Pune-based National Chemical Laboratory, said the affected area is not among the 10 locations from where waste water samples are collected for analysis.
Dr Rajesh Karyakarte, head of microbiology at Pune’s BJ Government Medical College, said there must be a widespread door-to-door survey to determine the number of patients who have suffered diarrhoea and vomiting. “We are undertaking that,” said Dr Ambadekar, from the Directorate of Health Services.
