The Guillain-Barré Syndrome (GBS) outbreak reported in Pune and other parts of India could indicate unhygienic water contamination on a very large scale — and a current potential example of this would be a site like the Maha Kumbh Mela, where the primary infections that can trigger GBS could have spread to millions of devotees in a very short time, an expert has said.
Jessy Skaria, a doctor and independent researcher, has said that the antecedent infections triggering GBS could have spread among crowds through faecal-oral or droplet transmission, resulting in this rare outbreak of over 100 GBS cases.
The GBS outbreak in Pune and its surrounding regions have been caused by Campylobacter jejuni and norovirus, primary investigations have revealed.
“Both these microbes can be abundant in water with faecal contamination, and with their potential to cause gastroenteritis, can trigger GBS too,” Skaria said.
She added that norovirus, a highly contagious agent known to cause gastroenteritis in outdoor enthusiasts who come in contact with contaminated water, is a “relatively unknown trigger for GBS”, meaning it’s not as well documented in the existing medical literature as a trigger for GBS as is Campylobacter jejuni.
The cases of GBS peaked to 163 in late January from Pune and neighbouring districts including Satara, Sangli, Khed, Talegaon and others, well outside city limits.
Skaria said the fact that while the disease is clustered in some parts, like Sinhagad, multiple sporadic cases in other geographically distant areas can only point to a large, single source of infection that could have potentially affected all these patients at different, distant places at a similar time period.
“If there were no increase in GBS cases outside Pune, then we could have looked at the primary source of water supply to all the residents of Pune, or a large gathering in Pune where people partook of the same contaminated food. But that is not the situation now,” she said.
As of February 5, the Pune Municipal Corporation identified 19 private RO purification plants with contamination and shut them down.
There have been many cases outside Pune, within Maharashtra and also in other states of India. Since GBS is not a notifiable disease, (except as a differential diagnosis of Polio in Acute Flaccid Paralysis cases in children below 15), it is almost impossible to know exactly how many cases are there currently in India, Skaria said.
She pointed out that even the reported burden of GBS cases and deaths from different states — West Bengal, Rajasthan, Assam, Telangana, Tamil Nadu, Jharkhand, Haryana and Delhi — in this same time span as the reported outbreak in Maharashtra, are enough to alert public health departments to look for a common source of contamination where Indians from all over the country have congregated — as at the Maha Kumbh.
“There is one report of different hospitals in Delhi together accounting for over 100 cases. I am at a loss why nobody is concerned about that,” she told Down To Earth.
“We have tested all the patients for travel history in the past two months and for other major viruses for active infections and anti-bodies including zika, dengue and others that could have potentially triggered the GBS, but all the tests resulted in negative," said Nina Borade, health chief at Pune Municipal Corporation.
Skaria stressed that not all patients need to have travelled to the Kumbh Mela to have been exposed to the triggering infection. Any connection such as consuming ganga jal or prasad brought from the pilgrimage site or contact with anyone who caught the primary infection at the Mela, could be the cause of the triggering infection in these GBS patients.
“GBS is not infectious or contagious, meaning it cannot spread from person to person. But the triggering infections are. The patient who presents with GBS could have acquired such an infection from another person who potentially only had a mild diarrhoea or respiratory infection with such microbes, and which they passed on to people who never had contact with the primary source of contamination,” she said.
She explained that this person-to-person transmission could be through multiple routes, like faecal-oral or respiratory. Hence, if any of the primary contacts touched water or food consumed by the GBS patient or shared the same private or public places, particularly toilets, then the patient who has no direct connection with the Kumbh Mela could be infected by organisms that originated there.
Skaria said that an initial outbreak in Pune also makes sense as a lot of residents from there have travelled to the Kumbh and may have returned with the primary infection — C. jejuni or norovirus or others like Escherichia coli — eventually spreading it to numerous contacts quickly, directly and indirectly.
“All the current cases in different parts of India, including Pune, likely acquired the triggering infectious pathogens from one very large contaminated source, like the Maha Kumbh Mela. This makes more medical sense than a rare syndrome suddenly spiking in different areas within India from different local contaminated sources. With millions jostling together in one place over days and weeks at the Maha Kumbh — 'the largest gathering of humans on earth' — the site can become a fertile ground for contagious diseases, despite the best efforts at cleanliness by the administration,” Skaria said.
Studies show that organisms like C. jejuni are found in abundance even in relatively unpolluted rivers owing to contamination with faeces of wild birds and animals.
With the addition of constant human contamination during the Mela and limited information on how the enormous waste and sewage generated at the festival are being handled, the presence of pathogenic organisms in the rivers at Prayagraj could be exceptionally high.
Hence, it is crucial for public health authorities to test those waters at multiple sites where the devotees come in contact with them. This should be done in an urgent and time-sensitive manner to try and halt the infections that could be triggering this GBS outbreak, she said.
Skaria said it is also likely that different strains of the same microbes can have different pathogenic potential. “As far as I understand, the National Institute of Virologyis looking into this angle with the Campylobacter and norovirus species isolated from the patients' stools, which is a positive step towards investigation,” she added.