PUNE: The search for what triggered Guillain-Barre Syndrome (GBS) outbreak in Pune and Pimpri-Chinchwad yielded a loose end Thursday after water samples tested for Campylobacter jejuni, found in stool samples of at least five patients, were found free of the bacterium.
As National Institute of Virology (NIV) contemplated other ways to unravel the mystery, the caseload increased to 130 with confirmation of three infections that weren’t accounted for in the tally. No fresh case was reported, while 20 patients remain on ventilator support across different hospitals.
NIV’s next step will be to study the C.jejuni found in patients to determine if they were struck by a more serious strain. Officials said genetically characterising the entire bacterial genome of C. jejuni would likely provide insights into virulence.
Dr Shahzad Beg Mirza, microbiologist at Dr DY Patil Medical College, told TOI that NIV analyses could reveal if a specific strain was responsible for triggering multiple GBS cases.
“Some C. jejuni strains with particular genetic traits are strongly linked to GBS. The key mechanism behind GBS involves ‘molecular mimicry’. Similarities between bacterial components and human nerve structures can lead the immune response to mistakenly attack the nervous system,” he said.
“Changes in a bacterial component called LOS (lipooligosaccharide) may be a factor in the outbreak’s severity. The genetic study will help determine if the strain involved in this surge carries these high-risk genetic traits, which could explain the increased number of GBS cases.”