Guillain-Barre syndrome: India faces outbreak of creeping paralysis

Last month, a primary school teacher in the western Indian city of Pune noticed her six-year-old son was becoming frustrated with his homework. She told The Indian Express, "I erased some words and asked him to rewrite them. I thought he was just angry, which is why he couldn't hold the pencil."

Little did she know that her son's difficulty holding a pencil was the first sign of Guillain-Barré Syndrome (GBS), a rare condition where the immune system attacks nerve cells, leading to muscle weakness and paralysis. Within days, the boy was in intensive care, unable to move his hands and feet. As the condition worsened, he lost the ability to swallow, speak, and eventually even breathe, requiring ventilator support. He is now on the road to recovery.

Since early January, Pune, an education and IT hub, along with surrounding industrial towns and villages, has reported approximately 160 cases of GBS, with 5 suspected deaths. According to official data, 48 patients are currently in intensive care, 21 require ventilator support, and 38 have been discharged. Guillain-Barré Syndrome initially manifests as numbness or tingling in the hands and feet, followed by muscle weakness and difficulty with joint movement. Symptoms typically worsen over two to four weeks, initially appearing in the arms and legs. The mortality rate is reportedly between 3% and 13%, depending on the severity of the condition and the quality of medical support.

The outbreak in Pune has been traced to a pathogen called Campylobacter jejuni, a major cause of foodborne infections and the biggest driver of GBS globally. The link between the two was discovered in rural China in the 1990s, when the pathogen was common in chickens, and GBS outbreaks occurred each rainy season as children played in water contaminated by chicken or duck feces. GBS is not entirely uncommon in India. Monojit Debnath and Madhu Nagappa at the National Institute of Mental Health and Neurosciences (NIMHANS) in Bangalore studied 150 GBS patients between 2014 and 2019 and found that over a third tested positive for Campylobacter jejuni.

Recently, outbreaks linked to the pathogen have been reported around the world. In the first seven months of 2023, Peru reported over 200 suspected GBS cases and at least 4 deaths, prompting the government to declare a national health emergency and strengthen public health measures. Two-thirds of the cases were linked to Campylobacter jejuni. Experts say that in countries with good hygiene, GBS cases linked to Campylobacter jejuni are less common, with respiratory infections being a major factor. There are other triggers as well. In 2015, Brazil reported a cluster of GBS cases linked to the Zika virus. Vaccines rarely trigger GBS, but in 2021, a COVID vaccine in the UK was reportedly linked to hundreds of GBS cases.

“Campylobacter jejuni is endemic, there are hundreds of thousands of cases all the time, it's always in the environment,” says Hugh Willison, a professor of neurology at the University of Glasgow. However, scientists say it's not easy to get GBS. There is a particular strain of Campylobacter jejuni that has a sugar coating on its outer layer, and in rare cases, its molecular structure matches the coating of human nerve cells. When a patient’s immune system attacks the bacteria, it can also end up attacking the nerves, a process called molecular mimicry, leading to GBS. However, only a small percentage of Campylobacter jejuni strains have this nerve-like coating.

Professor Willison says, “In Pune, it is likely that a strain of Campylobacter jejuni with this molecular signature is spreading, and the surge in infections has led to an increase in GBS cases.” Most experts estimate that about one in 100 Campylobacter jejuni strains carry the risk of GBS, and one in 100 people infected with that strain will develop GBS, making the overall risk about one in 10,000. Willison describes it as “immunological Russian roulette,” triggering an “acute neurological tsunami” that sweeps through the peripheral nervous system. Once the immune response subsides, the attack diminishes, but the body still needs time, medical care, and support to repair the damage.

To make matters worse, there is no cure for GBS. In GBS, the body produces antibodies against Campylobacter jejuni, and these antibodies then attack the nerves. Doctors use "plasma exchange" therapy, which filters the blood to remove harmful antibodies, while also administering intravenous immunoglobulin (IVIG), a therapeutic antibody extracted from normal blood, to help reduce the severity of the illness. Another challenge is that there is no single test to diagnose GBS. Doctors say the diagnosis is primarily based on clinical features. It presents as a paralysis that can also be caused by polio, viruses, or rare neurological disorders.

“Diagnosis is a constellation of clinical features. It is easy to misdiagnose, miss, or delay diagnosis,” says Willison. India’s public health system is unevenly developed, and doctors in rural areas may struggle to diagnose GBS. This may be one reason why a team from the World Health Organization (WHO) is in Pune, working with federal and state health workers to track, detect, and monitor cases, and analyze trends to support effective treatment. Authorities say they have surveyed over 60,000 households, collected 160 water samples for testing, and are asking people to drink boiled water, eat fresh, clean food, and avoid “stale food and half-cooked chicken or mutton.”

Experts say that while most GBS cases around the world come from undercooked poultry, it can also spread through water, like cholera or salmonella. Contaminated water used for washing or preparing street food can easily spread the bacteria. Clearly, in Pune, a strain of Campylobacter jejuni with a unique molecular signature is spreading, affecting a large number of people. It is unclear whether this is due to widespread water contamination or many people eating infected poultry. Health officials advise, "We urge people not to panic." But in the face of uncertainty, that's easier said than done.