Mystery outbreak of deadly disease in Peru baffles experts

A national state of emergency has been declared in Peru as doctors battle an outbreak of a rare disease that can cause lifelong paralysis or death.

More than 230 cases of Guillain-Barré syndrome, or GBS, have been reported in the South American country, with more than half the cases occurring in a brief five-week period from June to July.

Normally a rare disorder, GBS typically strikes only about 3,000 people per year in the US, according to Johns Hopkins Medicine.

Four people in Peru have reportedly died of the disease since the beginning of the year, and the still-unknown cause of the outbreak has health officials scrambling.

“I think the origins of this [outbreak] remain still not completely investigated,” Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center in Nashville, Tennessee, told Healthline.

“We haven’t solved that puzzle,” Schaffner added.

Peru, with numerous tourist attractions including archaeological sites like Machu Picchu, remains popular with travelers, though officials are warning that common-sense precautions are in order.

What is Guillain-Barré syndrome (GBS)?

When Guillain-Barré syndrome occurs, it typically follows an upper respiratory or gastrointestinal infection, such as the flu, COVID-19 or gastroenteritis. In some cases, it’s seen after a surgical procedure, an injury or a reaction to an immunization, including the COVID-19 vaccine.

GBS is a neurological disorder in which the immune system attacks the nervous system. The first symptom is often a tingling, “pins-and-needles” sensation in the legs, which can gradually creep upward to the arms and upper body.

This feeling can strike quickly or may develop slowly over several weeks. Other symptoms include difficulty breathing, double vision, unsteady walking, fever and problems with bladder control or bowel function.

In severe cases, muscles may not function at all, resulting in paralysis, and even breathing becomes difficult, making GBS a medical emergency that needs to be treated promptly.

There is no cure for GBS, and even among those people who recover, there is often some lingering paralysis or nerve damage. Recovery can take from six months up to several years.

The World Health Organization (WHO) issued a statement on Tuesday about the outbreak, noting that a similar outbreak of GBS with about 700 cases occurred in 2019 in Peru.

Health officials determined that the 2019 outbreak was largely due to infections caused by the Campylobacter jejuni bacteria, which is a common precursor of GBS.

What is Campylobacter jejuni?

Campylobacter infection is the leading cause of diarrheal illness in the US, according to the Centers for Disease Control and Prevention (CDC). It’s usually caused by eating foods or drinking water that are contaminated with bacteria.

“It takes very few Campylobacter bacteria to make someone sick,” the CDC states. “A single drop of juice from raw chicken can contain enough bacteria to infect someone.”

And Campylobacter infection is the most commonly identified cause of Guillan-Barré syndrome. Indeed, laboratory testing in the current outbreak in Peru found Campylobacter infection in many of the GBS cases, according to the WHO.

More cases of Campylobacter infection occur in summer than in winter. Health experts advise caution, focusing on hand hygiene and food choices — especially for people traveling to areas with GBS caused by bacterial infections.

But safe food and water precautions are important for people everywhere: In 2015, testing by the National Antimicrobial Resistance Monitoring System (NARMS) found Campylobacter on 24% of raw chicken bought from retailers in the US.

When it comes to food safety, there are simple, common-sense strategies you can use to reduce your risk of infection with Campylobacter and other germs, Schaffner said.

“As one of my past professors used to say — he was an expert in travel medicine — don’t eat anything that you can’t either cook or peel,” Schaffner added.