Eight people were hospitalized in California after eating a homemade salad that was contaminated with Clostridium botulinum – a deadly neurotoxin that can cause paralysis. 

A new CDC report detailed that on June 21 and June 22, 2024, about 31 people attended two events in Fresno County where a salad made of uncooked nopales – prickly pear cactus pads – was served. 

Within hours, a 42-year-old woman began to complain of dizziness, blurry vision, a drooping eyelid, sore throat, gastrointestinal symptoms and difficulty swallowing. 

Despite initially dismissing her symptoms, doctors began to suspect that she was suffering from botulism – a rare but serious poisoning that attacks the body’s nerves and causes difficulty breathing, muscle paralysis and even death. 

By June 27, 10 attendees – all of whom had eaten the salad – had sought treatment at one of two hospitals in Fresno County (five patients at each hospital) for symptoms resembling those of botulism. 

As a result, the CDC, the Fresno County Department of Public Health and California Department of Public Health launched an investigation to discover the cause of the widespread illness. 

After days of lab testing, officials were ultimately able to discover that the uncooked nopales present in the salad – which had been left unrefrigerated in 100 degree Fahrenheit heat and served on both days – was contaminated with C botulinum. 

Soon after, eight of the 10 patients were diagnosed with the condition – marking it as one of the largest documented foodborne outbreaks of the infection in California. 

Eight people were hospitalized in California after eating a homemade salad made of uncooked nopales that was contaminated with C botulinum – a deadly neurotoxin that can cause paralysis

Nopales, a popular food in traditional Mexican dishes also known as prickly pear cactus, has recently gained popularity in dishes as a healthy ingredient. 

Officials confirmed that one of the eight patients had made the salad using fresh onions, fresh tomatoes and home-preserved nopales stored in reused commercial glass jars.

According to the CDC case report, the salad-maker had immersed empty jars into boiling water and then added chopped, uncooked nopales mixed with a small amount of salt. 

Once stuffed to the brim, she sealed the jars with new metal lids and stored them for six weeks in an outdoor shed behind her house – a technique she said she had been practicing for years.

However, she was unaware that she had created the perfect breeding ground for C botulinum spores as they thrive in a low-oxygen, low-acid, canned environment with moderate to high moisture and temperatures between 38F and 113F to grow. 

Norma Sanchez, communicable disease specialist with Fresno County Department of Public Health, later said they identified the contaminated cactus after sifting through trash cans.

Spores of this bacteria are often found on the surfaces of fruits and vegetables and in seafood and, in this case, rapidly grew on the surface of the uncooked and canned nopales. 

All eight patients diagnosed with botulism had double vision, seven had a hoarse voice, six were experiencing dizziness and six also found it difficult to swallow. 

The eight patients with clinical botulism were the only attendees who ate the nopales salad; the 42-year-old woman, who experienced the most severe symptoms, ate this item at both events. 

Once stuffed to the brim, she sealed the jars with new metal lids and stored them for six weeks in an outdoor shed behind her house – a technique she had been practicing for years

Eight of the 10 patients were diagnosed with botulism caused by C botulinum – marking it as one of the largest documented foodborne outbreaks of the infection in California 

As a result, all of the patients had to stay at the hospital for between two and 42 days – out of which six were admitted to an intensive care unit and two required invasive mechanical ventilation. 

The CDC later confirmed in its case report that all the people diagnosed with botulism had survived and recovered. 

Botulism is a rare but serious infection caused by a bacterial toxin that attacks the nervous system and is mostly commonly a result of food or wound contamination. 

Common symptoms of botulism include difficulty swallowing, muscle weakness, double vision, drooping eyelids, blurry vision, slurred speech, difficulty breathing, and trouble moving the eyes, according to the CDC.

In cases of foodborne botulism, these symptoms of typically begin 12 to 36 hours after the toxin enters the body depending on the level of exposure to the toxin. 

If left untreated, the infection can cause muscle weakness, paralysis and in certain cases, death. 

Patients who are paralyzed need to relearn how to walk, talk, and perform everyday tasks.

The CDC estimates that there are just 25 cases of foodborne botulism in the US each year, making it rare.

About five percent of people who develop botulism die, according to the CDC. For others, it can cause lifelong disability and extreme physical therapy. 

The Fresno health department is urging people to follow proper storing and cooking methods to lower their risk of botulism. 

Any food at risk of contamination should be heated up to 240–250F, and heated all the way through.