Public health officials in California are investigating an outbreak of botulism infections related to family events on June 21 and 22 in Clovis, CA.

Staff from the California Department of Public Health and the U.S. Centers for Disease Control and Prevention are working together on the investigation.

During a news conference, Dr. Rais Vohra, Interim Health Officer for Fresno County, said the outbreak is a reminder of how important it is to follow proper guidelines for home canning. The food served at the family gatherings was prepared by family members. It can take up to 10 days for symptoms of botulism infection to appear.

The families have been advised to not eat any more of the implicated food. Officials did not report how many people have become ill, merely saying that multiple patients are being treated and about 30 people were exposed. At least eight patients have been hospitalized. Vohra said the size of the outbreak is unprecedented.

“Our local health department is working closely with area hospitals, state, and national health agencies on this outbreak. While the risk to the general population is low, we are actively tracing those who may have consumed the contaminated food to ensure they get timely monitoring and treatment,” Vohra said.

Investigators are gathering information about the events and what foods were served. 

Vohra said that the risk to the public is low but the health department is still searching for anyone who may have consumed the contaminated food in an effort to ensure they get timely monitoring and treatment.

Botulism is a rare but serious illness caused by a toxin produced by Clostridium botulinum and related bacteria. The toxin can attack the body’s nerves leading to muscle paralysis-particularly of facial nerves, and in severe cases difficulty breathing and even death. Individuals can get botulism by ingesting the toxin through improperly home-canned, preserved or fermented foods, or through wounds infected with the bacteria. 

Symptoms of botulism usually begin with weakness and dizziness, followed by blurred vision, drooping eyelids, and difficulty speaking or swallowing. As the illness progresses, it can cause paralysis that begins in the upper body and moves down to the lower extremities. Anyone ill with symptoms of botulism are advised to visit a health care provider immediately to be assessed.