Outbreaks of botulism in the 19th and early 20th centuries played a key role as a catalyst for the food safety regulations we take for granted today.
But, while there are only a few hundred cases of the primarily food-borne infection documented each year in the United States, experts from the US Centers for Disease Control and Prevention (CDC) describe it as a “constant preoccupation for public health practitioners” because its diagnosis is “often missed or delayed” because most clinicians lack direct experience with it. And, although the foods with which the infection has been associated in the past, such as blood sausages, have largely disappeared from western diets, “outbreaks caused by homemade foods, foods mishandled by consumers, and, occasionally, modern industrially produced foods continue to this day,” even as diagnostic approaches have largely remained unchanged over the past 100 years.
In a special supplement to the January 15th issue of Clinical Infectious Diseases (CID), researchers from the CDC and their colleagues from various institutions across the country shared the latest findings on the diagnosis and management of botulism and highlighted the need for greater clinical understanding of its symptoms and related complications. They also provide an update as to what the agency is doing to address the potential future challenges posed by botulism.
“We present outbreak investigations, case reports, and systematic reviews in this supplement that illustrate how challenging diagnosing botulism can be and the importance of early treatment,” Agam Rao, MD, CDC medical officer and lead clinician on the agency’s Botulism Clinical Guidelines project told Contagion®. “Guidelines are needed because diagnosis can be challenging and, yet, effective treatment is dependent on clinical diagnosis of this life-threatening illness. Whether for sporadic cases or outbreaks, national guidelines will assist physicians in managing patients. The findings from these manuscripts are being used to inform clinical guidelines that are being developed by us at CDC.”
The 15 articles in supplement cover virtually every facet of botulism. Several articles trace the evolution of clinical understanding regarding the symptoms and clinical presentation of both the food-borne and wound-associated forms of the disease, as well as the course of disease progression in special populations—namely, children and pregnant women. Others discuss the history of diagnostic tests for botulism, where screening is at present, and the need for innovation in this area going forward. Recent outbreaks of the infection are chronicled, as are clinical experiences with equine-origin botulinum antitoxin therapy used in its treatment. The increasing therapeutic and cosmetic use of botulinum toxin is also addressed.
Although the public health infrastructure in the United States is prepared to assist clinicians in the diagnosis and management of suspected botulism infection—and can be quickly mobilized in the event of an outbreak—a key take-home of the supplement content is the need for new research into disease presentation and treatment as well as guidelines based on the data currently available. On this latter point, the supplement includes an article summarizing the progress of the Joint Task Force—which is made up of representatives from the American Academy of Allergy, Asthma & Immunology (AAAAI); Food Allergy, Anaphylaxis, Dermatology and Drug Allergy (FADDA) (Adverse Reactions to Foods Committee and Adverse Reactions to Drugs, Biologicals, and Latex Committee); and the CDC Botulism Clinical Treatment Guidelines Workgroup—on efforts to quantify the risk for allergic reactions following botulinum antitoxin treatment and the usefulness of skin testing to assess patient risk. Notably, the risk of anaphylaxis was <2% for all antitoxins, based on data from multiple studies. Many of these same stakeholders are currently working with the CDC to develop diagnosis and treatment guidelines for both food-borne and wound-associated botulism.
“Most physicians have never seen a case of botulism,” Dr. Rao said. “Our intention is to bring awareness to, and provide a resource for, recognition of the clinical presentation and treatment of botulism so that physicians know when to suspect botulism and quickly seek public health assistance. The sooner botulism is suspected, the sooner treatment can be administered, resulting in better health outcomes.”
Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous health care-related publications. He is the former editor of Infectious Disease Special Edition.