United States botulism cases

The least common form of human botulism, botulism from intestinal colonization, includes cases in patients greater than 1 year of age not associated with ingestion of contaminated food or wound infection with the only possibility being intestinal colonization (38). Stool in these patients will contain toxin and C. botulinum, and the suspected food may contain spores without preformed toxin. Some cases occur in patients with a history of gastrointestinal surgery or inflammatory bowel disease, conditions that could support enteric colonization of B. botulinum (38). In 2001, in the United States, one case of adult colonization botulism occurred in a 45 year old who survived (39). 

Food-borne botulism results from the ingestion of food contaminated with preformed toxins or toxin-producing spores from C. bo-tulinum. C. botulinum poisoning is relatively rare only 110 cases are reported per year in the United States. Botulism is almost always associated with improper preparation or storage of food. Seven distinct toxins (A to G) have been described. The toxins, which are produced by the bacteria and released on lysis, are the most potent biologic or chemical toxins known to humans. The toxin prevents the release of acetylcholine at the peripheral cholinergic nerve terminal. Toxin activity has prompted the use of minute locally injected doses to treat select spastic disorders, such as blepharospasm, hemifacial spasm, and certain dystonias. ... 

Botulism is a potent neurotoxin produced from Clostridium botulinum that is an anaerobic, spore-forming bacterium. There are three different types ofbotulism Foodborne botulism occurs when a person ingests a pre-formed toxin that leads to illness within a few hours or days. Foodborne botulism is a public health emergency because the contaminated food may still be available. Infant botulism occurs in a small number of susceptible infants each year who harbor C. botulinum in their intestinal tract. Wound botulism occurs when wounds are infected with C. botulinum that secretes the toxin. Approximately 100 cases of the three types of botulism are reported within the United States each year about 5 percent are wound botulism, 25 percent are foodborne botulism, and a full 70 percent are infant botulism. Death can result from respiratory failure, but those who survive may have fatigue and shortness of breath for years. 

The form with which most of the public is familiar is foodborne botulism. There are approximately 30 cases of foodborne botulism reported in the United States each year, most of which are related to home processing of foods. The botulinum toxin produced by C. botulinum is actually a group of distinct toxins with similar paralytic effects on the neurologic system. Botulinum toxin is the most poisonous substance known to mankind less than one microgram is a fatal dose for an adult (Arnon et al., 2001). 

Foodborne botulism accounts for approximately 1,000 cases per year worldwide, of which approximately 30 occur in the United States. Home processed foods account for 94% of U.S. cases. Infantile botulism, a form of the disease in which C. botulinum spores are ingested by infants due to food contamination, occurs in approximately 60 children per year in the United States, more than half of which are in California. Wound botulism, typically involving intravenous drug users who either inject drugs intravenously or in the subcutaneous tissue (a practice known as skin-popping ), is reported one to three times per year in the United States. It can also occur in other types of contaminated wounds such as a severe crush injury or other areas of contaminated avascular tissue. Botulism due to intestinal colonization by C. botulinum is extremely rare only seven cases have been reported in the literature (CDC, 1998). 

Botulism is caused by the neuroparalytic toxin produced by the bacterium, C. botulinum, a common soil contaminant. This toxin has been divided in several groups. Types A, B, and E are the major types producing disease in humans, with Type A accounting for 44%, Type B, 36%, and Type E, 12.5% of cases. Type A botulism generally occurs in the western United States, while Type B is typically found in central and northeastern states. The majority of Type E botulism cases... 

Natural human botnlism, a relatively rare disease, occurs in four epidemiologic forms food-borne, infantile, wound, and adult botulism from intestinal colonization (38). None of these is transmissible person to person. All four forms result from absorption of the toxin into the bloodstream through the mucosa, such as the gastrointestinal tract or a wonnd. The toxin cannot penetrate intact skin, hi the United States, fewer than 200 cases of human botuhsm occur each year (36). 

Wound botulism, a relatively rare form of the disease, results from the production of toxin by organisms that multiply in a contaminated wound. Wounds associated with botulism may not appear obviously infected (38). Before 1980, wound botulism was most likely associated with complicated wounds, such as extensive crush injuries, compound fractures and other wounds associated with avascular areas. Since 1980, most cases have occurred in illicit drug users, including intravenous drug users with contaminated needle puncture sites or drug users with nasal and sinus wounds secondary to chronic cocaine sniffing (38). In 2001, there were 23 reported cases of wound botulism in the United States, with one death (39). 

Clinicians most often confuse botulism with a polyradiculoneuropathy, such as Guillain-Barre or Miller Fisher syndrome, myasthenia gravis or central nervous system disease (36) (see Table 2.14). In the United States, a cluster of cases of flaccid paralysis is more likely secondary to botulism than to GuiUain-Barre syndrome or polio. In addition, compared to other causes of flaccid paralysis, unique features of botulism include (36) ... 

Although infant botulism was not recognized until a large outbreak occurred in Califomia in 1976 (Pickett et ah, 1976), it is currently the most prevalent form of botulism in the United States, accounting for approximately 70% of all cases (Shapiro et al., 1998). Because infant botulism results from a continual production of BoNT, it appears to be more effectively treated by antitoxin than is foodborne botulism. In a recently concluded 5 year randomized clinical trial carried out with a human botulinum immune globulin (BIG-IV), it was found that administration of BIG-IV within 3 days of hospitalization resulted in a 3 week reduction in the mean hospital stay, as well as substantial reductions in the time needed for intensive care and mechanical ventilation (Amon et al., 2006). In a nationwide open label study, BlG-lV was found to be effective even when administered 4—7 days after hospital admission, although to a somewhat lesser extent than when infusion was initiated at 3 days (Arnon et al., 2006). 

One other mode of botulinum toxin poisoning has a significant number of cases in the United States infant botulism.1 These cases involve an ongoing colonization of the intestines of infants, usually in the first year of life, by the usually benign C botulinum organism. Apparently, the flora of newborns, their intestinal environment, or both is such that the organism can grow and produce toxin there are no well-documented cases of intestinal infections in adult humans. 

In the United States an average of 110 cases of botulism are reported each year. Of these, approximately 25% are foodbome. 72% arc infant botulism, and the rest are wound bomlism. Outbreaks of foodbome botulism involving two or more persons occur most years and usually caused by eating contaminated home-canned foods. The number of cases of foodbome and infant botulism has changed little in recent years, but wound botulism has increased because of the use of biack-tar heroin, especially in California. 

Human foodborne botulism outbreaks have typically been linked to the consumption of toxin-contaminated home-prepared or home-preserved foods (Maselli, 1998). The vast majority of foodborne botulism cases are attributed to toxin types A, B, or E. Maselli (1998) reports that type B is the most prevalent (52%) in the United States, followed by type A (34%) and type E (12%), while the CDC (1998) suggests 37.6% of all foodborne botulism outbreaks since 1950 were caused by type A, 13.7% by type B, 15.1% by type E, 0.7% by type F, and 32.9% were unidenhfied with respect to toxin type. Outbreaks of type F and G botulism are rare (Sonnabend et al., 1981 Maselli, 1998 Richardson et al., 2004), and only anecdotal reports of isolated type Cl and D botulism cases can be found in the published literature (e.g., Lamanna, 1959). 

The natural epidemiology of foodborne botulism provides additional insight into the similarities and discrepancies between the human disease and that represented in various animal models. In the United States, around 25% of reported human botulism cases are classified as foodborne and 72% are infant (Mackle et al., 2001). Human type A and B foodborne botulism cases occur worldwide and constitute the vast majority of reported human intoxications (Maselli, 1998). The majority of other botulism cases are attributed to serotype E and are typically associated with the consumption of contaminated seafood. Generalizations have been made regarding the geographic distribution of the most common C. botulinum strains within the United States. Most human foodborne botulism outbreaks occurring west of the Mississippi are due to type A toxin type B strains are more prevalent east of the Mississippi, while type E strains are typically isolated to Alaska and the Pacific Northwest (Amon et al., 2001 Richardson et al., 2004). 

---