Equine Botulinum Antitoxin for the Treatment of Infant Botulism

Abstract

Infant botulism is the most common form of human botulism in Argentina and the United States. BabyBIG (botulism immune globulin intravenous [human]) is the antitoxin of choice for specific treatment of infant botulism in the United States. However, its high cost limits its use in many countries. We report here the effectiveness and safety of equine botulinum antitoxin (EqBA) as an alternative treatment. We conducted an analytical, observational, retrospective, and longitudinal study on cases of infant botulism registered in Mendoza, Argentina, from 1993 to 2007. We analyzed 92 medical records of laboratory-confirmed cases and evaluated the safety and efficacy of treatment with EqBA. Forty-nine laboratory-confirmed cases of infant botulism demanding admission in intensive care units and mechanical ventilation included 31 treated with EqBA within the 5 days after the onset of signs and 18 untreated with EqBA. EqBA-treated patients had a reduction in the mean length of hospital stay of 23.9 days (P ‫؍‬ 0.0007). For infants treated with EqBA, the intensive care unit stay was shortened by 11.2 days (P ‫؍‬ 0.0036), mechanical ventilation was reduced by 11.1 days (P ‫؍‬ 0.0155), and tube feeding was reduced by 24.4 days (P ‫؍‬ 0.0001). The incidence of sepsis in EqBA-treated patients was 47.3% lower (P ‫؍‬ 0.0017) than in the untreated ones. Neither sequelae nor adverse effects attributable to EqBA were noticed, except for one infant who developed a transient erythematous rash. These results suggest that prompt treatment of infant botulism with EqBA is safe and effective and that EqBA could be considered an alternative specific treatment for infant botulism when BabyBIG is not available.

Workgroup Report by the Joint Task Force Involving 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 Centers for Disease Control and Prevention Botulism Clinical Treatment Guidelines Workgroup—Allergic Reactions to Botulinum Antitoxin: A Systematic Review

“…The total number of patients in the combined review was 687; most were adults. In one study, all 31 treated patients were infants; there were no reports of anaphylaxis [19]. Because not all articles specified individual patients' ages, there were insufficient data to specifically comment on age as a predisposing factor (Table 2).…”

“…In 3 studies, the method of ST was noted as "intradermal" [17,19,21]; one study did not report the ST method [16]. Reported PPVs of ST in these studies ranged from 0 to 56% and NPVs ranged from 50% to 100%.…”

“…Information from 4 studies was available for 302 patients who underwent ST [14,15,17,19]. In 3 studies, the method of ST was noted as "intradermal" [17,19,21]; one study did not report the ST method [16].…”

Issues associated with formula milk: the Hong Kong’s experience

“…Some also debated if equine botulinum antitoxin be used for infants in case of an outbreak in Hong Kong instead of BabyBIG ® . [6,7] BabyBIG ® is available as a public-service orphan drug for infants in the United States, but is not immediately available in Hong Kong. [6] It is recommended that treatment with BabyBIG ® be given as soon as possible after hospital admission and should not be delayed for confirmatory testing of feces or enema.…”

“…[6,7] BabyBIG ® is available as a public-service orphan drug for infants in the United States, but is not immediately available in Hong Kong. [6] It is recommended that treatment with BabyBIG ® be given as soon as possible after hospital admission and should not be delayed for confirmatory testing of feces or enema. [7] This would potentially mean that many infants with "probably" infantile botulism (infants on the culprit milk formula with a little bit of tiredness or constipation but anxious parents) will have to be treated without delay for shipping of the vaccine or confirmatory testing.…”