Descriptive Epidemiology of Infant Botulism in Pennsylvania, 2004-2013

BACKGROUND:  Infant botulism is the most commonly reported form of botulism, with approximately 100 cases reported in the US each year; no deaths have been reported since 2004. Pennsylvania (PA) is one of a handful of states that consistently leads reporting of the condition.

METHODS: A 10-year review of the descriptive epidemiology in the Commonwealth is presented.

RESULTS:  Case counts range from 8 to 20 annually, with median age ranging from 15 weeks to 23 weeks. Geographic distribution of cases in Pennsylvania is markedly found in the southeastern part of the state; this phenomenon of case clustering as a “discrete ring” around Philadelphia, first described in medical literature in 1985, continues through 2013. The vast majority of cases reported in Pennsylvania in the past five years have been toxin type B. Although some studies suggest a seasonal trend of case occurrence in March through October, this trend has not been observed in Pennsylvania.

CONCLUSIONS:   Risk factor data for infant botulism has been collected inconsistently in PA; however, transmission of botulism through environmental sources is postulated as the primary risk associated with infant botulism in PA.