The Center for Disease Control (CDC) is collaborating with public health officials in many states and the United States Food and Drug Administration (FDA) to investigate a multistate outbreak of human infections due to Salmonella serotype Saintpaul.

Since mid-March, 35 persons infected with the outbreak strain of Salmonella Saintpaul have been reported from 7 states.  The number of ill persons identified in each state is as follows: Michigan (17), Minnesota (4), Ohio (3), Pennsylvania (6), South Dakota (2), Utah (1), and West Virginia (2).  Cases are still being reported, and possible cases are in various stages of laboratory testing, so illnesses may be reported from other states.  No deaths have been reported to date.

Authorities have linked this outbreak to alfalfa sprouts. Most of those who became ill reported eating raw alfalfa sprouts, although some reported eating sprouts at restaurants and others purchased sprouts at retail outlets.

The initial investigation has traced the contaminated raw alfalfa sprouts to multiple sprout growers in multiple states. This suggests a problem with the seeds used, as well as the possible failure of the sprout growers involved to appropriately and consistently follow the FDA Sprout Guidance issued in 1999  – see http://www.cfsan.fda.gov/~dms/sprougd1.html.

The guidance recommends an effective seed disinfection treatment immediately before the start of sprouting (such as treating seeds in a 20,000 parts per million calcium hypochlorite solution with agitation for 15 minutes) and regularly testing the water used for every batch of sprouts for Salmonella and E coli O157:H7.

This outbreak appears to be an extension of an earlier outbreak in February and March of 2009, when an outbreak of  120 Salmonella Saintpaul infections occurred in Nebraska, South Dakota, Iowa, Kansas, and Minnesota.  That outbreak was linked to raw alfalfa sprouts produced at a single facility, and the outbreak strain was indistinguishable from that of the recently reported cases.

The CDC is also currently working with public health officials in several states and the FDA to investigate an outbreak of Listeria monocytogenes infections linked with eating alfalfa sprouts.