Investigation Update: Outbreak of Human Salmonella Typhimurium Infections Associated with Contact with Water Frogs

Infections with the outbreak strain of Salmonella Typhimurium, by week of illness onset (n=48 for whom information was reported as of 12/7/09)*

* Some illness onset dates have been estimated from other reported information: for all 48 cases the date of illness onsets range from 6/24 ?11/14 (actual onset (n=18) range 6/24 ?11/7).

The outbreak can be visually described with a chart showing the number of persons who became ill each week. This chart is called an epidemic curve or epi curve. Illnesses that occurred after November 14, 2009 may not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 3 weeks. Please see the Salmonella Outbreak Investigations: Timeline for Reporting Cases for more details.