Health officials in North Dakota are investigating a salmonella outbreak centered around the Ward County area, which has sickened some 22 people since July. The outbreak strain has been identified as Salmonella Thompson and because the infections all have the same genetic pattern, they may have all originated from a common source. However, so far the investigation has not revealed a common food item, place or event where all of the cases may have been exposed.

Salmonella bacteria (red)/National Institute of Allergy and Infectious Diseases (NIAID)
Salmonella bacteria (red)/National Institute of Allergy and Infectious Diseases (NIAID)

Of the 22 cases, 14 have been from Ward County. The cases who were not from Ward County reported travel to that area, according to Laura Cronquist, an epidemiologist with the Division of Disease Control. “These investigations can be very complex when there is no obvious common exposure. One of the challenges is getting good histories from people. People can forget what or when they consume specific foods or drinks,” she adds

The North Dakota Department of Health (NDDoH) will be collecting information from randomly-contacted people who have not been ill and will compare that information to data that has been collected from people who were ill. This may help narrow down the cause of the infection. The NDDoH is working with the public health programs at the University of North Dakota and North Dakota State University to gather this information. “If a resident happens to receive one of these calls, we hope they will take time to answer the surveyor’s questions,” said Cronquist.