Contribution of individual serovars within serogroups isolated in the United States in 2012. Contribution of individual serovars within serogroups isolated in the United States in 2012. Only serovars responsible for 2% or more of cases within each serogroup are represented individually. In 2012 in the United States, serovar I 4,[5],12:i:− accounted for 15.8% of all cases associated with serogroup B NTS. These data are included within the S. Typhimurium slice of the pie chart. Data are from the U.S. Centers for Disease Control and Prevention. Fabien J. Fuche et al. Clin. Vaccine Immunol. 2016; doi:10.1128/CVI.00243-16