CD40LG and infection: S1 Table has the serologic test results for the mother at the time of diagnosis of her child that documents her seropositivity. This includes children diagnosed at birth. There were no false positives or false negatives. Test characteristics, including sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio, are in Tables 1–3. The Toxoplasma ICT IgG-IgM test proved highly sensitive (100%) and specific (100%) in testing human sera from patients with infections with T. gondii strains circulating in the United States.