CD40LG and cytomegalovirus infection: All Ugandan participants were HCMV IgG-positive, all but five had high avidity IgG antibodies (all non-TB), and 1/49 samples from 25 TB patients and 6/242 control individuals were positive for HCMV IgM (none of whom had low HCMV IgG avidity), suggesting that very few individuals had acute HCMV infection (characterized by positive HCMV IgM) at time of sampling, but all individuals had been infected with HCMV at some point at least six months before sampling.