When Republican vice presidential candidate JD Vance claimed Haitian immigrants had caused infectious-disease rates to “skyrocket” in Springfield, Ohio, local health commissioner Chris Cook checked the records. They showed that in 2023, for example, there were four active tuberculosis cases in Clark County, which includes Springfield, up from three in 2022. HIV cases had risen, but sexually transmitted illnesses overall were decreasing. “I wouldn’t call it skyrocketing,” said Cook, noting that there were 190 active cases in 2023 in all of Ohio. “You hear the rhetoric. But as a whole, reportabl…