Tetanus -- United States, 1987 and 1988 During 1987 and 1988, state health departments reported 101 cases of tetanus to the MMWR (48 in 1987 and 53 in 1988). The average annual incidence rate for 1987-1988 was 0.02 per 100,000 U.S. population, compared with 0.39 per 100,000 in 1947, when national ...