Trends in Tetanus Epidemiology in the United States, 1972-2001
Pamela Srivastava, Kristin Brown, Jufu (Jeff) Chen, Katrina Kretsinger, and Martha Roper. National Immunization Program/ESD, Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS E-61, Atlanta, GA, USA
BACKGROUND: Tetanus is severe and often fatal. The introduction and widespread use of tetanus toxoid (TT) vaccine in the late 1940s accelerated reductions in both tetanus morbidity and mortality.
OBJECTIVE: To describe the epidemiology of tetanus from 1972 to 2001 in the United States.
METHOD: We analyzed all reports of tetanus cases submitted to the National Notifiable Diseases Surveillance System, CDC, from January 1972 through December 2001.
RESULT: Between 1972 and 2001, 1842 cases of tetanus were reported. The average annual incidence per million decreased from 0.39 in 1972-1976 to 0.16 in 1997-2001; the case fatality rate (CFR) decreased from 45% to 16%. Among the 932 cases (51%) for whom TT vaccination history was reported: 644 (69%) were unvaccinated and had a CFR of 28%; 172 (18%) had received 1 or 2 TT doses (CFR of 17%), and 114 (12%) had received 3 or more doses (CFR of 4%). Only 4 of 520 persons dying from tetanus (0.7%) had a history of at least 3 TT doses. Tetanus incidence and mortality were highest throughout the study period among persons 60 and older, with an overall incidence of 0.78/million and CFR of 40%. Diabetics were at increased risk for fatal tetanus [age-adjusted relative risk 1.9 (95%CI 1.4-2.6)], compared to non-diabetics. Injection drug users (IDUs) accounted for 12% of tetanus cases in 1992-2001, an almost 3-fold increase compared with the previous decade.
CONCLUSION: Between 1972 and 2001, reported tetanus incidence decreased by 59% and CFR decreased by 64%. Receipt of > 3 TT doses protects against both disease and mortality. Older adults, diabetics, and IDUs are at particular risk for tetanus disease and death.
LEARNING OBJECTIVES: To understand the epidemiology of tetanus in the United States today so that immunization programs can target persons at increased risk.