Diphtheria epidemic in the Republic of Georgia, 1993-1997.

Epidemic diphtheria reemerged in the republic of Georgia in 1993. From 1993 to 1997, 1405 cases were reported (28 in 1993, 312 in 1994, 429 in 1995, 348 in 1996, and 288 in 1997), with a cumulative incidence of 25.8/100,000 and a case fatality ratio of 9.5%. During 1993-1997, 53% of the diphtheria cases occurred among persons >/=15 years of age. Unvaccinated patients were more likely to have toxic forms (relative risk=2.24; 95% confidence interval=1.69-2.96) or to die of diphtheria (relative risk=2.24; 95% confidence interval=1. 36-3.68) than those who had received at least one dose of diphtheria toxoid. Improvement in routine childhood vaccination coverage and implementation of mass adult vaccination campaigns have been critical to bringing the epidemic under control. By mid-1998, the overall diphtheria situation in Georgia appeared to have been controlled. Only 53 cases were reported from January to June 1998, representing a 64% decrease from the 148 cases during the corresponding period in 1997.