Epidemic diphtheria in the Kyrgyz Republic, 1994-1998

The Kyrgyz Republic experienced a widespread diphtheria epidemic during 1994-1998. National diphtheria surveillance and vaccination coverage information were used to describe the course of the epidemic. The epidemic began in August 1994, reached a peak in 1995 with 704 cases (incidence rate: 15.4/100,000 population) and 30 deaths, and declined to an incidence rate of 4.0/100,000 during the first 8 months of 1998. Age-specific incidence was highest in 1995 among persons 15-19 and 20-29 years old. Three rounds of mass vaccination with tetanus and diphtheria toxoids for adult use (Td) were conducted; reported coverage was 69% in 1995 and >95% in 1996 and 1997. Reported routine vaccination coverage with three doses of diphtheria toxoid by age 12 months increased from 62% in 1989 to 98% in 1997. Mass vaccination of the adult population with Td and improvements in childhood vaccination coverage played a major role in controlling the epidemic.