[Diphtheria: apropos of an epidemic]

Since Ramon developed the anti-diphtheria anatoxin in 1924 widespread vaccination has almost eliminated diphtheria, but since the acquired immunity is anatoxic and not anti-bacterial, carriage of the causal agent Corynebacterium diphteriae remains possible. In 1990, 1214 declared cases of diphtheria inaugurated an epidemic which spread through Russia, Ukraine and neighboring countries and even reached a few subjects in Europe and North America. Mortality in Russia was 10.15 per 100000 cases in 1993. Higher rates were observed in children. The question is raised as to the level of protection in Western countries despite generalized vaccination programs. In France, a recent survey showed that only 49.3% of the 1004 subjects evaluated had complete protection and 20.4% had no protection at all. While 95% of young adults in the 15 to 24 age range were protected, the rate of protection was below one-third in subjects over 65. These results emphasize the importance of anti-diphtheria vaccination programs and continued surveillance in adult populations. Current French legislation requires vaccination before the age of 18 months but without any requirement for re-vaccination in adults. The current situation clearly demonstrates that the risk of a diphtheria epidemic still exists, even in our Western countries. To completely protect the population, the present vaccination policy should include re-vaccinations of the adult population every 10 years, as for tetanus. Use of a preparation containing a reduced dose of vaccine, given with the tetanus and polio booster shots, is to be recommended. Re-vaccination with DT or the reduced dose dT would also be indicated after injury instead of tetanus alone. Surveillance and typing of C. diphteriae strains isolated from clinical cases should also be maintained.