Disappearance of epiglottitis during large-scale vaccination with Haemophilus influenzae type B conjugate vaccine among children in Finland.

Surveillance of blood-culture-proven epiglottitis was conducted in Finland from 1985 through 1992. Among children (< 16 years), all bacteria causing epiglottitis, and among adults, Haemophilus influenzae were included. H influenzae type b (Hib) caused 226 (97%) of cases among children. Among adults with H influenzae epiglottitis (total of 20), 19 were caused by Hib. In 1986, vaccine trials with Hib-conjugate vaccines started in Finland, with vaccination coverage of 94% to 98% of infants. Vaccinations did not yet have an effect on the occurrence of epiglottitis in 1985 or 1986 when the annual incidence among children was 5.3/100,000, among those less than 5 years of age was 13.2/100,000, and among adults was 0.08/100,000. In 1987 through 1992 the proportion of vaccinated children increased steadily while the incidence of Hib epiglottitis decreased from 50 to 60 cases seen annually in 1985 and 1986 to 2 cases in 1992. There was no increase in the occurrence of epiglottitis caused by other pathogens. In conclusion, there is now a safe and efficient way to prevent the majority of epiglottitis cases among children with the new Hib-conjugate vaccines.