Long-term surveillance of invasive group A streptococcal disease in The Netherlands, 1994-2003.

A nationwide laboratory-based surveillance study of invasive group A streptococcal (GAS) infections was conducted in The Netherlands from May 1994 until December 2003 (average population during this period was 15 729 704). Microbiologically invasive isolates were obtained from 1504 patients, with most (70%) isolates cultured from blood. There was a clear seasonal pattern in invasive streptococcal infections, with an estimated annual incidence that peaked in 1996 (4.0 cases/100 000 individuals/year) and was at its lowest in 1999 (2.0 cases/100 000 individuals/year). Twenty-eight different M-types were identified, of which the most frequent were M1 (339/1504, 23%), M3 (187/1504, 12%), M89 (174/1504, 12%), M28 (164/1504, 11%), M12 (109/1504, 7%) and M6 (55/1504, 4%). There was a high degree of variation in the relative annual contributions of the predominant M-types, but variations in M1 and M3 combined correlated with overall changes in the annual incidence. The contribution of the patient group aged > or = 56 years to all cases of invasive GAS disease increased during the study period, whereas that of the group aged 0-20 years decreased. A peak in the incidence of invasive GAS disease among the patient group aged 30-34 years did not vary during the study period, indicating that the high incidence of invasive GAS disease in this age group was age-specific rather than cohort-related.

Epidemiological features of invasive and noninvasive group A streptococcal disease in the Netherlands, 1992-1996.

A prospective, nationwide, laboratory-based surveillance of invasive group A streptococcal infections was conducted in the Netherlands from 1992 through 1996. Clinical and demographic data were obtained and all isolates were T/M typed. All noninvasive group A streptococcal isolates were registered from 1994 through 1996. A total of 880 patients with invasive streptococcal disease were identified. The annual incidence was found to be 2.2 per 100,000. Predominant M types were M1 (21%), M3 (11%), M6 (5%), M12 (5%), and M28 (8%). Particular age and M-type distributions were observed in different clinical entities. The case-fatality rate was 18% overall, but it reached 59% among cases of toxic shock-like syndrome. Older age, necrotizing fasciitis, sepsis without focus, pneumonia, infection with type M1 or M3 strains, and underlying cardiopulmonary disease were associated with fatality. A total of 10,105 patients with noninvasive group A streptococcal disease were registered. These patients differed significantly from patients with invasive disease with regard to age distribution and primary foci of infection.