Invasive pneumococcal disease in Greenland

Abstract

Introduction: The Inuit of Alaska and Canada have a higher incidence of invasive pneumococcal disease than non-inuit. The purpose of the present study was to evaluate incidence and outcome of these infections in Greenland with special reference to pneumococcal serotypes.

Study design: Retrospective study of invasive pneumococcal infections in Greenland in the period 1996-2002.

Methods: Cases were defined as patients with positive cultures of Streptococcus pneumoniae from blood and/or CSF samples received at the microbiological laboratory of Dronning Ingrids Hospital Nuuk. Isolates were sent to Statens Serum Institut in Copenhagen for serotyping. Medical charts were reviewed.

Results: Fifty one cases were identified. The incidence among Inuit was 54 and among non-inuit 17 per 100,000 per year. Twenty one patients were in the age group 35-49 years and 20 in the age group 50-64 years. Twenty patients had meningitis (incidence 6 per 100,000/year). Seventeen patients died (33%). The most common serotypes were 1 (6 cases) and 12F (8 cases). The mortality rate was significantly higher among patients with 12F than among others (p < 0.01). No patients with serotype 1 died.

Conclusion: As in Canada and Alaska the incidence of invasive pneumococcal disease, especially meningitis, is high among the Inuit in Greenland. Young and middle aged adults were most frequently affected. Pneumococcal serotype seems to be an important determinant for the outcome of invasive pneumococcal disease.