CNS infections in Greenland: A nationwide register-based cohort study.
BACKGROUND
Indigenous Arctic people suffer from high rates of infectious diseases. However, the burden of central nervous system (CNS) infections is poorly documented. This study aimed to estimate incidence rates and mortality of CNS infections among Inuits and non-Inuits in Greenland and in Denmark.


METHODS
We conducted a nationwide cohort study using the populations of Greenland and Denmark 1990-2012. Information on CNS infection hospitalizations and pathogens was retrieved from national registries and laboratories. Incidence rates were estimated as cases per 100,000 person-years. Incidence rate ratios were calculated using log-linear Poisson-regression. Mortality was estimated using Kaplan-Meier curves and Log Rank test.


RESULTS
The incidence rate of CNS infections was twice as high in Greenland (35.6 per 100,000 person years) as in Denmark (17.7 per 100,000 person years), but equally high among Inuits in Greenland and Denmark (38.2 and 35.4, respectively). Mortality from CNS infections was 2 fold higher among Inuits (10.5%) than among non-Inuits (4.8%) with a fivefold higher case fatality rate in Inuit toddlers.


CONCLUSIONS
Overall, Inuits living in Greenland and Denmark suffer from twice the rate of CNS infections compared with non-Inuits, and Inuit toddlers carried the highest risk of mortality. Further studies regarding risk factors such as genetic susceptibility, life style and socioeconomic factors are warranted.
Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark.
Anne Christine
AC
Nordholm
Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark.
Bolette
B
Søborg
Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark.
Mikael
M
Andersson
Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
Steen
S
Hoffmann
Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
Peter
P
Skinhøj
Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark.
Anders
A
Koch
D000293:Adolescent; D000328:Adult; D002494:Central Nervous System Infections / Q000453:epidemiology* / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006116:Greenland / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult