In East Greenland, a dramatic increase of tuberculosis (TB) incidence has been observed in recent years. Classical genotyping suggests a genetically similar Mycobacterium tuberculosis (Mtb) strain population as cause, however, precise transmission patterns are unclear. We performed whole genome sequencing (WGS) of Mtb isolates from 98% of culture-positive TB cases through 21 years (n = 182) which revealed four genomic clusters of the Euro-American lineage (mainly sub-lineage 4.8 (n = 134)). The time to the most recent common ancestor of lineage 4.8 strains was found to be 100 years. This sub-lineage further diversified in the 1970s, and massively expanded in the 1990s, a period of lowered TB awareness in Greenland. Despite the low genetic strain diversity, WGS data revealed several recent short-term transmission events in line with the increasing incidence in the region. Thus, the isolated setting and the uniformity of circulating Mtb strains indicated that the majority of East Greenlandic TB cases originated from one or few strains introduced within the last century. Thereby, the study shows the consequences of even short interruptions in TB control efforts in previously TB high incidence areas and demonstrates the potential role of WGS in detecting ongoing micro epidemics, thus guiding public health efforts in the future.

ObjectivesTo estimate age- and gender-specific incidence rates among Greenlandic stroke-survivors.Study designThe study was performed as a cross-sectional observational study.MethodsAll Greenlandic patients admitted to Queen Ingrid's Hospital (QIH) with stroke in 2011 and 2012 were included in the study. Data were obtained from patient files and the Central Civil Registration System. Age- and gender-specific incidence rates were estimated as cases/100,000 adults/year. Direct age-standardized incidence rate was calculated using the WHO 2000–2005 population as the standard.ResultsIn 2011 and 2012, 156 cases of stroke were registered, 72 (46.2%) males and 84 (53.8%) females. The overall incidence rate of stroke was 155/100,000 person-years (95% CI 121–190), with ischemic stroke accounting for 89.1% of these. No significant differences were seen between men and women. Direct age-standardized incidence rate was 149/year/100,000 (95% CI 192–264). Median age at time of diagnosis was 60 years (interquartile range 53–69).ConclusionsThis study reports an age-standardized all-stroke incidence rate of Greenlandic stroke-survivors in Greenland within the wide range as incidences in Western Europe. A noticeable difference when compared to Denmark was that male and female incidence were approximately the same, and that incidence rates were high in the younger age groups. The majority of strokes were of ischemic origin.