This is serious. Via Nature Climate Change: Emerging Vibrio risk at high latitudes in response to ocean warming. The abstract:
There is increasing concern regarding the role of climate change in driving bacterial waterborne infectious diseases. Here we illustrate associations between environmental changes observed in the Baltic area and the recent emergence of Vibrio infections and also forecast future scenarios of the risk of infections in correspondence with predicted warming trends.
Using multidecadal long-term sea surface temperature data sets we found that the Baltic Sea is warming at an unprecedented rate. Sea surface temperature trends (1982–2010) indicate a warming pattern of 0.063–0.078 °C yr−1 (6.3–7.8 °C per century; refs 1, 2), with recent peak temperatures unequalled in the history of instrumented measurements for this region.
These warming patterns have coincided with the unexpected emergence of Vibrio infections in northern Europe, many clustered around the Baltic Sea area. The number and distribution of cases correspond closely with the temporal and spatial peaks in sea surface temperatures.
This is among the first empirical evidence that anthropogenic climate change is driving the emergence of Vibrio disease in temperate regions through its impact on resident bacterial communities, implying that this process is reshaping the distribution of infectious diseases across global scales.
The Mail Online has a news story on this finding.