During June to August this year, 200 cases of TBE in the country were reported to the Public Health Agency. Ten cases were reported in Värmland, which can be compared with only one reported case in the summer of 2009. In total so far this year, 13 cases of TBE have been reported in Värmland. This means that the sharp increase in the infection over the past two years seems to be sustaining.
- One explanation for the increase is that the virus is spreading in the country and especially to the west, to Västra Götaland, Värmland and Västmanland. In these areas, vaccination coverage is also likely to be lower than where the infection has been for a long time, says Marika Hjertqvist, epidemiologist at the Public Health Agency, to the Siren News Agency.
There is no simple explanation as to why the number of cases of TBE is increasing. Probably it is a complicated interaction between various factors, such as the weather and the occurrence of ticks and the so-called reservoir animals, mainly mice and sores, that carry the virus, according to Marika Hjertqvist.