Many people fear ticks. Fear of being infected by diseases. Perhaps the best known are Lyme disease and forest tick encephalitis. The latter is an infection of the central nervous system caused by the TBE virus. It can cause serious illness and it is recommended that people who spend a lot of time in the forest take the vaccine. In recent years, registered cases of forest tick encephalitis have increased considerably, but one place has researchers scratching their heads. Brønnøysund. Why does no one get infected by the TBE virus there? Have you experienced being bitten by a tick this summer? Two epidemics More and more cases of infection have been registered in the last three years. In 2015 there were only nine, last year the number had risen to 72. The number is also rising in Europe. Ørjan Olsvik, professor of medical microbiology at UiT, tells news that there are several reasons for the upward curve. First, clinicians and laboratories are doing a better job of diagnosis. They also have better conditions for detecting the virus than they did a few years ago. But there will also be more virus in the tick, Olsvik explains. In recent years, the tick has moved further and further north in the country. Previously, many believed that it was no further north than Brønnøysund. Photo: Erik Karits – A long time ago there was no TBE in the tick. The virus has come with time, he says to news. – We have two epidemics in terms of ticks. There will be more of it and there will be more viruses in it. The TBE virus is mostly detected in ticks where there are ticks to be found. Also in Brønnøysund. Snorre Stuen, tick researcher at NMBU, says it is difficult to answer why no one there gets sick. – This should be investigated further, he says to forskning.no – which first mentioned the mystery in Brønnøysund. There could be several reasons Arnulf Soleng at FHI tells news that there could be several reasons why no one is registered with infection in Brønnøysund. – We find the virus in the tick in Brønnøysund, and there could be several reasons why no infection has been registered. Less virus in ticks – One of the reasons may be that there is less of the TBE virus in ticks in Northern Norway due to the climate. Brønnøysund is located in the far north of Norway. The climate can presumably affect the amount of TBE in the tick. Photo: Ole-Christian Olsen / news Different races – There can be different races of strains, or races of the tick. Other strains may be less pathogenic, i.e. they do not cause disease. The doctors don’t think about TBE – A final theory is that the doctors don’t think that ticks have caused the disease. Therefore, it is not checked for TBE after encephalitis. news has tried to get in touch with the municipal superintendent in Brønnøy – who has not responded to our inquiries. Another type of the virus? Olsvik at UiT points out that it may be that the tick in Brønnøysund may have a different type of the TBE virus. – It is assumed that we in the north do not have TBE of the same type as in the south. Possibly a variant that causes little or no disease. He adds: – This does not just apply to Brønnøy, but to the whole of Northern Norway. Could it be that different races of the tick can explain why it infects less in some places? Photo: Per Eikeset Knudsen The theories vary, but there seems to be little doubt about one thing; There will be more ticks – and it’s not going anywhere anytime soon. – There is no chance of us getting rid of the tick. If you are bitten, you should see a doctor if you notice symptoms, says Olsvik. Soleng at FHI adds that some people, such as people along the southern coast, are recommended to take the vaccine. – People who live in places where you are often bitten should get vaccinated. So far we have no advice on vaccination in Nordland or around Brønnøysund, he explains and adds: – But you have to think about ticks in Brønnøysund as well. There is a lot of it and it is important that you check yourself.
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No one gets TBE despite lots of ticks – news Nordland
