Researchers have discovered that bank tellers in Skåne, southern Sweden, carry a virus that can cause hemorrhagic fever in humans. This find was made more than 500 kilometers south of the previously known area. The strain of the virus discovered in Skåne appears to be more closely related to strains from Finland and Karelia than to the variants found in northern Sweden and Denmark. This is revealed in a new study from Uppsala University, carried out in collaboration with infectious disease doctors in Kristianstad and published in the scientific journal Emerging Infectious Diseases.
We were surprised that such a large percentage of the relatively few bulbs we caught actually carried a hantavirus that makes people sick. And this was in an area more than 500 kilometers south of the virus’ previously known range.”
Elin Oikonomou Ludeberg, an infectious disease specialist at Kristianstad Central Hospital, one of the first authors of the study
Hantaviruses are a family of viruses that occur naturally mainly in rodents such as mice, rats and voles. Some hadaviruses can infect humans and cause two main groups of diseases: hemorrhagic fever with renal syndrome (HFRS) and hadavirus pulmonary syndrome (HPS). Both types of diseases are notifiable under the Communicable Diseases Act as they can cause serious problems and even death. In northern and central Europe, a variant of the virus, Puumala hantavirus, causes a relatively mild form of HRFS popularly known as “bulb fever” (nephropathia epidemica). However, studies have shown that this hantavirus can also cause very severe HRFS, which in the worst case can be fatal. In Sweden 100-450 cases of fever require hospital treatment each year, exclusively in the northern part of the country.
In 2018, locally affected fever was reported in Skåne, more than 500 km south of the previously known southernmost incidence of the disease in Sweden, which was north of Uppsala. Another case was discovered in 2020, also in Skåne. In both cases, the patients concerned had not traveled away and were infected in their area of residence. In an attempt to understand how this was possible, table tops were caught near the patients’ homes and analyzed for hantavirus. It turned out that 9 of the 74 trapezoids caught carried hantavirus genes. Genetic studies have now shown that the virus is significantly different from the virus variants circulating in northern Sweden and Denmark, and that it is more closely related to viruses from Finland and Karelia.
The next step in the research is to find out where the virus comes from and map its distribution in the southern parts of Sweden.
“If the virus has been in the area for a long time and just hasn’t been discovered, why aren’t more people getting sick? Or, has it settled in Skåne recently and just started spreading? And how did it get there?” asks Professor Åke Lundkvist of Uppsala University, co-author of the study. “Unfortunately, the COVID-19 pandemic intervened, which significantly delayed the completion of this study. These findings are very interesting and show how important it is to investigate the causes as quickly as possible when we see an infectious disease in a new geographic area. “
The study was funded by the EU (Horizon 2020) and SciLifeLab (Pandemic Laboratory Preparedness), along with local R&D funding from Kristianstad Central Hospital.
Source:
Journal Reference:
Ling, J., et al. (2024). Epidemic of Nephropathia caused by Puumala virus in Bank Voles, Scania, Southern Sweden. Emerging infectious diseases. doi.org/10.3201/eid3004.231414.
