‘Rat fever’ that can trigger an Ebola-like hemorrhagic virus is ‘spreading across parts of Europe’

A POTENTIALLY lethal virus that has the ability to jump from rodents to humans and can cause bleeding similar to Ebola is spreading across northern Europe.

Researchers have discovered that rodents in Sweden carry a pathogen that can reach humans and develop into hemorrhagic fever.

Cases of the disease are being detected hundreds of miles from where health authorities typically see the virus, causing concern among scientists.

It all started when doctors in the county of Scania, in southern Sweden, diagnosed a case of epidemic nephropathy, caused by the Puumala virus carried by bank rats, in 2018.

Epidemic nephropathy is also known as “rat fever” and is a rare disease with the potential to cause hemorrhagic fever in people.

Hemorrhagic fevers are a group of diseases caused by different viruses that can be serious and potentially fatal – they include yellow fever, the Ebola virus and Crimean-Congo hemorrhagic fever.

Doctors were stunned to detect a case of rat fever in the far south of the country, more than 500km south of where the disease had previously been detected.

Another case was detected in 2020, also in the county of Scania, Sweden.

In both cases, the patients did not travel and were infected in their area of ​​origin.

His symptoms were typical of hemorrhagic fever with symptoms of renal syndrome (HFRS), including fever, general malaise, nosebleed, and renal failure.

Both patients recovered from their infections, but it took scientists at Uppsala University to investigate why vole fever infections are emerging so far from where they usually appear.

They carried out genetic testing on voles in Scania County, capturing them near patients’ homes and analyzing them for any occurrences of hantavirus.

Hantaviruses are a family of viruses found mainly in rodents such as mice, rats and rats.

Certain hantaviruses are capable of infecting people and causing two types of illnesses: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS).

According to scientists at Uppsala University, 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 – called Puumala hantavirus – causes a relatively mild form of HFRS.

However, studies have shown that this hantavirus can also cause very serious HRFS, which in the worst case can be fatal.

In Sweden, around 100–450 cases of rat fever require hospital care every year in the northern part of the country alone.

The scientists’ analysis found that nine of 74 voles captured in southern Scania carried hantavirus genes.

They also discovered that the virus infecting rodents in this area was not the same strain found in northern Sweden.

Instead, it was a distinct variant, closely related to the Puumala viruses from Finland or Russian Karelia, hundreds of kilometers away.

Somehow, this strain of the virus that causes hemorrhagic fever emerged in the bank rat population in southern Sweden, most likely within the last decade.

Although only two human cases have so far been identified in southern Sweden, scientists feared that this emerging viral strain could pose a threat to public health.

“New strains of Puumala virus in a new geographic area could have a substantial effect on human health,” researchers wrote in a study published in the journal. Emerging Infectious Diseases.

Elin Economou Lundeberg, study author and infectious diseases doctor at Kristianstad Central Hospital, said: “We were surprised that such a high proportion of the relatively few mice we caught actually carried a hantavirus that leaves people sick.

“And this occurred in an area more than 500 kilometers south of the previously known range of the virus.”

Researchers now aim to find out where the virus comes from and map its distribution in southern Sweden.

Professor Åke Lundkvist from Uppsala University, co-author of the study, wondered: “If the virus has existed in the area for a long time and simply hasn’t been discovered, why haven’t more people fallen ill?

“Or has it recently established itself in Scania County and just started to spread? And how did it get there?

“Unfortunately, the COVID-19 pandemic intervened, which considerably 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.”

OTHER PRESENTATIONS OF HEMORRHAGIC FEVER

This is not the first time that alarms have been raised about cases of hemorrhagic fever in Europe.

Crimean-Congo hemorrhagic fever is a viral disease commonly detected in regions such as Africa, the Middle East, and west and south-central Asia.

But the virus has caused large outbreaks in the Balkans and Turkey, as well as in Russia, European Center for Disease Prevention and Control (ECDC) says.

It has also been seen in popular vacation spots like Spain.

In April 2024, a person died in the province of Salamanca after being infected with Crimean-Congo hemorrhagic fever while hiking.

A forestry worker in León province also died of a fever in 2022, while another person was infected by a tick bite but recovered.

Crimean-Congo hemorrhagic fever is typically transmitted by tick bites, which are “widely distributed across southern and eastern Europe,” according to the ECDC.