FARMERS in the region are being asked to take part in a national study investigating cases of a potentially-serious infection picked up from rats.
The move follows the first-ever discovery in the UK of rats infected with the rare hantavirus after a farmer from the Humber area developed haemorrhagic fever and kidney problems from rodents on his property.
The case is believed to be the second in the area in recent years.
Experts speculate the animals could have picked up the strain of the virus, which originates in Asia, from rats transported on ships docking at the Humber ports of Immingham, Grimsby, Hull or Goole.
Now scientists from the Health Protection Agency (HPA) are looking for people who work or live on farms in north and east Yorkshire and northern Lincolnshire to take part in a study to assess how often the disease infects people in England.
There have been around 40 cases confirmed in the UK in the last 30 years of infections from the virus, the majority linked to an outbreak in Somerset in 1992.
Most cases are mild with symptoms including fever, headache, blurred vision and back pain but a small number of those infected can go on to develop severe disease.
The infection is passed to humans through direct contact with rodents or material contaminated by them.
It cannot be transmitted from person to person.
But scientists and health experts from the agency say further research is needed to understand how widespread the disease is in England.
The findings could lead to new advice about the risks posed by the virus.
A report published last month on the case discovered in the Humber area last year tested rats, wood mice and bank voles trapped on the victim’s property and discovered a strain of the virus in two rats – the first isolated from wild rats in the UK.
Autilia Newton, director of North Yorkshire and the Humber Health Protection Unit, said: “The study is focusing on North Yorkshire and the Humber because in recent years two isolated cases of hantavirus, believed to have been acquired locally, have been confirmed in the Humber area.
“Both individuals, who had a type of hantavirus disease which causes haemorrhagic fever with renal syndrome, have now recovered.”
As part of the study, people who live or work on farms, who are at highest risk of the infection, will be asked to donate blood and saliva for laboratory tests to look for hantavirus.
Lisa Jameson, a research fellow in the virology and pathogenesis department at the Health Protection Agency’s laboratories at Porton in Wiltshire, said: “Currently there is no indication that this virus is becoming significantly more prevalent in the UK, but as with all rare infections it’s possible that more cases occur than are reported.
“It’s important to be aware that if any of the donated samples test positive, this will only indicate that a person has been in contact with a hantavirus at some time in the past.
“It does not indicate that the virus made the person ill, or that they are ill now.
“No further action will be needed for any individuals who are well if any of the donated samples test positive.
“However, if our overall findings indicate that further health protection advice is necessary, the HPA will work with the relevant partners to act on this.”
Barney Kay, regional director of the National Farmers’ Union, encouraged farmers to take part.
“While cases are clearly very rare, we welcome this study into the potential risk faced by our members and assessment of whether any further health protection advice is needed.”
The Health Protection Agency is looking for people aged 18 or over who live or work on farms in the area to take part in the study and will be attending farming events in coming weeks to carry out the testing.
Experts stress the strain of hantavirus which affected visitors to the Yosemite National Park in the United States last year is different to the type of the illness in the UK.
Around 10 people were affected, leading to three fatalities, after staying mainly in tent cabins in the park.
Anyone interested in taking part in the research can email firstname.lastname@example.org.