New cases of the Schmallenberg virus have been reported at farms in Essex, Norfolk and Suffolk. For the first time it has also being found on a farm in Cambridgeshire.
The virus, which causes birth defects and miscarriages in sheep and cattle, first emerged in Holland and Germany last year.
New cases have been reported at nine farms in the UK since Monday - bringing the total number to 121 farms affected. Scientists say it's very unlikely the Schmallenberg virus could spread to humans.
The virus with affects cattle and sheep has spread to Cambridgeshire and new cases have been reported elsewhere in East Anglia.
A Suffolk farmer who lost 75 lambs to the Schmallenberg virus claims many more have been hit by the virus but have not reported it.