BBC Radio 5Live Science Specialist Matt Mcgrath reports

The virus usually occurs in children and is regarded as harmless.

However, it can cause expectant women to abort if they catch the infection in the first 20 weeks of pregnancy.

"The number of true infections in the population will run into hundreds of thousands," says Dr Elizabeth Millar, an epidemiologist with the service.

"The majority of these will be very mild. It is only the cases where there is a need to be quite sure about the diagnosis - for instance a pregnant woman who has a rash - who actually get diagnosed and reported to us."

Slapped cheek

Human Parvovirus B19 was discovered by chance in 1975 and the Public Health Laboratory says there are epidemic outbreaks every 4 years.

The virus is often called fifth disease or slapped cheek syndrome because of the facial rash that often accompanies the infection.

The disease is spread by sneezing and through saliva.

Ten percent of pregnant women who come into contact with the virus will miscarry.

Joy Carter lost a baby 19 weeks into a pregnancy. She caught the virus after an outbreak at her son's school.

"The baby becomes severely anaemic and swells in a very unpleasant fashion," she says.

"When my baby was born - although you could see its beautiful face and its lovely features - it was also showing the signs of a tortuous deformity."

Public information

She believes schools should disseminate information about the infection in the same way that parents are warned about an outbreak of headlice.

"If a note had gone out to parents to warn them that there was an epidemic in the school, I would have asked someone else to take my son to school and I could possibly have avoided catching the virus."

Parvovirus is an infection with no known treatment. It runs its course in children, and up to 60% of the population has had it and will be immune to a repeat infection.

Dr Jon Kurtz, a virologist at the John Radcliffe Hospital in Oxford, says the danger posed by the virus means there is now a case for screening those at greatest risk.