Health chiefs are at a loss to explain the big rise in whooping cough cases in East Anglia, despite a higher take-up of pregnant women getting immunised.

New figures show that there were nearly ten times more cases of the infection reported in the east of England in 2012, compared to 2011.

However, the Health Protection Agency is no nearer to finding the cause or the reasons behind the outbreak, which has led to the death of 13 babies across the country in the last year.

In Norfolk, there were 157 whooping cough cases last year, compared to 14 in 2011, and in Great Yarmouth and Waveney there was a jump from four in 2011 to 60 last year. In Suffolk there were 174 whooping cough cases, compared to four the year before.

The news comes despite almost 60pc of pregnant women in the East receiving a whooping cough vaccination to protect their baby. However, in Norfolk almost 75pc of eligible pregnant women received the immunisation in December to protect themselves and their unborn babies.

Officials from Norfolk and Waveney NHS said take-up of the vaccine was on the increase and urged all pregnant women to have the jab.

Lucy Macleod, interim director of public health at the primary care trust, said: 'We have seen a large increase in the number of whooping cough cases both nationally and across Norfolk and Waveney, and while many adults will easily recover from the virus there is a very serious risk to infants who are too young to start their vaccinations.'

'We therefore strongly urge all expectant mothers to be vaccinated against whooping cough from week 28 of their pregnancy. By getting the jab mothers can protect their unborn child from the risk of getting whooping cough. The vaccination is available in Norfolk and Waveney and pregnant women should ask their GP or midwife for more information.'

The Health Protection Agency (HPA) has not been able to pinpoint a specific reason for the rise in whooping cough cases and it is too early to tell from Norfolk data why there has been such a spike.

The bacterial infection can affect anyone, but babies and young children are more at risk. Cases of whooping cough were prevalent in the 1950s, when it cased hundreds of deaths a year, which led to the introduction of a vaccine.

Mary Ramsay, head of immunisation at the HPA, said the number of whooping cough cases had seen a decrease in December and November, since a peak in October.

'It is very encouraging to see that nearly 58pc of pregnant women delivering in December in the east of England had accepted the offer of a vaccination against whooping cough. We would like to remind pregnant women how serious this infection can be in young babies and how it can, in some cases, cause death.

'It is important that, parents still ensure their children are vaccinated against whooping cough on time, even babies of women who have had the vaccine in pregnancy – this is to continue their baby's protection through childhood,' she said.

Last year saw 1,091 whooping cough cases in the east of England compared to 104 in 2011. The highest number of cases in the east of England were reported in those aged 15 and over.

For more information, visit www.nhs.uk/conditions/pregnancy-and-baby/pages/whooping-cough-vaccination-pregnant.aspx