SCOTLAND has seen a 2325% rise in incidence of whooping cough this year, according to experts.

General practitioners have reported 873 cases so far this year compared with 36 for the same period in 2011, with the rate north of the Border now at its highest level for at least 25 years.

Monitoring agency Health Protection Scotland believes the outbreak is yet to peak.

Around 60 babies under the age of one are among the confirmed cases, although there have been no deaths in this age group north of the Border.

Across the UK five infants have been killed by the illness since the outbreak began and experts are currently considering whether pregnant women should be immunised against the virus in the hope of protecting their children when they are first born.

Babies are vaccinated against whooping cough, with the first dose being given at two months, but until they have received all three injections they remain vulnerable to the virus.

Dr Martin Donaghy, medical director of Health Protection Scotland, said the effect of the vaccine wears off as people approach adulthood. It is thought one of the reasons for the current outbreak is the number of people no longer immune to the virus and the number of people infected has reached a tipping point where the spread of the illness has become likely.

A surge in the illness is anticipated every three to four years, but both the scale of the outbreak and the speed with which it has spread has exceeded expectations.

Offering a booster vaccine to adolescents is another potential means of controlling infection which is under consideration.

However, while unpleasant for an adult, whooping cough is mainly dangerous to the very young.

Dr Donaghy said: "It gives you paroxysms of coughing. It is like having a coughing fit and not being able to stop coughing. In a child or an infant, who do not have much lung capacity, that fit of coughing will do damage."

Infected adults do not make the "whoop" sound when they cough, he said, but the coughing can still be very uncomfortable. He advised people with a persistent cough to visit their doctor.

A UK-wide team is currently investigating how long the outbreak is likely to last. Dr Donaghy said it was expected to continue for at least a few more months, but it could run for more than a year.

At the end of last month the Health Protection Agency said it had confirmed 2466 cases of whooping cough in England and Wales using laboratory tests. This compares to 1118 cases for the same region for the whole of last year.

Dr Donaghy said cases of whooping cough often went undetected because there are so many causes of a chronic cough in adults. This suggests the actual number of people suffering is even higher than the figure reported by GPs.

Since the outbreak began, Scottish helpline NHS 24 has reissued guidance to staff and GP out-of-hours services on whooping cough and checked the computer algorithm which their nurses use when discussing symptoms with callers.

Professor George Crooks, medical director of NHS 24, said: "If you are concerned about whooping cough check with your GP and do not hesitate to contact NHS 24 if it is during the out-of-hours period if you have any concerns about a child."

The Joint Committee on Vaccination and Immunisation (JCVI), which advises the UK governments on vaccinations, is considering whether pregnant women should be immunised against the illness. At its June meeting, JCVI members recommended whooping cough vaccination for healthcare workers working with young babies to protect them against the infection and to stop any risk of them passing the infection on to other patients.