MORE than 200 people have fallen ill with whooping cough in Scotland since the start of the year – 10 times the number infected last January.

The outbreak started in 2012 and GPs have alerted officials to a total of 2241 cases in the past 13 months.

In the whole of 2011 just 85 people were reported to have the illness and the current surge has been described as the worst for at least 20 years.

Pregnant women are again being encouraged to accept the offer of vaccination against the infection, which can be life-threatening for babies. It is hoped mothers will pass protection against whooping cough on to their newborn infants and prevent them catching it before they are old enough to be vaccinated themselves.

Although no babies have died in the current whooping cough outbreak in Scotland, 14 have died in other parts of the UK. So far this year four cases have been confirmed in children under the age of one north of the Border.

Dr Alison Smith-Palmer, epidemiologist for Health Protection Scotland – the agency monitoring the outbreak – said the rate at which whooping cough is spreading appears to have slowed but it is too early to be sure the problem has peaked.

At one point she said Scottish laboratories were confirming 70 to 80 cases a week, but this has now dropped to 30 to 50.

There were 212 notifications of the illness from GPs between the end of 2012 and the week ending Friday, February 1, compared to 16 for the same period last year, before the germ took hold.

Dr Smith-Palmer said: "We do not know how long it is going to take to get back down to the baseline level. The key message is there is still a lot of it about and pregnant women should be really encouraged to take up the offer of the vaccine."

Experts advised that pregnant women should be offered the vaccine in the autumn as those contracting whooping cough soared.

It was agreed the injection should be available for six months, until the end of March. The Joint Committee on Vaccination and Immunisation is now expected to consider whether this period should be extended.

Dr Smith-Palmer said: "It is constantly being reviewed by the JCVI."

Whooping cough is caused by a bacterial infection in the lungs and airways that leads to persistent bouts of coughing. It can be treated with antibiotics if it is diagnosed within three weeks of infection.

Early symptoms can be similar to those of a cold, but it enters a second stage characterised by coughing fits which can lead to the whooping sound as the patient tries to take in air. It can take three months to clear up and is also known, therefore, as the "100-day cough".

Outbreaks of the illness are known to occur every three to four years but the scale of the current spread had exceeded expectations.

Protection offered by the vaccine, which is routinely given to babies in three doses, is known to wear off in some people in adolescence.

It is thought one of the reasons for the 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.