The number of people catching whooping cough across Sussex has almost doubled in one month.
Latest figures reveal there have been 136 cases of the disease so far this year compared to 71 four weeks earlier.
Health bosses say the overall rate of new infections is starting to slow down but that it is vital people continue to make sure they are up to date with their vaccinations.
The figure is still well short of the 537 adults and children in the county who fell ill with the virus in 2012.
Although the take-up rate for vaccinations in the county is good, the vaccine wears off with age so adults are not protected.
At the moment the NHS vaccinates all babies when they are two, three and four months old as part of their “five in one” jabs and then again as part of their pre-school booster.
Pregnant women are also being advised to have the vaccine between weeks 28 and 38 of their pregnancy to protect their baby in their first few months of life.
Parents should also be alert to the signs and symptoms of whooping cough, which include severe coughing fits accompanied by the characteristic ‘whoop’ sound in young children but as a prolonged cough in older children or adults.
Young infants are at highest risk of severe complications and death from whooping cough as babies do not complete vaccination until they are around four months old.
In older children and adults whooping cough does not usually lead to serious complications. People are advised to speak to their GP for more information.
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