GPs have notified officials of 1502 cases so far this year, compared to 54 for the same period in 2011.
Young infants are at greatest risk from whooping cough and 10 babies have died from related complications south of the Border this year.
In Scotland, tests have confirmed whooping cough in 117 babies, but there have been no fatalities.
Pregnant women are now being offered the relevant vaccine to protect newborns before they can be immunised. Infants are injected at eight weeks, but need three doses for immunity.