Some 127 cases of measles have been recorded in London, although it is not known where as precise figures are only published for boroughs that have seen 10 more cases.
When questioned about the outbreak by London politicians on Monday, Iyanger said: “We’re not at all being complacent.
“The numbers are fairly static in the last couple of weeks, but that’s not to say it won’t go up for down in the next few days.”
Asked if the situation was “contained”, she said: “We’re doing everything we can to control it but I couldn’t say that numbers won’t go up.”
In late January, Enfield Council wrote to parents in the borough warning them their children could be excluded from school if they were not fully vaccinated against measles.
The letter urged families to check their child’s vaccination status to limit spread of the disease.