Hertfordshire’s top public health boss has praised residents for their efforts in bringing down coronavirus infections but warned they can change “in as little as 24 hours”.

It comes as most districts across Hertfordshire are now seeing an infection rate of under 50 cases per 100,000 population, with plenty of neighbourhoods having now nearly eliminated the virus.

In our area, latest data shows that most wards across Watford, Hertsmere and Three Rivers had such a low number of cases in the seven days to March 18 that they did not appear on the government’s coronavirus map.

Areas that are covered in white are known as ‘supressed’ areas as there are fewer than three cases in the ward – the data is not shown to protect people’s identities.

Nine wards in Watford recorded fewer than three cases in the seven days to March 18, while there were seven in Three Rivers and 10 in Hertsmere.

Below you can see how many coronavirus cases there are in your area - a ward with N/A means there are fewer than three cases.

Speaking about the data in a press conference this morning, Hertfordshire’s director of public health Jim McManus praised residents but urged people not to get complacent.

He said: "We are doing brilliantly. Let's keep it up because actually, if we keep this going, we will be able to open up safely.

"But take your foot off the pedal too quickly and all the good work can be undone."

He added: "Infections can change in as little as 24 hours, so if you get one person who's infected who gets too close to three or four friends, then it's possible they could infect all those people, and we know that happens.

"There are cases where one person has infected over 30. That's an additional eight people from that one person infected in the space of 24 hours and if they then take the infection into their household or into their workplace, not knowing it, and they each infect another one person, you've got another eight or 16.

"Within the space of four days, you can have infections running in the hundreds. It is that quick."

He added that it is the asymptomatic people that “we don’t know about that really spread the infection”.

Mr McManus said: "If everybody behaves as if they're infected, you know (wears) masks, space outdoors even when you're meeting with your friends, it's not that difficult.

"Sit either end of the cafe table when you're meeting a friend, when you're able to meet them outdoors, and that's fine.

"And avoid the physical contact. That's all you need to do. You can still see one another, but if you each behave as if you might be infected we'll hammer infections down if we keep them there."