A council leader has confirmed coronavirus rates have been skewed in her district – but nevertheless warned cases are on the rise locally.

Councillor Sarah Nelmes says Covid-19 rates in Three Rivers district have been inflated by as much as a third following a national issue with test results.

Public Health England is seeking to rectify an issue, which has seen Covid-19 cases of university students registered in their hometown (e.g. Three Rivers) rather than their university address.

Figures on the government’s coronavirus dashboard showed Three Rivers had a rate of 120 cases per 100,000 population in the seven days to October 10 – the highest rate in Hertfordshire.

But this includes cases from university students who have misleadingly had their cases added to Three Rivers’ total rather than their university address.

Cllr Nelmes told the Observer: “We are absolutely aware that Three Rivers has been affected by the university students glitch – which is logical because we are an area of highly performing schools with students who head off to university.

“It is disappointing that we still have continuous issues with data. We’re aware that work is ongoing to determine the extent of the issue.

“Figures we’ve had between September 27 and October 3 suggested around a third of cases in Three Rivers were actually students elsewhere.”

Cllr Nelmes does not know how skewed the figures have been for the rest of October where cases, according to the dashboard, have doubled in the district.

But Cllr Nelmes is keen to stress that although figures are inflated, there are active cases within the district, particularly west of Rickmansworth and in the South Oxhey area.

She said: “We know there are clusters of active cases in Three Rivers. We know if there is an outbreak at a particular workplace or venue.

“The biggest positivity rate of Covid-19 in the district is those up to the age of 24. Young people need to know they are not invincible and while they may not get ill, they can bring it home to those who can.

“While the rates here aren’t as high as the figures suggest on paper, cases our going up locally and we have to be on our guard.

“Everyone must play their part to bring down the spread of the virus.”

On Monday night, the director of public health in Hertfordshire and the leader of Hertfordshire County Council urged residents in the county to “act now” after a “significant rise” in cases in Hertfordshire in the previous ten days.

Read more: County council issues statement on latest coronavirus situation in Hertfordshire

Jim McManus and Cllr David Williams said there is a “limited window of opportunity to stay in control of the spread of the virus in Hertfordshire” – warning residents risk tighter restrictions if coronavirus gets a “stronger grip”.

Among the areas with the highest rates are Three Rivers, Hertsmere, St Albans, Watford, and Dacorum - with rates over 100 in Hertsmere and Watford.

The mayor of Watford and leader of Hertsmere Borough Council have both said their areas have also had their cases inflated by university students, with the leader of St Albans District Council confirming the same to the Evening Standard.

The Observer understands public health officials in Hertfordshire are seeking a revised list of cases in the county which don’t include figures from university students living elsewhere.

Mr McManus said earlier this week: "There is a nationwide issue with some students’ positive coronavirus tests being attributed to their permanent home address rather than their term-time address, and this is undoubtedly having an impact on the reported figures for Hertfordshire.

"We are still analysing the data and working closely with Public Health England to understand the exact effect on our local figures.

"It is important to remember that even excluding students, the number of cases is continuing to rise across all age groups and areas of Hertfordshire and it’s important that we all play our part to control the spread of coronavirus."