Public health officials have written to everyone who attended a meeting of Hertfordshire County Council last week – after a councillor tested positive for Covid-19.

More than 70 councillors attended the six-hour meeting – with staff and members of the public also attending, either in part or in full.

But now it has emerged that one councillor has tested positive for Covid-19 two days after the meeting.

Although officials believe the infection is as a result of household transmission rather than attendance at the meeting, they have contacted everyone who was there.

In an email on Monday (October 25), councillors were told contact tracing of those who were seated next to the individual - who is publicly unidentified - in the council chamber is already in hand.

It recommends councillors continue to take lateral flow tests, as advised before attending meetings or events, and to self-isolate and take a PCR if they develop symptoms.

But even for those who have not been fully vaccinated, it offers the reassurance that "the nature of the circumstances is that your risk of transmission is low".

Related: Hertfordshire councillors ditch face coverings despite advice to keep them on

The meeting on October 19 was the first time that the full council had met in the council chamber, at County Hall, Hertford, since February 2020.

Council meetings had been held virtually until May, as part of measures put in place to halt the spread of Covid-19 in 2020.

The council had been holding its full council meetings at the larger Gordon Craig Theatre in Stevenage until the move to Hertford last week.

A number of the council’s committees – including cabinet, development control and Overview and Scrutiny Committee – have already met in the County Hall chamber over the last few months.

Commenting on the latest situation, a spokesperson for the county council said: "Public Health have advised that when an infection is reported following a large workplace based meeting where people are relatively easily contactable, everyone in attendance be informed in writing so they can take precautions.

"This has been done in addition to reassurance that contract tracing is underway so we can continue to encourage people wider than close contacts to follow national guidance including regular lateral flow tests and, should they develop symptoms, to isolate and book a PCR test."