The government has been accused of missing an opportunity after it failed to deploy 5,000 contact tracing experts employed by councils to help limit the spread of coronavirus.

Environmental health workers in local government have wide experience in contact tracing, a process used to prevent infections spreading and routinely carried out in outbreaks such as of norovirus, salmonella or legionnaires’ disease. But a spokesperson for Public Health England (PHE), which leads on significant outbreaks, said the organisation did not call upon environmental health workers to carry out contact tracing for coronavirus, instead using its own local health protection teams.

According to the Chartered Institute of Environmental Health the UK has, at a conservative estimate, 5,000 environmental health officers working in local councils nationwide.

The institute’s Northern Ireland director, Gary McFarlane, said government health bodies “absolutely should be drawing on the skills set of EHOs [environmental health officers] and if they aren’t, it’s a missed opportunity”. He said: “There is significant capacity that is sitting there for this kind of work to be done.”

PHE’s contact tracing response team was boosted to just under 300 staff, deemed adequate for the containment phase of handling the Covid-19 virus up to mid-March. In that time the team, working around the clock, traced 3,500 people and supported the 3% of contacts found to be infected to self-isolate. Tracing was scaled back when the UK moved to the delay phase of tackling coronavirus in mid-March. It is now carried out in limited form, mainly for vulnerable communities.

An environmental health worker for a council in Scotland, who does not want to be named, said: “If councils had been given the go-ahead from the start, they could have put plans in place and now have a much flatter curve.” Another, with decades of experience, said he was “struggling to figure out” why this was not the case.

One environmental health worker for a north-western council said his team were expecting a call at the start of the coronavirus outbreak. He said: “We are pretty good at infection control and contact tracing, it’s part of the job. We thought we’d be asked and were shelving other work.”

Environmental health workers have recently been tasked with ensuring the public stick to social distancing rules. They have also been monitoring takeaways and food deliveries. Environment health departments have, like other areas of local government, suffered austerity cuts since 2010.

Contact tracing involves getting in touch with everyone an infected person might have seen and asking them to self-isolate in an effort to contain the virus.

The government decision to all but abandon contact tracing is not consistent with WHO guidelines, which urge a test-and-trace approach. At a WHO media briefing on Covid-19 in March, director general Tedros Adhanom Ghebreyesus said: “Tracing every contact must be the backbone of the response in every country.”

The approach has been carried out in other countries, including Ireland, Germany, South Korea and Singapore. In Germany, thousands of contact tracers are still working – with more being recruited – in part clearing a backlog of infections that occurred before the nation’s shutdown measures, according to Dr Philipp Zanger , head of the Institute of Hygiene, Infection Control and Prevention at the Rhineland-Palatinate agency for consumer and public protection.

Contact tracing is also used to prepare to tackle any outbreaks when the lockdown is eased, since “once we let ourselves out again, we will see more transmission again,” he said.

The UK government approach is understood to be that once virus infection numbers have tipped, manual contact tracing is unworkable, while social distancing and self-isolation measures reproduce much of its effect.

But Anthony Costello, professor of global health and sustainable development at University College London, said giving up on it was a mistake. “You still need to do it,” he said, highlighting regions where infection numbers were relatively small. “In low-intensity areas you could ramp up your testing … use all your people to jump on it.”

Environmental health officers say that as well as helping to slow the spread of a virus, tracing could provide information on how it spreads and, if successful in containing outbreaks in specific areas, could help direct healthcare resources.

The UK, US and Germany are developing smartphone apps to help trace coronavirus infections to ease national lockdowns. Versions of this technology have been used in South Korea and Singapore. Initial reports suggest the UK app would operate on a voluntary basis, while there are privacy concerns around the security of health and location data provided.

A PHE spokesperson said that contact tracing was no longer useful because “with such a level of sustained community transmission there is limited value in doing so”.