In an update sent to primary care providers, NHS England reminded practices of the 'requirement and importance of reporting COVID-19 outbreaks'.
The update said an outbreak 'is defined two or more confirmed cased of COVID-19 among individuals associated within a specific setting' - and warned that prompt reporting was vital to guarantee 'continuity of primary care services and to enable commissioners to provide timely support'.
'Primary care providers should inform their commissioner as soon as they consider that delivery of the full contracted service may be compromised by staff absence due to the outbreak,' the update warned - adding that commissioners will 'work with the contractor to put business continuity arrangements in place and to maintain access to services for patients'.
The advice comes as cases of COVID-19 remain at record levels, with nearly 585,000 confirmed positive cases in the past seven days.
GP leaders have called for urgent adoption of additional restrictions to slow the spread of COVID-19, with BMA estimates suggesting close to 16,000 general practice staff could be off sick with the virus by Christmas Day.
A shortfall of that magnitude - part of a potential shortfall of more than 130,000 staff NHS-wide - would strip nearly three members of staff from each GP practice in England on average, and could severely undermine their ability to maintain services.
GPonline has reported that staff absences triggered by COVID-19 infection have forced some practices to place additional limits on services, to close sites or warn patients that calls may take longer than usual to answer.
Practices have already been advised to consider pausing routine and non-urgent work and to focus primarily on delivery of the accelerated COVID-19 vaccination programme - which has seen the health service deliver hundreds of thousands of jabs daily.
Part of the QOF and some enhanced services have also been suspended for the rest of the current financial year, with millions of pounds in funding from the Investment and Impact Fund diverted to incentivise practices to participate in the accelerated COVID-19 vaccination campaign.
On 18 December, official data showed that total COVID-19 jabs delivered UK-wide topped the 1m mark for the first time since the vaccination programme began just over a year ago.