During a pandemic, employers will face a conflict between the need to keep genuinely sick employees away from the workplace and the need to prevent unauthorised absence.
However, in these circumstances, concerns about whether someone is taking advantage should give way to the very real need to prevent the spread of the disease and ensure adherence to public health guidance.
Workplaces that have a culture of encouraging employees to struggle in when they feel sick will need to change their approach; indeed, not to do so could expose them to claims for breach of contract.
The hardest thing to manage is likely to be employee fear, particularly if there is public consensus that staying at home is safest. Employees should be required to attend work as normal, unless there is a particular risk posed in that workplace or in getting to and from that workplace.
Employers should take their cue from the government and generally implement their common sense.