Do you feel guilty when calling in sick at work? This might be why...

As many as half of people report working when sick. The reasons for this are complex, experts say. Officials and experts continue to monitor developments closely as the situation unfolds. Communities affected by the story are watching for further updates in the days ahead. Analysts say the implications could extend well beyond the immediate headlines, with policymakers and industry leaders expected to respond in the coming weeks.

Readers following this story should check back for the latest details as new information becomes available.