(Strip Number 620, Original Publication Date, 31 May 1984)
Panel 1: As Elly prepares dinner, Michael asks her how Lizzie is. Elly tells him that she's still not well.
Panel 2: Mike asks if he can see her only to be told that she's still asleep.
Panel 3: Mike looks in on a very sick-looking Lizzie and frowns.
Panel 4: His yelling "DUMB GERMS!!!" astonishes Elly.
Summary: I hate to be THAT guy but it looks to me that the reason that Elly is astonished is that Michael didn't immediately identify the real problem: her having to give up her identity as a librarian to become just another mother. Were he to care less about some sick child and worry more about someone whose suffering matters, she'd be less shocked.