There is good reason for investors in Carnival (CCL -3.43%) (CUK -2.84%), Royal Caribbean Cruises (RCL -2.99%), and Norwegian Cruise Lines (NCLH -2.37%) to have a sinking feeling about their stocks. COVID-19 was only just beginning to look like it was in the rearview mirror, and now we have a monkeypox outbreak on our hands.
The World Health Organization (WHO) says there are over 6,000 cases of the once-rare and sometimes…