Q: How do cruise ships keep you from getting sick on the Yangtze?

A: Yes, cruise ships prevent illness through onboard water treatment systems that chlorinate or UV-sterilize all potable water, plus vaccination of food handlers and mandatory hand-washing stations at buffet entrances. Air handling units use HEPA filters, and crew disinfect high-touch surfaces hourly.

Mike’s take: The real backbone is the water infrastructure. Freshwater tanks are sealed and dosed continuously with chlorine or bromine to kill bacteria like E. coli. The vacuum toilet system is separate—it uses negative pressure and minimal water, so pathogens from sewage can’t backflow into living spaces. Galley sinks have grease traps that get scraped daily, not just rinsed. If the ship’s watermaker (reverse osmosis unit) breaks, they lock the drinking fountains and switch to bottled stock. That’s how you stop a norovirus chain before it starts.

Actionable advice: Bring a small bottle of hand sanitizer with at least 60% alcohol for when you’re away from a sink. Never drink tap water from the bathroom—stick to bottles or the dining-room dispensers. Wipe down your cabin’s remote control and light switches with a disinfectant wipe the first night. And if you see a crew member skip the hand-wash station at the buffet, report it to the purser immediately.