It's well known that microbes traveled aboard long voyages like those of Christopher Columbus. But it was by no means inevitable that diseases like smallpox and measles would survive early ocean crossings that took more than a month. Researchers are now using mathematical models to predict the historical risk of pathogens lingering on ships for long periods of time and disembarking with passengers.
“These ships are not just carrying pathogens as extra cargo. They are…”
Source: www.newscientist.com