Plague upon the waters: How a disease-ridden steamboat spread yellow fever

When COVID-19 began to spread globally, the first large case cluster outside China wasn't in another country it was on a cruise ship, the Diamond Princess.

The ship, with 3,711 people aboard, remained quarantined off Yokohama, Japan, for more than a month, and, in the aftermath of that outbreak, cruise ships were turned away from ports worldwide over fears of contagion, leaving thousands of people stranded at sea.

In the late 19th century, there was another story of a plague ship that struck fear into the hearts of bystanders onshore.

In the summer of 1878, the steamboat John D. Porter was on its way up the Mississippi River, towing a freight of 14 barges. People thought little of it when the boat stopped at a city called Vicksburg on July 24 to drop off two sick crewmen.

The same day, a New Orleans newspaper reported that 14 people in that city had been diagnosed with yellow fever and seven of them had died. It was the very place where the Porter had picked up its cargo only days before.

Back on the river, the crew of the steamer didn't hear the news right away. As they continued upstream, word began to spread along the shorelines. Residents of Vicksburg telegraphed ahead to Memphis, Tenn., to warn the city that both crewmen the Porter had left behind had died.

The Porter was refused berth at Memphis. When confronted about the illness bedevilling his vessel, the captain admitted that three men had died but claimed their deaths were the result of "too free use of ice water while overheated."

The residents of the communities that lined the Mississippi weren't so cavalier. As rumours that the Porter was "a floating pest-house" spread up and down the river, the captain's coverup went from figurative to literal. He seems to have ordered that the boat's name be concealed with a canvas to prevent people ashore from hounding the vessel.

The occasional port, disbelieving the hearsay, still allowed the Porter to dock, which enabled sick or frightened crew members to disembark, carrying the fever with them. New crew members took their places, only to become infected themselves.

By the time the towboat reached Cincinnati, the crew were ready to get off, but they were forbidden to lay anchor. Instead, officials sent two doctors aboard and cut the vessel loose.

Now a complete pariah, the Porter meandered aimlessly upriver, stopping occasionally in the dark of night so the crew could bury their dead but moving on again before morning. Legend has it that locals patrolled the riverbanks with rifles to chase the boat away if it came too near the shore.

Finally, the steamer's engine broke down, and the crew were able to jump ship, leaving the boat and its barges below an Ohio town called Gallipolis. Curiosity-seekers, perhaps thinking the vessels were safe now that they had been abandoned, went to gawk at the deserted hulk. One after another, they, too, succumbed to the saffron scourge.

One woman came down with yellow fever after wearing clothing that had been taken off the boat. Another, who had gone aboard to rescue some starving birds, died just days later.

It became clear to everyone that the fever wasn't being transmitted person to person. There was something about the boat and barges themselves that was causing the infection, and they were eventually towed back to Cincinnati and burned.

Three years later, a Cuban doctor named Carlos Finlay would theorize that yellow fever was spread through the bite of infected mosquitoes, and he would be proven right before the turn of the century.

The summer of 1878 was unusually hot and humid, and the Porter's barges, half-filled with bilge-water, became a breeding-ground for the insects. Everywhere the boat made land, the flies dispersed, leaving a wake of disease behind.

Twenty thousand people perished in the Mississippi Valley epidemic that summer before cooling temperatures drove the mosquitoes into hibernation.

The towboat alone wasn't responsible for the spread of the illness. Tens of thousands of people fled afflicted cities, dispersing the fever widely throughout the region.

The Porter's tragic journey, though, was the most memorable event of the outbreak, a cautionary tale about the truth of Health Minister John Haggie's observation early in our own pandemic that "the virus only moves when people move." Unlike the Diamond Princess and other cruise ships, which strived to contain COVID when the disease was identified aboard, the Porter steamed rashly ahead.

Read more from CBC Newfoundland and Labrador