A Cholera outbreak continues to spread in earthquak-ravaged Haiti. Late last week, the Pan American Health Organization announced that the death toll in the outbreak has risen from 442 three days ago to 501, while the number of people admitted to hospital for the waterborne illness has gone from 6,742 to 7,359.

Authorities were very concerned that Hurricane Tomas, which struck on Friday, would drastically worsen the already critical lack of water sanitation.  Several hundred thousand people lack clean water in Port-au-Prince, the country’s capital, a city severely damaged by the earthquake, now home to an estimated 1.3 million in over 1,000 tent cities poorly equipped to handle severe weather.

It appears that Haiti missed the worst of the storm, which killed 7, but did not cause as much damage as had been feared.  But it did bring floodwaters, which has made the cholera epidemic worse.

As Food Safety News reported Tuesday, the U.S. Centers for Disease Control recently shed light on how the food- and water-borne bacteria, which is not historically found in Haiti, may have spread to the country. According to CDC, the cholera strain matches strains commonly found in South Asia, adding a new level of legitimacy to speculation that U.N. peacekeepers from Nepal could have recently brought the bacteria to Haiti.

Public health authorities are still investigating how the outbreak began, but remain more concerned about containing the outbreak, which could prove catastrophic if it spreads to the capital.

Florida health department officials worried about travelers bringing cholera to the states told doctors last week to be on the lookout for the disease. “We can expect that some travelers returning from Haiti may become symptomatic with cholera en route to, or shortly after arrival in Florida,” a health department letter said.

Cholera is a bacterial disease, transmitted primarily through contaminated food or water, that causes severe hydration, watery diarrhea, vomiting, and can be deadly if untreated.