New York (CNN) -- Three people who contracted cholera at a wedding in the Dominican Republic before returning to New York have recovered, and the risk of their infecting anyone else is low, officials said Sunday.
None of the three adults had to be hospitalized, said Erin Hughes, spokeswoman for New York City's health department.
Person-to-person transmission of the disease is highly unlikely, Hughes told CNN in an e-mail. "Cholera is spread by drinking water or eating food contaminated with the cholera bacteria. This happens in places with inadequate water treatment and poor sanitation. New York City's water is clean and safe."
On average, one case a year of cholera is reported in New York, she said, and it is "almost always in someone who has traveled abroad."
The Centers for Disease Control will test samples to confirm the illness and determine from which strain the people were sickened, said CDC spokeswoman Candice Burns Hoffman. Cholera is a "nationally notifiable" disease, she said, and samples from all suspected U.S. cases are sent to the CDC for lab testing and confirmation.
The Dominican Republic is investigating the outbreak at the wedding, Hoffman said.
"It's not uncommon for cholera outbreaks, like the one that has moved rapidly through Haiti, to spread to other countries," Hoffman said. "We have seen a few cases in travelers returning to the U.S. The risk for secondary infection in the U.S. is low."