The outbreak caused by an unusual strain of Salmonella is merely over in the United States, federal health officials said on Thursday. The strain sickened more than 1,400 people in the U.S.A.

The strain that caused the outbreak is known as Salmonella St.Paul. The Center for Disease Control and Prevention (CDC) traced the strain back to a Texas produce distribution center as well as a farm in Mexico that grew peppers.

A joint probe by the CDC and the Food and Drug Administration has found strong evidence that jalapeno peppers were a major carrier of the bacteria, and that serrano peppers were also a carrier. It is not known whether any tomatoes were contaminated as well but it is quite likely. However, tomatoes from Long Island, New York State and New Jersey seem to have not been implicated.

Salmonella poisoning has symptoms such as diarrhea, fever and abdominal cramps.

The CDC report called the outbreak, which affected 43 states, the "largest food borne disease outbreak identified in the United States in the past decade, based on the number of culture-confirmed cases," and said more cases were likely to be reported.

Dr. David Acheson of the U.S. Food and Drug Administration explained that the agency needed more powers to protect the supply of fresh fruits and vegetables. "We need to develop technologies which will enable us to detect pathogens in fresh produce more quickly," he added. The outbreak of Salmonella St.Paul began in April.

"None of us can provide a cast-iron guarantee that salmonella saintpaul will not re-emerge," said Dr. David Acheson. "We have not identified the total source of this."