Three people have died and at least 558 people have been sickened in a salmonella outbreak linked to cucumbers imported from Mexico, federal health officials announced Tuesday.

Earlier this month, the Centers for Disease Control and Prevention announced two people had died and 418 people had been infected in the outbreak that has now been reported in 33 states.

Deaths occurred in Arizona, California and Texas, and more than half of the people sickened by salmonella poona are children, according to the CDC.

Laboratory tests have diagnosed additional infections after companies voluntary recalled garden cucumbers, the kind of dark green cucumbers typically sold in bulk display in grocery stores and measuring seven to 10 inches long.

On Sept. 11, Custom Produce Sales recalled cucumbers grown in Baja California and sold under the "Fat Boy" label and distributed in California, Colorado, Illinois, Iowa, Nevada, North Dakota, Oklahoma and Texas.

San Diego, Calif.-based Andrew & Williamson Fresh Produce announced a voluntary recall on Sept. 4. The cucumbers were distributed between Aug. 1 and Sept. 3, sold under the label "Limited Edition," and their cases indicated they were grown and packed by Rancho Don Juanito in Mexico.

Children, adults over 65 and people with weakened immune systems are most susceptible to getting severely ill from being exposed to the bacteria. Common systems include diarrhea, fever and abdominal cramps.

The illness usually lasts between four and seven days, and many people don't require treatment, according to health officials. But salmonella can be deadly, particularly if a person doesn't receive antibiotics.

About 1.2 million people get sick and 450 die annually in the United States from salmonella exposure, according to CDC estimates.