The Centers for Disease Control and Prevention has released its final update on the deadliest outbreak of foodborne illness of the past quarter-century.

The listeria outbreak due to tainted cantaloupe from Colorado is over, now that the affected produce has been recalled and the two-month incubation period for the illness to develop in victims has passed. People began getting sick with listeria in July; the melons from Jensen Farms in Holly, Colorado, were recalled in September.

The number of people who died in the outbreak totaled 30, the CDC reports. Also, a pregnant woman miscarried while she was ill, and 146 were sickened in 28 states.

Unclean equipment at the cantaloupe packing facility was the likely cause of the outbreak, Food and Drug Administration investigators determined in September. They found pools of water potentially contaminated with the bacteria forming close to the machinery.

Symptoms of listeria include fever, muscle aches, nausea and diarrhea – although symptoms may not appear for up to two months after exposure to the bacteria. The elderly and those with weakened immune systems are at a higher risk of developing the illness.