A foodborne illness outbreak is affecting many parts of the country. The outbreak is linked to contaminated lettuce from Mexico. The Centers for Disease Control and Prevention, or CDC, is tracking the situation.

According to the CDC, the outbreak is worsening. More than 18,000 cases have been reported across 45 states, the CDC said. For more information on the outbreak, readers can consult the CDC or KTVU FOX 2 News for further details.