Four strains of listeria bacteria have been connected to tainted cantaloupe from Jensen Farms in Colorado.

Listeriosis is a serious foodborne infection that can cause illness and death in older adults, pregnant women and those with underlying medical conditions and compromised immune systems. Infections are usually caused by contaminated lunch meat, hot dogs and Mexican-style cheeses, not by produce.

Local, state and federal health experts are investigating the widening outbreak tied to Rocky Ford-region brand whole cantaloupe shipped by supplier Jensen Farms of Holly, Colo. On Sept. 14, the federal Food and Drug Administration announced a recall of cantaloupes linked to the multi-state outbreak of listeriosis. The affected cantaloupes were shipped between July 29 and Sept. 10 to at least 17 states and possibly more.