With the spread of an samonella outbreak, the number of people sicked by the disease has risen to more than 1,000, authorities said on Friday.

Meanwhile, Iowa’s Hillandale Farms said it was recalling more than 170 million eggs after laboratory tests confirmed salmonella.

The eggs were distributed to grocery distribution centers, retail groceries and food service companies which service or are located in fourteen states, the company said.

The latest recall puts the total number of potentially tainted eggs at over half a billion.

Earlier this week, Wright County Egg, another Iowa company, recalled 380 million eggs.

The two recalls are related, the Food and Drug Administration ( FDA) said.

Preliminary investigation has identified salmonella enteritidis as the strain of disease that caused the poisoning in both cases, FDA officials said.

Both plants could have a rodent problem, or both plants could have gotten hens that were already infected, or feed that was contaminated, according to health experts.

Health departments nationwide received almost 2,000 reports of illness from the strain of salmonella linked to both recalls between May and July, but about half have been confirmed as salmonella-related.

The number of illnesses is expected to rise as the Centers for Disease Control and Prevention (CDC) is continuing to receive information from state health departments as people report their illnesses, health officials said.

Salmonella is an organism which can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems. The most common symptoms are diarrhea, abdominal cramps and fever within eight hours to 72 hours of eating a contaminated product.