"We have found nothing wrong with the meat they sold," said Jessica Chittenden, a spokeswoman for the state Department of Agriculture and Markets. "It is not the source of the E. coli."
But health officials still don't know the cause of the month-long outbreak, which struck another victim this week, bringing the total to 26, said Dr. Joan Facelle, Rockland's commissioner of health.
The latest victim is a youngster from Monsey, where all but two of the victims live, she said. Tests have shown that the Orangeburg girls and the Monsey children are infected with different strains of E. coli O157:H7.
Investigators thought they had a strong lead toward finding the source of the bacteria responsible for infecting the Orangeburg girls.
Ground beef still in the freezer of the first Orangeburg girl's home was contaminated with E. coli O157:H7, a particularly toxic strain, state officials confirmed last week.
The meat was purchased May 12 at BJ's Wholesale Club in West Nyack by Orangeburg resident Ann Koesterer.
State investigators tested four packages of meat chosen at random at the store June 7, Chittenden said. It is not clear if the meat came from the same lot as the package purchased by Koesterer, she said.
All four of the tests were negative, leading investigators to believe that the meat was contaminated after it left the store.
The families dispute the findings, maintaining that the E. coli-tainted meat was contaminated when it was purchased.
"How else could she have gotten it?" Koesterer said. "It's ridiculous for them to say it wasn't contaminated in the store. They are not taking it seriously enough."
Koesterer's daughter became ill May 20 and was admitted to Westchester Medical Center in Valhalla a week later, where the diagnosis was hemolytic uremic syndrome. The condition, also called HUS, occurs when the bacteria attack blood cells and damage the kidneys.
The girl is still in the hospital, Koesterer said. Her parents said doctors don't know if the damage is permanent. The Journal News is not publishing the girl's first name.
The 11-year-old girl had severe cramps and diarrhea but recovered without hospitalization, said her father, Charlie Graff.
No one else who ate the hamburgers got sick, the families said.
"We have very high standards for testing and maintaining our meat," said Jeff Berman, a spokesman for BJ's.
Experts on E. coli said it is not uncommon for the bacteria to be in parts of some meat but not in others.