Efforts to reduce illnesses caused by one of the most dangerous foodborne bacteria, E. coli O157:H7, appear to be paying off, the Centers for Disease Control and Prevention reported Thursday, but sickness caused by other pathogens is rising.

Preliminary data released by the CDC showed a 2009 drop in the incidence of infections from E. coli O157:H7, which can be lethal and is most commonly associated with ground beef but has also been detected in leafy greens and raw cookie dough. E. coli infections were the lowest since 2004, the agency said.

But there was little or no recent progress for other pathogens, according to the data. Infections from salmonella, the most common cause of foodborne illness in the United States, decreased slightly in 2009but remain above the goals set by the government. The report also detailed increases last year in illnesses from campylobacter, listeria, vibrio and cryptosporidium.

“There is more work to do,” said David Goldman of the Department of Agriculture’s Food Safety and Inspection Service. “In particular, salmonella remains a challenge. We have not been as successful in moving the trend line in the right direction.”

Goldman credited the decrease in the E. coli infection rate to expanded testing in slaughterhouses last year and a renewed effort by USDA inspectors to flag sanitary problems.