After reviewing details of brucellosis illnesses from recent years, including a 19-state outbreak, researchers are saying their findings show a link between raw milk and such infections.

Although the researchers did not name the dairy farm associated with the multistate  outbreak, the CDC and the FDA investigated the those illnesses, which occurred during the period reviewed by the research team and were connected to raw milk from Miller’s Biodiversity Farm in Pennsylvania.

Information about the researchers’ work was published recently in the Morbidity and Mortality Weekly Report, which is posted by the U.S. Centers for Disease Control and Prevention. The group of researchers, made up of people from the CDC and a number of states’ agencies, says additional study is needed regarding the emerging health dangers of consuming raw milk.

“To eliminate infection risk from milkborne pathogens, including RB51, all milk should be pasteurized,” according to the report. “Because limited information is available about intermittent or continuous RB51 shedding among dairy cows, more research is needed to more fully understand this emerging public health threat for milk consumers.”

Patient records, dairy records and laboratory test results allowed the team to connect the dots. 

“During 2016-2018, ‘dairy A’ distributed raw milk potentially contaminated with RB51 (Brucella abortus RB51) to 19 states,” according to the research information. “ ‘Dairy A’ sold only raw milk and did not provide RB51 vaccination to cows born there — 16 of the 30-cow herd. The remaining 14 cows were born outside the dairy and had inadequate vaccination records to determine whether they had received RB51.

“These infections highlight the need to prevent RB51 infections. Raw milk consumption is also associated with serious illnesses caused by other pathogens, including Campylobacter spp., Shiga toxin–producing Escherichia coli, and Salmonella spp.”

The data review showed during 2007 to 2012, the number of raw milk outbreaks in the United States increased. Of 81 reported outbreaks, 66 (81%) occurred in states wher unpasteurized, raw milk sale is legal. 

The research team included people from the Epidemic Intelligence Service at the CDC; Pennsylvania Department of Health; New York State Department of Health; New Jersey Department of Health; Pennsylvania Department of Agriculture; and the Animal and Plant Health Inspection Services of the U.S. Department of Agriculture.

According to the CDC, brucellosis is a serious zoonotic infection. The most common sign is fever, followed by osteoarticular symptoms, sweating, and constitutional symptoms. Without proper treatment, infections can become chronic and potentially life-threatening.