Cattle are the primary reservoir for E. coli O157. The vaccines that are available for cattle are rarely used, but the latest study suggests the public health benefits could be significant.

The research was lead by a team of researchers at the University of Glasgow in collaboration with the University of Edinburgh, the Royal Veterinary College, Scotland’s Rural College, Health Protection Scotland, and the Scottish E. coli O157/VTEC Reference Laboratory.

The study, published in the online journal PNAS, used veterinary, human and molecular data to examine the risks of E. coli O157 transmission from cattle to humans, and to estimate the impact of vaccinating cattle.

The risk of E. coli O157 infection is particularly significant when the cattle are ‘super-shedding’ – excreting extremely high numbers of bacteria in their faeces for a limited period of time. Vaccines against the bacteria exist that can reduce super-shedding.

As a consequence, the researchers predict that vaccinating cattle could reduce human cases by nearly 85 percent, far higher than the 50 percent predicted by studies simply looking at the efficacy of current vaccines in cattle.