I was curious, it seems we have a prevalence goal of about 2% (which is achieved/maintained, but a bit less than two decades ago something changed & caused a spike). US follows the cases reported via health organisations and the human results are about the same.

From 1 January 2008, all Member States with Salmonella prevalence above 10% will have to vaccinate their laying hens against Salmonella, in order to reduce the spread of the disease and the contamination of eggs. The vaccinations used must be authorised at EU level, and must be distinguishable from the field bacteria during sampling and testing. National authorities may exempt a holding from this vaccination requirement provided satisfactory preventive measures are being applied or there has been no incidence of Salmonella on the holding over the previous 12 months.

ec.europa.eu