Application of variable number of tandem repeats typing to describe familial outbreaks of brucellosis in Argentina.

Consumption of inadequately pasteurized dairy products is the most common means of transmission of brucellosis. This report describes two foodborne outbreaks that occurred in families infected after consumption of fresh home-made cheese bought in different Argentine provinces. High resolution variable number of tandem repeats (VNTR)-based analysis revealed two well-defined groups comprising essentially identical profiles and corresponding to the two different outbreaks. Similar clinical findings in members of the same family could indicate that the differential virulence of different bacterial clones, as indicated by VNTR data, could have influenced the course of the disease. We observed the importance of adequate treatment in early stages of the disease; combination therapy and extended treatment for 6 weeks or longer yielded significantly better results. The risk of the foodborne transmission of this zoonotic disease and disease prevention should be considered.