Outbreak investigation of brucellosis in Thassos, Greece, 2008

In spring 2008, the Hellenic Center for Disease Control and Prevention was notified about human brucellosis cases in Thassos, a Greek island that had been up to that point under a brucellosis eradication programme. Following the verification of the outbreak a 1:1 case-control study was conducted in the island. The study revealed that consumption of locally produced raw cheese was a risk factor for Brucella melitensis infection (odds ratio (OR): 15.1, 95% confidence interval (CI): 6.56-34.7). Brucella melitensis biotype 3 was identified in two clinical samples. As a result of the outbreak, the island is no longer officially considered as an area with farms free of brucellosis and is currently under a brucellosis control programme. The investigation of this outbreak demonstrated that control and eradication of brucellosis is not only a question of designing a strategy, but rather of ensuring its continuous, strict implementation. Furthermore, it revealed the lack of appropriate education of the public regarding the risks associated with raw, non heat-treated cheese consumption.