[The 1817 outbreak of louse-borne typhus in the Leghorn area (Tuscany): relationship between Authorities, public Health and medical doctrine].

The authors recall the louse-borne typhus that took place in Leghorn in 1817. They analyse its causes and the health measures adopted to face it. Out of the historical reconstruction, there arise some issues on both the coming up again of such risk and the role played by health measures. Data concern the chronicles and the medical literature of those days. The method adopted implies comparison between historical circumstances, medical debate and provisions: in 1817 an epidemic of typhus exanthematicus caused hundreds of deaths and gave rise to much medical controversy incapable, however, of improving the existing knowledge. The analysis show a lack of health protection programs and a fallacious medical approach which did not help understand the relationship between pediculosis and disease. Following the health risks posed by migration pressures, this study stresses the importance of keeping the health agents' freedom of judgment away from political and administrative authority.