During the short life of the Ligurian Republic (1797–1805), public health governance underwent significant institutional transformation. In 1804 the Genoese Central Health Commission was called upon to contain the spread of a yellow fever outbreak in Leghorn (Tuscany). Yellow fever is a viral infection transmitted by mosquitoes. The disease may vary from mild to severe, and can be fatal. The term “yellow” refers to the appearance of jaundice, a yellowish discoloration of the skin and mucous membranes due to raised direct bilirubin levels that may occur in some patients.

To examine the measures adopted by the Central Health Commission to minimize and control the epidemic. Particular attention was paid on how the epidemic emergency reshaped public health authority policy. This triggered the selective reactivation of institutional models derived from how early modern Magistracies dealt with the plague.

Medical dogma at that time considered yellow fever as generated by miasma, which was typical of the filthy environmental conditions in urban ports. In this epistemological context, containment strategies relied exclusively on quarantine, maritime surveillance, and sanitary cordons. To implement these measures effectively, the Central Health Commission temporarily acquired expanded legislative, executive, and judicial enforcement powers in public health governance.

The response to the 1804–1805 yellow fever outbreak illustrates how epidemic crises produced non-linear processes of institutional adaptation. They reveal reactivation of ancien régime sanitary prerogatives within an emerging modern public health framework. This outbreak highlights the complex dynamics of institutional centralisation during periods of epidemic emergency in the early 19th century.