Even diagnosing the problem as an epidemic would solve nothing. The army had no proven weapons to combat typhus or any other contagious disease.

From The Illustrious Dead by Stephan Talty. Page 77.

The condition of the army was one of the main topics of debate, as it would be at each stop during the campaign. “War’s a game you’re good at,” the head of Napoleon’s commissariat snapped at the emperor. “But here we aren’t fighting men, we’re fighting nature.” “Nature” here refers to the lack of food, the weather, and distance—and disease, which emanated from the bogs and swamps.

With the momentum of the invasion momentarily stilled, Napoleon spent hours reviewing statistics from the various corps, detailing the losses to their ranks and the reinforcements flowing to each division. Many believed his generals were downplaying the deaths to typhus and other causes, hoping to escape charges of neglect or mismanagement (and fearing that, undermanned, they would be left out of coming battles). Dr. Larrey mentioned discrepancies between actual and reported number of sick, and one officer wrote darkly of “the cruel way in which [Napoleon] was being deceived by the reports made to him.”

The emperor contemplated stopping at several points during the advance. This was as close as he came to addressing the losses to typhus, as part of an overall plan to give his men a chance to give his men a chance to recuperate. The lack of a strong response mystifies the modern mind, but Napoleon was ill-informed and his options were vanishingly small. He also knew that even diagnosing the problem as an epidemic would solve nothing. The army had no proven weapons to combat typhus or any other contagious disease.