09/01/2025
The Wyoming Department of Health was notified of a human case of leptospirosis in August 2023, the first case reported in the state since 1983. The same week that the patient’s illness began, public health authorities received notification of increased leptospirosis illnesses among dogs in the same area. Although leptospirosis is typically more prevalent in temperate and tropical climates, other recent canine outbreaks have been reported in arid and semiarid regions of the United States, including California and Arizona. Because leptospirosis can cause severe illness in both dogs and people and because of the potential for dogs to spread the illness to other dogs and people, all dogs should be vaccinated against leptospirosis, even if they live in a geographic location where leptospirosis is less common. Health care providers should consider leptospirosis when evaluating patients with clinically compatible illness and inquire about occupational exposure to animals, even in historically low-risk areas, as early treatment can reduce disease severity and duration. Read more in this week’s MMWR: https://bit.ly/mm7327a1
