• Isolation of Leptospira sp. in an appropriate specimen; OR

• Detection of Leptospira sp. DNA by NAT in an appropriate specimen; OR

• A significant (e.g. fourfold or greater) increase in Leptospira agglutination titre by microscopic agglutination test (MAT) using acute and convalescent sera taken at least 10 days apart; OR

• Single Leptospira agglutination titre ≥ 800 in serum

Clinical illness and one of the following:

• Single Leptospira agglutination titre ≥ 200 but <800 in serum

• Epidemiologic link to a confirmed case​

Clinical features include fever, headache, chills, muscle aches, vomiting, jaundice, anemia, and sometimes a rash. The incubation period usually is 7 days, with a range of 2-29 days. If not treated, the patient could develop kidney damage, meningitis, liver failure, and respiratory distress. In rare cases, death occurs.