Walsh & Hoyt: Diagnosis

The diagnosis of leptospirosis should be suspected from the clinical setting. In patients with the icteric form, the ocular manifestations are typical. In addition, the serum creatinine phosphokinase is elevated with minor elevations of serum aspartate aminotransferase and alanine aminotransferase. In both the nonicteric and icteric forms of the disease, the organism can be isolated from blood and CSF only during the acute phase, because it is cleared rapidly by circulating antibodies. Thus, the diagnosis usually is made with serologic tests such as the microagglutination test (MAT) or an ELISA.