Anicteric leptospirosis is the more common and milder form, and often is biphasic. If the second phase occurs, symptoms tend to both milder and more varied than in the first phase - except that aseptic meningitis may occur. Early recognition of decreased renal function is critical to patient survival. Decreased hepatic function and jaundice are common, but hepatic failure is seldom a cause of death - though the degree of jaundice correlates with risk of death. Aseptic meningitis, myocarditis, pulmonary complications, and renal failure with hepatic involvement occur primarily in severe and untreated disease.
Pulmonary complications tends to occur earlier in the illness than other complications.
Less common complications include a variety of cardiac problems, ARDS, shock, and multi-organ failure. Leptospires are present in the blood for about one week after onset of the illness, and then are present in urine. Laboratory findings in icteric leptospirosis are as above except that renal function markers show greater pathology. The index of suspicion is increased by occupational or other exposure to contaminated water or other potential exposure to infected urine. As previously noted, leptospires are present in the blood for about one week after onset of the illness, and then are present in urine.