When to Consider Leptospirosis in Unexplained Myocarditis

Summary

Although the primary treatment for typical leptospirosis is antimicrobial therapy in the form of penicillin and doxycycline, assessment of left ventricular (LV) systolic function should also be performed in patients with this condition. Findings of new LV dysfunction (ejection fraction <50%) may provide evidence of associated myocarditis, which is an important finding.

  • Cardiology Clinical Trials
  • Inflammatory Disease
  • Bacterial Infections
  • Cardiology Clinical Trials
  • Cardiology & Cardiovascular Medicine
  • Inflammatory Disease
  • Bacterial Infections

Although the primary treatment for typical leptospirosis is antimicrobial therapy in the form of penicillin and doxycycline, assessment of left ventricular (LV) systolic function should also be performed in patients with this condition. Findings of new LV dysfunction (ejection fraction <50%) may provide evidence of associated myocarditis, which is an important finding. In addition, when patients such as farmers or others working closely with animals, present with unexplained myocarditis, the differential diagnosis should include leptospirosis according to Dabor Resiere, MD, Central University Hospital, Fort de France, Martinique.

Leptospirosis is an endemic disease in the Caribbean caused by Leptospira, a motile bacterium [Bharti AR et al. Lancet Infect Dis 2003] spread predominantly during rainy seasons as well as in the urine of infected animals such as dogs. In its virulent forms, leptospirosis may lead to liver failure, renal failure, severe pulmonary hemorrhage, myocarditis, and death. In 2012, the Dominican Republic's Minister of Agriculture died of leptospirosis. Even today, 5% to 10% of patients with leptospirosis in the Caribbean may die from the disease.

Some patients may present with flu-like symptoms, but others patients may be relatively asymptomatic or have insidious symptoms making the onset difficult to discern. When patients present with fewer than 8 days of symptomatology, Dr. Resiere recommends a polymerase chain reaction (PCR) test for diagnosis; this has been available in Martinique since 2006.

If leptospirosis is diagnosed, physicians should evaluate for new LV systolic dysfunction (ejection fraction <50%) as the complication of myocarditis can be devastating. In patients presenting with cardiogenic shock, mortality approaches 40%. Practioners evaluating patients with leptospirosis should also have a high degree of suspicion for meningitis, encephalitis, and other neurological manifestations, which occur in 5% to 10% of patients.

Treatment of leptospirosis includes not only antibiotics but supportive therapy (eg, including fluid and electrolyte regulation) and monitoring for new complications.

To evaluate cases of leptospirosis in a single institution, Dr. Resiere and colleagues conducted a retrospective analysis, looking at data from 82 patients admitted to University Hospital in Martinique, 29% of whom were admitted prior to the institution of PCR tests for diagnosis, from 2001 to 2006, and 63% of whom were admitted between 2006 and 2010. Of 32 patients admitted to the intensive care unit for leptospirosis, the most frequent abnormal vital sign was tachycardia. He also noted that <10 of the 20 patients admitted to the hospital with this diagnosis after 2006 required intensive care [Mehdaoui H et al. Critical Care 2012].

Greater awareness could vastly reduce the mortality associated with leptospirosis in the Caribbean improving the timing of diagnosis and early institution of care. Physicians should carefully consider leptospirosis in those presenting with symptoms. For those with symptoms <8 days, the physician should perform a PCR test for the early diagnosis of leptospirosis, if available. In cases where leptospirosis has been confirmed, the physician should not merely prescribe antibiotic and supportive therapy, but should evaluate for cardiac involvement as myocarditis is associated with high mortality rate and requires specialized care.

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